Production of recombinant lubricin.
Abstract
New recombinant isoforms of human-type lubricin or PRG4 glycoprotein having excellent lubrication properties and a novel glycosylation pattern, and methods for their manufacture at high levels that allow commercial production are disclosed.

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31 claims: 26 independent, 5 dependent
- 1REIVINDICACIONES 1. Un método para fabricar una glicoproteina de 5 lubricina recombinante que comprende los pasos de:cultivar, en un medio, de células de ovario de hámster chino (CHO) tranfectadas con y que expresan el gen PRG4 humano y glicosilar pos-translacionalmente el producto de expresión durante un tiempo y bajo las condiciones de 10 cultivo suficientes para producir una glicoproteina de lubricina que comprende al menos 30% en peso de residuos glicosidicos en una concentración en el medio de al menos 0.4 g/litro, y purificar la glicoproteina de la lubricina de 15 dicho medio.
- 2El método de conformidad con la reivindicación 1, en donde las células CHO son células CHO-M que comprenden un ácido nucleico que codifica el gen PRG4 humano.
- 3El método de conformidad con las reivindicaciones 20 1 ó 2, en donde las células CHO son transfectadas con un primer vector que comprende un ácido nucleico que codifica un elemento de la cromatina y un segundo vector que comprende un ácido nucleico que codifica el gen PRG4 humano.
- 4El método de conformidad con la reivindicación 3, en donde el elemento de la cromatina es un elemento límite, región de unión de matriz, región de control de locus o un elemento de abertura universal de la cromatina.
- 5El método de conformidad con la reivindicación 4, en donde el elemento de la cromatina es una región de unión de matriz.
- 6El método de conformidad con cualquiera de las reivindicaciones 1-5, en donde las células están cultivadas durante un tiempo y bajo las condiciones del cultivo suficientes para producir dicha glicoproteína de la lubricina en una concentración en el medio de al menos 0.5 g/litro.
- 7El método de conformidad con cualquiera de las reivindicaciones 1-5, en donde las células están cultivadas durante un tiempo y bajo las condiciones del cultivo suficientes para producir dicha glicoproteína de la lubricina en una concentración en el medio de al menos 0.8 g/litro.
- 8El método de conformidad con cualquiera de las reivindicaciones 1-5, en donde las células están cultivadas durante un tiempo y bajo las condiciones del cultivo suficientes para producir dicha glicoproteína de la lubricina en una concentración en el medio de al menos 1.0 g/litro.
- 9El método de conformidad con cualquiera de las reivindicaciones 1-8, en donde al menos 95% en peso de la glicosilación de la glicoproteina de la lubricina es glicosilación de núcleo 1.
- 10El método de conformidad con cualquiera de las reivindicaciones 1-8, en donde al menos 99% en peso de la glicosilación de la glicoproteina de la lubricina es glicosilación de núcleo 1.
- 11El método de conformidad con cualquiera de las reivindicaciones 1-10, en donde los residuos glicosidicos se enriquecen en cadenas laterales de sacárido sulfatado en comparación con la lubricina humana nativa.
- 12El método de conformidad con cualquiera de las reivindicaciones 1-11, en donde la glicoproteina de lubricina comprende una proteina multimérica que produce un coeficiente de fricción estático no mayor de 150% del coeficiente de fricción estático de la lubricina bovina nativa purificada como se midió en una prueba de fricción de cartílago sobre cartílago.
- 13El método de conformidad con cualquiera de las reivindicaciones 1-11, en donde la glicoproteina de lubricina comprende una proteína multimérica que produce un coeficiente de fricción estático no mayor de 120% del coeficiente de fricción estático de la lubricina bovina -65nativa purificada como se midió en una prueba de fricción de cartílago sobre cartílago.
- 14El método de conformidad con cualquiera de las reivindicaciones 1-11, en donde la glicoproteina de lubricina comprende una proteína multimérica que produce un coeficiente de fricción estático no mayor de 110% del coeficiente de fricción estático de la lubricina bovina nativa purificada como se midió en una prueba de fricción de cartílago sobre cartílago.
- 15El método de conformidad con cualquiera de las reivindicaciones 1-14, en donde la glicoproteina de la lubricina comprende una especie de lubricina monomérica copurificada de dicho medio de cultivo y en mezcla con una especie de lubricina multimérica.
- 16El método de conformidad con cualquiera de las reivindicaciones 12-14, en donde la glicoproteina de la lubricina comprende una especie de lubricina dimérica.
- 17El método de conformidad con cualquiera de las reivindicaciones 1-16, en donde la glicoproteina de la lubricina comprende por lo menos cinco cadenas de aminoácidos glicosilados individuales asociados de manera no covalente o enlazadas por disulfuro y tiene un peso molecular de al menos 1200 kDa.
- 18El método de conformidad con cualquiera de las reivindicaciones 1-17, en donde las células se cultivan en al menos 10, 50, o 100 litro de medio.
- 19El método de conformidad con cualquiera de las 5 reivindicaciones 1-18, en donde glicoproteina de la lubricina comprende por lo menos 35% en peso de residuos glicosidicos.
- 20La glicoproteina de la lubricina producida por el método de conformidad con cualquiera de las 10 reivindicaciones 1-19.
- 21Una composición de material que comprende:una glicoproteina de la lubricina multimérica recombinante expresada del gen PRG4 humano en un cultivo de célula huésped, que comprende al menos el 30% en peso de 15 los residuos glicosidicos, y que produce un coeficiente de fricción dinámico no mayor del 150% del coeficiente de fricción dinámico de la lubricina bovina nativa purificada como se midió en una prueba de fricción de cartílago sobre cartílago. 20
- 22La composición de conformidad con la reivindicación 21, en donde la glicoproteina de la lubricina se caracteriza por producir un coeficiente de fricción dinámico no mayor al 120% del coeficiente de fricción dinámico de la lubricina bovina nativa purificada -67como se midió en una prueba de fricción de cartílago sobre cartílago.
- 23La composición de conformidad con la reivindicación 21, en donde la glicoproteína de la lubricina se caracteriza por producir un coeficiente de fricción dinámico no mayor al 110% del coeficiente de fricción dinámico de la lubricina bovina nativa purificada como se midió en una prueba de fricción de cartílago sobre cartílago.
- 24La composición de conformidad con cualquiera de las reivindicaciones 21-23, en donde la glicoproteína de la lubricina comprende por lo menos 35% en peso de residuos glicosídicos.
- 25La composición de conformidad con cualquiera de las reivindicaciones 21-23, en donde la glicoproteína de la lubricina comprende por lo menos 40% en peso de residuos glicosídicos.
- 26La composición de conformidad con cualquiera de las reivindicaciones 21-25, en donde al menos 95% en peso de la glicosilación de la glicoproteína de la lubricina es glicosilación de núcleo 1.
- 27La composición de conformidad con cualquiera de las reivindicaciones 21-26, en donde los residuos glicosídicos se enriquecen en cadenas laterales de sacárido sulfatado en comparación con la lubricina humana nativa.
- 28La composición de conformidad con cualquiera de las reivindicaciones 21-27, que comprende además una especie de lubricina monomérica mezclada con especies de lubricina multimérica. 5
- 29La composición de conformidad con cualquiera de las reivindicaciones 21-28, que comprende una especie de lubricina dimérica.
- 30La composición de conformidad con cualquiera de las reivindicaciones 21-29, que comprende una especie de 10 lubricina que comprende por lo menos cinco cadenas de aminoácidos glicosilados individuales asociados de manera no covalente o enlazadas por disulfuro que tienen un peso molecular de al menos 1200 kDa.
- 31La composición de conformidad con cualquiera de 15 las reivindicaciones 21.-30, que comprende además ácido hialurónico o una sal del mismo en mezcla con dicha glicoproteina de la lubricina.
Independent claims31
201 paragraphs in 7 sections, as filed
(54) Title: RECOMBINING LUBRICINE PRODUCTION.
(54) Title: PRODUCTION OF RECOMBINANT LUBRICIN.
(57) Summary
New recombinant forms of human-type lubricin or PRG4 glycoprotein having excellent lubrication properties and a novel glycosylation pattern, and methods for their manufacture at high levels that allow commercial production are disclosed.
(57) Abstract
Disclosed are new recombinant isoforms of human-like lubricin or PRG4 glycoprotein having outstanding lubrication properties and a novel glycosylation pattern, and methods for their manufacture at high levels enabling commercial production.
RECOMBINANT LUBRICINE PRODUCTION
CROSS REFERENCE TO RELATED REQUESTS
This application claims priority and benefit from US Provisional Patent Application No. 61 / 894,366 filed October 22, 2013, the 'full content of which is incorporated herein in its entirety by reference.
FIELD OF THE INVENTION
The inventions disclosed herein relate to methods for producing commercial quantities of material compositions comprising recombinant human-type lubricin using transfected cells. More particularly, the inventions relate to the commercial scale production of novel forms of lubricin which have excellent lubricating properties and which can be formulated and used to treat prophylactically or therapeutically different conditions ranging, for example, from joint pain to disease. dry eye.
-2 BACKGROUND OF THE INVENTION
The proteoglycan gene 4 (PRG4) encodes highly glycosylated surface lubrication proteins called lubricin, megakaryocyte stimulating factor (MSF), or surface zone protein (SZP). (See Jay, Curr. Opin. Orthop. 15, 355 (2004); US Patent No. 6,743,774; US Patent No. 6,960,562). Lubricin is expressed from the PRG4 gene (SEQ ID NO: 2) with a full length spanning 12 exons, although multiple naturally occurring truncated versions have been reported. A large 940 amino acid mucin-like core domain (encoded by exon 6) comprises 70 + KEPAPTT-like sequences and is heavily glycosylated. The glycoprotein comprises core 2 glycosylation residues and a multiplicity of core 1 glycans (O-linked Gal-GalNAc β (1-3) Oligosaccharides), at least the latter of which has been shown to mediate their major physiological function. , boundary lubrication (Jay et al., Glycoconj J 18, 807 (2001)). PRG4 has been shown to be present on the surface of cartilage, synovium, tendon, and menisci, in the tear film, and at other anatomical sites. PRG4 has been shown to contribute to borderline lubrication of opposing surfaces of articular cartilage. It has been shown that PRG4 exists not only as a
-3 monomer but also as a disulfide-linked dimer and multimer through conserved cysteine-rich domains at both N- and C-terminals, (Schmidt et al., Biochim Biophys Acta. 1790 (5): 375-84 (2009 ); Kooyman et al., Paper No. 255, 56th Ann. Meet of Orthop. Res. Soc., 2010).
At the cartilage interface of the synovial joints there are at least two physicochemical modes of lubrication at work. These have been classified as 10 fluid film and limit. The modes of operative lubrication depend on the normal and tangential forces on the joint tissues, on the relative speed of tangential motion between these surfaces, and on the time history of both load and motion. The coefficient of friction, μ (a dimensionless unit, ratio of the friction force measured between two contact surfaces relative to motion to the applied normal force), provides a quantitative measure of lubrication.
One type of fluid mediated lubrication or fluid film mode is hydrostatic. At the onset of loading and usually for a prolonged duration, the interstitial fluid within the cartilage becomes pressurized, due to the biphasic nature of the tissue, the fluid 25 can also be forced into the roughnesses between the
-4 articular surfaces through an oozing mechanism. Pressurized interstitial fluid and entrapped lubricating groups comprising hyaluronic acid can therefore contribute significantly to normal load bearing with some resistance to shear force, facilitating a very low coefficient of friction. Also, at the beginning of the load and / or movement, the film is squeezed, the types of hydrodynamic lubrication, and fluid film elastohydrodynamics can occur, with pressurization, movement and deformation that acts to direct the viscous lubricant from and / or to through a space between two surfaces in relative motion.
In boundary lubrication, the load is borne by surface-to-surface contact, and the associated frictional properties are determined by surface lubricating molecules, that is, species of lubricin. This mode is important because the opposing cartilage layers contact over +/- 10% of the total area through interlocking, flattened roughnesses and this is probably where most of the friction occurs. Boundary lubrication, in essence, mitigates slip-seizure (Meyer et al., Nanoscience: Friction and Rheology on the Nanometer Scale, World Scientific Publishing Co. Pte. Ltd, River Edge, NJ,
-5 (2002), ρρ. 373), that is, spontaneous jerky movement that can occur while interfacing intermittently with the weight-bearing cartilage surfaces gliding over each other, and thus manifests as reduced resistance to both starting movement and stable movement. Typical wear patterns of cartilage surfaces suggest that boundary lubrication of the articular cartilage is critical for the protection and maintenance of the articular surface structure. For example, lubricin-deficient mice show wasting but newborn mice, which are not weight bearing, show no wasting. (Jay et al., Arthritis and Rheumatism, 56: 3662-3669 (2007).
With increasing load time and dissipation of hydrostatic pressure, lubricant-coated surfaces bear an increasing portion of the load relative to the pressurized fluid, and therefore, μ can become more and more dominated by the lubrication limit mode. A limiting mode of lubrication is therefore indicated by a coefficient of friction during a stable sliding invariable with factors influencing the formation of a fluid film, such as relative sliding speed and axial load. For articular cartilage, it has been concluded that borderline lubrication is safe to occur, although supplemented by
-6 pressurization of fluids and other mechanisms. The lubrication mechanism at the corneal and eyelid interface during the blink of the eye does not imply a significant load, thereby facilitating the physicochemical requirements for effective lubrication and is therefore likely to be very different from cartilage lubrication. . However, it has been proposed that a limit mode of lubrication may become dominant when the tear film is compromised, such as in dry eye disease.
The two mechanical components of synovial fluid were thought to be responsible for its remarkable lubricating properties which are lubricin and hyaluronic acid (or hyaluronate or HA, hereinafter used interchangeably). Lubricin has been shown to function as a boundary lubricant in the joints and to protect cartilaginous surfaces against frictional forces, cell adhesion, and protein deposition. For example, US Patent Nos. 6,960,562 and 6,743,774 disclose a lubrication polypeptide comprising substantially pure PRG4 isoforms, and methods for lubricating joints or other tissues by administering systemically or directly to tissues. HA per se has been shown to decrease μ over saline (0.12 in 3.3 25 mg / ml HA versus -0.24 in PBS) at a cartilage interface
-7cartilage under a limit lubrication mode, and the lubricin alone decreases μ to still lower levels, but the synovial fluid comprising the HA in combination with the lubricin can impart to interface with surfaces with a coefficient of friction not reached by lubricin alone or by synthetic mixtures of HA and lubricin. No synthetic composition of lubricin and HA has been able to completely duplicate the low coefficient of friction imparted by synovial fluid natively. HA from various sources and different molecular weights have been tested in mixtures with lubricins expressed in vitro from synoviocytes, bovine lubricins, lubricins extracted from synovial fluid and reconstituted in HA, and lubricins expressed in microgram quantities in initial efforts to do so using technology. recombinant DNA.
Previous attempts at recombinant production of full-length lubricin on a scale suitable for commercial exploitation have not been successful. The very low, single or double digit milligram per liter production rate of human lubricin species from CHO cells is considered too low to support a commercial product. One approach to solve this problem was to truncate the number of repeats in exon 6 and thus reduce the mass of the side chains of
-8glycosylation while retaining at least some lubrication ability (See, eg, US Patent Nos. 7,642,236 and 7,893,029). This approach appears to have resulted in a crude productivity (before purification) of the truncated construct of three to four hundred milligrams per liter.
BRIEF DESCRIPTION OF THE INVENTION
It has now been discovered that the human PRG4 gene can be used to produce large commercial quantities, of a novel form of highly glycosylated human type lubricin, hereinafter simply referred to as lubricin, multimeric lubricin, rhlubricin, or rhPRG4. This is accomplished as disclosed herein by transfer of the human PRG4 (hPRG4) gene into certain modified Chinese hamster ovary (CHO) cells that have been found to be competent for post-translationally expressed glycosylated proteins on a large scale, and then culturing the cells in commercial scale volumes of media, eg, at least 10 liters, more usually at least 50 liters, preferably at least 100 liters or at least 500 liters, and more preferably 1,000 liters or more.
The lubricin of this invention comprises polydisperse lubricin monomer units that form dimers and multimers and optionally free monomers. Each unit is variably and heavily glycosylated, with glycosid residue side chains contributing at least 30%, often 35% or 40%, and possibly as high as 45% or more of its molecular weight.
In native human lubricin, glycosylations consist of core 1-linked disaccharide (N-acetylgalactosamine-galactose) GalNAc-Gal O-linked, at least 60% which is terminally substituted with a sialic acid and also core 2 glycosylation which entails the addition for nucleus 1 of monosaccharides (Nacetylglucosamine) GlcNac in different isomeric configurations. (See, for example, Estrella et al., Biochem J., 429 (2): 359-67 (2010)).
The recombinant material produced as disclosed herein is enriched for core 1 glycans, as compared to native human lubricin. Its glycosylation comprises at least 95% of core 1 side chains, more likely more than 98% or 99%. Furthermore, the side chains are often sulfated to an extent not seen in native human lubricin. This distinguishes the rhPRG4 of this invention from the native hPRG4. Higher sulfation content is believed to add negative charges
-10 additions to mucinous glycoprotein that can serve to improve its ability to repel nearby biomolecules and thus increase its lubricity and to stiffen the molecular structure, making it more rigid from a molecular point of view, which can help in its ability to function in reducing of friction nanoscale and mesoscale.
The full-length (untruncated) lubricin monomer sequence (SEQ ID NO: 1) comprises 1404 amino acids, or approximately 151 kDa in core protein. The human lubricin signal sequence is residues 1-24 of SEQ ID NO: 1. Accordingly, the mature form of human lubricin is residues 25-1404 of SEQ ID NO: 1. Exhaustive reduction of the recombinant product produced in accordance with what is disclosed herein produces a monomeric species with an apparent molecular weight of approximately 300 kDa-460 kDa, as estimated by comparison to molecular weight standards in a number of techniques. determination of molecular weight including 3-8% SDS tris-acetate polyacrylamide gel electrophoresis. Analysis of glycosylation using mass spectrometry techniques and other work in combination suggested that the true molecular weight of a glycosylated recombinant monomer (as opposed to inferred from gel mobility)
-11 is probably in the 220-280 kDa range and is unlikely to exceed around 300kDa. Out of a total of approximately 329 possible O-linkages (284 of which are threonines) potentially available as O-linked glycosylation sites in the lubricin monomer sequence, a large number that varies and is unknown (100 to 150, maybe as high as 200 or 220). Of the total glycosylation, about half comprise two sugar units (GalNAc-Gal) and half comprise three sugar units (sialic acid-GalNAcGal). The most abundant form is sulfated Gal-GalNac, the next most abundant is sialylated Gal-GalNac.
The lubricin expression product is resistant, although not immune to decomposition into monomeric or dimeric lubricin species. The exhaustive reduction results imply that it comprises disulfide crosslinks between and within monomer units. Also, treatment with denaturing Lampons without reduction can result in lower molecular weight products, suggesting higher quaternary order structures where the chains are also held together by hydrophobic interaction, hydrogen bonding, physical entanglement and / or other non-covalent associations that allow self-assembly. Dimers and Multimers are polydisperse. The molecular species within
-12 themselves typically have molecular weights of at least around 450-600 kDa and multimeric species often 2,000 kDa or more. Typically, some species of the non-reduced complex essentially do not enter the 3-8% SDS-PAGE gel in an electrophoresis experiment. The largest species in the complex are believed to comprise between three and five, and perhaps as many as 20 monomer units.
Without wishing to be bound by theory, it is believed that such larger supramolecular components are formed as a function of monomer / dimer concentration. Currently, a concentration of at least about 0.5 mg / ml monomer / dimer is believed to be optimal for the spontaneous formation of the larger complex. Concentrations well below this, eg, less than about 0.1 mg / ml, comprise monomers and dimers, and only a minor amount of complex; concentrations far above may form aggregates visible to the naked eye as a cloudy or cloudy solution. Surfactants, preferably physiologically compatible with nonionic surfactants that are generally referred to as safe, for example, polyoxyethylene-based surfactants or excipients can be used to prevent the formation of large aggregates while allowing complex formation, which seems to always be present. present along with dimeric species.
The test of the preparations comprising lubricin of the invention shows that their properties of tissue protection and lubrication under load can exceed those recombinant lubricin preparations hitherto known in the art. Without wishing to be bound by theory, the inventors of the same assume that while the slip-stick phenomenon occurs during the movement of non-lubricated tissues that interface under load, a coating of the lubricin of the invention can transfer shear away from the surface. of cartilage underlying layers within the coating of the polydisperse lubricin. That is, the inventors believe that under load and reciprocal movement, the underlying surface experiences less shear, preserving its integrity, while the lubricin molecules within the coating slide over each other, then likely rearrange when the load is removed. (See, for example, Lee et al., PNAS, 110 (7): E567-574 (2013)). The authors state that joint wear is not directly related to the coefficient of friction, but is more directly related to slip-binding slip, and that the different molecular components of the joint work synergistically to prevent wear.
-14 In any event, the lubricin product of the invention, when tested, exhibits outstanding lubrication properties, resulting in coefficients of friction (both static and dynamic) often within 150%, 120%, 110% or essentially equal to the coefficients of native, purified bovine lubricin, as measured in the cartilage-on-cartilage lubrication test as disclosed herein. In these tests, the human-type glycoprotein of the invention achieves static coefficients of friction at or below 0.5 and less than 0.2 (depending on test conditions as disclosed herein) and coefficients of kinetic friction often at or below below 0.1, both measured by depressurized cartilage on cartilage pads in vitro, with a fixed area of contact. When combined with hyaluronic acid (HA), these values improve below 0.3 and less than 0.1 for the certain static measurement (depending on the residence time) and less than 0.1 for the kinetic measurement, quite close to the accepted value for the fluid. synovial. Consequently, such compositions can greatly decrease wear on the joint.
Accordingly, one aspect of the invention comprises a method for the commercial production of lubricin. In one embodiment, the method includes the steps
-15 of culturing, in medium, Chinese hamster ovary (CHO) cells, transected with and expressing the human PRG4 gene, and post-translationally glycosylating the expression product for a time and under culture conditions sufficient to produce a glycoprotein of lubricin, and purifying the lubricin glycoprotein from said medium. For example, in some embodiments, the lubricin glycoprotein is separated from host cell proteins and other contaminants in the extracellular broth to at least partially purify it. The recombinant protein only needs to be enriched from the culture medium, rather than purified to homogeneity to be purified for the purposes of the method of the invention. The method is sufficient to produce a lubricin glycoprotein having at least 30% by weight of glycosidic residues in a concentration in the medium of at least 0.4 g / L.
In some embodiments, CHO cells are CHO-M cells that comprise a nucleic acid encoding the human PRG4 gene. In other embodiments, CHO cells are transfected with a first vector comprising a nucleic acid encoding a chromatin element and are transfected with a second vector comprising a nucleic acid encoding the human PRG4 gene. The chromatin element can be a boundary element, a region of
-16 matrix junction, a locus control region or a universal chromatin opening element. In a preferred embodiment, the chromatin element is a matrix binding region.
In still other embodiments, CHO cells are transfected with a first vector comprising a nucleic acid encoding a chromatin element and encoding the human PRG4 gene and are transfected with a second vector comprising a nucleic acid encoding elements of chromatin and encoding the human PRG4 gene. In a preferred embodiment, the chromatin elements in the first and second vector are a binding region of the matrix.
In some embodiments, at least 30%, at least 35%, at least 40%, or at least 45% of the weight of the dimeric or multimeric lubricin glycoprotein is the weight of the glycosidic residues. In some embodiments, greater than 30%, greater than 35%, greater than 40%, or greater than 45% of the weight of the dimeric or multimeric lubricin glycoprotein is the weight of the glycosidic residues. The glycosidic residues may differ from those of native human lubricin as the glycosylation of recombinant human-type lubricin is at least 90%, at least 95% or at least 99% by weight of core 1 glycosylation. Also, in some modalities, the residues
-17 glycosidics are enriched in sulfated monosaccharides compared to native human lubricin.
Unexpectedly, the process is capable of producing commercially viable amounts of the full-length lubricin glycoprotein. For example, cells can be grown for a time and under culture conditions sufficient to produce lubricin glycoprotein concentrations in a culture medium of at least about 0.4 grams or 0.5 grams of recombinant lubricin per liter, preferably at least 0.8. grams per liter, and more preferably at least 1.0 grams of lubricin per liter of the culture medium in a culture, for example, of at least about 10, 50 or 100 liters. The process when optimized can produce as much as 2.0, at least 2.5 or at least 3.0 grams of lubricin per liter of culture. Depending on the development of an optimized purification protocol, it will be possible to obtain at least about 200 milligrams of purified recombinant lubricin per liter, preferably at least 300 mg / L, more preferably at least 500 mg / L, and more preferably more. Applicants are aware that these levels of productivity have never been achieved before in recombinant expression of any mucin-like protein, or a protein comparable in size to lubricin, and have no prior attempts at the
-18 expression of PRG4 that have been successful in producing material that has the properties of the product described herein.
In preferred embodiments, the monomeric lubricin species are often co-purified from the culture medium in admixture with the multimeric protein species. Multimeric species are rich in dimeric lubricin species. For example, in some embodiments, the method produces a mixture of recombinant lubricin that includes monomeric, dimeric, and multimeric lubricin species. In some embodiments, the lubricin glycoprotein comprises at least five individual glycosylated amino acid chains non-covalently associated or disulfide-linked and has a molecular weight of at least 1200 kDa.
Glycoprotein produced according to the methods of the invention, when tested using the protocol described below, produces a coefficient of friction approaching the lowest values ever observed for purified native mammalian lubricin. For example, in some embodiments, the recombinant lubricin glycoprotein is a multimeric protein that produces a coefficient of static friction not greater than 150% of the coefficient of static friction of purified native bovine lubricin as measured in a do-friction test.
-19cartilage on cartilage. In other embodiments, recombinant lubricin glycoprotein is a multimeric protein that produces a coefficient of static friction not greater than 120% of the coefficient of static friction of purified native bovine lubricin as measured in a cartilage-on-cartilage friction test. In still other embodiments, the recombinant lubricin glycoprotein is a multimeric protein that produces a coefficient of static friction no greater than 110% of the coefficient of static friction of purified native bovine lubricin as measured in a cartilage-on-cartilage friction test.
Another aspect of the invention is directed to compositions of a recombinant multimeric lubricin glycoprotein expressed from the human PRG4 gene in a host cell culture. The recombinant lubricin glycoprotein is at least 30% by weight of glycosidic residues and produces a dynamic coefficient of friction not greater than 150% of the dynamic coefficient of friction of purified native bovine lubricin in a cartilage-on-cartilage friction test. .
In some embodiments, the recombinant lubricin glycoprotein is at least 35%, at least 40%, or at least 45% by weight of glycosidic residues.
-20 In some modalities, recombinant lubricin glycoprotein produces a dynamic coefficient of friction not greater than 110% or not greater than 120% of the dynamic friction coefficient of purified native bovine lubricin as measured in a cartilage friction test on cartilage.
In some embodiments, the glycosidic residues of recombinant lubricin. may differ from those of native human lubricin as the glycosylation of recombinant lubricin is at least 90%, at least 95% or at least 99% by weight of core 1 glycosylation. Also, in some embodiments, the residues Glycosidics from recombinant lubricin are enriched for sulfated monosaccharides compared to native human lubricin.
In some embodiments, recombinant lubricin is a mixture of monomeric, dimeric, and multimeric species. In some embodiments, lubricin includes monomeric species. In some embodiments, lubricin includes dimeric species. In some embodiments, lubricin includes multimeric species. In some embodiments, lubricin is a mixture of monomeric and multimeric species.
In some embodiments, the lubricin glycoprotein comprises at least five individual glycosylated amino acid chains associated with each other.
-21 is not covalent or disulfide linked and has a molecular weight of at least 1200 kDa.
In some embodiments, the composition of the recombinant lubricin glycoprotein further includes hyaluronic acid or a salt thereof in admixture with the lubricin.
In another embodiment, the invention is directed to a composition comprising a solution comprising 100 grams of human lubricin where the glycosylation of lubricin is at least 99% by weight of core 1 glycosylation. In one embodiment, the lubricin is lubricin recombinant human. In another embodiment, the concentration of lubricin in the solution is at least 0.5 g / L. In yet another embodiment, the solution is a cell culture medium.
The compositions of the invention can be used for the preparation of a medicament for any medical use discovered hereinafter or known or other use of glycoprotein PRG4, including as a coating for various devices intended to contact the body. (See, for example, U.S. Patent Application Publication No. 2009/0068247 and 2011/0142908); for the treatment of a joint in a human or animal by improving the lubrication of the joint (Publication of patent application
US-22 No. 2004/0229804) or viscosupplementation (US Patent Application Publication No. 2008/0287369); for topical application to the tissue surface, for example, during surgery to inhibit subsequent formation of adhesions or fibrotic connective tissue (US Patent Application Publication No. 2004/0229804); for the treatment of dry eye disease (U.S. Patent Application Publication No. 2011/0059902); for treatment of dry mouth disease (US Patent Application Publication No. 2013/0039865); for the treatment of interstitial cystitis (US Patent Application Publication No. 2012/0321693); as a vaginal lubricant (US Patent Application Publication No. 2012/0052077); for a Contact Lens Storage and Care Solution (U.S. Patent Application Publication No. 2012/0321611) or by systemic injection, for example, to inhibit cell-cell adhesions or mobility within the vasculature (see, for example, US Provisional Application 61 / 908,959 filed November 26, 2013).
BRIEF DESCRIPTION OF THE DRAWINGS
-23 FIGS. 1 and 2 are plasmid maps of the vectors used in the development of the CHO-M clone expressing lubricin used in the process of the invention and encoding the full-length sequence of hPRG4.
FIGS. 3 and 4 represent polyacrylamide gels useful in evaluating the structure of the rhlubricin of the invention.
FIG. 5 is a graphical representation of the productivity of a lubricin production cycle measuring the micrograms of lubricin produced over time per liter of culture of transfected CHO-M cells. There are three bars on each harvest date. The bar on the left is standard curve Jun 24, 14. The bar in the middle is standard curve Jul 24, 14, and the bar on the right is standard curve Jul 25, 14.
FIG. 6 is a diagram showing the rhlubricin core 1 glycans of the invention.
FIG. 7 is a chromatograph, with marked peaks, showing the relative abundance of the different di- and trisaccharides pending SER and THR residues in the rhlubricin of the invention.
FIG. 8 is a diagram showing the largest range of glycans extending in the structures of
-24 nucleus 2 in native lubricin extracted from human synovial fluid.
FIG. 9 is a chromatograph, with sharp peaks, showing the relative abundance of the different sugar residues in native human lubricin.
FIGS. 10A, 10B and 10C are plots of surface tension against rhPRG4. and / or polyoxyethylene surfactant concentrations showing reduction in surface tension with higher rhPRG4 concentration.
FIGS. 11A and 11B represent the data comparing the static (FIG. 11A) and kinetic (FIG. 11B) coefficients of friction of the rhPRG4 solution for purified native bovine PRG4, saline solution (PBS) and bovine synovial fluid, with both preparations of PRG4 of 450 pg / mL. The designations a, b and c signify statistically significant differences in the results (p <0.05). n = 7. There was no statistically significant difference in the results for rh-PRG4 (recombinant) and nPRG4 (native) as indicated by the presence of b above each bar in FIG. 11B.
FIGS. 12A-B represent data comparing the coefficients of static (FIG. 12A) and kinetic (FIG. 12B) friction of a rhPRG4 plus HA solution to saline, rhPRG4 alone and bovine synovial fluid with rhPRG4 at 450 pg / mL and HA ( 1.5 MDa) 3.33 mg / mL. Designations a, b, c
-25y d above each bar in FIG. 12B means statistically significant differences in the results (p <0.05), n = 4.
FIG. 13 depicts data showing restoration of lubricity at interface surfaces of bovine tissue after digestion of native bovine PRG4 and application of rhPRG4.
FIGS. 14A-D represent data showing the effect of rhPRG4 on boundary lubrication at a human eyelid-cornea interface (FIG. 14Ά - static, FIG. 14B-kinetic) and human cornea-PDMS interfaces (FIG. 14C - static, FIG 14 D-kinetics) of native bovine PRG4 and rhPRG4 at 300 pg / ml in saline and saline alone. Values are mean ± SEM (n = 6) with a normal mean tension of 14.1 ± 2.2 and 16.9 ± 5.3 (mean ± SD) for the eyelid-cornea (AB) and corneal-PDMS (CD) interfaces, respectively. These data illustrate the virtually identical lubrication properties of rhPRG4 and purified native PRG4 in low load lubrication tasks.
FIG. 15 is the full length human lubricin amino acid sequence which is 1404 amino acids in length. Signal sequence residues (1-24) are shown in bold.
-26 FIG. 16 is the nucleic acid sequence encoding full-length human lubricin.
DETAILED DESCRIPTION OF THE INVENTION
The present inventors investigated options for the production of the known human lubricin glycoprotein using recombinant DNA techniques, with the aim of generating a production process that involves suspension in culture that exploits mammalian cells in a free growth medium. serum. Unlike any previous effort known to applicants to produce proteins using recombinant DNA techniques, the challenge was to produce commercial quantities of a large, complex biopolymer whose value lies in its nanoscale mechanical properties, in contrast to its biochemical properties and those physical properties that depended on the successful exploitation of post-translational glycosylation events on a scale never before seen in a modified cell.
Previous attempts at recombinant production of full-length lubricin have provided only low milligram per liter amounts, and a method was needed to produce at least about one to two grams per liter. A review of the literature did not reveal
-27 reports of successful commercial-scale recombinant production of adequately glycosylated full-length lubricin, without commercial-scale expression of any mucin or mucin-like protein. The search revealed reports suggesting such a highly glycosylated glycoprotein while lubricin was very difficult to express. See, for example, US Patent No. 7,642,236 which states: In order to optimize the expression parameters and investigate the functional necessity of all the approximately similar sequences-KEPAPTT 76-78, the lubricin expression constructs were designed allowing the synthesis of the recombinant lubricin proteins with degrees of variation of O-linked oligosaccharide substitution. The productivity data of the recombinant cell lines expressing the truncated lubricin constructs was not disclosed in the patent.
The inventors sought out and ultimately employed Selexis SA of Geneva, Switzerland to produce clonal cultures expressing lubricin, based in part on the reported ability of Selexis technology, which involves the expression of epigenetic regulators, to enhance the production of difficult proteins. To express. (See Selexis US Patent Nos. 7,129,062 and 8,252,917 and. US Patent Application Nos.
282011/0061117, 2012/0231449 and 2013/0143264, the disclosures of which are incorporated herein by reference; Girod et al., Nat Methods 4 (9): 747-53 (2007); Harraghy et al., Curr Gene Ther. 8 (5): 353-66 (2008)).
The application of Selexis technology resulted in the development of clones successfully expressing lubricin. After analysis, upscaling and purification, it was discovered that newly developed recombinant production procedures gave rise to differently glycosylated and heavy, multimeric forms, never before described, of human-type lubricin, and produces it at levels unprecedented for such glycoproteins. Mucin-type, high molecular weight, heavily glycosylated. Testing the preparations rich in the new form of recombinant lubricin demonstrated unexpected properties and allowed the production of improved physiologically compatible tissue lubrication compositions.
The manufacturing process of rhlubricin
Host Cells
Production work on the Selexis clone was performed using their proprietary CHO-M cell line, which contains DNA-based elements that control the dynamic organization of chromatin, called matrix binding regions. The CHO-M cell line is a line
-29 Chinese hamster ovary cell derived from CHO-K1 cells (ATCC, Cat. # CCL-61, Lot. 4765275) adapted to serum-free culture conditions and used for the production of recombinant proteins. See Girod et al., Nat Methods 4 (9): 747-53 (2007) and the US patents and publications identified above in relation to matrix binding regions (MARs) for methods that are used of MARs for the development of Eukaryotic cell lines expressing high stability such as CHO and to cells transected to express proteins involved in translocation of expression products through the ER membrane and / or secretion through the cytoplasmic membrane. CHO-M is used for the production of therapeutic recombinant proteins and allows a higher and more stable expression. Its use allows the isolation of clones exhibiting the desired high-level expression for use in the production of recombinant proteins.
The binding regions of. Matrix (MARs) are DNA sequences that link isolated nuclear base structures or in vitro nuclear arrays with high affinity (Hart et al., Curr Opin Genet Dev, 8 (5): 519-25 (1998). As such, they can define chromatin domain boundaries independent, such that only encompassing cisregulatory elements control gene expression
-30 within the domain. MAR sequences have been shown to interact with stimulators to increase the accessibility of local chromantin (Jenuwein et al., Nature, 385: 269-272 (1997)) and can stimulate the expression of heterologous genes in cultured cell lines. . Co-transfection of a plasmid carrying the chicken lysozyme 5 'MAR element with one or more expression vectors results in a higher stable transgene expression that showed a production greater than 20 times in expression compared to the control construct.
MARs are a type of chromatin element (also referred to herein as Selexis Genetic Elements or SGEs) that are disclosed in the Selexis applications and publications referenced herein. Chromatin elements or SGEs are used to prevent the chromatin surrounding the integration site of a heterologous gene on a host chromosome from influencing the level of expression of the incorporated gene. Chromatin elements include border elements or isolating elements (BEs), matrix binding regions (MARs), locus control regions (LCRs), and universal or ubiquitous chromatin aperture elements (UCOEs). SGEs form chromatin, once the expression vector has integrated into the chromosome of the host cell and thus
-31 maintains the transgene in a high transcriptionally active state.
The CHO-M host cells were cultured in SFM4CHO medium (HyClone), supplemented with 8 mM L-glutamine, hypoxanthine and thymidine (Ix HT, Invitrogen). The cells were kept shaking (120 rpm, 25 mm stroke) in a humidified incubator at 37 ° C and 5% CO2.
Vector construction
Encoding the PRG4 gene encoding the full-length AA 1404 human lubricin protein (SEQ ID NO: 2) was inserted into commercially available and patent-pending plasmid vectors from Selexis SA (Geneva, Switzerland) for improved gene expression in cells. mammals. Another sequence that encodes full-length human lubricin is available under GenBank accession number NM_005807.3.
Two expression vectors were constructed. The lubricin gene was cloned into expression vectors carrying puromycin resistance and another carrying hygromycin resistance. The vector including the puromycin resistance was designated pSVpuro_C + _EFlalpha (KOZAK-ext9) EGFP_BCH pA> X_S29 (2 * HindIII, Salí filled) (Mw = 9861). The vector including the hygromycin resistance was designated pSVhygro_C + _EFlalpha (KOZAK-ext9) EGFP_BCH pA> X_29 (2 * HindIII, Salí filled) (Mw = 10299). Vectors
The expression -32 cells contain the bacterial Transposon Tn3 beta-lactamase gene (AmpR), which confer ampicillin resistance and ColEl bacterial origin of replication. As derivatives of pGL3Control (Promega), the terminator region of the expression vectors contains an SV40 stimulator positioned downstream of the BCH p'oliadenylation signal. Each vector also includes a human X 29SGE downstream from the cassette expression and a puromycin or hygromycin resistance gene under the control of the SV40 promoter. X_29SGE refers to a Selexis Genetic Element (SGE), in this case a matrix binding region (MAR), which are disclosed in the Selexis applications and publications referenced here both expression vectors encode the gene of interest (PRG4) under the alpha-l-hEF promoter control coupled to a CMV stimulator. The plasmids were verified by sequencing.
Plasmid maps of the vector carrying the puromycin resistance gene and carrying the hydromycinase resistance gene are shown in FIG. 1 and FIG. 2, respectively.
Transfection
Cells were transfected by microporation using a MicroPorator ™ (NanoEnTek Inc., Korea) that defines pulse conditions for CHO-M cells (1250V,
-3320 ms and 3 pulses). The transfection efficiency was controlled using a GFP expression vector in parallel and it showed transfection efficiency between 50-70%. CHO-M cells were first transected with the puromycin expression vector PRG4, and stably transected cells were first selected by culturing in puromycin-containing medium. More particularly, the dilutions were dispensed into 96-well plates, fed within the following week by adding 100 pL of fresh selection medium to all wells (SFM4CHO medium supplemented with 8 mM L-glutamine, lx HT including 5 pg / mL of puromycin). Twenty-seven minigroups were rearranged to 24-well plates 15 days after plating by transferring the entire cell suspension out of the corresponding 96-wells into one well of a 24-well plate primed with the same medium. Within four days the 24-well supernatants were analyzed and 14 minigroups were transferred to 6-well plates (1 mL of cell suspension + 2 mL of fresh growth medium including selection). Eight minigroups with better expression were expanded three days later by suspension and collection in centrifuge tubes (5 mL working volume) and three days later cultured in
-34 shake flasks (20 mL working volume). A further step was taken before depositing them.
Clusters of resistant cells were expanded in shake flasks to generate the necessary material for preliminary studies (1-2 mg total). Cell-free medium samples were acquired by centrifugation of the cell culture at 800g for 5 min. The expression of recombinant PRG4 was evaluated by dot blot analysis. Ten microliters of cell-free media (concentrated sample) was applied to a PVDF membrane (Millipore) and the samples were allowed to dry. A standard PRG4 was created by serially diluting PRG4 in 80 pg / ml down to 2.5 pg / ml. Recombinant PRG4 was detected by means of a polyclonal antibody directed against a synthetic peptide of PRG4 lubricin (Pierce).
Cells from the best performing minigroups were then super-transected (additional transection of a population of minigroups already selected), using the second selection marker, the hygromycin resistance cassette. The same transfection protocol was used as described above. One day after this second transfection, selection was started in SFM4CHO medium, supplemented again with 8 mM L-glutamine and 1x HT, but including 1000 pg / mL of
-35hygromycin. After a media exchange, within four days the three groups were transferred to 6-well plates; All three (3) groups were expanded to centrifuge tubes (5 mL working volume) four days later and to shake flasks (20 mL working volume) within three days.
Generation of clones
The super-transfected pools were then cultured and analyzed for growth potential in 10 serial and multiple experiments in an attempt to maximize cellular properties.
In the first experiment, three super-transfected groups (designated P01ST, P05ST and P14ST) were transferred to 6-well plates after the exchange of medium at the concentration of 100 cells / mL (2 plates for each group), in a semisolid medium. (2x SFM4CHO (HyClone) and CloneMatrix (Genetics) medium, including 8 mM Lglutamine, Ix HT and Cell Boost 5 ™ (HyClone), (no selection). Plated cells were screened 16 days 20 later, (ClonePix ™ system (molecular devices)) and 22 candidates were collected and transferred to 96-well plates with growth medium described above (but without selection). All 18 growth candidates were rearranged to 24-well plates six 25 days later, transferring the cell suspension
-36 complete out of the corresponding 96-well plate into one well of a 24-well plate (primed with 1 mL of medium). Within three days, the 24-well supernatants were analyzed and 12 candidates were transferred to 6-well plates (1 mL cell suspension + 2 mL of fresh growth medium including selection). The seven best expression candidates were expanded five days after culturing the suspension in centrifuge tubes (5 mL working volume) in medium (no selection) and within five days in shake flasks (20 mL working volume ).
All cell lines were deposited. The performance of the three best candidates was compared in shake flasks (seeding 3x105 cells / mL, culture volume 20 mL) within the batch-fed culture (feeding strategy - 16% of the original volume of the CB5 solution (HyClone) , 52 mg / mL, fed on day 0, 3, 4, 5, 6, 7). On day 8, the cultures contain 4.22 x 106 to 4.95 x 106 cells / mL and 94% to 96% viability. The cell populations from these groups were counted and diluted to plate a single cell (concentration 1 cell / well, two plates). Individual colonies were fed by adding 100 µΐ of growth medium per well after 11 days (no selection). After 17 days, 99
-37 clones were rearranged to 24-well plates by transferring the whole cell suspension out of the corresponding 96-well plate into a well of a 24-well plate (primed with 1 mL of medium). Within four days 24 were transferred to 6-well plates (3 mL of fresh growth medium including selection). Eight clones were expanded to suspension culture in centrifuge tubes (5 mL working volume) after four days and all eight clones were expanded to shake flasks (20 mL working volume) after a medium exchange ( SFM4CHO medium, supplemented with 8 mM L-glutamine and lx HT). A further step was carried out before depositing all the candidates.
The comparison of the performance of the five best candidates was carried out in shake flasks (seeding 3x105 cells / mL, culture volume 20 mL) with the batch-fed culture (feeding strategy A 16% of the original volume of the CB5 solution ( HyClone), 52 mg / mL, fed on day 0, 3, 4, 5, 6, 7). On day three the cell numbers in the respective cultures ranged from 1.61 x 106 to 3.46 x 106 cells / mL with twice that varying from 19.8 to 30.7 hours. On day 8, cell concentrations ranging from 4.02 x 106 to
-3810
9.48 χ 106 cells / mL with cell viability ranging from 88.6% to 97.7%.
In the second experiment, three different super transfected groups (designated P14STcpO8, P05ST11 and P14ST33) were treated with the same procedure as indicated above. This resulted in four clonal cell lines. Again, the performance of these clones was compared in shake flasks, resulting in cell concentrations on day 8 ranging from 3.5 x 106 to 9.48 x 106 cells / mL and viability between 75.3% and 88.1%.
A clone from the first round of selection of the ClonePix ™ system described above (P14ST15) that presented 6.03 x 106 cells / mL and 95.5% viability on day eight was thawed in a shake flask (20 mL working volume). The candidate was transferred to a single plate after a subsequent step, at the concentration of 200 cells / mL (1 plate) in the semisolid medium described above plus CloneMatrix, including 8 mM Lglutamine, lx HT and Cell Boost 5 ™, without selection. Cells on the plates were screened using the ClonePix ™ system 12 days later, 84 clones were harvested and transferred to 96-well plates (no selection). Individual colonies were fed by adding 100 μΐ of growth medium per
-39well. Screening of the 96-well supernatants was done 18 days after plating. The 24 best growing clones were rearranged to 24-well plates by transferring the whole cell suspension out of the corresponding 96-well plate into a well of a 24-well plate (primed with 1 mL of medium (no selection) ). Within three days, the 24-well supernatants were analyzed and 12 clones were transferred to 6-well plates (1 mL cell suspension + 2 mL fresh growth medium including selection). The six best expressing clones were expanded four days after culturing the suspension in centrifuge tubes (5 mL working volume) and within four days in shake flasks (20 mL working volume). Two further steps were taken before depositing them. Six clonal cell lines were deposited.
The performance of the top six candidates was compared in shake flasks as described above. On day 8 the cell densities varied between 9.04 x 106 and 6.40 x 106 cells / mL and viabilities were between 74.6% and 93.1%.
Cryopreservation and Testing
After multiple passages of the clonal groups (from 6 to 31), the groups were cryopreserved in vials in
-406x106 cells / vial and stored in liquid nitrogen. The absence of mycoplasma was confirmed for all cell lines by using a Gem Venor® mycoplasma detection kit (Minerva Biolabs). Sterility tests were inoculated and incubated according to the manufacturer's protocol (Heipha, Caso-Bouillon TSB). Sterility was confirmed for all minigroups and super transfected minigroups.
Scaled up crops
The designated cell line P05STll-cp05 was selected to scale up. For a 200 liter run, the following conditions and protocol were used:
<td>Container</td><td>XDR-200 Bioreactor</td>
<td>pH</td><td> 7.1 ± 0.2</td>
<td>Dissolved oxygen</td><td> 50%</td>
<td>Temperature</td><td>37 ° C, see change notes below</td>
<td>Start volume</td><td>100L</td>
<td>Inoculant density</td><td>le6VC / mL</td>
<td>Base medium</td><td>SFM4CHO Supplemental p / 1XHT (8 mM) of Glutamax (Gibco®)</td>
<td>Feeding</td><td>CéUBoostó (52 gT,) 16% v: v on days 0, 3,5.7 * CellBoost5 (52 g / L) 10% vv days 10 and 12, more if necessary.</td>
<td>Target culture glucose</td><td>Maintain 4-4.5 gL Feed 40% of the reserve as needed, see "GlucoseOsmolarity" below</td>
<td>WFI Supplement</td><td>As necessary to maintain Osm <410mOsm / kg, see "Glucose / Osmolarity" below</td>
<td>Harvest criteria for cell viability</td><td>60% viability</td>
<td>Agitation</td><td>95 RPM</td>
<td>Gas back design</td><td>(5) O.Snmi by 2um porosity disk drilled holes</td>
<td>Cell Boost ™ Power</td><td>16% of 52 gL on days 0, 3.5, 7 10% of 52 gl · on day 10.12, and more if necessary</td>
<td>Glucose / Osmolarity</td><td>measurement protocol: Feeding - Glucose measurement Add glucose if necessary - Osmolarity measurement Add water if necessary Glucose criteria: 4-4.5 g / L Osmolarity criteria: If MIO mOsm, add H ^ O to reach 300</td>
<td>Glutamax / Glutamine</td><td>Glutamine monitoring - if drop to = '0.5 mM, supplemental to 2mM</td>
<td>Temperature change</td><td>Change to 34C at 80% or 12x10 ° cells / ml</td>
<td>Harvest criteria</td><td>Viability <60%</td>
The expression of rhPRG4 increases in tandem with variable cell density (VCD) from day 1 to 8 in a 200 liter culture. The VCD plateau on day 8 later begins to fall, which is normally seen once conditions are not optimal for the metabolic demands of a dense cell culture system. Despite this, the
-42 expression of rhPRG4 remains unchanged and its expression in the culture system with VDC of 12-14 x 10 6 cells / ml reached a maximum concentration on culture day 13. FIG. 5 show the cumulative amount of recombinant lubricin over time as measured using the area under the curve of an HPLC graph, and interpret this area in comparison to three different standard curves made by HPLC purification of serially diluted samples from the which is believed to be at least 99% pure lubricin. As illustrated, this procedure estimated the production of recombinant lubricin at about 2.5 g / ml. Additional production runs in variety in its apparent yield measured by various techniques. One run produced lubricin at a level of 1.5 g / liter as measured by competitive ELISA. Another produced a reading of 1.4 g / liter.
Recombinant PRG4 Purification
The development goal of the purification protocol is to preserve the lubrication function of the expressed lubricin product and its multimeric complexes while separating from contaminants, avoiding aggregation, and maintaining high performance. This was challenging due to the heavy glycosylation of lubricin, its high molecular weight, its surface lubrication and anti-stick properties, and its tendency
-43 to complex, and aggregate to form insoluble microparticles while increasing purity. Previous experiments suggested that because the lubricin titer in the harvested media was high, discard flow mode chromatography may be necessary to avoid purification losses. A strategy was developed to remove the contaminants by chromatographic adsorption while preserving the lubricin product in the waste stream. During the course of development, the performance was found to be sensitive to the use of nonionic surfactant components such as, for example, polyoxyethylene derivative of sorbitan monolaurate. The omission of said surfactant in the lubricin group resulted in a significant loss of product during ultrafiltration / diafiltration and 0.2pm of filtration after the chromatographic separation steps. The use of as little as 0.1% by weight of surfactant greatly improved performance. By trial and error it was found that lower concentrations of surfactant were successful in retention function and improved performance.
In addition to the nonionic surfactants used in the purification process, physiologically compatible excipient forms, such as [(3-cholamidopropyl) dimethylammonium] -1-propanesulfonate (CHAPS) and / or lysine can be mixed with solutions of the
-44lubricin of the invention and may have beneficial effects in stabilizing solutions, for example, to avoid or reduce the aggregation of lubricin in solutions containing more than a concentration of 0.4 or 0.6 mg / ml.
The iterative test resulted in the development of a purification procedure that is set out below.
The clarified medium by sedimentation (100 mL) was diluted with 5 mL 200 mM Tris, 40 mM MgC12, pH 8.2 and mixed with 400 units of Benzonase (250 units / μΐ, Novagen) to remove soluble polynucleotides. The solution was mixed for four hours at room temperature, then 37.8 g of urea were mixed to adjust the urea concentration to 6 M, and to result in 120 mL of solution. To this was added IN of NaOH to adjust to pH 11 and 0.01% Tween 20 (sorbitan monolaurate, Sigma).
The post-Benzonase material was then treated using GE Q Big Beads ™ anion exchange resin with a pH of 11 in the presence of 6M Urea and 0.01% Tween 20 run in a discard flow (ET) mode where contaminants bind to resin and product no. The column was first disinfected with 0. IN of NaOH; then it was loaded with 100mM NaPO4, 1.5M NaCl, pH 7.2; and rebalanced with 200 mM Tris-borate, 6M Urea, pH 10.
The 30 ml volume column (XK 26 x 6 cm) was then loaded with the 120 ml solution in 4 ml / ml resin at a flow rate of 20 ml / min (240cm / hr), followed by a Equilibrium Buffer Wash - 100mM Tris-borate, 100mM NaCl, 6M Urea, 0.01% Tween 20, pH 11. Shortly after loading, the product was collected through washing (290mL total volume) until adding a strip of 0.1N NaOH + 1M NaCl solution.
This partially purified waste flow lubricin pool was adjusted to pH with 1M citrate pH = 7.5 and passed through a hydroxyapatite column (BioRad CHT), column volume - 14ml (XK 16x7 cm), Loading of column - 21 ml load / ml resin, flow rate = 10 ml / min (300 cm / hr). The column was first disinfected with 0.1N NaOH and 1M NaCl, Loading with 500 mM NaPO4, pH 6.5; re-equilibrate with 500 mM NaPO4 / 6M Urea, pH 7.4; and loaded with 290 mL of discard flow from the previous step. This was followed by washing with equilibration buffer, 15mM NaPO4, 6M Urea, 0.01% Tween 20, pH 7.4, to produce 305 ml of waste flow containing the product.
The discard flow from the hydroxyapatite column was adjusted to pH 4.8 with 1M citrate and diluted with water, then passed through a GE SP Big Bead resin, column volume - 6ml (XK 1.6 x 3cm), Loading
-46 column - 58 ml resin load / ml, Flow rate = 6.7 ml / min (200cm / hr). First the column was disinfected with 0.5N NaOH, loaded with 100 mM NaPO4, 1.5M NaCl, pH 7.4; re-equilibrate with 50 mM Na citrate / 6M urea, 0.01% Tween 20, pH 4.8; and load it with 350 mL of discard flow from the previous step. This was followed by washing with equilibrium buffer, 50mM Na citrate / 6M Urea, 0.01% Tween 20, pH 4.8, to produce 378 ml of waste flow containing the product. The waste stream was then neutralized with ION NaOH (pH 7.2).
To concentrate and exchange the buffer, the product pool from the discard stream after cation exchange was filtered using a 50 kDa molecular weight TangenX 0.01m2 cut-off flat sheet membrane (TangenX Technology Corporation), LP sieve channel. The diafiltration buffer was 10mM NaPO4, 150mM NaCl, pH 7.2 (PBS) and 0.1% Tween 20. After disinfection with 0.1N NaOH; rinse with MilliQ water; and equilibrated with IOmM NaPO4, 150mM NaCl, pH 7.2, the membrane was loaded at 15,000 ml / m2; Cross flow 70 ml / min; transmembrane pressure = 0.0413685 MPa-0.0482633 MPa (6-7 psi); perneed flow = 5-6 ml / min to concentrate the solution to approximately 50 ml.
Finally, the pos UFDF product group was subjected to 0.2 pm filtration through a Sartorius Sartopore
-472, 150-0.015 m2 of membrane at a membrane load of ~ 17,000 ml / m2, and a flow rate of 45-50 ml / min. The membrane was first primed with 10 mM NaPO4, 150 mM NaCl, pH 7.4, then the product was filtered, followed by a chase filter with ~ 40 ml of buffer and finally the filter was drained.
Additional excipients are currently being examined to improve the recovery of UFDF and 0.2um filtration of the final purified product. This process can produce large amounts of product per liter of harvested medium of at least 96% purity. Alternative purification strategies will be apparent to those of skill in the art.
Lubricin Product Characterization
Electrophoresis.
The molecular weight of the full-length lubricin amino acid backbone is 150,918 Daltons. The extent and type of glycosylation varies from molecule to molecule. Recombinant PRG4 made as disclosed herein as a dimeric species is believed to have an average molecular weight of greater than about 450 kDa. The monomers should have a weight of 220-280 kDa, and no more than about 300 kDa.
FIG. 3 depicts a Coomassie staining gel (SDS-48PAGE NuPAGE® Tris-Ac 3-8% Polyacrylamide Gel Electropheresis System, Invitrogen) of rhPRG4, both not reduced as purified and reduced and alkylated. All numbered bands were confirmed as lubricin by MS / MS, having 5 amino acid sequence coincidence with PRG4 homo sapiens (UniProt Accession number Q92954; SEQ
ID NO: 1). As illustrated, recombinant lubricin produced as described above (NR) contains major bands that have approximate molecular weights, as estimated in comparison to molecular weight standards 10, of ~ 460kDa, slightly above the same, and one in the upper part of the gel that was unable to migrate into the gel.
Identification of posttranslational processing constituents was performed by digestion of rhPRG4 with neuraminidase (NaNase 1) and Oglucosidase DS at the same time to expose the molecular weight of the rhPRG4 amino acid core as shown in the lane marked L-NO in the FIG. 4. The predicted molecular weight of the core is 151 kDa which is confirmed experimentally by this 4-12% SDS-PAGE. Digestion with neuraminidase alone had a molecular weight lowering effect illustrating that glycosylation is incompletely covered by neuraminic acid. Digestion with DS O-glucosidase that removes 25 β (1-3) GalNAc Gal O-bound residues and neuraminidase resulting in
-49 implies that this lot of protein is glycosylated about 30% by weight. Digestion with O-glycanase alone is likely to only be effective in removing some uncovered GalNAC Gal residues.
Glycosylation analysis
To further characterize the protein, mass spectrometric analysis of the 0-glycans of recombinant lubricin and normal synovial lubricin was carried out and compared. Briefly, synovial lubricin was isolated from synovial fluid by DEAE chromatography. Recombinant and synovial lubricin were separated by SDS-PAGE using 3.-8% Tris acetate gels before transferring to the PVDF membrane. The 0-glycans were then released from the lubricin stains by reductive β15 removal followed by cleaning for LC-MS / MS analysis. O-glycans were separated by porous graphitized carbon chromatography prior to MS / MS analysis in negative mode using a linear ion trap mass spectrometer-dependent data method, LTQ (Thermo Scientific).
Analysis of the recombinant lubricin sample identified only the core 1 O-glycan structures (FIG. 6). The extracted ion chromatograph showing the identified glycans is shown in FIG. 7. The sialylated structure, [MH] -675, is shown as two
-50 main peaks. These are the same isomer with the second peak at the retention time 21.4 min which is a chemical derivative created during the β-elimination process. Three isomers of the sulphated structure ([ΜΗ] - 464) were identified. Several isomers of the monosulfated monosialylated structure were also identified. The disialylated structure was of very low abundance and cannot be seen on the chromatograph. An estimate of the proportion of each of the identified glycans is shown in Table 1 (to determine the sugar structures, see FIG. 6). This analysis combines all the isomers, derivatives, and adducts for each of the structures in Table 1.
Table 1 The percentage of each of the identified glycans in recombinant lubricin. The data includes all isomers, derivatives and adducts for each of the structures mentioned in the table.
<td></td><td>O -D</td><td> 0¾</td><td>Jk. _ ▼ XJ</td><td>o — o</td><td></td>
<td>Glycan</td><td> 384</td><td> 464</td><td> 675</td><td> 755</td><td> 966</td>
<td>Percentage</td><td> 19.8</td><td> 34.3</td><td> 33.2</td><td> 12.1</td><td> 0.6</td>
Normal human synovial lubricin has a greater range of glycans that extend into core structures 2 (FIG. 8). The most abundant of these structures
-51 is shown in FIG. 9 on the extracted ion chromatograph.
The glycosylation pattern of rhlubricin is very different from that of native human glycoprotein, as can easily be appreciated, for example, from a comparison of FIG. 7 with FIG. 9. In native synovial lubricin, the sialylated core 1 structure is the most abundant glycan, but there is significant core 2 glycosylation of several types, and only minor amounts of sulfated polysaccharides. In the recombinant glycoprotein, the sialylated and unmodified nucleus 1 constitutes more than half of the glycans, and the sulphated nucleus 1 structure constitutes about a third of the identified O-glycans, with all three isomers identified.
Physicochemical properties of rhlubricin
Surfactant-like (unfriendly) properties
An important attribute of rhPRG4 is its ability to coat both biological and non-biological surfaces by means of physicochemical adsorption. Native PRG4 is surface active and incorporates terminal globular domains separated by the large mucin-like domain. These can be separated into polar and nonpolar domains within their structure. The central mucin domain, as shown by force apparatus studies
-52surface of human synovial fluid lubricin, may fold back on itself suggesting that glycosylations are directed away while this orientation is reached. In general, the mucin domain becomes more hydrophilic than either its N- or C-terminal. The importance of this is confirmed by the knowledge that the digestion of glycosylations will remove the lubrication capacity (Jay et al., J Glycobiol 2001). This unsympathetic nature is also present in rhPRG4. It can be easily measured by evaluating the reduction in interfacial tension between an aliphatic and aqueous interface.
In an experiment designed to test the properties of the rhlubricin surfactant performed using the process of the invention, an increase in the concentration of rhPRG4 was presented in a PBS solution that was covered by undiluted, hydrophobic cyclohexane. A Du Noüy ring was recorded in the aqueous sub-phase containing rhPRG4 was pulled up and the critical stress (Ei) where the ring was broken through the interface. Measurements were collected five times at each concentration on an Attension Sigma 702ET blood pressure monitor. A rhPRG4 concentration dose response curve was plotted against Γί, see FIG. 10A. As illustrated, as the concentration of rhPRG4 increases in the
-53 aqueous sub-phase containing PBS, decreases the interfacial tension.
Because the rhlubricin solution contained residual non-ionic surfactant (Tween 20), the experiment was repeated to investigate whether this was responsible for the dramatic reduction in surface tension induced by the addition of the recombinant product, first using different concentrations of the surfactant alone. and then with very low concentrations of the rhPRG4 of the invention. Microliter amounts of the surfactant and PRG4 were added to 15mL of the aqueous sub-phase. The results are shown in FIG. 10B and FIG. 10C. As illustrated, PRG4 alone (FIG. 10C) reduces surface tension better than commercial surfactant alone by 0.1% (FIG. 10B). Thus, rhPRG4 containing 0.1% Tween and that containing no Tween reduced the interfacial tension of PBS and cyclohexane more than 0.1% Tween only when they all had the same amount of the solution of interest added.
These data show that even at low concentrations, rhPRG4 preferentially populates the aliphatic-aqueous interface, reducing the interfacial tension. This phenomenon recapitulates the surface bonding interaction required in friction reduction and mimics the behavior of native lubricin. Furthermore, the interfacial tension reducing activity
-54 can be used as quality control procedures for rhPRG4 production.
Lubrication properties
Cartilage lubrication
Fresh osteochondral specimens (n = 16) were prepared for friction test from the patello-femoral groove of excised joints of skeletally mature bovine, as described above. Briefly, nuclei (radius = 6mm) and rings (outside radius = 3.2mm and inside radius = 1.5mm) were harvested from the osteochondral blocks, both with central holes (radius = 0.5mm) to allow fluid depressurization. . The samples were vigorously rinsed overnight in PBS at 4 ° C to rid the articular surface of residual synovial fluid, and this was confirmed by testing for the presence of lubrication. The samples were then frozen in PBS with proteinase inhibitors at -80 ° C, thawed, and re-shaken overnight in PBS to further deplete the surface of any residual PRG4 on the surface. The samples were then fully immersed in about 0.3 ml of the respective test lubricants (described below) at 4 ° C overnight prior to the next day's lubrication test, and rinsed again with
-55PBS after each test before incubation in the next lubrication test.
A Bose Electroforce® A test instrument (ELE 3200, Eden Prairie, Minnesota) was used to analyze the limiting lubrication capacity of each of the PRG4 controls and shapes, using an established cartilage-on-cartilage friction test. Briefly, all samples were compressed at a constant rate of 0.002 mm / s at 18% of the total thickness of the cartilage and allowed to relax the tension for 40 minutes to allow depressurization of the interstitial fluid. The samples were then rotated at an effective speed known to maintain limit mode lubrication at a depressurized cartilage-cartilage interface (0.3 mm / s) at ± 2 revolutions. After being left in a pre-slip stationary period of 1200, 120, 12, and 1.2 seconds, the samples are rotated after each subsequent stationary period, +2 revolutions. The test sequence was then repeated in the opposite direction of rotation, - /! 2 revolutions.
Two test sequences were evaluated for the cartilage boundary lubrication ability of rhPRG4, both alone and in combination with HA. In both test sequences, PBS served as the negative control lubricant and bovine synovial fluid as a control lubricant.
-56positive. Both purified native bovine rhPRG4 and PRG4 were prepared in PBS at a concentration of 450 pg / mL and HA (1.5M from DA Lifecore Biomedical, Chaska, MN) was also prepared in PBS at a physiological concentration of 3.33 mg / mL. The lubricants were tested in an assumed order of increasing lubrication capacity (decreasing the coefficient of friction). In test sequence 1, rhPRG4 versus nbPRG4, the sequence was PBS, rhPRG4, nbPRG4, synovial fluid (n = 7); in test sequence 2, rhPRG4 against rhPRG4 + HA, the sequence was PBS, rhPRG4, rhPRG4 + HA, synovial fluid (n = 4).
The two coefficients of friction; static (pstatic, Neq) (resistance at the start of motion of the static condition) and kinetic (<p<sub>C</sub>Inetic, Neq>) (stable sliding resistance) were calculated for each lubricant as described above. The results were shown in FIGS. 11 and 12. Data are presented as mean ± SEM. ANOVA was used to evaluate the effect of lubricant and pre-slip stationary period as a repeated factor in plague, Neq and <Pkinetic, Neq>, with Tukey post-hoc test in <p<sub>C</sub>Iinetic, Neq> in a stationary pre-slip period of 1.2 s. Statistical analysis was implemented with Systatl2 (Systat Software, Inc., Richmond, CA).
-57 As shown in FIG. 11, there was no statistical significance between the measured lubrication property, coefficients of kinetic friction, of the recombinant PRG4 and the slightly lower values of native bovine PRG4. As shown in FIG. 12, rhPRG4 in combination with HA improves both static (FIG. 12A) and kinetic (FIG. 12B) lubricity compared to rhPRG4 alone. All measurements were highest in PBS and lowest in bovine synovial fluid, with rh-PRG4 and rhPRG4 + HA being intermediate. The mixed solution of rhPRG4 + HA tended towards a significantly lower coefficient of friction than rhPRG4 alone (p = 0.075) and was statistically similar to bovine synovial fluid (0.021 ± 0.001, p = 0.20).
Efforts have also been made to ensure the removal of native lubricin from bovine cartilage intended to be used as bearings using a two-hour enzymatic digestion with hyaluronidase. Hyaluronidase digestion is intended to remove native PRG4 (P <0.050) from the superficial zone of cartilage explants. This treatment removes superficial PRG4 without significantly affecting the mechanical characteristics of the articular cartilage. Applying rhPRG4 to these surfaces and comparing the frictional response to BSF and PBS controls shows that a low COF
-58 can be restored with the rhPRG4 of the invention. FIG. 13 shows COF values for bovine medial condyle cartilage explants treated with hyaluronidase with rhPRG4, BSF and PBS as intervening lubricants. The osteochondral explants were tested after the aforementioned lubricants following the protocol discussed above. As shown, recombinant human type PRG4 restored a low COF (rhPRG4 N = 18; BSF N = 6; PBS (N = 8).
Ocular surface lubrication
Normal human corneas with 3 mm sclera were obtained from the Lions Eye Bank in Southern Alberta. Human eyelids were harvested from fresh corpses from the University of Calgary's Body Donation Program. Approval for use and appropriation of these tissues was obtained from the Health Research Ethics Council. The corneas (n = 6) were stored in corneal storage media based on chondroitin sulfate (Optisol-GS) at 4 ° C and used within 2 weeks. The eyelids (n = 6) were frozen and thawed within the time of use.
The purity of the rhPRG4 species was evaluated to be 50% by sodium dodecyl sulfate 3-8% Tris-Acetate NUPAGE polyacrylamide gel electrophoresis. The concentration of the enriched rhPRG4 preparation was
-59evaluated and adjusted to take purity level into account.
The tissue samples were mounted on a Bose ELF3200 with axial and rotational actuators and axial load and torsion sensors. The resected cornea was fixed to the end of a semi-spherical silicone rubber plug (radius = 6 mm), applying cyanoacrylate glue (instantaneous) on the sclera. A silicone rubber sheath was fitted around the corneal plug apparatus, which served to hold the lubricating fluid. This apparatus was then attached to the rotary actuator of the Bose ELF3200 thus forming the hinge surface of the bottom. A ring (outer radius = 3.2 mm, inner radius = 1.5 mm) was drilled from PDMS model material (~ 0.4 mm thickness UntrSylgard 184, Dow Corning,) or human eyelid tissue and glued to a ring holder. This ring bracket was then attached to the linear actuator, thus forming the upper hinge surface.
After mounting the samples, 0.3 ml of test lubricant was placed on the cornea to form a lubricant bath and the articulating surfaces were allowed to equilibrate with the test lubricant for a minimum of five minutes. The tissue samples are contacted in three corresponding manually determined axial positions with loads
-60axials of 0.310.02, 0.510.03 and 0.710.03 N, resulting in axial pressures ranging from 12.2 to 28.5 kPa based on a contact area of (24.6 mm2). Once in contact in the given axial position, the samples were subjected to four revolutions in both directions at four different effective sliding speeds (vef = 30, 10, 1.0, 0.3 mm / s) where vef = ω-ref and ref = 2/3 [(ro3-ri3) / (ro2-ri2)]. The axial load and torsion were collected at 20 Hz during the rotations. There was a 12 second dwell time between each revolution. Each test sequence, described below, included a preconditioning step where tissues were subjected to the described testing protocol in a saline bath.
To determine the limiting lubrication capacity of the rhPRG4 preparation in a human cornea-eyelid (Test 1) and the human cornea - polydimethylsiloxane interface (PDMS, Test 2), the following test sequence was used: 300 pg / mL PRG4 in saline solution, 300 pg / mL of rhPRG4 in saline solution, then saline solution (Sensitive Eyes Saline Plus, Bausch & Lomb).
To evaluate the effectiveness of the test lubricants at the two interfaces, the coefficients of kinetic and static friction were calculated. As illustrated in FIG. 14, both PRG4 and rhPRG4, significantly and similarly, are
-61 reduced friction at a PDMS-human cornea interface (cf. FIGS. 14C and 14D) and at the eyelid-cornea interfaces (FIGS. 14A and 14B).
Contents7
36 sheets
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51 members in 22 offices
Priority claims3
| Document | Office | Kind | Date |
|---|---|---|---|
| 61894366 | United States of America | – | |
| 201361894366 | United States of America | P | |
| 2014061827 | United States of America | W |
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| CA2927949A1 | Canada | A1 | |
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| IL245236D0 | Israel | D0 | |
| KR20160086843A | Republic of Korea | A | |
| CN105899527A | China | A | |
| EP3060577A1 | European Patent Office (EPO) | A1 | |
| US2016250286A1 | United States of America | A1 | |
| US2016304572A1 | United States of America | A1 | |
| JP2016535590A | Japan | A | |
| MX2016005302AThis record | Mexico | A | |
| EP3060577A4 | European Patent Office (EPO) | A4 | |
| BR112016008923A2 | Brazil | A2 | |
| RU2016119532A | Russian Federation | A | |
| RU2016119532A3 | Russian Federation | A3 | |
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| EP3060577B1 | European Patent Office (EPO) | B1 | |
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| EP3971203A1 | European Patent Office (EPO) | A1 | |
| US11485764B2 | United States of America | B2 | |
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Numbers
- Publication
- 2016005302
- Application
- 5302
Titles2
- Spanish
- PRODUCCION DE LUBRICINA RECOMBINANTE.
- English
- RECOMBINANT LUBRICINE PRODUCTION.
Classification
- CPC, 12
- A61K9/0014
- C07K14/4725
- C12P21/00
- A61K9/0019
- A61K9/0048
- A61K31/728
- A61K9/008
- A61K47/36
- A61K38/1709
- A61P19/02
- C12P21/005
- A61K9/08
- IPC, 1
- C07K14 47