Composition and Methods of Using Umbilical Cord Lining Stem Cells

Abstract

The invention provides methods for using Umbilical Cord Lining Stem Cells (ULSCs) to produce therapeutic factors including growth factors, cytokines, chemokines and extracellular matrix components. ULSCs are mesenchymal stem cells isolated from umbilical cord lining. They can be efficiently propagated and expanded in vitro. Under specific conditions ULSCs produce useful therapeutic factors that can be used to treat injuries and degenerative conditions.

Claims

1. A method of using ULSCs to produce therapeutic factors which comprises: a. Propagating ULSCs in an in vitro cell culture system; b. Harvesting therapeutic factors from ULSC conditioned media.

2. The method of claim 1 wherein therapeutic factors may be one type of factor or a mixture of factor types selected from the group consisting of: growth factors, cytokines, chemokines, and ECM components.

3. The method of claim 2 wherein growth factors may be one or a mixture of factors selected from the group consisting of: SCF, VEGF family proteins, EGF family proteins, FGF family proteins, TGF-β family proteins, Angiopoietin family proteins, BDNF family proteins.

4. The method of claim 3 wherein cytokines maybe one or a mixture of cytokines selected from the group consisting of: GM-CSF, INF family proteins, interleukin family proteins and TNF-α family proteins.

5. The method of claim 4 wherein chemokines maybe one or a mixture of chemokines selected from the group consisting of: C chemokines, CC chemokines, CXC chemokines, CX3C chemokines (CX3CL1).

6. The method of claim 5 wherein ECM components may be one or a mixture of ECM components selected from the group consisting of: heparan sulfate, chondroitin sulfate, keratin sulfate, hyaluronic acid, collagens, elastins, fibronectins and laminins.

7. The method of claim 6 comprising the further step of purifying therapeutic factors from ULSC conditioned media;

8. A method of using ULSCs to produce therapeutic factors which comprises: a. Propagating ULSCs in an in vitro cell culture system; b. Harvesting therapeutic factors from ULSC cells.

9. The method of claim 8 wherein therapeutic factors may be one type of factor or a mixture of factor types selected from the group consisting of: growth factors, cytokines, chemokines, and ECM components.

10. The method of claim 9 wherein growth factors may be one or a mixture of factors selected from the group consisting of: SCF, VEGF family proteins, EGF family proteins, FGF family proteins, TGF-β family proteins, Angiopoietin family proteins, BDNF family proteins.

11. The method of claim 10 wherein cytokines maybe one or a mixture of cytokines selected from the group consisting of: GM-CSF, INF family proteins, IL family proteins, TNF-α family proteins.

12. The method of claim 11 wherein chemokines maybe one or a mixture of chemokines selected from the group consisting of: C chemokines, CC chemokines, CXC chemokines, CX3C chemokines (CX3CL1).

13. The method of claim 12 wherein ECM components may be one or a mixture of ECM components selected from the group consisting of: heparan sulfate, chondroitin sulfate, keratin sulfate, hyaluronic acid, collagens, elastins, fibronectins and laminins.

14. The method of claim 14 comprising the further step of purifying therapeutic factors from ULSC cells.

15. A ULSC cell culture system consisting of cells and conditioned media further comprising: a. Growth Factors; b. Cytokines; c. Chemokines; d. ECM components.

16. The ULSC cell culture system of claim 16 wherein the growth factors maybe one or a mixture of factors selected from the group consisting of: SCF, VEGF family proteins, EGF family proteins, FGF family proteins, TGF-β family proteins, Angiopoietin family proteins, BDNF family proteins.

17. The ULSC cell culture system of claim 17 wherein cytokines maybe one or a mixture of cytokines selected from the group consisting of: GM-CSF, INF family proteins, IL family proteins, TNF-α family proteins.

18. The ULSC cell culture system of claim 18 wherein chemokines maybe one or a mixture of chemokines selected from the group consisting of: C chemokines, CC chemokines, CXC chemokines, CX3C chemokines (CX3CL1).

19. The ULSC cell culture system of claim of 19 wherein ECM components may be one or a mixture of ECM components selected from the group consisting of: heparan sulfate, chondroitin sulfate, keratin sulfate, hyaluronic acid, collagens, elastins, fibronectins and laminins.

20. The ULSC cell culture system of claim of 15 wherein SCF, VEGF, GM-CSF, IL-4, IL-7, IL-8, MIP-1β, MCP-1, TNF-α, HA, CS and Collagen are the therapeutic factors present.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0053] FIG. 1. contains histograms of cytokines and chemokines in ULSC and BMSC conditioned media assayed by a quantitative multiplexed immunoassay system (MAPs).

[0054] FIG. 2. contains histograms of growth factor release in ULSC and BMSC conditioned media assayed by Enzyme Linked Immunosorbent Assay (ELISA).

[0055] FIG. 3. contains fluorophore-assisted carbohydrate electrophoresis (FACE) analysis demonstrating size and quantity of HA and CS in ULSC and BMSC conditioned media.

[0056] FIG. 4. contains an image of a hyaluronan size analysis by agarose gel electrophoresis.

[0057] FIG. 5. contains an image of a hyase digest size analysis by agarose gel electrophoresis.

[0058] FIG. 6. contains a histogram depicting levels of HA and CS in both conditioned media samples and the cells that produced said media.

[0059] FIG. 7. contains a data table and absorbance curve of Collagen in ULSC conditioned media assayed by dilution and absorbance analysis.

DETAILED DESCRIPTION OF THE INVENTION

[0060] Various embodiments of the invention are described in detail and may be further illustrated by the provided examples. As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes the plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.

[0061] Throughout this specification and claims, the word “comprise,” or variations such as “comprises” or “comprising” will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

[0062] Terms used in this specification generally have their ordinary meanings in the art, within the context of the invention, and in the specific context where each term is used. Certain terms that are used to describe the invention are discussed below, or elsewhere in the specification, to provide additional guidance to the practitioner in describing the compositions and methods of the invention and how to make and use them. For convenience, certain terms may be highlighted for example using italics and/or quotation marks. The use of highlighting has no influence on the scope and meaning of a term; the scope and meaning of a term is the same, in the same context, whether or not it is highlighted. It will be appreciated that the same thing can be said in more than one way. Consequently, alternative language and synonyms does not exclude the use of other synonyms. The use of examples anywhere in this specification, including examples of any terms discussed herein, is illustrative only, and in no way limits the scope of the invention so long as the data are processed, sampled, converted, or the like according to the invention without regard for any particular theory or scheme of action.

[0063] Further, whenever the name of a specific growth factor, cytokine, chemokine or extracellular matrix component is given, it is assumed to include all homologues, family members and splice variants of that factor which may also be present.

[0064] In all of the following examples which represent non-limiting preferred embodiments of the invention, pure ULSC cell lines obtained according to prior art methods (U.S. Pat. No. 8,778,679) and BMSC lines are propagated based upon the following protocol. Culture vessels are seeded with cells at density of 1×10.sup.3 cells per cm.sup.2 in Dulbecco's Modified Eagle Medium (DMEM) with low glucose and 15% fetal bovine serum (FBS), hereafter referred to as expansion media. Every 3 days the expansion media is replaced with fresh sterile expansion media. ULSCs are allowed to grow in a CO.sub.2 incubator at 37° C. until they reach 80-90% confluency. Once confluent the media is replaced with sterile conditioning media consisting of 98% Roswell Park Memorial Institute Medium (RPMI), 2% FBS, 1 milliliter (ml) 100× Penicillin and Streptomycin, 1 ml 100× Non Essential Amino Acids (NEAA), 1 ml 100× Modified Eagle Medium (MEM), 1 ml Insulin, Transferrin, Selenium (ITS) supplement, 1 mL 100× Glutamine supplement. Conditioned media is collected at regular intervals into a sterile polyethylene terephthalate (PET) container that is stored at −20° C. and replaced with fresh sterile conditioning media. The process of collecting conditioned media by this method may be continued indefinitely.

[0065] Where applicable in the examples conditioned media may be purified and concentrated according to the following protocol. Collected conditioned media is thawed at 4° C. Collected lots are pooled and then filtered with a 0.22 micron (um) filter. Filtered conditioned media is added to sample filter centrifugation cup which is then added to the filtrate collection cup and the combination is placed in a balanced centrifuge. The centrifuge is spun at up to 3500×g until a desired concentration is obtained, typically between 50-90 minutes. Concentrated media may then be transferred from the filtrate collection cup for further application as desired.

EXAMPLE 1

Cytokine and Chemokine Assay

[0066] Media from ULSCs, two sets from passage 3 and two sets from passage 6, in both expansion and conditioned media and four identical cultures of BMSCs were assayed for the presence of cytokine and chemokine proteins by quantitative multiplexed immunoassay analysis (MAPs). The cytokines and chemokines profiled included: GM-CSF, INF-γ, IL-3, IL-4, IL-6, IL-7, IL-8, IL-18, MIP-1β, MCP-1, TNF-α. The MAPs analysis is based upon a capture-sandwich wherein capture antibodies are attached to fluorescently encoded microspheres. After capture of antigen from a biological sample such as cell culture media the antigen is detected and quantified using specific detection antibodies coupled to a fluorescent probe. Results obtained from this analysis were given as weight per volume of each analyte. The results were then normalized per number of cells from the corresponding well.

[0067] The results in FIG. 1 demonstrate that ULSCs express and secrete considerably more GM-CSF, IL-4, IL-7, IL-8, MIP-1β, MCP-1, and TNF-αthan BMSCs. ULSCs express all the factors made by BMSCs and at least seven more factors not found at significant levels in BMSCs, These results are indicative but not exhaustive of the cytokines and chemokines which may be present in ULSCs conditioned media and cell culture tissue. Other cytokines which may be present include those from all four cytokine families: the four a-helix bundle family (the IL-2 subfamily, the interferon subfamily, the IL-10 subfamily), the IL-1 family (primarily IL-1 and IL-18), the IL-17 family and the cysteine-knot family (transforming growth factor beta superfamily including TGF-β1, TGF-β2, TGF-β3). Other chemokines which may be present include those from all four classes including C chemokines (XCL1 and XCL2), CC chemokines (CCL1-CCL28), CXC chemokines (CXCL1-CXCL17), CX3C chemokines (CX3CL1).

EXAMPLE 2

Human Growth Factor Assay

[0068] Conditioned media obtained from ULSCs and BMSCs was assayed for the presence of VEGF and SCF proteins by an Enzyme Linked Immunosorbent Assay (ELISA). Conditioned media was collected from a total of 12 cultures, two sets of ULSCs and two sets of BMSCs at 3, 6, and 9 days. Controls tested included 2% FBS media, 0% FBS media, 0% media plus vitamin B3, ULSCs in chondro media, and ULSCs in a transwell plate with a chondrocyte pellet. Concentrated conditioned media from each sample was added to each ELISA test strip well and incubated for one hour with gentle shaking. The ELISA strip was washed with assay buffer to stop the reaction and the optical density of each ELISA strip well was measured with a microplate reader at 450 nm.

[0069] The results in FIG. 2 demonstrate that SCF is expressed and secreted at a considerably higher level in both sets of ULSCs at all time points compared to both sets of BMSCs. The results also show that both ULSCs and BMSCs express significant levels of VEGF but that after 9 days BMSCs secrete less VEGF than ULSCs. These non-limiting examples are indicative but not exhaustive of the growth factors which may be present in ULSCs conditioned media and cell culture tissue. Other growth factors which may be present include VEGF family proteins, Epidermal Growth Factor (EGF) family proteins, Fibroblast Growth Factor (FGF) family proteins, Transforming Growth Factor beta (TGF-β) family proteins, Angiopoietin family proteins, Brain Derived Neurotrophic factor family proteins.

EXAMPLE 3

Hyaluronic Acid and Chondroitin Sulfate Assays

[0070] Media was collected from both ULSCs and BMSCs either daily or every third day from cell cultures propagated in either growth media or conditioning media. The cell layers in each well were also analyzed. The filtered and concentrated media is treated with proteases and nucleases to remove protein and nucleic acid, then treated with detergent and alcohol to remove lipids, leaving a mixture enriched with complex carbohydrates including glycosaminoglycans (GAGs). The GAGs mixture was then treated with a hyaluronidase enzyme which cleaves the GAGs into their constituent parts. The hyaluronic acid fragments were then separated by either polyacrylamide gel electrophoresis (PAGE) or agarose gel electrophoresis.

[0071] In FIG. 3, the cleaved GAGs were treated with mercuric ion, and then tagged by reductive amination giving an identical fluorescent signal for every free reducing group. The fluoro-tagged products were then separated by PAGE and scanned by CCD camera then analyzed with quantitative image analysis software. The results shown here demonstrate the presence of significant levels of HA and CS in the conditioned media of both ULSCs and BMSCs. These non-limiting examples are indicative but not exhaustive of the extracellular matrix constituents which may be present in ULSCs conditioned media and cell culture tissue. Other extracellular matrix constituents which may be present include: heparan sulfate, keratin sulfate, elastin fibers, fibronectins and laminins.

[0072] In FIG. 4 and FIG. 5, the cleaved GAGs were then separated on an agarose gel and stained for visualization prior to imaging. The results in FIG. 4 and FIG. 5 demonstrate that a considerable fraction of the HA present is in the media of both ULSC and BMSC cultures is high molecular weight up to at least 2500 kD. When further digested with Hyase (FIG. 5), HA accumulates in low molecular weight fragments at the bottom of the gel.

[0073] FIG. 6 provides a quantitation of the amounts of HA and CS present in both ULSC and BMSC cells and conditioned media. ULSC cells have increased quantities of both HA and CS compared to BMSCs and in conditioned media ULSCs produced more CS than BMSCs whereas HA levels were similar.

EXAMPLE 4

Collagen Assay

[0074] Collagen standards are prepared at 3.sup.0, 3.sup.−1, 3.sup.−2, 3.sup.−3 and 3.sup.−4 dilutions from 3 mg/ ml stock in phosphate buffered saline. Ten microliters of ULSC conditioned media is used to make Collagen samples in triplicate. Sample A is cell culture medium supplemented with 2% fetal bovine serum and 1% ITS conditioned for 2 days by confluent ULSCs. Sample B is sample A concentrated 10 fold by centrifugation filter. Sample C is sample B filtered through 3MM Whatman paper. The test samples are deposited in a well of a 96-well cluster, and air-dried. Sample A is tested as 3.sup.0, and 3.sup.−1 dilutions; samples B and C are tested as 3.sup.0, 3.sup.−1, 3.sup.−2, and 3.sup.−3 dilutions. One hundred microliters Bouin's fluid were added to each well and incubated at 37° C., for 1 hour, in a humidified enclosure. The Bouin's fluid was removed by aspiration, and the well was washed five times, each time with 200 μl deionized water, and air-dried. Seventy five microliters working Sirius Red solution were added to each well, and also to a set of 3 empty wells, serving as background controls, and incubated at 37° C., for 1 hour, in a humidified enclosure. The dye solution was removed by aspiration, and the well was washed five times, each time with 400 μl deionized water, and air-dried. One hundred microliters of 0.1 N NaOH were added to each well and agitated for 1.5 hours at ambient temperature. Absorbance at 540 nm (A 540) was determined using a microtiter plate reader. Standard collagen amounts were plotted vs. the average A-540 values to produce a standard curve with best fit equation of two variables. One average A-540 value of each conditioned medium sample was selected to substitute for the abscissa variable, to yield the ordinate value, which was corrected for the dilution factor and the volume of material used for testing (10 μl) to give the estimated collagen concentration in the original conditioned medium.

[0075] The results in FIG. 7 demonstrate that human Collagen is present at approximately 0.28 milligram/milliliter of ULSC conditioned media and may readily be concentrated to 1 mg/ml.