Method of enhancing proliferation and/or survival of mesenchymal precursor cells (mpc)

Abstract

The present invention relates to methods of enhancing proliferation and/or survival of mesenchymal precursor cells (MPC) and/or progeny derived therefrom in vitro or in vivo comprising exposing the MPC or progeny to SDF-1 or analog thereof. The invention also relates to compositions comprising isolated MPCs or progeny derived therefrom and SDF-1 or analogues thereof. The present invention also relates to using such methods and compositions for ex vivo or in vivo bone formation in mammals.

1 . A method of enhancing proliferation and/or survival of mesenchymal precursor cells (MPC) or progeny derived therefrom, the method comprising exposing the MPC or progeny to SDF-1 or an analog thereof. 
     
     
         2 . A method as claimed in  claim 1  wherein the MPC are positive for at least one marker selected from the group consisting of STRO-1 bright , VCAM-1 bright , THY-1 bright , CD146 bright  and STRO-2 bright . 
     
     
         3 . A method as claimed in  claim 1  wherein the MPC carry at least two markers selected from the group of surface markers specific for mesenchymal precursor cells consisting of STRO-1 bri , LFA-3, THY-1, VCAM-1, ICAM-1, PECAM-1, P-selectin, L-selectin, CD49a/CD49b/CD29, CD49c/CD29, CD49d/CD29, CD29, CD18, CD61, beta-1 integrin, 6-19, thrombomodulin, CD10, CD13, SCF, PDGF-R, EGF-R, IGF1-R, NGF-R, FGF-R, Leptin-R, RANKL and CD146 or any combination of these markers. 
     
     
         4 . A method as claimed in  claim 1  wherein the MPC are negative for at least one marker selected from the group consisting of CBFA-1, collagen type II, PPARγ2, and glycophorin A. 
     
     
         5 . A method as claimed in  claim 1  wherein the MPC are present in an enriched composition in vitro and constitute at least 1% of the total cells of the composition. 
     
     
         6 . A method as claimed in  claim 1  wherein the MPC are in situ. 
     
     
         7 - 9 . (canceled) 
     
     
         10 . A method as claimed in  claim 1  wherein the SDF-1 analog is a ligand that activates CXCR4 signalling. 
     
     
         11 . A method as claimed in  claim 10  wherein the SDF-1 analog is selected from the group consisting of the HIV-1 coat protein gp120, AMD3100 and ALX40-4C. 
     
     
         12 . (canceled) 
     
     
         13 . A method of developing a tissue specific committed cell population, the method comprising
 exposing MPC or progeny derived therefrom to exogenous SDF-1 or an analog thereof to enhance proliferation and/or survival of the MPC or progeny, and   subjecting the proliferated population to conditions biasing differentiation of the MPC or progeny derived therefrom to a specific tissue type.   
     
     
         14 . A method as claimed in  claim 13  wherein the tissue type is selected from the group consisting of cardiac muscle tissue, vascular tissue, bone tissue, neural tissue and endothelial tissue. 
     
     
         15 . A composition comprising isolated MPC or progeny derived therefrom and SDF-1 or an analog thereof. 
     
     
         16 . A composition as claimed in  claim 15  wherein the composition comprises substantially purified MPC or progeny, comprising at least about 0.1% of total cells of the composition. 
     
     
         17 . (canceled) 
     
     
         18 . A composition as claimed in  claim 15  wherein the composition comprises an additional stimulatory factor selected from the group consisting of PDGF, SCF, FL, G-CSF, IL-3, IL-6, 1,25D, TNF-α and IL-1β. 
     
     
         19 - 22 . (canceled) 
     
     
         23 . An MPC or precursor cell derived therefrom that has been genetically modified to overexpress SDF-1 or an analog thereof. 
     
     
         24 . An MPC or precursor cell derived therefrom as claimed in  claim 23  wherein the MPC or precursor cell derived therefrom is transfected with a polynucleotide encoding SDF-1. 
     
     
         25 . (canceled) 
     
     
         26 . A composition comprising a population of genetically modified MPC as claimed in  claim 23 . 
     
     
         27 - 31 . (canceled) 
     
     
         32 . A method of generating bone in a subject, the method comprising exposing MPC or progeny derived therefrom in the subject to exogenous SDF-1 or an analog thereof. 
     
     
         33 . A method as claimed in  claim 32  wherein the SDF-1 analog is a ligand that activates CXCR4 signalling. 
     
     
         34 . A method as claimed in  claim 33  wherein the SDF-1 analog is selected from the group consisting of the HIV-1 coat protein gp120, AMD3100 and ALX40-4C. 
     
     
         35 - 36 . (canceled) 
     
     
         37 . A method as claimed in  claim 32  wherein the method further comprises administering to the subject a synthetic glucocorticoid and/or a bone morphogenic protein. 
     
     
         38 - 40 . (canceled) 
     
     
         41 . A method of generating vascular tissue in a subject, the method comprising exposing MPC or progeny derived therefrom in the subject to exogenous SDF-1 or an analog thereof. 
     
     
         42 . A method as claimed in  claim 41  wherein the SDF-1 analog is a ligand that activates CXCR4 signalling. 
     
     
         43 - 45 . (canceled) 
     
     
         46 . A method of generating cardiac muscle or smooth muscle in a subject, the method comprising exposing MPC or progeny derived therefrom in the subject to exogenous SDF-1 or an analog thereof. 
     
     
         47 . A method as claimed in  claim 46  wherein the SDF-1 analog is a ligand that activates CXCR4 signalling. 
     
     
         48 . A method as claimed in  claim 47  wherein the SDF-1 analog is selected from the group consisting of the HIV-1 coat protein gp120, AMD3100 and ALX40-4C. 
     
     
         49 - 50 . (canceled) 
     
     
         51 . A method for generating bone ex vivo, the method comprising
 exposing MPC or progeny derived therefrom to exogenous SDF-1 or an analog thereof to enhance proliferation and/or survival of the MPC or progeny, and   subjecting the proliferated population to conditions biasing differentiation of the MPC to bone precursor cells, or to conditions biasing differentiation of bone precursor cells to bone.   
     
     
         52 . A method as claimed in  claim 51  wherein the conditions biasing differentiation involve culturing the cells in αMEM supplemented with FCS, L-ascorbate-2-phosphate, dexamethasone and inorganic phosphate. 
     
     
         53 . A method as claimed in  claim 51  wherein the conditions biasing differentiation involve culturing the cells in the presence of a compound selected from the group consisting of type I collagen, fibrinogen, fibrin, polyglycolic acid, polylactic acid, osteocalcin and osteonectin or any combination thereof.