Conferring indirect allospecificity on CD4+CD25+ Tregs by TCR gene transfer favors transplantation tolerance in mice.
T cell responses to MHC-mismatched transplants can be mediated via direct recognition of allogeneic MHC molecules on the cells of the transplant or via recognition of allogeneic peptides presented on the surface of recipient APCs in recipient MHC molecules - a process known as indirect recognition. As CD4(+)CD25(+) Tregs play an important role in regulating alloresponses, we investigated whether mouse Tregs specific for allogeneic MHC molecules could be generated in vitro and could promote transplantation tolerance in immunocompetent recipient mice. Tregs able to directly recognize allogeneic MHC class II molecules (dTregs) were obtained by stimulating CD4(+)CD25(+) cells from C57BL/6 mice (H-2(b)) with allogeneic DCs from BALB/c mice (H-2(d)). To generate Tregs that indirectly recognized allogeneic MHC class II molecules, dTregs were retrovirally transduced with TCR genes conferring specificity for H-2K(d) presented by H-2A(b) MHC class II molecules. The dual direct and indirect allospecificity of the TCR-transduced Tregs was confirmed in vitro. In mice, TCR-transduced Tregs, but not dTregs, induced long-term survival of partially MHC-mismatched heart grafts when combined with short-term adjunctive immunosuppression. Further, although dTregs were only slightly less effective than TCR-transduced Tregs at inducing long-term survival of fully MHC-mismatched heart grafts, histologic analysis of long-surviving hearts demonstrated marked superiority of the TCR-transduced Tregs. Thus, Tregs specific for allogeneic MHC class II molecules are effective in promoting transplantation tolerance in mice, which suggests that such cells have clinical potential.
MRC Centre in Transplantation, King's College London, Guy's Campus, London, UK.
Julia Yuen-Shan
JY
Tsang
Yakup
Y
Tanriver
Shuiping
S
Jiang
Shao-An
SA
Xue
Kulachelvy
K
Ratnasothy
Daxin
D
Chen
Hans J
HJ
Stauss
R Pat
RP
Bucy
Giovanna
G
Lombardi
Robert
R
Lechler
D000818:Animals; D015704:CD4 Antigens / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D003433:Crosses, Genetic; D018014:Gene Transfer Techniques; D019672:Genes, T-Cell Receptor; D000949:Histocompatibility Antigens Class II / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008822:Mice, Transgenic; D012190:Retroviridae / Q000235:genetics; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D014161:Transduction, Genetic; D023001:Transplantation Tolerance / Q000235:genetics / Q000276:immunology*; D014184:Transplantation, Homologous
D015704:CD4 Antigens; D000949:Histocompatibility Antigens Class II