Long-term survival of skin allografts induced by donor splenocytes and anti-CD154 antibody in thymectomized mice requires CD4(+) T cells, interferon-gamma, and CTLA4.
Treatment of C57BL/6 mice with one transfusion of BALB/c spleen cells and anti-CD154 (anti-CD40-ligand) antibody permits BALB/c islet grafts to survive indefinitely and BALB/c skin grafts to survive for approximately 50 d without further intervention. The protocol induces long-term allograft survival, but the mechanism is unknown. We now report: (a) addition of thymectomy to the protocol permitted skin allografts to survive for > 100 d, suggesting that graft rejection in euthymic mice results from thymic export of alloreactive T cells. (b) Clonal deletion is not the mechanism of underlying long-term graft survival, as recipient thymectomized mice were immunocompetent and harbor alloreactive T cells. (c) Induction of skin allograft acceptance initially depended on the presence of IFN-gamma, CTLA4, and CD4(+) T cells. Addition of anti-CTLA4 or anti-IFN-gamma mAb to the protocol was associated with prompt graft rejection, whereas anti-IL-4 mAb had no effect. The role of IFN-gamma was confirmed using knockout mice. (d) Graft survival was associated with the absence of IFN-gamma in the graft. (e) Long-term graft maintenance required the continued presence of CD4(+) T cells. The results suggest that, with modification, our short-term protocol may yield a procedure for the induction of long-term graft survival without prolonged immunosuppression.
Markees
T G
TG
Diabetes Division, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA.
Phillips
N E
NE
Gordon
E J
EJ
Noelle
R J
RJ
Shultz
L D
LD
Mordes
J P
JP
Greiner
D L
DL
Rossini
A A
AA
D000069594:Abatacept; D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000502:physiology*; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology*; D023201:CD40 Ligand; D060908:CTLA-4 Antigen; D005260:Female; D006085:Graft Survival; D018796:Immunoconjugates; D007371:Interferon-gamma / Q000502:physiology*; D015847:Interleukin-4 / Q000502:physiology; D008297:Male; D008562:Membrane Glycoproteins / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D016038:Skin Transplantation / Q000276:immunology*; D013154:Spleen / Q000166:cytology*; D013934:Thymectomy; D014184:Transplantation, Homologous
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000943:Antigens, Differentiation; D060908:CTLA-4 Antigen; C556707:Ctla4 protein, mouse; D018796:Immunoconjugates; D008562:Membrane Glycoproteins; D023201:CD40 Ligand; D015847:Interleukin-4; D000069594:Abatacept; D007371:Interferon-gamma