[Study on the improved effect of anti-TCR alpha beta monoclonal antibody on the induction of transplantation tolerance to the allogeneic skin graft in mice and its mechanisms].
OBJECTIVE
To study skin allograft tolerance induced by intravenous injection of allogeneic spleen cells and intraperitoneal injection of cyclophosphamide (CP), followed by anti-TCR monoclonal antibody injections in adult recipient mice and its mechanisms.


METHODS
Injecting the spleen cells of BALB/c mice (H-2(d)) were injected to C57BL/6 mice (H-2(b), B6) via the tail vein. Two days later an intraperioneal injection of cyclophosphamide was given to the B6 mice, and followed by anti-TCR alpha beta monoclonal antibody injection via the tail vein, after which skin of BALB/c mice were grafted to the tolerance-induced B6 mice. The control groups were: (1) normal B6 mice grafted with BABL/c skin; (2) normal B6 mice grafted with KM skin; (3) B6 mice treated with SC + CP + anti-TCR alpha beta monoclonal antibody administration and grafted with BALB/c skin allograft; (4) B6 mice treated as group 3, and grafted with KM skin instead of BALB/c skin. Detection of chimerism, adoptive transfer assay and the effect of exogenous IL-2 on MLR were performed to explore tolerance mechanisms. Group data in each experiment were compared with Group's t-test.


RESULTS
The survival of BALB/c skin allograft in recipient B6 mice was 66.3 days, P < 0.001 compared with the other three groups. The results of FACS analysis showed that a mixed microchimerism was developed in the thymus and spleen of tolerant mice. The percentage of cells of BALB/c origin in the thymus on day 15, 35, and 70 after induction of tolerance was 2.67%, 1.61%, and 0.47%, and in the spleen is 7.66%, 5.99%, and 3.87%, respectively. No suppressive activity in the spleen cells of tolerant mice was observed by in vivo and in vitro cell transfer experiments. MLR of spleen cells in the tolerant B6 mice to spleen cells of BALB/c origin was specifically suppressed, which was 4 725 +/- 406 cpm by (3)H-TdR incorporation. However, the specific inhibition of MLR of tolerant B6 mice could be partially reversed (P < 0.01), the (3)H-TdR incorporation reached 18 175 +/- 3 642 cpm by adding exogenous IL-2.


CONCLUSIONS
Chimerism and clonal anergy are the main mechanisms of the tolerance.
Hao
J
J
Immunology of Department, Peking University Health Science Center, Beijing 100083, China.
Liu
J
J
Xie
S
S
D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage* / Q000276:immunology; D003520:Cyclophosphamide / Q000494:pharmacology; D006085:Graft Survival / Q000187:drug effects / Q000276:immunology; D007166:Immunosuppressive Agents / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology*; D016038:Skin Transplantation / Q000276:immunology*; D013154:Spleen / Q000166:cytology / Q000276:immunology / Q000637:transplantation; D013950:Thymus Gland / Q000276:immunology; D013997:Time Factors; D018183:Transplantation Chimera; D023001:Transplantation Tolerance / Q000187:drug effects
D000911:Antibodies, Monoclonal; D007166:Immunosuppressive Agents; D016693:Receptors, Antigen, T-Cell, alpha-beta; D003520:Cyclophosphamide