The Mechanism Of B Lymphocytes In Immune Tolerance Induced With Anti-CD45RB Antibody

Objective:The research has four parts, first of all, we treat B lymphocytes with anti-CD45RB mAb and observe their influence on T lymphocyte subsets in vitro.The second part, detect the impact of the mAb to CD3+CD45RBhiT lymphocytes in vivo with the absence of B lymphocytes.Next we research whether can B lymphocytes treated with anti-CD45RB mAb induce tolerance.Finally,we study the situation of B lymphocytes move to thymus.Through these parts,we investigate the potential mechanism of B lymphocyte subsets in anti-CD45RB antibody-induced immune tolerance.Methods:After the intraperitoneal injection of anti-CD45RB mAb into BALB/C nude mice in0,1,3,5,7days,spleen cell were isolated and co-cultured with T lymphocytes of BALB/C mice and spleen cell from C57BL/6 mice.Detect the percentage of Th1,Th2,Treg,Ts (CD8+CD28-),Tm in 0,1,3,5,7 days after co-culture by flow cytometry.μMT mice as receptor of skin from BALB/c mice received anti-CD45RB monoclonal antibody in0,1,3,5,7days after transplantation.Detect the percentage of CD3+CD45RBhiT lymphocytes in0,1,3,5,7days after transplantation. Co-cultured spleen lymphocytes of BALB/C mice with spleen cell from C57BL/6 mice with in presence or absence of anti-CD45RB mAb in0,1,3,5,7days in vitro.B lymphocytes were enriched from co-culture after the 7th day with Nylon Fiber Column,then injected intoμMT mice. TheμMT mice as receptor received heart from BALB/c mice.Observe the The survival rate of the receptor.Inject B lymphocytes labeled with CFSE intoμMT mice. TheμMT mice as receptor received heart from BALB/c mice and received anti-CD45RB in0,1,3,5,7days. Detect the situation of B lymphocytes move to thymus by flow cytometry.Results:Co-cultured T lymphocytes with the B lymphocytes treated by anti-CD45RB mAb. The percentage of Th2,Treg cells were up-regulated and Thl cells were down-regulated,at the same time Tm cells were not altered when compared with control either in vitro.In vivo,without B lymphocytes, anti-CD45RB mAb can also down-regulate the expression of CD45RB on T lymphocytes.However the reduction was faster and the percentage of CD3+CD45RBhiT cell was not altered when compared with control.The B lymphocytes treated by anti-CD45RB mAb in vitro can prolong the lifetime of receptor,but failed to induce tolerance. We can detect the labeled B lymphocytes inμMT mice which was received CFSE labeled B lymphocytes and heart transplantation in the 5t day after transplantation,and the percentage of it increased in the 10th day.Besides, the B lymphocytes can be detected a little in 10th day in the control team.Conclusion:In immune tolerance induced by anti-CD45RB antibody, the alteration of T lymphocyte subsets may be mediated by B lymphocytes.B lymphocytes play a definite role in central tolerance.However, induced the tolerance of B lymphocytes can prolong the lifetime of receptor,but failed to induce tolerance. Without B lymphocytes, anti-CD45RB mAb can also down-regulate the expression of CD45RB on T lymphocytes.However the reduction was faster than control,and the percentage of CD3+CD45RBhiT cell was not altered when compared with control.