ABSTRACT
AIM:To investigate the role of B cells in CD45RB antibody-induced transplantation immune toler-ance.METHODS:Single cell suspension was made from the spleen of BALB/c nude mice disposed by CD45RB antibod-y, then mixed cultured with T cells of BALB/c mice and spleen cells of C57BL/6 mice.The Th1, Th2, Treg and Tm cells were monitored by flow cytometry during the culture process .The skin graft model was set up with B 6.μMT-/-mice as re-ceptors and BALB/c mice as donors.CD45RB antibody was intraperitoneally injected into the receptors after transplantation and then CD3+CD45RBhi cells were detected by flow cytometry .In another mixed lymphocyte culture , CD45RB antibody was added, and then B cells were isolated and injected into B6.μMT-/-mice through the tail vein.The heart transplanta-tion model was established with B 6.μMT-/-mice as receptors and BALB/c mice as donors, and then the survival and the migration of B cells to the thymus were observed .RESULTS:When T lymphocytes were co-cultured with B lymphocytes treated with anti-CD45RB monoclonal antibody (mAb) in vivo, the percentages of Th2 and Treg cells were up-regulated and Th1 cells were down-regulated, but Tm cells were not altered as compared with the control .In vivo without B lympho-cytes, anti-CD45RB mAb also down-regulated the expression of CD45RB in T lymphocytes.The reduction was faster and the percentage of CD3 +CD45RBhi T cells was not altered as compared with the control .The B lymphocytes treated with an-ti-CD45RB mAb in vitro prolonged the lifetime of receptor in heart transplantation model but failed to induce complete toler -ance.After recieving B cells treated with anti-CD45RB mAb and allogeneic heart transplantation , B cells migrated to the thymus in B6.μMT-/-mice.CONCLUSION:B lymphocytes play a definite role in the transplantation immune tolerance induced by anti-CD45RB mAb through their affection on T-cell subgroups and also in the central tolerance .However, the induction of immune tolerance can not only rely on B cells .
ABSTRACT
Objective:To investigate the role of dendritic cells (DCs) in the anti-CD45RB antibody-induced immune tolerance,and the mechanism of immune tolerance induced by anti-CD45RB antibodies.Methods:DCs were induced by conventional methods(rmGM-CSF,IL-4 and LPS),different doses of anti-CD45RB antibodies were added in the induction process.Then,mature cells were harvested,and flow cytometry(FCM) was used to determine cell phenotypes,cycle and phagocytosis,ELISA method was performed to examine the concentration of IL-12 and the ability of T cell proliferation was observed by mixed lymphocyte culture.Results:The DCs preparation was shown a high expression of CD11C and CD83,a low expression of CD86,with strong proliferative and phagocytic capacity after treated with anti-CD45RB antibody.Its secretion of IL-12 was decreased,and it could less effectively stimulate T cell proliferation after treated with anti-CD45RB antibody.Conclusion:One of the mechanisms of anti-CD45RB monoclonal antibody-induced tolerance is to generate tolerogenic dendritic cells(tDCs),significantly inhibiting the proliferation of T cells.