Effects of dendritic cells on T cells oligoclonal expansion of patients with aplastic anemia / 中国免疫学杂志

ABSTRACT

Objective:To investigate the effects of dendritic cells(DCs)in pathogenesis of aplastic anemia,especially its roles in T cell abnormal activation.Methods:Direct immunofluorescence assays and flow cytometry(FCM)were used to determined proportion and kinds of DCs in bone marrow sample of patients with AA.The DCs were got from standard method by culturing mononuclear cells isolated from peripheral blood of normal person in medium with recombinant human granulocyte macrophage colony stimulating factor(rhGM-CSF)and interleukin 4(IL-4)in vitro.The phenotype of DCs were determined by FCM.After pulsed with purified cord blood CD34+ cells and stimulated with recombinant human CD40 ligand(rhCD40L),the ability of those cultured CDs to activate and promote auto T lymphocytes to proliferation was tested.The changes of TCR V? gene repertorie of those T cells were also investigated by real time quantitative PCR(RQ-PCR).Results:The CD1a+CD11c+ and CD11c+CD83+ double positive cells increased in bone marrow of patients of AA,especially the proportion of CD11c+CD83+ cells increased significantly in those patients.After primed with CD34+ cells,DCs induced from peripheral monocytes could activate T lymphocytes and promote T cells to proliferation.The restricted usage of TCR V? genes was confirmed by RQ-PCR in those activated T cells by DC as those in AA patients.Conclusion:DCs,especially with phenotype of CD11c+CD83+,may have great impact on oligoclonal expansion of lymphocytes in patients AA,but the antigen which recognized by auto T cells and stimulated it to proliferation are still needed to further investigation.