ABSTRACT
Objective To investigate the phenotype and the immunoregulatory function of CD8αα+TCRαβ+regulatory T cells in peripheral blood samples from mice.Methods The distribution profile and the phenotype of CD8αα+TCRαβ+regulatory T cells in C57BL/6 mice were detected by flow cytometry.The cytokines released by CD8αα+TCRαβ+regulatory T cells upon the stimulation with anti-CD3 antibody were analyzed by cytometric bead array.The in vitro immunosuppressive activity of CD8αα+TCRαβ+regulatory T cells on activated CD4+T cells was analyzed by using flow cytometry and carboxyfluorescein succinimidyl ester ( CFSE ) .An adoptive cell transfer assay was set up to evaluate the immunoprotective effects of CD8αα+TCRαβ+ regulatory T cells in a mouse model of experimental autoimmune encephalomyelitis ( EAE) .Results CD8αα+TCRαβ+regulatory T cells were detected in liver, spleen and peripheral blood samples collected from na?ve C57BL/6 mice.Compared with CD8αβ+TCRαβ+regulatory T cells, CD8αα+TCRαβ+regulatory T cells showed a memory-activated phenotype of CD25+CD122high CD44high CD62Llow CD69high NK1.1+DX5+.CD8αα+TCRαβ+regulatory T cells could produce IL-2 after 24 hours stimulation with anti-CD3 antibody, followed by producing IFN-γ, TNF-α, IL-4, IL-17A and traces of IL-6 and IL-10. In vitro, CD8αα+TCRαβ+regulatory T cells specifically suppressed the proliferation of activated CD4+T cells ( P<0.01 ).Moreover, they could delay the onset of EAE in mice and reduce clinical score (P<0.01).Conclusion CD8αα+TCRαβ+regulatory T cells were a unique population with immunoregula-tory function, which could be used as a potential therapeutic target in the treatment of autoimmune disease.
ABSTRACT
Understanding germinal center reactions is crucial not only for the design of effective vaccines against infectious agents and malignant cells but also for the development of therapeutic intervention for the treatment of antibody-mediated immune disorders. Recent advances in this field have revealed specialized subsets of T cells necessary for the control of B cell responses in the follicle. These cells include follicular regulatory T cells and Qa-1-restricted cluster of differentiation (CD)8+ regulatory T cells. In this review, we discuss the current knowledge related to the role of regulatory T cells in the B cell follicle.