Inhibitory effect of small molecule compound BD691 on activated T cell proliferation and its mechanism / 医学研究生学报

ABSTRACT

Obej ctive Abnormal proliferation of T cells plays an important role in the development of autoimmune diseases. The article aimed to study the inhibitory effect of small molecule compound BD691 on T cell proliferation and its mechanism. Methods Human peripheral blood T-lymphocytes were isolated and purified by the immunomagnetic microbeads,then T cells were ac-tivated with anti-CD3/CD28 mAbs or alloantigen.The inhibitory effect of BD691 on activated T cell proliferation, the cytotoxic effect BD891 on resting T cells and the expression of activated T cells marker CD25 were measured by flow cytometry.Furthermore, ELISA was used to detect the secretion of cytokines associated with T cell differentiation. Results BD691 significantly inhibited the prolif-eration of T cells being stimulated by anti-CD3/CD28 mAb or alloantigen in a dose-dependent manner, and IC50 values are (8.5 ± 1.5)μmol/L and (7.2 ±1.3)μmol/L, respectively.However, BD691 had no obvious cytotoxic effects on resting T cells and periph-eral blood mononuclear cells, even at a high concentration ( up to 100μmol/L) .In T cells which were not activated by anti-CD3/CD28 mAb, the percentage of CD25+T cells is only 1.6%of the total cells, while the number increased to 68% after activating treatment.Mean-while, in T cells which were activated by 0, 3.3, 10, 30μmol/L BD691, no obvious change of CD25 expression were observed, while immunosuppressant FK506 (0.1μmol/L) significantly decreased the expression of CD25 +T cells (14.9%).In unactivated T cells, 95.6%cells were at G0/G1 phase, while after activation, the percentage of cells at G0/G1 phase reduced to 57.7%.In addition, BD691 inhibited the secretion of IFN-γ, IL-6 and IL-17 in activated T cells, but had no effects on the secretion of IL-2, IL-4 and IL-10. Co nclusion BD691 exerts no effects on T cell activation, but it inhibits T cell proliferation by inducing T cell cycling arrest at G0/G1 phase.Moreover, BD691 inhibits the secretion of key cytokines (such as IFN-γ, IL-6, IL-17) closely related to the differ-entiation of Th1 and Th17 cells.The results suggest that BD 691 is a potential lead compound to develop a new immunosuppressant for the inhibition of abnormal proliferation and differentiation of T cells.