经RNA干扰技术修饰CD80和CD86基因的受体树突状细胞可通过促进T细胞凋亡导致T细胞低反应

espite extensive research, the mechanisms of immature dendritic cells (DCs) induced immune hyporesponsiveness remain incomplete. Recipient DCs from C3H mouse bone marrow cells were incubated with donor antigen from splenic lymphocyte of C57BL/6 mouse, these DCs were transfected with CD80/86 specific siRNA using lentiviral vectors. Flow cytometry was used to evaluate expression of CD80/86 on the antigen-pulsed recipient DCs. Immune regulatory activity was examined by mixed lymphocyte reaction, in which irradiated DCs were cultured with C3H spleen T cells. After the reaction, IL-2, IL-4, IL-10 and INF-γ levels of mixed lymphocyte reaction culture supernatant were measured by enzyme-linked immunosorbent assay. The apoptotic T lymphocytes were identified by Annexin V and CD3 staining. There was a significant inhibition of CD80/86 expression in DCs transfected with CD80/86 lentiviral vectors compared with the control groups (P <0.05), indicating the specificity of RNA interference. Enzyme-linked immunosorbent assay results showed a significant reduction of INF-γ, IL-2 and IL-10 in the CD80/86 lentivirus transfected group compared to the control groups (P <0.05). There was no significant difference in IL-4 levels between the groups (P >0.05). We also showed that CD80/86 low DCs loaded with alloantigen 1) stimulated low T cell proliferative responses via the indirect recognition pathway and 2) enhanced apoptotic activity (P <0.05) in co-cultured T cells. Lentiviral vector transfection can effectively and specifically knock down target genes in DCs. The CD80/86 low DCs may show tolerogenic activity via induction of T-cell apoptosis, thereby modulating activity of recipient-derived DCs. The use of this approach may potentially be clinically applicable.