Combination of R848 and Poly（I:C）promotes antigen presentation by DC and enhances killing effect of CTL on lung adenocarcinoma A549 cells / 中国病理生理杂志

ABSTRACT

AIM: To investigate the effect of R848(a Toll-like receptor 7/8 agonist)combined with poly-inosinicpolycytidylic acid [Poly(IC),a Toll-like receptor 3 agonist] on dendritic cell(DC)maturation,and the killing effect of DC-induced cytotoxic T-lymphocytes(CTL)on human lung adenocarcinoma A549 cells.METHODS:Mononu-clear cells were isolated from human peripheral blood and induced to differentiate into DC.The whole-cell lysate of A549 cells,namely tumor cell lysate(TCL), was used as antigen.R848 combined with Poly(IC)was used as adjuvant to stimulate the DC.DC surface markers were analyzed by flow cytometry.The DC stimulated by antigen was co-cultured with T-lymphocytes for 7 d to induce CTL.The culture supernatant and CTL were collected.The levels of interleukin-12(IL-12)p70,interferon-γ(IFN-γ)and tumor necrosis factor-α(TNF-α)in the supernatant were measured by ELISA.The CTL and A549 cells were co-cultured for 16 h,and the cytotoxicity was observed by LDH assay.RESULTS:The expres-sion of CD83 and CD80 on the DC surface,and the secretion of IL-12 p70 in DC-R848+Poly(IC)group were significant-ly increased compared with DC-TCL group(P<0.01).In addition,the cytotoxicity of CTL for A549 cells in DC-R848+Poly(IC)group was significantly enhanced compared with DC-TCL group(P<0.01).The secretion levels of IFN-γand TNF-αin DC-R848+Poly(IC)group were significantly elevated compared with DC-TCL group(P<0.01).CONCLU-SIONR848 combined with Poly(IC)significantly promotes DC maturation and activation, and enhances the antigen-presenting effect of DC and the cytotoxicity of DC-induced CTL.