细胞膜异位表达钙网蛋白的CD4~+T细胞诱导EAE小鼠保护性免疫

目的:研究细胞膜表面异位表达钙网蛋白(calreticulin,CALR)对T细胞疫苗(T-cell vaccine,TCV)诱导的保护性免疫效果的影响。方法:采用小鼠髓鞘少突胶质细胞糖蛋白35-55(MOG_(35-55))免疫C57BL/6小鼠建立实验性自身免疫性脑脊髓炎(EAE)模型,分别以MOG_(35-55)特异性T细胞(CALR~+T及CALR~-T)为疫苗,通过尾静脉注射免疫小鼠。检测指标包括EAE小鼠临床评分比较、脾CD4~+ CD25~+ Foxp3~+调节性T细胞百分比测定及血清中细胞因子干扰素γ(IFN-γ)、白细胞介素4(IL-4)、IL-10和IL-17A含量测定。结果:射线照射可诱导活化CD4~+T细胞表面异位表达CALR;CALR~+T免疫组症状显著轻于CALR~-T免疫组(P0.01);CALR~+T免疫组小鼠脾CD4~+ CD25~+ Foxp3~+调节性T细胞百分比及血清中IL-4和IL-10含量显著高于对照组(P0.01),而IFN-γ和IL-17A含量显著低于对照组(P0.01),结论:细胞膜表面异位表达CALR与TCV诱导的保护性免疫效果有关。

Calreticulin expression is necessary for protective immune effect of T-cell vaccine in EAE mice

AIM:To study the role of cell membrane ectopic calreticulin (CALR) expression on the protective immunie effect of T-cell vaccine (TCV) on experimental autoimmune encephalomyelitis (EAE). METHODS:EAE model was established by myelin oligodendrocyte glycoprotein 35-55 (MOG_35-55) immunization in C57BL/6 mice, and the mice were immunized with MOG_35-55-specific CALR⁺ and CALR^- T-lymphocytes. Symptomatic scores were compared at the maximum of the disease. On the 15th day after immunization, the proportion of CD4⁺ CD25⁺ Foxp3⁺ regulatory T cells (Treg) in the spleen, and the expression of interferon-γ (IFN-γ), interleukin-4 (IL-4), IL-10 and IL-17A in the serum were measured. RESULTS:Increased expression of CALR in activated T cells after γ-irradiation was observed. Blockade of CALR on the vaccinating T-cell surface reduced the protective effect of TCV. Furthermore, blockade of CALR reduced the number of Treg in the spleen and up-regulated pro-inflammatory cytokines. CONCLUSION:CALR expression in the T cells is necessary for the protective immunity induced by TCV in EAE mice.