NK1.1+细胞在实验性自身免疫性重症肌无力疾病发病中的免疫调节作用

目的:探讨NK1.1 细胞在实验性自身免疫性重症肌无力(EAMG)疾病发病中的作用以及其调节机制。方法:腹腔注射抗小鼠NK1.1单克隆抗体(mAb)清除C57BL/6(B6)小鼠体内的NK1.1 细胞,建立NK1.1 细胞缺陷小鼠模型;用AChR CFA免疫小鼠诱发EAMG,通过Lennon等的肌无力评分标准分析各组小鼠之间EAMG的发病情况和病情严重程度;应用ELISA法检测单核细胞(MNC)上清液中IFN-γ、IL-4的分泌和表达;应用放射免疫测定法检测血清中AChRIgG含量;用抗IFN-γmAb中和小鼠体内IFN-γ,观察发病情况及血清中AChRIgG的含量。结果:NK1.1 细胞缺陷的小鼠同正常免疫组小鼠相比,发病率和病情严重程度均明显降低(发病率:36%vs86%,P<0.01);免疫后NK1.1 细胞缺陷组和正常免疫组小鼠相比,发病率和病情严重程度无明显统计差异;NK1.1 细胞缺陷降低IFN-γ的表达,但是IL-4的分泌和表达无统计学意义;NK1.1 细胞缺失降低AChR特异性抗体的产生;中和体内IFN-γ后,EAMG的发病率和病情严重程度均减轻,并且AChR特异性抗体减少。结论:NK1.1 细胞在EAMG发病初期发挥重要作用。在EAMG发病中,NK1.1 细胞可以使AChR特异性T细胞产生IFN-γ,增加AChR特异性抗体产生,从而加重EAMG的发病。

Immunoregulative effect of NK1.1+ cells on the development of experimental autoimmune myasthenia gravis

AIM: To investigate the effect and immuoregulative mechanisms of NK1.1(+) cells on the development of experimental autoimmune myasthenia gravis (EAMG). METHODS: The NK1.1(+) cells were depleted by intraperitoneal (i.p.) administration of anti-mouse NK1.1 mAb to C57BL/6 mice. Mice were immunized subcutaneously with AChR in CFA. The incidence and severity of EAMG was determined according to the Lennon disease symptoms grading. IFN-gamma and IL-4 in MNCs culture medium were measured by ELISA. AChR IgG of serum was measured by radioimmunoassay. In some experiments, the anti-IFN-gamma mAb was injected (i.p.) to neutralize IFN-gamma. RESULTS: The onset of EAMG was delayed and the severity was decreased obviously in NK1.1(+) cell-depleted mice. However, depletion of NK1.1(+) cells after immunization had no impact on the development of EAMG. Depletion of NK1.1(+) cells could significantly reduce the expression of AChR-specific antibody as well as the production of IFN-gamma. The development of EAMG and production of AChR specific Ab in NK1.1(+) cell-depleted mice were decreased obviously after treating with anti-IFN-gamma antibody. CONCLUSION: NK1.1(+) cells are involved in the early EAMG, and NK1.1(+) cells could enhance the production of IFN-gamma released by AChR-specific T cells as well as the AChR-specific antibodies, which may enhance the outcome of EAMG.