CTLA-4Ig抑制嗜酸性粒细胞的抗原呈递过程

CTLA-4Ig inhibits antigen presentation of eosinophils

目的 探讨嗜酸性粒细胞 (EOS)在体外培养条件下将抗原呈递给致敏T淋巴细胞的机制。方法 应用流式细胞仪检测了小鼠EOS于重组粒细胞 巨噬细胞集落刺激因子刺激前后表达作为协同刺激因子主要成员的CD80和CD86分子的水平 ;并观察应用细胞毒性T淋巴细胞相关蛋白 4融合蛋白 (CTLA 4Ig)封闭CD80和CD86分子以阻断协同刺激通路对EOS呈递抗原的影响。结果 小鼠EOS即使新鲜分离也可以表达CD80和CD86 ,经粒细胞 巨噬细胞集落刺激因子刺激 2 4h后所表达的CD80和CD86水平明显升高 (P <0 0 1) ,CTLA 4Ig明显地抑制EOS的抗原呈递过程。结论 EOS必须提供协同刺激信号才可作为抗原呈递细胞将摄入和处理的抗原信息传递给T细胞 ,从而促使后者出现增殖反应。

Objective To explore the antigen presentation of eosinophils to sensitized T lymphocytes in vitro . Methods Flow cytometry was used to detect the expression of costimulatory molecules CD80 (B7 1) and CD86 (B7 2) on murine eosinophils before and after treatment with recombinant murine granulocyte macrophage colony stimulating factor. During the co culture of HLA DR bearing eosinophils and T cells, a fusion protein of cytotoxic T lymphocyte associated protein 4 (CTLA 4Ig) was added to block CD80 and CD86 molecules to observe the roles of B7 molecules in antigen presentation of eosinophils. Results Freshly isolated mouse eosinophils expressed both CD80 and CD86, treatment of granulocyte macrophage colony stimulating factor increased the expression of CD80 and CD86 (both P <0.01),and CTLA 4Ig was able to inhibit antigen presentation of eosinophils by blocking CD80 and CD86. Conclusion Costimulatory signals were required for eosinophils to present antigen to T cells and thus induce the proliferation of T cell.