MIP-1a细胞因子与痘苗病毒天坛株终身免疫保护性的相关性

Relationship between MIP-1a and persistent immune protection of vaccinia virus Tiantan strain

目的分析MIP-1a细胞因子与痘苗病毒天坛株(vaccinia virus Tian Tan strain,VTT)终身免疫保护性的相关性。方法将VTT分别经肌肉注射免疫C57/BL6小鼠和MIP-1a的KO小鼠模型B6.129P2-Ccl3,每只剂量2×107PFU/ml,每组10只,30和180 d后,再次用相同剂量的VTT进行激发,激发3 d后,处死小鼠,取脾淋巴细胞,采用流式细胞术分析CD44+CD62L-CD4+的外周效应记忆性T细胞(effector memory T cell,Tem)在两种小鼠体内的差异;同时用四聚体(tetramer)对荷载痘苗病毒特异性的CD8+T细胞表位(VACV-B8R20-27 Kb)进行染色,分析MIP-1a的缺失对长效免疫记忆的影响。结果获取的CD4+的记忆性T细胞的表型以CD4+CD44+CD62L-为主,即以Tem为主;获取的CD8+的记忆性T细胞也以Tem(CD44+CD62L-)为主,数量很少。B6.129P2-Ccl3小鼠受到再次激发后,体内VTT特异性CD8+T细胞在30和180 d的比例均明显少于C57/BL6小鼠;在30 d激发时,tetramer+CD8+T细胞的比例明显高于180 d激发。结论 MIP-1a细胞因子与痘苗病毒产生长效免疫记忆相关,本实验为延长疫苗的免疫记忆提供了参考。

Objective To analyze the relationship between MIP-1a and persistent immune protection of vaccinia virus Tiantan strain（VTT）. Methods Ten C57 / BL6 mice and ten B6.129P2-Ccl3 model mice with MIP-1a gene knock out（KO）were immunized i. m. with VTT at a dosage of 2 × 107 PFU / ml respectively, and excited with VTT at the same dosage 30 and 180 d later. The mice were killed 3 d after excitation, of which the splenic lymphocytes were collected and determined for peripheral CD44＋CD62L-CD4＋effector memory T（Tem） cells by flow cytometry. The effect of deletion of MIP-1a on persistent immune memory was analyzed by staining of tetramer loading vaccinia virus-specific CD8＋T cell epitopes（VACV-B8R20-27 Kb）. Results The phenotypes of obtained CD4＋ memory T cells were mainly CD4＋CD44＋CD62L-, i. e. Tem, while those of CD8＋memory T cells in a small quantity were mainly Tem（CD44 ＋CD62L-）. The percentages of VTT-specific CD8＋T cells in B6.129P2-Ccl3 mice 30 and 180 d after excitation were significantly lower than those in C57 / BL6 mice. However, the percentage of tetramer＋CD8＋T cells 30 d was significantly higher than that180 d after excitation. Conclusion MIP-1a was associated with the persistent immune memory induced by vaccinia virus, which provided a reference for prolonging the immune memory of vaccine.