抗鼠T细胞受体抗体抑制胸腺细胞的迁出

Emigration of mature T cells from the thymus is inhibited by T cell receptor monoclonal antibody

目的 通过检测抗仓鼠T细胞受体抗体对胸腺T细胞输出的影响,进一步研究胸腺是提供外周免疫细胞输出的有关机理。方法 体内注射抗TCR抗体48 h后FACS分析新迁出细胞在胸腺、淋巴结的表达。结果 小鼠成熟髓质区高表达T细胞受体的单阳性细胞数目成倍增加,同时皮质区低表达T细胞受体的不成熟双阳性细胞数目减少。成熟的单阳性胸腺细胞高表达归巢受体L-Selectin,表型分析(TCRαβ、CD69、HAS、Vβ7-integrin、Qa-2)显示增加的这群细胞为胸腺的新迁出细胞,此群成熟细胞的高表达,表明胸腺的细胞迁出受到了抑制。胸腺内注射异硫氰酸荧光素16 h后,抗TCR抗体注射小鼠外周淋巴结及脾脏CD4^+、CD8^+新迁出细胞数量减少。结论 抗TCR抗体能抑制胸腺T细胞向外周迁移。

Objective In order to study the relationship between the thymus and mechanism involved in the cellular export processes. We examined the ability of anti-TCRmAb to effect T cells export from the thymus. Methods Balb/c mice were injected intraperitoneally with anti-TCRmAb(H57.597)for 48 h, and expressin of L-selectin in thymus and peripheral blood was analyzed. Results The mice showed a marked increase in the total number fo mature medullary thymocytes(CD4^+ CD8^- and CD4^- CD8^+)as well as a slight decrease in the doublepositive cell(CD4^+ CD8^+) ratio. Phenotypic analysis (TCRαβ, CD69, HAS, Vβ7-integrin, Qa-2) revealed that these increased subsets represent possible peripheral recent thymic emigrants. High level expression of L-Selectin by these subsets further suggests that they were prevented from leaving the thymus. By intrathymic labeling with fluorescein isothioeyanate, decrease in the number of CD4^+ and CD8^+ recent thymic emigrants in the lymph nodes and spleen of anti-TCRmAb treated mice was found compared to PBS-treated control mice. Conclusion Taken together, these results suggest that the effect of anti-TCRmAb could be due to its inhibition on T cell emigration from the thymus to the periphery.