CD39和CD73在CD4^+CD25^(high)Foxp3^+调节性T细胞发挥免疫抑制功能中的作用研究

A study on the expression and function of extracellular adenosine metabolism molecules CD39 and CD73 in CD4^+CD25^(high)Foxp3^+ regulatory T cells

本研究旨在检测正常人CD4^+CD25^(high)Foxp3^+Treg表面腺苷代谢分子的表达,并探索该分子在CD4^+CD25^(high)Foxp3^+Treg发挥抑制功能中的作用。采用流式细胞术检测10例健康献血者外周CD4^+CD25^(high) Foxp3^+Treg表面腺苷代谢分子CD39、CD73的表达,免疫组化染色检测了5例健康人皮肤中腺苷代谢分子CD39、CD73及Foxp3的表达。对5例健康献血者,流式细胞仪分选得到CD4^+CD25^(high)、CD4^+CD25^(high) CD39^+、CD4^+CD25^(high) CD39^+CD73^+共3部分细胞,采用3H-TdR掺入方法检测这3部分T细胞对CD4^+CD25-T细胞增殖的抑制作用。同样采用流式细胞术对10例斑块型银屑病患者外周CD4^+CD25^(high)Foxp3^+Treg表面CD39和CD73分子的表达进行分析。结果显示,正常人外周血CD4^+CD25^(high) Foxp3^+Treg与CD4^+CD25mid和CD4^+CD25-T细胞相比,CD39明显高表达(P<0.01),CD73低表达(P<0.05)。正常人皮肤中,CD39主要表达在表皮角质形成细胞,而CD73则主要分布于真皮中。CD39^+CD73^+Treg对CD4^+CD25-T细胞增殖的抑制最强(P<0.01)。银屑病患者外周血CD73^+CD4^+CD25^(high)Foxp3^+Treg比例较正常人明显降低(P<0.01)。由此推测腺苷代谢分子是CD4^+CD25^(high)Foxp3^+Treg发挥抑制功能的重要物质,并可能参与银屑病的发生。

To analyze the expression and function of molecules CD39/CD73 produced during extracellular metabolism of adenosine of CD4＋ CD25highFoxp3＋ regulatory T cells, 15 healthy people and 10 patients with psoriasis vulgaris were selected. The percentage and attributes of CD39/CD73-expressing regulatory T cells in peripheral blood were measured by flow cytometry. Immunohistochemical staining was used to analyze expression of Foxp3, CD39 and CD73 in biopsy tissue from healthy controls. Using the flow sorting, CD4＋ CD25high, CD4＋ CD25highCD39＋ and CD4＋ CD25highCD39＋ CD73＋ regulatory T cells were isolated from peripheral blood from 5 healthy controls, [3 H] thymidine incorporation assay was performed to analyze the inhibition of CD4＋ CD25- T cells proliferation by the above three different subgroups of regulatory T cells. Compared to CD4 ＋ CD25mid and CD4＋ CD25 T cells, normal healthy peripheral blood CD4＋ CD25high Foxp3＋ regulatory T cells showed significantly higher ex- pression levels of CD39（P〈0.01）and less CD73（P〈0.05）. In normal control biopsies, CD39＋ cells were scattered through out the epidermis and dermis, while CD73＋ cells were localized predominantly in the dermis. The inhibitory capacity of CD39＋ CD73- Treg cells was significantly higher than that of the unfractionated Treg cell-pool（P〈0.01）. The expression of CD73＋ CD4＋ CD25highFoxp3＋ Tregs was markedly reduced in psoriasis vulgaris patients（P〈0.01）. Therefore, the adenosine metabolism is an important part in regulatory T cells function and related to the pathogenesis of psoriasis vulgaris.