角蛋白置换肽配体对银屑病患者外周血T细胞的抑制作用

In vitro inhibition of peripheral blood T lymphocytes isolated from patients with psoriasis by altered peptide ligands of keratin

目的筛选下调银屑病患者T细胞功能的置换肽配体。方法分离和纯化寻常型银屑病患者和健康人外周血T细胞,通过MTT法和ELISA法分别检测T细胞增殖情况和IFN-γ、IL-2、IL-4和IL-10等细胞因子的变化,筛选得到抑制银屑病患者外周血T细胞功能的APL。结果APL 119R和355L可显著下调银屑病患者T细胞的增殖,分别与谷胱甘肽巯基转移酶和空白对照比较,在10μg/mL和100μg/mL浓度下,P<0.05;而对健康人T细胞无明显作用。同时二者可显著下调银屑病患者外周血T细胞的IFN-γ和IL-2,上调IL-4和IL-10的分泌表达,分别与相对应的野生型表位比较,在10μg/mL和100μg/mL浓度下,P<0.05。结论APL 119R和355L具有体外下调银屑病患者外周血T细胞增殖和增强Th2极化的作用。

Objective To evaluate the ability of altered peptide ligands （ APLs ） to inhibit the activities of psoriatic T cells. Methods Peripheral blood T cells were isolated from 52 patients with psoriasis and 48 healthy human controls. The APLs targeting T cell epitopes of keratin 17 were synthesized. The peripheral blood monocytes were incubated with the wild T cell epitopes, APLs or control peptides （glutathione S-transferase, GST ）. These monocytes were then used as antigen presenting cells to interact with T lymphocytes from the same individuals. MTT method was used to detect the proliferation of T lymphocytes, and ELISA assay to measure the levels of IFN-γ IL-2, IL-4 and IL-10 in the culture supernatants of these T lymphocytes. Results Compared with GST and blank control, the APLs, 119R and 355L at a concentration of 10 and 100 μg/mL significantly down-regulated the proliferation of psoriatic T cells （ P 〈 0.05 ）; no obvious inhibition of proliferation of cells from healthy controls was noted. APLs at 10 and 100 ixg/mL also decreased the secretion of IFN-γand IL-2 in the supernatants ofT cells, and increased the levels of IL-4 and IL-10 in comparison with the wild epitopes （ all P 〈 0.05 ）. Conclusion Our findings show that APLs, 119R and 355L, are capable of inhibiting the proliferation of psoriatic T cells and facilitating the differentiation to Th2 cells in vitro.