可溶性组织相容白细胞抗原诱导自然杀伤细胞和T细胞耐受作用的研究

目的探讨可溶性组织相容性白细胞抗原(HLA—G1)对自然杀伤细胞(NK)、T细胞的致耐作用。方法借助基因工程技术构建表达可溶性HLA-G1的真核表达质粒;把重组质粒转染入宿主细胞LcL721．221,表达可溶性HLA—G1并借助免疫亲和层析技术纯化可溶性HLA-G1蛋白;探讨可溶性HLA-G1分子对NK细胞杀伤活性的影响,对混合淋巴细胞培养中T细胞增殖的影响,对活化T细胞凋亡的影响。结果可溶性HLA—G1能够有效抑制NK细胞的杀伤活性;能够抑制混合淋巴细胞培养中T细胞的增殖;能够促进活化T细胞发生凋亡。可溶性HLA—G1对NK、T细胞的上述作用无HLA限制性。结论可溶性HLA—G1为一种免疫致耐分子。

Immune tolerance inducing effects of soluble human leucocyte antigen G1 on natural killer cells and T cells

Objective To investigate the immune tolerance inducing effects of soluble human leucocyte antigen G1 (sHLA-G1) on natural killer (NK) cells and T cells. Methods A recombinant plasmid expressing sHLA-G1 was constructed and transfected into human lymphoblastoid cells LCL 721.221. sHLA-G1 in the supernatant was purified by immuno-affinity chromatography and then added into the culture of NK cells obtained from the peripheral blood mononuclear cells of 3 unrelated individuals. Target cells, K562 cells, were added too. The killing rate of NK was calculated. Peripheral blood lymphocytes (PBLs) were obtained and stimulated by Ebstein-Barr-virus-transformed B lymphoblastoid cell line (EBV-LCL). The proliferation of the T cells in the mixed lymphocyte culture was examined by enzyme linked immunosorbent assay. The antigen-specific T cells in the peripheral blood was activated. sHLA-G1 was added into the culture. Then the T cells were suspended in the solution of fluorescence isothiocyanate (FITC)-annexin-V. Flow cytometry was used to detect the fluorescent intensity of FITC so as to examine the apoptosis of T cells. Results sHLAG-1 inhibited the cytotoxicity of NK cells dose-dependently. sHLAG-1 inhibited the proliferation of activated T cells, and induced the apoptosis of T cells dose-dependently, with a dose-saturation character and without antigen-specificity. Conclusion sHLAG-1 is a kind of immune tolerance inducing molecule.