气道上皮细胞衍生的胰岛素样生长因子触发偏移CD8^+T细胞极化

Airway epithelial cell-derived insulin-like growth factor-1 triggers skewed CD8^+T cell polarization

目的探讨气道上皮细胞衍生的胰岛素样生长因子(IGF1)对CD8+T细胞极化的影响。方法人气道上皮细胞株RPMI2650与鼠过敏原Der p1共培养72 h,用定量PCR及Western免疫印迹检测其IGF1表达情况。将前述上皮细胞、重组IGF1和IGF1抗体分别加入抗体激活的CD8+T细胞中培养,用流式细胞仪检测细胞凋亡。检测Der p1活化的上皮细胞及IGF1对CD8+T细胞p53基因甲基化及表达的影响。结果加入Der p1共同孵育后,RPMI2650细胞IGF1mRNA(23.1%±5.2%vs 5.2%±2.3%,P<0.01)和蛋白表达(33.4±6.4 vs 9.2±4.6,P<0.01)均明显增加。将CD3/CD28抗体激活的CD8+T细胞与Der p1活化的上皮细胞共培养,凋亡细胞增加的趋势被抑制(41.7%±8.2%vs5.2%±1.8%,P<0.01)。直接加入重组IGF1有同样效果,而IGF1抗体能阻断该效应。Der p1活化的上皮细胞能抑制活化CD8+T细胞p53基因mRNA(29.1%±5.9%vs 16.2%±4.3%,P<0.01)和蛋白表达(63.3±8.9 vs 26.9±5.6,P<0.01),加入IGF1抗体后这种作用消失。重组IGF1使CD8+T细胞p53基因甲基化增加。结论 Der p1蛋白能够诱发RPMI2650细胞产生IGF1,后者通过诱导p53基因甲基化抑制CD8+T细胞凋亡。

Aim To investigate the effects of airway epithelial cell-derived insulin-like growth factor-1( IGF1) on CD8+T cell polarization. Methods Human airway epithelial cell line,RPMI2650 cells,was cultured in the presence of a mice allergen,Der p1,for 72 h. IGF1 expression was checked with quantitative RT-PCR and Western blot. Der p1-primed RPMI2650 cells,recombinant IGF1 and anti-IGF1 antibody was cocultured respectively with CD8+T cells,which were activated by anti-CD3 / CD8 Ab. Apoptotic cells frequency was calculated with flow cytometry.The alteration of p53 gene hypermethylation in CD8+T cells elicited by Der p1-primed airway epithelial cell and IGF1 was plotted. Results Both mRNA( 23. 1%± 5. 2% vs 5. 2% ± 2. 3%,P < 0. 01) and protein( 33. 4 ± 6. 4 vs 9. 2 ± 4. 6,P < 0. 01) expression of IGF1 in RPMI2650 cells markedly increased after exposure to Der p1. The increase of apoptotic CD3 / CD28Ab-activated CD8+T cells was abolished by the presence of Derp1-primed epithelial cells( 41. 7% ± 8. 2%vs 5. 2% ± 1. 8%,P < 0. 01). The results were confirmed by the addition of recombinant IGF1. Anti-IGF1antibody abolished the effect of the epithelial cells.Derp1-primed epithelial cells inhibited p53 gene mRNA( 29. 1% ± 5. 9% vs 16. 2% ± 4. 3%,P < 0. 01)and protein( 63. 3 ± 8. 9 vs 26. 9 ± 5. 6,P < 0. 01) expression. Anti-IGF1 antibody abolished the effect. Recombinant IGF1 promoted CD8+T cells' p53 gene hypermethylation. Conclusion Der p1 induces RP-MI2650 cells to produce IGF1,and this factor prevents CD8+T cell apoptosis by inducing p53 gene hypermethylation.