IRE1α调控CD155表达影响NK细胞对结肠癌细胞的杀伤敏感性

The expression of IRE1α regulatory CD155 affects the killing sensitivity of NK cells to colon cancer cells

目的:探讨肌醇的跨膜激酶/核酸内切酶1α(inositol-requiring transmembrane kinase/endonuclease 1α,IRE1α)调控CD155表达对自然杀伤(nature killer,NK)细胞杀伤结肠癌细胞作用的影响。方法:免疫组织化学法检测结肠癌组织及癌旁组织中IRE1α的表达;qRT-PCR与Western blot检测IRE1α与CD155的mRNA及蛋白表达;流式细胞术检测人外周血CD3^(-)CD56^(+)NK细胞百分比及与其纯度和NK细胞表面T细胞免疫球蛋白和ITIM结构域蛋白(T cell immunoreceptor with Ig and ITIM domains,TIGIT)的表达;乳酸脱氢酶释放法检测NK细胞对结肠癌细胞的杀伤率。结果:IRE1α在结肠癌组织和细胞中的表达高于癌旁组织及人正常结肠上皮细胞;结肠癌患者外周血CD3^(-)CD56^(+)NK细胞百分比低于健康者。si-IRE1α组结肠癌细胞的IRE1α表达水平低于si-NC组(P<0.05),CD155表达水平高于si-NC组(P<0.05),NK细胞对si-IRE1α组结肠癌细胞的杀伤率高于si-NC组的杀伤率(P<0.05),NK细胞对si-IRE1α+TIGIT-mcAb组结肠癌细胞的杀伤率高于si-IRE1α组的杀伤率(P<0.05)。Pc-IRE1α组结肠癌细胞的IRE1α表达水平高于Pc组(P<0.05),CD155表达水平低于Pc组(P<0.05),NK细胞对Pc-IRE1α组结肠癌细胞的杀伤率低于Pc组的杀伤率(P<0.05)。Pc-IRE1α+si-CD155组结肠癌细胞CD155表达水平高于Pc-IRE1α+si-NC组(P<0.05),NK细胞对Pc-IRE1α+si-CD155组结肠癌细胞的杀伤率高于Pc-IRE1α+si-NC组(P<0.05),NK细胞对Pc-IRE1α+si-CD155+TIGIT-mcAb组细胞的杀伤率高于Pc-IRE1α+si-CD155组(P<0.05)。结论:结肠癌组织和细胞中IRE1α高表达,IRE1α负调控结肠癌细胞CD155的表达,影响NK细胞对结肠癌细胞的杀伤敏感性。

Objective:To investigate the effect of IRE1α regulating the expression of CD155 on the killing of colon cancer cells by NK cells.Methods:Immunohistochemistry was used to detect the expression of IRE1αin colon cancer tissues and adjacent tissues to the cancer.qRT-PCR and Western blot were performed to detect the mRNA and protein expression of IRE1α and CD155.Flow cytometry was utilized to evaluate the percentage and purity of CD3^(-)CD56^(+)NK cells in human peripheral blood NK cells and the expression of TIGIT in NK cells.LDH releasing assay was used to detect cytotoxicity of NK cells against colon cancer cells.Results:The expression of IRE1α in colon cancer tissues and cells was higher than that in adjacent tissues and human normal colon epithelial cells.The percentage of CD3^(-)CD56^(+)NK cells in peripheral blood of colon cancer patients was lower than that of healthy people.The expression level of IRE1α in colon cancer cells in the si-IRE1α group was lower than that in the si-NC group(P<0.05),and the expression level of CD155 was higher than that in the si-NC group(P<0.05),the killing rate of NK cells on colon cancer cells in the si-IRE1α group was higher than that in the si-NC group(P<0.05),and the killing rate of NK cells on colon cancer cells in the si-IRE1α+TIGIT-mcAb group was higher than that of si-IRE1α group killing rate(P<0.05).The expression level of IRE1α in colon cancer cells in the Pc-IRE1α group was higher than that in the Pc group(P<0.05),and the expression level of CD155 was lower than that in the Pc group(P<0.05),the killing rate of NK cells to colon cancer cells in the Pc-IRE1α group was lower than that of the Pc group(P<0.05).The expression level of CD155 in colon cancer cells in the Pc-IRE1α+si-CD155 group was higher than that in the Pc-IRE1α+si-NC group(P<0.05),the killing rate of NK cells to colon cancer cells in the Pc-IRE1α+si-CD155 group was higher than that in the Pc-IRE1α+si-NC group(P<0.05),and the killing rate of NK cells to the Pc-IRE1α+si-CD155+TIGIT-mcAb group was higher than that of the Pc-IRE1α+si-CD155 group(P<0.05).Conclusion:IRE1α is highly expressed in colon cancer tissues and cells IRE1α negatively regulates the expression of colon cancer cells CD155 to affects the killing sensitivity of NK cells to colon cancer cells.