摘要
目的:通过对Vav1与肿瘤浸润T淋巴细胞(tumor infiltrating Tlymphocytes,TITL-T)活性关系的研究,提出T细胞失能的可能分子机制;初步探讨TIL-T中Vav1的表达情况及其与肿瘤局部微环境中吲哚胺2,3双加氧酶(indoleamine-2,3-dioxvgenase,IDO)表达的相关性。方法:收集天津医科大学附属肿瘤医院肺外科手术切除的新鲜肺癌标本、癌旁正常肺组织及蜡块40例,通过实时定量RT-PCR检测TIL-T中Vav1 mRNA表达变化;免疫印迹及免疫沉淀技术检测Vav1蛋白表达及磷酸化活性。BrdU法检测T细胞增殖活性此外,运用Real time-PCR法检测肺癌组织中IDO mRNA表达水平,免疫印迹及免疫组化检测IDO蛋白表达情况。结果:部分肺癌局部浸润的T细胞处于功能抑制状态,这种抑制状态可能与细胞内重要的信号传导蛋白Vav1的表达量及活性相关。IDO表达阳性组肺癌标本局部TIL-T中Vav1 mRNA水平及Vav1蛋白的表达和磷酸化水平明显低于IDO表达阴性组(P<0.05)结论:Vav1的表达和活化在TIL-T功能中具有重要的作用。肿瘤局部微环境中的IDO蛋白可能是影响TIL-T中Vav1表达和活化的重要因素之一。IDO可能通过抑制Vav1的表达及磷酸化活化过程,使TIL-T的主动免疫受损,从而降低宿主的抗肿瘤免疫效应。
Objective： This study explored the relationship between Vavl and tumor-infiltrating T lymphocytes （ TIL - T ）, which provide a molecular mechanism inducing a state ofT cell anergy. The expression of Vavl in TIL-T and indoleamine 2,3-dioxygenase （ IDO ） from the tumor microenvironment was invetigated in order to present a possible molecular mechanism for tumor-induced T cell immune tolerance. Methods： A total of 40 lung cancer patients who had undergone surgery in the Tianjin Medical University Cancer Institute and Hospital were involved. The expression levels of Vavl mRNA in TIL-T were detected by real-time PCR, while the expression and activation of Vavl were determined using Western blot and immunoprecipitation. T cell proliferation was detected using the BrdU method. The levels of IDO expression in lung cancer and corresponding normal lung tissues were determined using semi-quantitative RT-PCR, immunohis-tochemistry, and Western blot. The SPSS17.0 software was used for statistical analysis. Results： TIL-Ts are a part of cancer tissues and are in a state of functional suppression. This suppressive condition may involve the key signal transducer Vavl. Both mRNA and protein levels of Vavl in T cells were significantly decreased in lung cancer tissues with IDO-positive expression compared with those with IDO-negative expression. In addition, the levels ofVavl phosphorylation was decreased （ P 〈 0.05 ）. Conclusion： The expression and activation of Vavl play critical roles in the function of TIL-T. IDO, secreted by the tumor cells themselves or antigen-presenting cells, has an important impact on the expression and activation of Vav 1 in TIL-T. IDO may suppress the expression and phosphorylation of Vav 1, leading to inhibition of the T cell active immune response, which may consequently reduce the anti-tumor defenses of the host.
出处
《中国肿瘤临床》
CAS
CSCD
北大核心
2012年第9期524-528,共5页
Chinese Journal of Clinical Oncology
