CD8+T淋巴细胞功能衰竭在口腔白斑病发生与逆转中的作用及机制研究

Inhibiting the exhausting progression of CD8+ T cell and reversing the abnormal proliferation of epithelum is new field, which has been notably concerned. How utilize these special makers of these cells to predict its reversal potential is the frontier subjects of this field (SCIENCE, 2016). We found that the exhaustion of CD8+ T cell may exist in the oral leukoplakia (OLK). Researching on relevant papers, we proposed that CD8+ T cell exhaustion may prompt OLK tissue taking malignant manner, so restoring the normal function of these cells may be an alternative way to reverse the feasibility of OLK canceration. In order to verify the hypothesis, three studies are designed. ① Whether the exhausted CD8+ T cell existing in OLK, and whether these cells correlated with pathological grades and prognosis. ② Which subset of exhausted CD8+ T cell is the dominant one in OLK. Could We futher take full use of this molecular subtyping to guid clinical treatment? ③ Futher studies will be designed to elucidate the molecular mechanisms of exhaustion in CD8+ T cell, which may provide a new strategy to reverse the feasibility of OLK canceration. The objective of the study will not only help to find more effective against OLK therapeutic targets, and to elucidate the pathogenesis of abnormal epithelial hyperplasia diseases provides the basis for further.

阻断CD8+T细胞功能衰竭，逆转上皮异常增生是受关注的新领域，但如何利用此类细胞表面不同的分子标志预判其逆转潜能是学科的前沿（SCIENCE, 2016）。我们发现，口腔白斑病（OLK）组织中存在CD8+T淋巴细胞功能衰竭表型，结合相关的研究，因此假设：CD8+T淋巴细胞功能衰竭可促进OLK异常增生的衍进，若恢复其功能，可逆转此进程。为印证该假设，拟研究：①OLK衍进中是否存在CD8+T淋巴细胞功能衰竭，其与OLK病理分级和预后的关系如何？②OLK中衰竭性CD8+T淋巴细胞是否存在优势亚群，其表面表达的分子标志是否具临床治疗指示意义？③OLK衍进中，导致CD8+T细胞功能衰竭的分子机制是什么？研究不仅有助于寻找针对OLK更有效的逆转靶点,也为阐明利用CD8+T细胞表面的分子标志预判其治疗潜能提供了范例。

口腔白斑病是临床常见口腔潜在恶性疾患之一，发展为口腔鳞状细胞癌可能性较大，预后多不良。在口腔白斑病衍进过程中，T细胞衰竭是否扮演重要角色尚不明确。我们收集健康对照者、口腔白斑病及口腔鳞癌患者的临床标本，用PD-L1、CD86、CD8、PD-1、CTLA-4抗体进行免疫组化染色。同时，采用4-硝基喹诺酮-n -氧化物诱导建立化学诱导小鼠口腔白斑病、口腔鳞癌模型。用流式细胞术检测脾脏T细胞的衰竭状态，用多重免疫组化方法检测口腔白斑病衍进多阶段中的分子变化，及在癌前和OSCC阶段的小鼠上评估PD-1阻滞加或不加顺铂治疗的疗效。通过临床研究，我们发现PD-1在人口腔黏膜的OLK和OSCC组织中表达高于正常，而CTLA-4在口腔黏膜组织中表达较低。动物实验表明，CD4+T细胞衰竭早于CD8+T细胞衰竭早得多，且实验组中干细胞样衰竭性T淋巴细胞部分衰竭T淋巴细胞比例增加。免疫检查点标志物(PDCD1、CTLA4、HAVCR2)的表达与细胞因子(IFNG、IL-2)呈强正相关。综上所述，T细胞衰竭在口腔白斑病癌变过程中发挥着重要作用，PD-1阻断可能阻止口腔白斑病癌变进程。