肿瘤源性Reg3驯导树突状细胞促进胰腺癌免疫逃逸的作用及机制研究

Cancer cells can release a variety of tumour-derived factors (TDFs) to induce the functional shift of immune cells, which could then facilitate tumor escape through evasion of immune surveillance. Our previous researches found that Regenerating islet-derived protein 3 (Reg3), an inflammatory molecule highly expressed in pancreatic tissue, contributed to inflammation-related pancreatic cancer (PaC) development via its proliferation-promoting effect; mice treated with a lentivirus system encoding for Reg3 displayed suppressed dendritic cell(DC) function; and overexpression of endogenous Reg3 was found in PaC cells treated with exogenous Reg3,indicating its self-induction. These results suggested that: Reg3 continuously released by PaC cells could act as a TDF to “educate” DCs, the most important antigen presenting cells, contribute to immunosuppressive tumor microenvironment and facilitate PaC escape and progression. In this research, short-hairpin RNA (shRNA) / lentivirus plasmids will be used to silence/ over-express Reg3 in different PaC cells, then human peripheral blood-derived DCs will be co-cultured with PaC cells in a Transwell co-culture system, to confirm the role of tumour-derived Reg3 in the regulation of PaC microenvironment to the differentiation, survival and function of DCs; the effects of tumour-derived Reg3-educated DCs on PaC progression will be determined by intraperitoneal transfer in PaC-implanted SCID mice reconstituted with T cells; the expression of JAK/STAT3, NF-κB and possible Reg3 receptor EGFR in tumour-derived Reg3-educated DCs will be studied to investigate the mechanism. This study focuses on the new immune modulating function of Reg3 as a TDF responsible for immune escape of PaC, to further reveal the multifunctional role of Reg3 in the inflammation-linked pancreatic carcinogenesis.

癌细胞通过产生肿瘤源性因子(TDFs)诱导免疫细胞功能转化，促肿瘤免疫逃逸。前期发现：胰腺炎症分子Reg3除通过经典促增殖作用参与胰腺炎症恶性转化外，尚抑制动物树突状细胞(DCs)功能，且在胰腺癌(PaC)细胞中有自身诱导现象。据此推测：PaC细胞持续分泌的Reg3，以TDF身份训导位于免疫调节上游的DCs，营造免疫抑制微环境以利肿瘤逃逸进展。本研究拟以shRNA、过表达质粒对PaC细胞的Reg3进行干预，体外Transwell模型中PaC细胞/人外周血来源DCs共培养，明确肿瘤源性Reg3在PaC微环境影响DCs中的关键作用；免疫重建SCID小鼠PaC移植瘤模型DCs过继转移，了解肿瘤源性Reg3训导后的DCs对PaC在体进展的影响；以JAK/STAT3,NF-κB及EGFR等为切入点，分析肿瘤源性Reg3驯导DCs的可能机制。以期全面揭示Reg3在胰腺炎症恶性转化中关键效应和调控规律。

癌细胞通过产生肿瘤源性因子(TDFs)诱导免疫细胞功能转化，促肿瘤免疫逃逸。分泌型胰腺炎症分子Reg3可通过在胰腺癌(PaC)细胞中的自身诱导现象及其经典促增殖作用参与胰腺炎症恶性转化。以全面揭示Reg3作为一种多功能关键分子在胰腺炎症恶性转化中的潜在效应和调控规律为目标，本项目研究了肿瘤源性人Reg3产物Reg3A以TDF身份对免疫调节上游最重要的抗原提呈细胞-树突状细胞(DCs)的影响及机制。主要包括①利用Transwell模型观察PaC细胞Reg3A功能过表达和缺失对共培养人外周血来源DCs的直接作用，证实肿瘤源性Reg3A使DCs成熟过程受阻而停留于未成熟的耐受状态、使DCs对抗原的内吞能力提高、对下游T淋巴细胞的免疫刺激作用减弱、减少DCs凋亡、使DCsIL-12p70分泌减少、IL-23产生增加，而“驯导”DCs，营造免疫抑制微环境以利肿瘤逃逸进展。②将肿瘤源性Reg3A“驯导”后的DCs过继转移至免疫重建SCID小鼠PaC移植瘤模型中，证实了其加速PaC在体进展的作用。③机制方面，发现肿瘤源性Reg3A可上调DCsSTAT3表达，而STAT3对DCs分化成熟具有已知的抑制效应；且发现Reg3A在PaC细胞及DCs中均呈现与TLR4的共定位且可能存在相互作用。并以Reg3A和DCs等为关注点，在炎性疾病或肿瘤背景下进行了药物干预研究。目前已发表SCI收录论文17篇，其中Q1区4篇、Q2区7篇、Q3区2篇。培养硕士4名。本研究从肿瘤免疫视角，解释炎症分子Reg3A在PaC细胞中呈现自身诱导现象的后效应，与前期研究结果一道，以Reg3A为关键衔接节点，串联和完善“非可控性炎症→恶性转化→通过TDF营造免疫抑制性微环境→加速恶性转化”的胰腺炎癌转化过程，为将Reg3A用于PaC的预测、诊断、治疗及药物靶标奠定了基础。