The Role Of 4-1BBL Reverse Signal In Biological Function Of Lung Cancer Cells And Treg Cells

4-1BBL/4-1BB belongs to TNF/TNFR superfamily and exhibits the biological functions via its bidirectional signaling, including forward and reverse signaling. Previous reports revealed that 4-1BBL/4-1BB played an important role in antigen presenting and cytoxic T lymphocyte activating. More and more studies showed that 4-1BBL/4-1BB signaling linked the innate immunity and adaptive immunity, regulated the immune response and participated in the pathological process of inflammation, tumor and autoimmune disease. Hence, researchers attempt to arouse the anti-inflammatory response and anti-tumor immune response by regulating 4-1BBL/4-1BB signaling.Lung cancer is a disease with high incidence and mortality in the world. Our study found that 4-1BBL was expressed highly on tumor cells and Treg cells from lung cancer patients. Did it take part in the pathological process in lung cancer? We discussed this scientific question as follows,PartⅠ4-1BBL expression on lung cancer cells and its biological effectsObjective:Explore 4-1BBL expression on lung cancer cells and its biological effects.Methods:Observed 4-1BBL expression on lung cancer tissues with Immunohistochemistry. Analyzed 4-1BBL expression of 95D cells with immunofluorescence staining, flow cytometry and RT-PCR. Stimulated 95D cells with agonistic anti-human 4-1BBL monoclonal antibody 1F1, and then, observed the proliferation of 95D cells with cell counting, analyzed the expression of CXCR-4, CD95L and PD-L1 by immunofluorescence staining and flow cytometry, evaluated immigration ability of 95D cells with transwell assay.Conclusion:4-1BBL expressed on lung cancer tissues and lung cancer cell line 95D. The proliferation of 95D cells could be enhanced, the expression of CD95L, PD-L1 and CXCR4 could be upregulated and the immigration ability could be increased by triggering 4-1BBL reverse signaling.PartⅡ4-1BBL expression on Treg cells of PBMCs from lung cancer patients and its biological effectsObjective:Explore 4-1BBL expression on Treg cells from lung cancer patients and its biological effects.Methods:Isolated PBMCs from lung cancer patients and analyzed 4-1BBL expression of Treg cells with immunofluorescence staining and flow cytometry. Enriched CD4+CD25+CD127-Treg cells from PBMCs of lung cancer patients and stimulated Treg cells with agonistic anti-human 4-1BBL monoclonal antibody. 1F1. And then, observed the proliferation of Treg cells with cell counting, analyzed the Foxp3 expression of Treg cells by immunofluorescence staining and flow cytometry, evaluated IL-10 and TGF-P secretion of Treg cells with ELISA assay.Conclusion:4-1BBL expressed highly on Treg cells from lung cancer patients. The proliferation of Treg cells could be enhanced, the expression of Foxp3 could be upregulated and the secretion of IL-10 and TGF-βcould be increased by triggering 4-1BBL reverse signaling.In all, our study found that 4-1BBL expressed on tumor cells and Treg cells from lung cancer patients.4-1BBL mediated its reverse signaling and played an important role in the proliferation and inhibitory molecule expression of tumor cells and Treg cells and migration of tumor cells. Therefore,4-1BBL is a potential target of immunological intervention for tumor therapy.