title: [Effects of anti-PD-L1 monoclonal antibody and EGFR-TKI on the expression of PD-L1 and function of T lymphocytes in EGFR-mutated lung cancer cells].
abstract: Objective:To investigate the effects of anti-PD-L1 monoclonal antibody and EGFR-TKI on expression of soluble PD-L1 and function of T lymphocytes in EGFR-mutated lung cancer cells.Methods:Flow cytometry was used to analyze the expression of membrane PD-LI. ELISA was performed to detect the level of sPD-L1 in the supernatant of cultured EGFR-mutated and wild type lung cancer cells before and after erlotinib treatment.After treated with anti-PD-L1 monoclonal antibody alone and in combination with erlotinib, the proliferation of T lymphocytes in co-culture system was measured using Cell Counting Kit-8 (CCK-8) assay. The expression levels of PD-LI and IFN-γ in tumor cells and T lymphocytes treated with erlotinib in co-culture system were analyzed by flow cytometry and ELISA, respectively.Results:PD-L1 was highly expressed in EGFR-mutated lung cancer PC9 cells (78.7±3.1)% and HCC827 cells (82.7±2.6)%.After treated with erlotinib, the expression rates of membrane PD-L1 in PC9 and HCC827 cells were down-regulated (64.7%±3.1% and 73.0%±2.6%, respectively), significantly lower than that in the two cell lines without erlotinib treatment (P<0.05), and the expression levels of sPD-L1 in the supernatant of PC9 and HCC827 cells were also down-regulated (0.680±0.120)ng/ml and (0.903±0.047)ng/ml, respectively, significantly lower than that in the two cell lines without erlotinib treatment (P<0.01). However, no significant changes of membrane PD-L1 and sPD-L1 expression were found in EGFR wild type lung cancer cells (H1299 and A549) before and after erlotinib treatment. In the co-culture system composed of T cells and EGFR-mutated lung cancer cells, treatment with erlotinib alone promoted the proliferation of T lymphocytes (P<0.05), and combined treatment of anti-PD-L1 monoclonal antibody with erlotinib had a stronger effect (P<0.05). In the co-culture system composed of T cells and EGFR wild type cell lines, the proliferation of T cells was not changed after using erlotinib alone or combination of erlotinib and anti-PD-L1 monoclonal antibody (P>0.05). Before and after treatment with erlotinib, the secretion levels of IFN-γ were (856.0±70.3)pg/ml and (1 697.3±161.0)pg/ml, respectively, showing a significant difference (P<0.001). The expression rates of membrane PD-L1 were (76.2±0.5)% and (50.9±0.9)%, respectively, also showing a significant difference (P<0.001). However, no significant changes in the expression of IFN-γ and membrane PD-L1 were found in the co-culture system composed of T cells and A549 cells.Conclusions:Anti-PD-L1 monoclonal antibody combined with EGFR-TKI can effectively promote the proliferation and secretion function of T lymphocytes in the microenvironment of EGFR-mutated lung cancer cells.
authors.affiliation: Department of Respiratory Medicine, the Second Affiliated Hospital of Soochow University, Suzhou 215004, China.
authors.forename: Y
authors.initials: Y
authors.lastname: She
authors.affiliation: Department of Respiratory Medicine, the Second Affiliated Hospital of Soochow University, Suzhou 215004, China.
authors.forename: X
authors.initials: X
authors.lastname: Pan
authors.affiliation: Department of Respiratory Medicine, the Second Affiliated Hospital of Soochow University, Suzhou 215004, China.
authors.forename: Y F
authors.initials: YF
authors.lastname: Xing
authors.affiliation: Department of Respiratory Medicine, the Second Affiliated Hospital of Soochow University, Suzhou 215004, China.
authors.forename: T
authors.initials: T
authors.lastname: Zhou
authors.affiliation: Department of Respiratory Medicine, the Second Affiliated Hospital of Soochow University, Suzhou 215004, China.
authors.forename: Z L
authors.initials: ZL
authors.lastname: Zhang
authors.affiliation: Department of Respiratory Medicine, the Second Affiliated Hospital of Soochow University, Suzhou 215004, China.
authors.forename: M H
authors.initials: MH
authors.lastname: Shi
authors.affiliation: Institute of Biotechnology, Soochow University, Suzhou 215004, China.
authors.forename: Y J
authors.initials: YJ
authors.lastname: Chen
mesh_terms: D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D060890:B7-H1 Antigen / Q000037:antagonists & inhibitors / Q000276:immunology* / Q000378:metabolism; D002289:Carcinoma, Non-Small-Cell Lung; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D018920:Coculture Techniques; D004797:Enzyme-Linked Immunosorbent Assay; D066246:ErbB Receptors / Q000494:pharmacology*; D000069347:Erlotinib Hydrochloride / Q000627:therapeutic use; D005434:Flow Cytometry; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D008175:Lung Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D047428:Protein Kinase Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors*; D013601:T-Lymphocytes / Q000187:drug effects* / Q000502:physiology
chemical_list: D000911:Antibodies, Monoclonal; D060890:B7-H1 Antigen; D047428:Protein Kinase Inhibitors; D007371:Interferon-gamma; D000069347:Erlotinib Hydrochloride; D066246:ErbB Receptors; D011505:Protein-Tyrosine Kinases