Expression And Clinical Significance Of Treg Cell Subsets In Bronchoalveolar Lavage Fluid And Peripheral Blood Of NSCLC Patients

Background:Recent research has shown that patients with non-small cell lung cancer(NSCLC)had higher levels of regulatory T cells(Tregs)in tumor tissue,lymph nodes and peripheral blood,and the tumor microenvironment will reshape the gene expression of Tregs.The significance of Treg in the genesis and development of NSCLC tumors will be made clearer by exploring the alterations of Treg cell subsets in the tumor microenvironment of NSCLC patients.By identifying the frequency variations of Treg cell subsets in bronchoalveolar lavage fluid(BALF)and peripheral blood of NSCLC patients,this study preliminarily clarified the relationship between Treg and the onset and progression of NSCLC.Methods:A total of 36 NSCLC patients and 17 control subjects were enrolled in this study.All participants had peripheral blood samples taken,and 31 NSCLC patients and 11controls had BALF samples taken.There was no difference in age between the two groups of participants,and there were more males than females in the NSCLC patient group.In this study,we further followed up NSCLC patients who received combined chemotherapy with platinum and paclitaxel for two cycles,and collected peripheral blood samples from 5 patients with complete follow-up records after treatment.The frequency of T cell subsets in BALF and peripheral blood of participants was detected by flow cytometry.The serum CYFRA21-1 level of NSCLC patients was detected by electrochemiluminescence immunoassay.The differential expression in T cell subsets,Tregs,TIGIT~+,Helios~+,RORγt~+and Nrp-1~+Treg cell subsets,as well as TIGIT~+,Helios~+CD4~+non-Treg and CD8~+T cells between the NSCLC patient group and control group were compared and analyzed,and their correlation with clinical indicators was analyzed.In addition,in order to investigate the functional variations of Helios~+TIGIT~+and Helios~-TIGIT~-Treg cell subsets,the peripheral blood of 15healthy people were also taken for cell function experiments.Results:1.The frequency of CD4~+CD25~+Fox P3~+Treg in BALF and peripheral blood of NSCLC patients was higher than that of control group.2.The expression of TIGIT~+,Helios~+and Helios~+TIGIT~+Treg cell subsets in BALF of NSCLC patients was significantly higher than that of the control group,while the expression of Helios~-TIGIT~-Treg cells was lower than that in the control group.3.The positive expression rate of PD-1 in Helios~+TIGIT~+Treg of healthy people was higher than that in Helios~-TIGIT~-Treg,and the former contains less IFN-γ~+and more IL-17A~+cells than the latter.4.The frequency of Helios~+and Helios~+TIGIT~+Treg cell subsets in BALF of NSCLC patients was positively correlated with disease progression.The frequency of Treg,TIGIT~+,Helios~+and Helios~+TIGIT~+Treg cell subsets was positively correlated with serum CYFRA 21-1 level.5.After two cycles of combined chemotherapy with platinum and paclitaxel,the serum CYFRA 21-1 level of NSCLC patients decreased,and the frequency of Tregs,TIGIT~+,Helios~+,RORγt~+and Nrp-1~+Treg cell subsets in peripheral blood did not significantly change.Conclusions:1.Tregs may participate in the progression of NSCLC tumor by increasing the expression levels of Helios~+and Helios~+TIGIT~+.2.Targeting Helios and TIGIT molecules on Treg cells may be effective in the treatment of NSCLC.3.The effects of combined chemotherapy with platinum and paclitaxel on the expression of Tregs,TIGIT~+,Helios~+,RORγt~+and Nrp-1~+Treg cell subsets in peripheral blood of NSCLC patients were not significant.