Expression And Clinical Significance Of Immune-Related Chemokine Receptor CXCR5 And Immunosuppressive Factor In Diffuse Large B-Cell Lymphoma

Objective: γδ T cells have anti-tumor,anti-virus and anti infection functions,can specifically recognize antigens without MHC restriction and can overcome tumor resistance to a certain extent,which has good potential applications for the treatment of patients with refractory/ relapsed DLBCL.However,different γδ T cell subsets in DLBCL patients may play tumor-suppressive or tumor-promoting roles,and further studies on their related regulatory factors are urgently needed.Chemokine receptor axis and immunosuppressive factors may play an important role in regulating the expression of γδ T cell functional subsets.Therefore,in this study,we firstly analyzed the expression of chemokine receptor CXCR5 and immunosuppressive factors TIGIT and PD-1 in γδ T cells of DLBCL patients;secondly,we analyzed the expression distribution of chemokine receptor CXCR5 and immunosuppressive factors TIGIT and PD-1 in γδ T cell subpopulations of DLBCL patients in different states and explored their correlation with the clinical prognosis of DLBCL patients.patients’ clinical prognosis.To help select for the acquisition or translational induction of more effective γδ T cell functional subpopulations and provide a new and more desirable strategy for specific anti-refractory relapsed DLBCL over-the-counter immunotherapy.Methods:(1)Peripheral blood samples,tumor tissues and paraneoplastic tissues were collected from 30 DLBCL patients and 20 healthy subjects,and the expression levels of γδ T cell-associated chemokine receptor CXCR5 and immunosuppressive factors TIGIT and PD-1 subsets were measured by real-time fluorescence quantitative PCR.(2)Analysis of the expression of γδ Tcell subsets,γδT-cell-associated chemokine receptor CXCR5 and immunosuppressive factors TIGIT and PD-1 subsets in peripheral blood of DLBCL patients by flow cytometry.(3)To detect the expression of γδ T cells in tumor tissues and paraneoplastic tissues of DLBCL patients by immunohistochemistry,as well as the expression of chemokine receptor CXCR5 and immunosuppressive factors TIGIT,PD-1 and its ligands.(4)Correlation between the expression levels of γδ T cell-associated chemokine receptor CXCR5 and immunosuppressive factors TIGIT and PD-1 subpopulations and clinical regression and prognosis of DLBCL.Results:(1)The results of real-time fluorescence quantitative PCR showed that the expression levels of CXCR5,TIGIT and PD-1 genes in peripheral blood γδ T cells of DLBCL patients were significantly higher than those of healthy controls.(2)The results of flow cytometry showed that the expression ratio of the total γδ T cells in peripheral blood was decreased in DLBCL patients compared with healthy controls.The expression ratio of CXCR5+γδ T、TIGIT+γδ T and PDI+γδ T cell subsets was significantly higher in DLBCL group compared with healthy controls(P<0.05);further analysis revealed that the expression proportions of both TIGIT+ CXCR5+ and PD-1+ CXCR5+γδ T cell subsets were significantly higher compared to healthy controls(P<0.05).(3)Immunohistochemical assays showed that γδ T cells were differentially expressed in DLBCL tumor tissues and some paraneoplastic tissues;chemokine receptor CXCR5 and its ligand CXCL13 were lowly expressed in DLBCL tumor tissues but not in paraneoplastic tissues;PDL-1(ligand of PD1)was highly expressed in DLBCL tumor tissues but lowly expressed in paraneoplastic tissues CD155(ligand of TIGIT)was lowly expressed in DLBCL tumor tissues and not expressed in paraneoplastic tissues.(4)Further analysis of the clinical outcome and regression of patients revealed that high expression of CXCR5+,TIGIT+ and PD1+ γδ T cell subsets were risk factors for the prognosis of DLBCL patients.Conclusions: CXCR5,TIGIT and PD-1 were proportionally more expressed in peripheral blood γδT cells of DLBCL patients,γδ T cell infiltration was present in tumor tissues of DLBCL patients.CXCR5 and its ligands CXCL13 and CD155(ligands of TIGIT)were lowly expressed in DLBCL tumor tissues and not expressed in paraneoplastic tissues,PDL-1(ligand of PD1)was highly expressed in DLBCL tumor tissues and low in paraneoplastic tissues;high expression of CXCR5+,TIGIT+ and PD1+γδ T cell subsets were prognostic risk factors for DLBCL patients.These results suggest that CXCR5+,TIGIT+ and PD1+ γδ T cell subsets may be related to the occurrence,development and prognosis of DLBCL.Intervening the expression of chemokine receptor CXCR5 and immunosuppressive factors TIGIT and PD1 in γδ T cells may be able to improve the killing function of γδ T cells to a certain extent and provide a more desirable alternative for specific anti-refractory relapsed DLBCL.Immunotherapy for refractory DLBCL provides a new and more desirable strategy.