The Phenotype Of Tumor Infiltrating T Cells And The Expression Of PD1,PD-L1 In Prostate Cancer

Objective To explore the characteristics of the prostate cancer tumor immune microenvironment,the study analyzed the phenotype of tumor infiltrating T cells and the expression level of PD1,PD-L1 protein in the tissue of prostate cancer,then aimed to guide the development of immunotherapy.Methods Patients who were pathologically diagnosed as T2-T4 prostate cancer were included in this study.The tissue specimens of prostate cancer patients were collected after operation,and then tissue specimens were embedded in paraffin and were made into tissue sections.Tumor infiltrating T cells and PD1,PD-L1,CK protein in prostate tissue were performed Immunofluorescent staining using Immunohistochemistry and multiplexed immunofluorescent staining which was based on tyramine signal amplification(TSA)technology.The positioning and quantitation of tumor infiltrating T cells subsets and PD1,PD-L1,CK protein were analyzed by multi-spectral imaging system.Results T lymphocytes subsets are mainly located in the interstitial tissue of prostate,but they rarely distribute in the glandular tissue.The distribution of CD4+T cells and CD8+T cells in the adjacent stroma is clearly more than that of the tumor stroma,but the distribution of Foxp3+T cells is not significantly different between the tumor and adjacent stroma.As the tumor progresses,the number of CD4+T cells and CD8+T cells in the adjacent stroma gradually decreases while the number of Foxp3+T cells does not change clearly,and the number of the above cells in the tumor stroma does not change clearly.The level of PD1 protein in the adjacent tissue is significantly more than that in the tumor tissue,while the level of PD-L1 protein is on the contrary.As the tumor progresses,the level of PD1 protein increases in the adjacent tissue,while PD-L1 protein increases in the tumor tissue.Conclusion The overall characterization of the tumor immune microenvironment of prostate tissue is achieved by multiplexed immunofluorescent staining and multi-spectral imaging technique,revealing that the tumor microenvironment of prostate cancer is in the state of immune suppression.The distribution of tumor infiltrated T cells and the expression level of PD1 and PD-L1 protein is heterogeneous in both space and stage,and prostate cancer requires individualized immunotherapy.