Characteristics of Tumor Infiltrating Lymphocytes in Patients with Benign and Malignant Sinonasal Neoplasms

Abstract

Introduction. Tumor infiltrating lymphocytes are a major component of sinonasal neoplasms, actively populating tumor tissue, yet their role remains poorly understood. The aim is to characterize subsets and functional profiles of tumor infiltrating lymphocytes in patients with benign and malignant sinonasal tumors. Materials and methods. Tumor infiltrating lymphocytes were isolated from the biopsy material of 58 patients: 18 with sinonasal malignancies, 23 with inverted papilloma and 17 with polypous rhinosinusitis (control group). Flow cytometry was used for tumor infiltrating lymphocytes immunophenotype estimation. The production of γ-interferon in tissue homogenates was measured by enzyme-linked immunosorbent assay kit. Further, statistical analysis was done using GraphPad Prism 8. Results and discussion. The microenvironment of sinonasal malignancies is characterized by increased CD3+T cells (p = 0.049) among tumor infiltrating lymphocytes as well as high levels of extracellular γ-interferon in tissue (p = 0.044). In this group, the decreased γ-interferon-positive CD3+T cells (p = 0.010) and CD56+CD16+NK cells (p = 0.027) were detected as compared to control group. In patients with benign and malignant sinonasal tumors, a significant elevation of regulatory T cells and increased cytotoxic T lymphocyte associated protein 4-positive CD3+T cells have been observed. Conclusions. The application of tissue resident regulatory T cells, cytotoxic T lymphocyte associated protein 4-, and CD16-positive CD3+TILs, as well as intracellular γ-interferon production may be considered as potential prognostic biomarkers for malignancy in sinonasal tumors and requires further investigation.