ABSTRACT
PURPOSE: Adenoid cystic carcinoma (ACC) of the head and neck is a rare and highly malignant tumor, characterized by perineural growth and early distant metastases. The composition of immune cells in the peripheral blood and the tumor microenvironment is critical to tumor growth and control. However, little is known about the frequency and function of the relevant immune cell subsets in this entity. METHODS: In ACC patients (n = 11) and matched healthy donors (n = 11), the frequency of peripheral blood T and B cells was measured by flow cytometry at different treatment stages of disease (24 samples). Cells were further characterized by their expression of CCR7, PD-1, CD39 and CD73. Tumor-infiltrating lymphocytes (TIL) were analyzed by immunohistochemistry for ten patients and for three patients by flow cytometry. RESULTS: CD4+ T cells had significantly lower frequency after radiotherapy (RT). All other cell frequencies, including Treg, were stable through course of the disease. In B cells, CD73 was reduced after RT. CCR7 expression on T and B cells in patients with relapse/metastases (R/M) differed significantly from patients with active disease. PD-1 remained stable. Treg were more present in TIL compared to peripheral blood. CONCLUSION: Composition of lymphocyte subgroups behaves similar to squamous cell carcinoma in the head and neck, except for Treg, which remained stable. Nevertheless, the CD4+/Treg ratio was lower after RT, which could stand for an immunosuppressive effect in these patients. Therefore, it could be beneficial treating ACC with combined RT and immunomodulatory drugs.
Subject(s)
B-Lymphocytes/metabolism , Biomarkers, Tumor/blood , Carcinoma, Adenoid Cystic/immunology , Head and Neck Neoplasms/immunology , T-Lymphocytes/metabolism , Adult , Aged , Biomarkers, Tumor/immunology , Carcinoma, Adenoid Cystic/blood , Carcinoma, Adenoid Cystic/pathology , Case-Control Studies , Female , Flow Cytometry , Head and Neck Neoplasms/blood , Head and Neck Neoplasms/pathology , Humans , Lymphocyte Count , Lymphocytes, Tumor-Infiltrating/metabolism , Male , Middle Aged , Neoplasm Recurrence, Local , Neoplasm Staging , Tumor MicroenvironmentABSTRACT
BACKGROUND: For head and neck squamous cell cancer (HNSCC), standard therapy consists of surgery, radiation, and/or chemotherapy. Antineoplastic immunotherapy could be an option in an adjuvant setting and is already in palliation. A functional immune system is a prerequisite for successful immunotherapy. However, effects of the standard-of-care therapy on the patients' immune system are not fully understood. METHODS: Peripheral blood mononuclear cells (PBMC) were collected from patients with HNSCC (nâ¯= 37) and healthy controls (nâ¯= 10). PBMC were stimulated with staphylococcal enterotoxin B (SEB). Simultaneous expression of various cytokines was measured in CD4+ and CD8+ T cells by multicolor flow cytometry, and polyfunctional cytokine expression profiles were determined on a single-cell basis. RESULTS: Expression levels of all measured cytokines in CD4+ T cells were higher in patients after chemoradiotherapy (CRT) as compared to untreated HNSCC patients or normal controls. After CRT, the frequency of polyfunctional CD4+ T cells, which simultaneously expressed multiple cytokines, was significantly increased as compared to untreated patients (pâ¯< 0.01). CONCLUSION: CRT increases polyfunctionality of CD4+ T cells in HNSCC patients, suggesting that standard-of-care therapy can promote immune activity in immune cells. These polyfunctional CD4+ T cells in the blood of treated HNSCC patients are expected to be responsive to subsequent immunotherapeutic approaches.
