The percentage of iNKT cells among other immune cells at various clinical stages of laryngeal cancer.

Abstract

Invariant natural killer T (iNKT) cells constitute a small population of immune cells that share functional and phenotypic characteristics of T lymphocytes and NK cells. Due to their involvement in specific and non-specific immune responses, iNKT cells may represent an important component of antitumor and anti-infectious immunity. Using flow cytometry, we analyzed the percentages of iNKT cells as well as T and B lymphocytes in peripheral blood of 50 laryngeal cancer patients at various clinical stages in comparison to healthy controls (n=15). Moreover, we determined the expression of CD25, CD69 and CD95 antigens on T lymphocytes. The percentage of CD4+/CD3+ T lymphocytes in the controls was higher than in laryngeal cancer patients, both with early and late stages of the disease. The percentage of CD8+/CD3+ T lymphocytes in healthy controls was lower than in patients with early and late clinical stages of laryngeal cancer. Patients with advanced laryngeal cancer showed a lower percentage of iNKT cells and higher frequencies of T regulatory cells (Tregs) than the controls. Advanced clinical stages of laryngeal cancer are associated with impaired activation of lymphocytes. Our study confirmed that laryngeal cancer cells exert a strong suppressor effect on the immune system of the host. This is reflected by a decrease in the percentage of iNKT cells that are capable of cancer cell elimination, and a concomitant increase in the percentage of Tregs. However, further studies are needed in order to explain the underlying mechanisms of immunosuppression and understand interactions between immune and cancer cells.