Cross talk between NKT and regulatory T cells (Tregs) in prostatic tissue of patients with benign prostatic hyperplasia and prostate cancer

Regulatory T cells (Tregs) and NKT cells are two subpopulations of T lymphocytes that independently regulate innate and adaptive immunity, but there is some evidence for cross-talk between Tregs and NKT cells, which allow a new immunoregulatory networks. Activated NKT cells may modulate quantitatively and qualitatively the function of Tregs through IL-2-dependent mechanisms, while Tregs can suppress the proliferation, cytokine release and cytotoxic activity of NKT cells by cell-contact-dependent mechanisms. Tregs may control tumor expansion at the priming, as well as the effector’s phase of T immune responses. Tumor cells provide antigenic stimulation of T cells and interact with the tumor-infiltrated innate immune cells secreting cytokines that are crucial for T-cell differentiation. In this study we examined the prostate tissue infiltrating lymphocytes of patients with prostate cancer (PCa) and benign prostatic hyperplasia (BPH) by flow cytometric technique (FACSCalibur) for determine the number of T, B, NK, NKT and Tregs and investigate the local regulatory immunosurveillance which allows the tumor’s immuneescape. Our results have shown the statistically significantly elevated number of Tregs in prostatic tissue and slightly diminished percentage of NKT cells in prostate cancer patients in comparison to patients with benign prostatic hyperplasia. Although the exact mechanism is still unknown, increased infiltration of prostate tissue with T regulatory cells seems that stimulate the tumor to secrete factors (chemokines) that attract these cells in the tissue of the prostate where they achieve their anti-tumor effect and thus may contribute the tumor progression.