Survival Proteins Encourage Human T Helper 17 Cells to Escape from Cell Death

Abstract

IL-17 producing T helper 17 (Th17) cells are identified as a distinct subset of CD4+ T helper cells. They play a role in immune response. Abnormal regulation of Th17 cells can play a role in different type of pathologies such autoimmune diseases and cancer. The apoptotic and survival mechanisms of Th17 cells are not well known in different type of diseases. Therefore, the aim of the study was to investigate Bcl-2 family proteins to understand the regulation network of apoptosis in human Th17 cells. To do that, Peripheral blood (PB) were drawn from the healthy volunteers. Peripheral Blood Mononuclear Cells (PBMCs) were isolated from blood by Ficoll gradient isolation method. The naïve CD4+ T cells were isolated from PBMC. Sorted naive CD4+ T cells were cultured under Th17 polarizing conditions. Th17 cells were characterized by Flow cytometry. Cell lysates were obtained from negative controls and Th17 cells. Bcl-2 family members (Bik, BID and Puma) in Th17 cells were detected by western blot. Data showed that naive T cells were differentiated into Th17 cells. Then, cell lysate of this cells were used for western blot experiments. In the Th17 cell lysate, BH3 family members Bik and Puma were not detectable but Mcl-1 expression was increased. Overall data indicated that the pro-apoptotic BH3-only subgroup proteins Bik and Puma was not detectable, however anti-apoptotic Mcl-1 protein expression was increased.

Keywords

• Th17 cells
• Bik
• Puma
• survival