γδ T cell homeostasis is established in competition with αβ T cells and NK cells

Abstract

γδ T cells are a diverse population of lymphocytes that play an important role in immune regulation. The size of the γδ T cell pool is tightly regulated, comprising only 1-10% of total lymphoid T cells in mice and humans. We examined the homeostatic regulation of γδ T cells using a model of lymphopenia-induced homeostatic expansion. We found that IL-15 and, to a lesser extent, IL-7 play an important role in lymphoid γδ T cell homeostasis. Moreover, γδ T cell homeostatic expansion was limited not only by γδ T cells themselves but also by natural killer cells and αβ T cells. Our results suggest that CD8⁺ αβ T cells are the most potent inhibitors of γδ T cell homeostasis and exert their effect by competing for IL-15.

• CD4 T cells
• CD8 T cells
• homeostatic proliferation