Interleukin‐15 preferentially promotes the growth of intestinal intraepithelial lymphocytes bearing γδ T cell receptor in mice

摘要

AbstractSeveral cytokines including stem cell factor (SCF) and interleukin (IL)‐7 are known to be required for development of γδ T cell receptor (TCR) intestinal intraepithelial lymphocytes (i‐IEL) in mice. We show here the effects of IL‐15 on the proliferation and maintenance of murine γδ i‐IELin vitro. γδ i‐IEL constitutively expressed a high level of IL‐15 receptor α mRNA and proliferated in response to IL‐15 more vigorously than αβ i‐IEL. Vγ/δ repertoire analysis revealed that IL‐15, like IL‐2, induced polyclonal expansion of γδ i‐IEL, whereas γδ i‐IEL responding to IL‐7 showed a Vγ/δ repertoire skewed towards Vγ1/Vδ4, Vδ5. IL‐15 efficiently prevented γδ i‐IEL from apoptosis induced by growth factor deprivation. This rescue was accompanied by up‐regulation of Bcl‐2 expression. These results suggest that IL‐15 plays imp