TH9 cells are required for tissue mast cell accumulation during XXXX .

@entity32 @entity42315 @entity55 @entity19 @entity61 @entity56 @entity5350 @entity1312
BACKGROUND: @entity42315 is important for the growth and survival of mast cells. @entity42315 is produced by T cells, natural killer T cells, mast cells, eosinophils, and innate lymphoid cells, although the cells required for mast cell accumulation during @entity32 remain undefined. OBJECTIVE: We sought to elucidate the role of TH9 cells in promoting mast cell accumulation in models of @entity55 . METHODS: Adoptive transfer of ovalbumin-specific @entity61 and TH9 cells was used to assess the ability of each subset to mediate mast cell accumulation in tissues. Mast cell accumulation was assessed in wild-type @entity19 and @entity19 with PU.1-deficient T cells subjected to acute and chronic models of @entity32 . RESULTS: Adoptive transfer experiments demonstrated that recipients of TH9 cells had significantly higher mast cell accumulation and expression of mast cell proteases compared with control or @entity61 recipients. Mast cell accumulation was dependent on @entity42315 , but not @entity1312 , a cytokine required for many aspects of @entity32 . In models of @entity56 , decreased @entity42315 levels in @entity19 with PU.1-deficient T cells corresponded to diminished tissue mast cell numbers and expression of mast cell proteases. @entity19 with PU.1-deficient T cells have defects in @entity42315 production from CD4(+) T cells, but not natural killer T cells or innate lymphoid cells, suggesting a TH cell-dependent phenotype. @entity5350 (-/-) @entity19 subjected to a chronic model of @entity32 displayed reduced mast cell infiltration comparable with accumulation in @entity19 with PU.1-deficient T cells, emphasizing the importance of @entity42315 produced by T cells in mast cell recruitment. CONCLUSION: TH9 cells are a major source of @entity42315 in models of @entity32 and play an important role in mast cell accumulation and activation.
