Activated XXXX and a functional role for IL-12 in @entity1 Peyer's patches.

@entity1 @entity17754 @entity225 @entity1198 @entity10071 @entity379 @entity7116 @entity3646
T cells in the Peyer's patches (PP) of the @entity1 ileum are exposed to a myriad of dietary and bacterial Ags from the gut lumen. Recall proliferative responses to common dietary @entity17754 are readily demonstrable by PP T cells from healthy individuals, and the cytokine response is dominated by @entity379 . Consistent with @entity1198 skewing, PP cells spontaneously secrete IL-12p70, and IL-12p40 protein can be visualized underneath the PP dome epithelium. In this study, we have analyzed IL-12 signaling in PP and investigated whether IL-12 plays a functional role. CD3+ T lymphocytes isolated from PP and adjacent ileal mucosa spontaneously secrete @entity379 with negligible @entity3646 or @entity225 . RNA transcripts for IL-12Rbeta2, the signaling component of the IL-12R, are present in purified CD4+ and CD8+ T PP lymphocytes. Active @entity7116 , a transcription factor essential for IL-12-mediated @entity1198 differentiation, is readily detectable in biopsies from PP and ileal mucosa and @entity7116 -DNA binding activity is demonstrable by EMSA. Nuclear proteins from CD3+ T PP lymphocytes contain @entity7116 and @entity10071 , a transcription factor selectively expressed in @entity1198 cells. Stimulation of freshly isolated PP cells with staphylococcal enterotoxin B dramatically enhanced the production of @entity379 , an effect which was largely inhibited by neutralizing anti-IL-12 Ab. These data show that IL-12 in @entity1 PP is likely to be responsible for the @entity1198 -dominated cytokine response of the @entity1 mucosal immune system.
