Intestinal intraepithelial lymphocytes are activated and cytolytic but do not proliferate as well as other T cells in response to mitogenic signals.

摘要: Compared with T lymphocytes from other organs, intestinal intraepithelial (IEL) proliferate weakly in response to CD3/TCR ligation, and they do not respond at all treatment mitogenic stimuli. These signals also failed induce expression of the IL-2R alpha-chain on surface most IEL. IEL germ-free mice, V gamma 1.1-transgenic beta 2-microglobulin-deficient mice gave a weak proliferative response. Therefore, low is linked level exposure gut bacterial flora, region expressed by TCR-gamma delta + IEL, or presence class I molecules that may be recognized CD8+ The relatively small amount proliferation TCR signaling, therefore, likely result induction anergy caused previous contact Ag. In contrast, ligation complex could elicit rapid cytotoxic serine esterase release unusual functional capabilities activation state are independent isotype these cells. Freshly isolated have high intracellular microtubule-associated protein kinase-2 (MAP-2K) activity level, further suggesting cells activated despite their Consistent this, MAP-2K tyrosine-phosphorylated both untreated PMA-treated tyrosine phosphorylation occur only when PMA treatments. elevated demonstrating does depend normal levels flora. kinases such as reflect differentiation Ag receptor stimulation some epithelial preparation.