Absolute counts and distribution of lymphocyte subsets in small intestine of BALB/c XXXX change during weaning.

@entity1 @entity8236 @entity3415 @entity19 @entity5168 @entity1961 @entity3414 @entity37996
The gut immune system is an essential part of the barrier function of the gut. At weaning, major changes can be expected in the number and subset composition of lymphocytes in the small intestine since the gut is exposed to a wide variety of food and microbial antigens, especially when @entity1 milk is gradually replaced by weaning foods. The purpose of this study was to evaluate the changes in small intestine lymphocyte subsets in @entity19 during weaning. BALB/c male @entity19 at weaning (3 wk old) were fed a nonpurified diet for 18 d and were killed at different times (0, 4, 7, 12 and 18 d). Lymphocyte populations from lamina propria (LPL), Peyer's patches (PPL) and intestinal epithelium (IEL) were isolated. The expression of different antigens ( @entity5168 , @entity1961 , @entity3414 , @entity3415 , @entity37996 and @entity8236 ) in those lymphocyte populations was analyzed by flow cytometry. The percentages of cells expressing T-cell antigens, such as @entity5168 , were significantly higher in LPL during weaning compared to d 0. The percentages of cells expressing @entity3414 and @entity3415 increased in both IEL and LPL. However, the percentage of @entity1961 + cells tended (P = 0.07) to decrease in IEL and to increase in LPL. The percentages of cells expressing B-cell antigens, such as @entity37996 or @entity8236 R in PPL increased. Changes in the specific phenotypes of intestinal lymphocyte populations at weaning are apparently related to the maturation of the intestinal immune system during early life. Thus, B cells increase in PPL and T cell increase in IEL and LPL.
