Abstract
Severe protein deficiency at weaning even after re-feeding on a 20% casein diet for 21 days, provokes alterations in IgA+ B and T cell populations from gut and GALT (gut-associated lymphoid tissue) that are reverted by immunomodulator IM-104 (Inmunol. 12:59-63, 1993). We investigated the influence of RN-301 (quite similar to IM-104) given by the oral route in the seeding of BALT with IgA+ B and T cells. Weaning Wistar rats were fed a protein free diet (PFD) together with RN-301 in the drinking water and refed a 20% casein diet for 21 days (RN-R21). Controls received: (1) PFD and the same casein diet (R21), (2) commercial laboratory diet (C). RN-301 contains LPS from Escherichia coliand membranous and ribosomal fractions of Propionibacterium acne(NEOMAR SRL). The number of IgA B cells was significantly diminished in the protein refed rats when compared to the control (C vs. R21, p < 0.01). When RN-301 was orally administered during the protein deprivation period the number of IgA B cells attained control values and was significantly different from the R21 group (RN-R21 vs. R21, p < 0.001). The T cell population followed the same pattern (C vs. R21, p < 0.001 and RN-R21 vs. R21, p < 0.001). The oral treatment with RN-301 during the protein deprivation period allowed a recovery from the immunodeficient state. This finding may be due to the LPS contained in the RN-301 that is capable to rescue and stimulate the IgA B cells left in the BALT lamina propria during and after protein deprivation at weaning.