engleski

Experimental F4AC+ Escherichia Coli Vaccine Increases Numbers of Small Intestinal Immune Cell Subsets

The aim of this study was to test the effectiveness of a live attenuated mucosal vaccine against porcine post-weaning colibacillosis (PWC) by analyzing quantitative differences in the small intestinal leukocyte subsets of immunized vs control nonimmunized pigs. Four week old pigs were intragastrically vaccinated with a vaccine candidate F4ac+ nonenterotoxigenic E. coli (non-ETEC) strain 2407 at day 0, challenged with a virulent ETEC strain 11-800/1/94 7 days later, euthanatized at day 13 and sampled for immunohistology. Nonvaccinated pigs received saline at day 0 and were processed as the principals. Within jejunal/ileal lamina propria immunophenotypes of lymphoid cell subsets were demonstrated by immunohistochemical ABC method and corresponding morphometric data were analyzed using software program Lucia G for digital image analyses (DIA). The mAbs reactive with surface molecules on porcine immune cells such as CD3, CD21, CD45RA, CD45RC, SWC3, and IgA enabled clear insight into distribution and proportion of T/B lymphocytes, dendritic and plasma cells within the gut-associated lymphoid tissues (GALT) compartments examined. Vaccinated pigs had highly increased numbers of all immune cells tested as compared to those recorded in the nonvaccinated pigs. Based on DIA analyses the intestinal immune response of pigs induced by an experimental mucosal vaccine, i. e. PWC, may be undoubtedly differentiated from that found in the respective mucosal sites of GALT in nonimmunized pigs.

mucosal immunity; weaned pigs

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