Submitted to: American Society of Parasitologists
Publication Type: Abstract Only
Publication Acceptance Date: July 2, 1998
Publication Date: N/A
Intestinal immune responses to enteric pathogens that lead to protective immunity involve the complex interplay of soluble factors, leukocytes, epithelial cells, endothelial cells, and other physiological factors of the gut-associated lymphoid tissues (GALT). Different effector mechanisms may be involved depending on the type of enteric pathogens and on whether a primary or secondary response is occurring. It is likely that these complex interactions have contributed to the difficulties in developing an effective vaccine against enteric pathogens. In contrast to mammals, limited information is available concerning the intestinal immune system of chickens. In chickens, the GALT include organized lymphoid structures such as the bursa of Fabricius, cecal tonsils (CT), Peyer's patches (PP), Meckel's diverticulum and lymphocyte aggregates scattered along the intraepithelium and LP of the gastrointestinal tract. The composition of various T cell subpopulations in the intestine depended upon host age, the regions of the gut examined and host genetic background. Various growth stimulatory and growth inhibitory autocrine growth factors are potential modulators of intestinal epithelial cell growth and local immune responses.