title: Immunoglobulin A response of the bovine fetus and neonate to Escherichia coli.
abstract: The chronologic appearance of immunoglobulin (Ig) A-containing plasma cells and their distribution and numbers in the intestinal tract, spleen, and mesenteric lymph nodes were determined in beef calves inoculated in utero with Escherichia coli O26-K60:NM bacterin or with saline solution. Secondary responses were assessed by oral revaccination or by challenge exposure to live E coli. Specific immunofluorescent procedures were used to count IgA-containing plasma cells. Appreciable numbers of IgA-containing plasma cells were seen in in utero-vaccinated calves at birth. Oral vaccination or challenge exposure with E coli increased the number of plasma cells. The caudal part of the jejunum and the ileum and related lymph nodes had more IgA-containing cells than any of the other tissues examined. In revaccinated and challenge exposed calves, the spleen was especially active in the formation of IgA-containing plasma cells. The results indicate that the entire small intestine, the draining lymph nodes, and the spleen were involved in IgA formation in these young calves. Age as a factor in IgA production was seen in the control calves which had no indication of IgA-containing cells before 9 days of age. None of the in utero-vaccinated calves at birth or at necropsy had evidence of IgA in serum.
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000276:immunology*; D002417:Cattle / Q000276:immunology*; D004926:Escherichia coli / Q000276:immunology*; D005333:Fetus / Q000276:immunology*; D005455:Fluorescent Antibody Technique; D007082:Ileum / Q000276:immunology; D007070:Immunoglobulin A / Q000032:analysis*; D008198:Lymph Nodes / Q000276:immunology; D010950:Plasma Cells / Q000276:immunology; D013154:Spleen / Q000276:immunology*; D014611:Vaccination / Q000662:veterinary
chemical_list: D007070:Immunoglobulin A