title: Distribution and quantitation of plasma cells, T lymphocyte subsets, and B lymphocytes in bronchus-associated lymphoid tissue of chickens: age-related differences.
abstract: Development of the lymphoid cell compartment in bronchus-associated lymphoid tissue (BALT) of specific pathogen free chickens was examined. Specifically, B lymphocytes, T cell subsets (CD4 and CD8), and IgA-, IgG-, and IgM-producing plasma cells were labeled using immunocytochemical methods. Immunoglobulin-producing cells (IgPC) were quantitated, and comparisons of IgPC numbers were made among chickens of different ages, among immunoglobulin isotypes, and between lymphoid (BALT) and nonlymphoid (non-BALT) areas in the primary bronchus. At hatching, BALT was devoid of IgPC, but by 2 weeks of age cells producing IgA, IgG, and IgM were present. Initially, there were approximately equal numbers of IgA-, IgG-, and IgM-PC; after 2 weeks of age, however, IgG- and IgM-PC outnumbered IgA-PC. At all ages, IgPC were more numerous in non-BALT regions of the primary bronchus than in BALT regions. Small numbers of T and B lymphocytes were present in BALT from 1-day old chickens, but substantial populations of these cells were not seen until 1-2 weeks of age. T helper (CD4+) cells were found near B cell regions in BALT lymphoid nodules, while T cytotoxic/suppressor (CD8+) cells were more evenly distributed throughout the nodules and in the epithelium. B lymphocytes predominated in germinal centers and also overlapped CD4+ populations adjacent to germinal centers. Lymphocyte cell types needed to initiate and regulate immune responses are present in chicken BALT and may be involved in protecting poultry from respiratory pathogens.
authors.affiliation: Department of Veterinary Pathology, Iowa State University, Ames 50011.
authors.forename: J A
authors.initials: JA
authors.lastname: Fagerland
authors.forename: L H
authors.initials: LH
authors.lastname: Arp
mesh_terms: D000375:Aging / Q000276:immunology / Q000473:pathology; D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology; D001980:Bronchi / Q000166:cytology / Q000276:immunology*; D002645:Chickens / Q000033:anatomy & histology / Q000276:immunology*; D007136:Immunoglobulins / Q000096:biosynthesis; D008221:Lymphoid Tissue / Q000166:cytology* / Q000254:growth & development / Q000276:immunology*; D010950:Plasma Cells / Q000166:cytology / Q000276:immunology; D013047:Specific Pathogen-Free Organisms; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology
chemical_list: D007136:Immunoglobulins