title: The influence of exogenous antigenic stimulation on the specificity repertoire of background immunoglobulin-secreting cells of different isotypes.
abstract: The total number of spontaneously occurring ("background") IgM-, IgG-, and IgA-secreting cells and the frequency of antigen-specific IgM-, IgG-, and IgA-secreting cells were determined in germ-free BALB/c mice fed a chemically defined ultrafiltered diet (GF-CD), in specific pathogen-free BALB/c mice fed an autoclaved natural ingredient diet (SPF-NI), and in conventional BALB/c mice fed nonautoclaved natural ingredients (CV-NI). This was done by means of the ELISA-plaque assay. The results did not show differences among the various groups of mice with regard to the total numbers of IgM-secreting cells in the various lymphoid organs. Also the frequencies of IgM-secreting cells specific for DNP27-BSA and the anti-idiotypic monoclonal antibodies Ac38 and Ac146 did not differ significantly among GF-CD, SPF-NI, and CV-NI mice. GF-CD mice, however, did show substantially decreased numbers of IgG- and IgA-secreting cells in their lymphoid organs. Furthermore, there were striking differences in the frequencies of antigen-specific IgG- and IgA-secreting cells between GF-CD mice and the two other groups of mice. These results indicate that exogenous antigenic stimulation has a great effect on both the total numbers and the specificity repertoires of background IgG- and IgA-secreting cells. Such an influence could not be detected with regard to the background IgM-secreting cells. This suggests two distinct compartments of background Ig-secreting cells: a very stable, endogenously regulated compartment consisting mainly of IgM-secreting cells, and another compartment, consisting mainly of IgG- and IgA-secreting cells, whose numbers and specificity repertoire appeared to be influenced by exogenous antigenic stimulation.
mesh_terms: D000818:Animals; D000921:Antibody-Producing Cells / Q000145:classification* / Q000276:immunology / Q000378:metabolism; D004140:Dinitrophenols / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology*; D005260:Female; D006241:Haptens / Q000276:immunology; D006462:Hemolytic Plaque Technique; D007130:Immunoglobulin Idiotypes / Q000276:immunology; D007132:Immunoglobulin Isotypes / Q000096:biosynthesis*; D008221:Lymphoid Tissue / Q000166:cytology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D012710:Serum Albumin, Bovine / Q000276:immunology; D013205:Staphylococcal Protein A
chemical_list: D004140:Dinitrophenols; D000939:Epitopes; D006241:Haptens; D007130:Immunoglobulin Idiotypes; D007132:Immunoglobulin Isotypes; D013205:Staphylococcal Protein A; C034638:dinitrophenyl-bovine serum albumin; D012710:Serum Albumin, Bovine