title: The induction and expression of IgA anti-DNP antibodies in rat bile and secretions.
abstract: Pregnant rats were immunized with dinitrophenylated type III-pneumococcal vaccine by the intravenous, gastric, or intramammary routes. Anti-DNP antibody responses in the IgA, IgG and IgM isotypes were measured in serum, secretions and bile. Gastric intubation was most effective at eliciting IgA antibody responses in bile and secretions, whereas the other routes were more effective at inducing IgG responses in serum and bile. IgM antibody responses were infrequent and were found in fluids most closely associated with the immunization route. Isoelectric focusing studies of IgA antibodies appearing in secretions and bile revealed that the gastric route consistently elicited antibody spectrotypes with shared components. Intravenous and intramammary immunization resulted in IgA spectrotypes possessing less homology, suggesting that these protocols lead to independent antibody responses triggered in spleen, draining lymph nodes, or secretory sites. After gastric stimulation, the appearance of IgA antibodies with identical spectral components in secretions and bile favours the concept that IgA precursor cells with identical clonotype potential migrate from the gastrointestinal area to secretory sites. Antibody expression in bile appears to result from the selective transfer of IgA populations gaining access to serum after synthesis at a secretory site.
mesh_terms: D000818:Animals; D001646:Bile / Q000276:immunology*; D001826:Body Fluids / Q000276:immunology; D004140:Dinitrophenols / Q000276:immunology*; D005260:Female; D007114:Immunization; D007070:Immunoglobulin A / Q000096:biosynthesis*; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D007525:Isoelectric Focusing; D011247:Pregnancy; D011270:Pregnancy, Animal; D011863:Radioimmunoassay; D051381:Rats
chemical_list: D004140:Dinitrophenols; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M