Detection of pregnancy associated alpha 2-glycoprotein (alpha 2-PAG), an immunosuppressive agent, in IgA producing plasma cells and in body secretions.
Using a combined indirect immunoperoxidase (PAP)/direct immunofluorescence (IF) staining technique, pregnancy associated alpha 2-glycoprotein (alpha 2-PAG) has been shown to be present solely in the IgA producing plasma cells. alpha 2-PAG was undetectable in plasma cells synthesizing any of the other immunoglobulin isotypes (IgG, IgM, IgD and IgE). Furthermore, we have observed increased numbers of alpha 2-PAG positive cells in sites recognized for their local IgA production e.g. lactating breast, salivary gland, respiratory and gastrointestinal mucosae. In support of this cellular association with IgA, alpha 2-PAG was measured by enzyme immunoassay in colostrum, breast milk, saliva, jejunal secretions, bile and urine. The relevance of this novel and preferential association of immunosuppressive alpha 2-PAG with IgA is discussed with regard to the regulation of gut immunoresponsiveness.
D000328:Adult; D000368:Aged; D001646:Bile / Q000032:analysis; D001826:Body Fluids / Q000032:analysis*; D003126:Colostrum / Q000032:analysis; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D007124:Immunoenzyme Techniques; D007070:Immunoglobulin A / Q000096:biosynthesis*; D007419:Intestinal Secretions / Q000032:analysis; D008875:Middle Aged; D008895:Milk, Human / Q000032:analysis; D010950:Plasma Cells / Q000032:analysis* / Q000276:immunology; D011257:Pregnancy Proteins / Q000032:analysis*; D012463:Saliva / Q000032:analysis
D007070:Immunoglobulin A; D011257:Pregnancy Proteins