Antigen detected by immunization of diseased glomeruli and by dispersion of the deposits in passive Heymann nephritis (PHN)

Investigation of antigens in immune-complexes deposited in glomeruli has been performed on elution study of the antibody or on application of FITC-labelled antibody corresponding to the antigen. In the present study described, detection of the antigen deposited in the glomeruli, using three kinds of experimental glomerulonphritis (GN) (PHN, CSS and MN) in rats were established by following two procedures. The first is an investigation of antibody activity in serum from the animal immunized with diseased glomeruli. The sera obtained from the rabbits immunized with the extract from glomeruli with PHN were performed indirect immunofluorescence on the kidney section of rats. The rabbit lgG was found to react with brushborder of the proximal tubules. The serum obtained from rabbit immunized with glomeruli of CSS was tested by Ouchterlony test against BSA. Single precipitation line was found to form between the immune serum and BSA.. The serum obtained from rat immunized with GBM of Masugi nephritis was also tested against rabbit IgG. Single precipitation line was found to form between the serum and rabbit IgG. The second is dissociation of IgG deposits or the associated antigen from glomeruli by applying excess of antigen on the frozen sections of these diseases. Although the BSA staining in glomeruli of CSS disappeared following incubation of excess amount of BSA, the IgG remained in the glomeruli, suggesting that binding site of IgG was not only on the BSA, but also on a different site in the glomeruli . The staining of rat IgG in the glomeruli from second phase of Masugi nephritis disappeared following incubation with rabbit IgG. In passive Heymann nephritis, rabbit IgG was not even abolished following inc ubation with Fx1A, suggesting that rabbit IgG may bind tightly with the antigen on the epithelial cells. These results indicate that the immunization procedure of the diseased glomeruli or the incubation of excess of antigen will become very usefull to detect an antigen in the glomeruli.