Evaluation of sequential glomerular eluates from rats with Heymann nephritis.
This study was undertaken to characterize the antigen-antibody content of sequential glomerular eluates from rats with Heymann nephritis. Serum and renal tissue were harvested every 2 wk after immunization with renal tubular antigen (Fx1A). Circulating antibody to the tubular antigen was detectable in the circulation from days 7 to 98. Direct immunofluorescence of renal tissue demonstrated an increase in IgG deposits through day 49 with stabilization thereafter. Tubular antigen deposits peaked at day 49 and then declined. One-hour and 3-hr acid eluates of isolated glomeruli were analyzed for IgG content, antibody specificity, and antigen content. Antibody from the 1-hr eluate bound to the tubular brush border but not the glomerulus, whereas the 3-hr eluate demonstrated binding to the glomerulus and not to the tubular brush border. In addition to rat IgG, the 1-hr eluate demonstrated a 70 kD band and the 3-hr eluate demonstrated a 45 kD band by polyacrylamide gel electrophoresis. By Western blot, antibody to the brush border bound to the 70 kD band. Anti-idiotypic antibody to anti-Fx1A, which binds to the glomerulus by indirect immunofluorescence, bound to the 45 kD band. The 3-hr eluate, but not the 1-hr eluate, precipitates radiolabeled F(ab')2 fragments from anti-Fx1A antibody but not from normal rat IgG. Quantitative analysis of the sequential eluates demonstrated that the 70 kD-anti-Fx1A system predominated early in the course of disease, whereas the 45 kD-anti-idiotype antigen-antibody system predominated late in the course of the disease. These observations confirm that two antigen-antibody systems contribute to the immune deposits in Heymann nephritis.
D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000032:analysis; D000936:Antigen-Antibody Complex / Q000032:analysis* / Q000378:metabolism; D001666:Binding Sites, Antibody; D004591:Electrophoresis, Polyacrylamide Gel; D005921:Glomerulonephritis / Q000209:etiology / Q000276:immunology*; D007074:Immunoglobulin G / Q000378:metabolism; D007130:Immunoglobulin Idiotypes / Q000276:immunology; D007678:Kidney Glomerulus / Q000276:immunology*; D008297:Male; D011507:Proteinuria / Q000276:immunology; D051381:Rats; D011917:Rats, Inbred Lew
D000888:Antibodies, Anti-Idiotypic; D000936:Antigen-Antibody Complex; D007074:Immunoglobulin G; D007130:Immunoglobulin Idiotypes