Glomerular capillary wall charge and antibody binding in passive Heymann nephritis.
The interaction between nephritogenic antibodies and antigens in the glomerular capillary wall is influenced by physicochemical determinants such as the electrical charge. We studied the effect of neutralization of a negative glomerular capillary wall (GCW) charge by polyethyleneimine (PEI) on the binding of anti-renal tubular epithelium (RTE) IgG in passive Heymann nephritis. For these studies, glomerular binding of intravenously administered radiolabeled anti-RTE IgG was determined in Wistar rats preinjected 30 minutes earlier with either 0.2 ml 0.05% PEI (molecular weight 40,000 kd) or 0.2 ml saline solution; control rats received 0.025 mg radiolabeled nonimmune rabbit IgG (NRIgG) after PEl or saline solution. Glomerulus-bound antibody was measured in saline solution-perfused isolated glomeruli 1 hour after this injection. Intravenously administered radiolabeled anti-RTE IgG binding was found to be significantly increased in rats pretreated with PEI compared with those given saline solution. Intravenously administered radiolabeled NRIgG with or without pretreatment with PEl did not bind to the GCW. Administration of PEl had no effect on blood pressure, glomerular filtration rate, or renal plasma flow during antibody administration, which means that hemodynamic changes could not have been responsible for the observed differences in antibody binding. We conclude that binding of PEI to the GCW enhances fixation of anti-RTE IgG, probably because of neutralization of charged sites of the GCW leading to greater accessibility of intrinsic antigens present in the GCW to anti-RTE antibody.
Hogendoorn
P C
PC
Department of Pathology, University of Leiden, The Netherlands.
de Heer
E
E
Weening
J J
JJ
Daha
M R
MR
Hoedemaeker
P J
PJ
Fleuren
G J
GJ
D000818:Animals; D001485:Basement Membrane / Q000276:immunology / Q000473:pathology; D006439:Hemodynamics; D007074:Immunoglobulin G / Q000032:analysis; D007678:Kidney Glomerulus / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D008297:Male; D009393:Nephritis / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D011094:Polyethyleneimine / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D007074:Immunoglobulin G; D011094:Polyethyleneimine