Antibody-dependent cellular cytotoxicity and chemiluminescence as a tool for studying the mechanism of anti-glomerular basement membrane nephritis. The role of the cytotoxic potential of polymorphonuclear granulocytes and monocytes.

An in vitro system was elaborated to study the mechanisms inducing tissue injury in anti-glomerular basement membrane (GBM) nephritis. Collagenase-digested GBM (CGBM) was covalently attached to Fab' specific for chicken red blood cells (CRBC). The preparation of the CGBM-Fab' conjugate was effected by using iodoacetyl chloride coupling in analogy to a procedure described by Chiang & Koshland (1979). This conjugate was used for coating CRBC (CGBM-CRBC). In this system the antibody-dependent cellular cytotoxicity (ADCC) and the chemiluminescence mediated by purified bovine polymorphonuclear (PMN) and mononuclear cells (MNC) as well as rabbit MNC against CGBM-CRBC were compared in the presence of sheep anti-GBM IgG. All three cell populations were potent effectors in ADCC and chemiluminescence and evidence was obtained that the cytotoxic potential of MNC has to be attributed to monocytes. If compared at low effector target cell ratios in a 2 hr assay bovine PMN, however, were significantly more efficient than bovine MNC. The extent of both ADCC and chemiluminescence was directly related to the amount of anti-GBM IgG present in the system. Based on the inhibition experiments with oxygen intermediate scavengers, both ADCC and chemiluminescence by bovine PMN is dependent on generation of reactive oxygen species indicating that such radicals could play a role in vascular (endothelial) injury as documented in the loss of structural integrity of GBM.