Cell-mediated immunity in interstitial nephritis. IV. Anti-tubular basement membrane antibodies can function in antibody-dependent cellular cytotoxicity reactions: Observations on a nephritogenic effector mechanism acting as an informational bridge between the humoral and cellular immune response

Anti-tubular basement membrane antibodies (αTBMA) were tested in vitro in an antibody-dependent cellular cytotoxicity (ADCC) reaction utilizing tubular antigen-coated targets. A selected subpopulation of normal guinea pig spleen cells induced significantly more target cell lysis in the presence of sera containing αTBMA than in the presence of control sera. This ADCC reaction using αTBMA exhibited a characteristic dose responsiveness and the αTBMA binding was specific for species-independent tubular antigens. The spleen effector cells used in this assay were characterized as nonadherent, non-T cells bearing Fc-receptors similar to other previously described natural killer cells found in guinea pigs. These studies suggest that natural surveillance systems may be able to use αTBMA as an informational bridge to tubular antigens. Such a potential nephritogenic effector mechanism has not been previously described.