The isolation of cross-reactive monoclonal antibodies: hybridomas to streptococcal antigens cross-reactive with mammalian basement membrane.

Based upon the assumption that post-streptococcal sequelae are the result of cross-reactive antibodies, hybridomas were prepared from the spleens of mice immunized with Group A type 12 streptococcal cell membranes (SCM) specifically to screen for such cross-reactive antibodies. One fusion produced a cell population displaying antibodies reactive to both SCM and glomerular basement membrane (GBM) antigens as demonstrated by ELISA technique. Ascites produced by this cell population also showed reactivity to lung basement membrane (LBM). Limiting dilution procedures have produced 15 monoclonal hybrids with both anti-SCM and anti-GBM activity. Confirmation of the cross-reactive and monoclonal nature of the antibody was accomplished by both direct and indirect competitive ELISA. These observations have established that unique cross-reactive antibody-secreting hybrid cells with reactivity to both SCM and basement membrane (BM) antigens can be isolated by standard cloning procedures.