Blocking by anti-idiotypic antibodies of monoclonal antibody mediated protection in mice against encephalomyocarditis virus induced diabetes and lethal disease

Detection of a shared idiotope on two encephalomyocarditis virus neutralizing monoclonal antibodies by neutralization inhibition enzyme immunoassay

Idiotypic cross-reactivity between encephalomyocarditis virus (EMCV) neutralizing monoclonal antibodies UM 21.1 (IgG2b) and UM 21.3 (IgG2a) was detected by neutralization inhibition enzyme immunoassay using polyclonal and monoclonal anti-idiotypic antibodies. One strongly cross-reactive anti-idiotypic monoclonal antibody, designated 21.1A5 (IgG2b), might recognize a recurrent idiotope on EMCV neutralizing antibodies but it did not induce EMCV neutralizing anti-anti-idiotypic antibodies in homologous BALB/c mice.

Detection by a solid phase independent enzyme immunoassay of monoclonal anti-idiotypic antibodies against monoclonal antibodies neutralizing Semliki Forest virus and encephalomyocarditis virus

Neutralization inhibition enzyme immunoassay (NI-EIA) was evaluated for its usefulness to detect monoclonal anti-idiotypic antibodies (ab2mAbs) against idiotypic monoclonal antibodies (ab1mAbs) neutralizing either Semliki Forest virus (SFV) or encephalomyocarditis virus (EMCV). Purified ab1mAbs were coupled to keyhole limpet hemocyanin (KLH) mixed with the adjuvant Quil A and then injected intracutaneously into homologous BALB/c mice. Successful fusions were performed 5, 6 and 7 days after intracutaneous booster immunizations of these mice. Ab2mAbs in hybridoma supernatant fluids were detected by their capacity to block virus neutralization by ab1mAbs in NI-EIA. Two stable ab2mAb producing hybridomas were obtained against SFV neutralizing mAb UM 1.13, and twelve against EMCV neutralizing mAb UM 21.1.

Comparison between direct binding, competition and agglutination assays in the characterization of polyclonal anti-idiotypes against anti-HBs human monoclonal antibodies

Polyclonal anti-idiotypic antibodies to human monoclonal anti-HBs antibodies (MoAb1) were raised in rabbits and designated Ab2-H1 and Ab2-H2. These Ab2 were characterized using three assays. A direct binding ELISA evaluated specificity towards a panel of human monoclonal antibodies and gamma globulins. Competition radioimmunoassay (CRIA) revealed Ab2 specificities towards Ab1 antigen binding sites by inhibition of HBsAg/Ab1 binding. Ab2-H1 and Ab2-H2 had comparable reactivities in ELISA and CRIA, whereas, using affinity purified Ab2, a fast (10 min) agglutination test (Spherotest) revealed different Ab1/Ab2 binding properties. Ab2-H1 reacted in this Spherotest with the Ab1 against which it was known to be specific (Ab1-H1), whereas in the same assay Ab2-H2 showed no activity towards the variable regions of the Ab1 used for its production (Ab1-H2). When injected into rabbits Ab2-H1 induced anti-HBs Ab3 antibodies but Ab2-H2 did not, thereby confirming the assay results.