Production and Characterization of Mouse Monoclonal Antibodies Recognizing Human Pan-IgG Specific Conformational or Linear Epitopes

Background: pan-igg specific monoclonal antibodies (mabs) are essential tools for assessment of humoral immunity, immune deficiency and gam- mopathy. in this study, four hybridoma clones producing mabs with different specificities for human igg isotypes were established. methods: splenocytes from balb/c mice immunized with fc fractions of human igg were fused with sp2/0 myeloma cells. hybridoma cells were selected in hat selective medium and cloned by limiting dilution assay. antibody-secret- ing cells were screened by enzyme-linked immunosorbent assay (elisa) and the specificity of secreted mabs was further analyzed using a panel of purified myeloma igg proteins by elisa and immunoblotting. cross-reactivity to im- munoglobulins (igs) of other species was studied by indirect elisa using serum samples collected from 9 animals. results: immunoblotting studies revealed recognition of either linear or con- formational epitopes by these mabs. the most abundant cross-reactivity (100%) was observed with monkey igs, while no cross-reactivity was detected with rabbit, guinea pig, sheep, goat, cat and hen sera. two of the mabs cross- reacted with either dog or horse sera. the affinity constant of two mabs was measured by elisa and found to be 0.74×108 m-1 and 0.96×107 m-1 . conclusion: our results indicate that these pan-igg specific mabs recognize re- stricted linear or conformational epitopes located on all human igg subclasses with no cross-reactivity to igg from most species studied. these mabs are po- tentially useful tools for quantification of total or antigen-specific igg levels.