Fig. 3

Binding studies of selected IgG antibodies induced in the post-Td booster immunization sample. a Fourteen highly induced HC-LC pairs including one known TT antigen-specific HC-CDR3 sequence were cloned into IgG HC and LC expression vectors, co-transfected, and expressed in HEK 293T cells for production of IgG mAbs. b Indirect ELISA using TT antigen and transfected HEK 293T cell supernatants reveals four novel anti-TT antibodies (named Top1, Top2, Top3, and Top4). A commercial TT-specific mAb used as positive control in the assays (anti-TT mAb) resulted in a strong signal while the negative controls (Mock – Mock transfection; HEK 293T – Cell culture supernatant from untransfected cells) resulted in low background signals