Production and Partial Characterization of Monoclonal Antibodies against Erythrogenic Toxins Type A and C from Streptococcus pyogenes

Abstract

ABSTRACT

Hybridoma cell lines producing monoclonal antibodies against streptococcal erythrogenic toxins type A and C were established from fusions of immunized BALB/c mice splenocytes with P3X63-Ag8.653 myeloma cells. Six MAbs recognize ETA and 11 MAbs bind to ETC. Two MAbs (designated ETA-2 and ETC-10) were produced in ascitic fluid and further characterized. ETA-2 (IgG_2a) binds to ETA with an affinity constant of 1.8 × 10¹⁰ M⁻¹ and ETC-10 (IgG₁ binds to ETC with an affinity constant of 3.5 × 10⁹ M⁻¹. The specificities of the MAbs were evaluated by ELISA and immunoblotting. Both MAbs ETA-2 and ETC-10 are useful in developing specific double-sandwich ELISAs, in which the MAbs were used as solid-phase capture antibodies for the quantitative determinations of ETA and ETC.