Protective Effects of Murine Monoclonal Antibodies in Experimental Septicemia: E. coli Antibodies Protect Against Different Serotypes of E. coli

Murine monoclonal antibodies that bind outer membrane antigens of the J5 mutant of Escherichia coli 011OlB4 were derived from spleen cells of BALB/c mice immunized with killed whole cells and boosted with lipopolysaccharide (LPS) and LPS-associated proteins. Seven hybridomas were selected for their reactivity against the J5 LPS; they crossreacted with 0111, 055, 0127, and 0128 E. coli LPS. One (B7B3) also reacted with the Serratia marcescens LPS and Klebsiella pneumoniae lipid A. A protective effect was obtained with D6B4 antibody in a lethal endotoxemia model induced by LPS from 0111, 0127, and 0128 E. coli serotypes in D-galactosamine-sensitized mice. D6B4 and D6B3 antibodies protected mice infected with E. coli 0111:B4, when administered before infection. The D6B4 antibody was also protective when administered after infection. The antibodies D6B3 and D4B5 were protective in heterologous infection induced by E. coli 02:K1.