Characterization of a Human Monoclonal Antibody to Lipopolysaccharides of Pseudomonas Aeruginosa Serotype 5: a Possible Candidate As an Immunotherapeutic Agent for Infections with P. Aeruginosa

A human monoclonal antibody, P3D9 (IgG2, lambda type), that bound to Pseudomonas aeruginosa Homma serotype 5 cells with high specificity was produced by cell fusion between a human tonsillar lymphocyte and a mouse plasmacytoma cell, P3-X63-Ag8-U1 (P3U1). The yield of P3D9 secreted into the culture supernatant from the mouse-human hybridoma was 2-10 micrograms/ml, and this hybridoma cell line has been stably producing this antibody for six months. Antibody P3D9 alone did not cause agglutination of serotype 5 cells, but the cells were agglutinated after addition of goat antibody to human IgG. Antibody P3D9 was proven to have protective activity against infection with P. aeruginosa, and the 50% protective dose estimated for experimental peritoneal infection with P. aeruginosa was 2.4 micrograms per mouse.