A human-human hybridoma secreting anti-Pseudomonas aeruginosa exotoxin-A monoclonal antibody with highly potent neutralizing activity.

A hybridoma secreting human monoclonal antibody (MAB) against Pseudomonas aeruginosa exotoxin A (PEA) was constructed by fusing Epstein-Barr virus-transformed peripheral blood lymphocytes with human B lymphoblastoid cell line TAW-925. The human-human hybridoma stably produced human IgG2 MAB at the rate of 0.4-0.5 microgram/ml per 10(6) cells per day for more than six months, and the MAB was capable of neutralizing the in vitro cytotoxic and in vivo lethal effects of PEA with approximately 100- and 70-fold, respectively, higher activity than serum polyclonal antibody preparations.