Monoclonal antibodies against O and K antigens of uropathogenic Escherichia coli O4:K12:H- as opsonins

Abstract

IgG2b and specific for the 04 antigen of Esche-richia coli 20025 (04: K12: H-) and the capsular K12 polysaccharide of the same strain (IgM) were obtained with the hybridoma technique using spleen cells from Balb/c mice, immunized with a crude bacterial extract, and Sp2/O-Ag8 myeloma cells. The anti-O4 antibodies reacted exclusively with the 04 lipopolysaccharide and not with those from serologicaUy O-cross reactive E. coli. The anti-K12 antibodies recognized as epitope (part of) the KDO moiety of the capsular K12 polysac-charide. Not only anti-K12, but also anti-O4 anti-bodies effectively phagoopsonized ncapsulated E. coli 20025. The opsonized bacteria were killed in subsequent in vitro phagocytosis by huma