ESCHERICHIA-COLI BOUND TO THE PRIMATE ERYTHROCYTE COMPLEMENT RECEPTORVIA BISPECIFIC MONOCLONAL-ANTIBODIES ARE TRANSFERRED TO AND PHAGOCYTOSED BY HUMAN MONOCYTES IN AN IN-VITRO MODEL

We have prepared cross-linked, bispecific mAb complexes (heteropolymer s) that facilitate rapid and quantitative binding of a prototype patho gen, Escherichia coli, to the complement receptor (CR1) on primate ery throcytes. Incubation of the erythrocyte-heteropolymer-E. coli complex es with freshly isolated human mononuclear cells leads to rapid remova l of the E. coli from the erythrocytes, and phagocytosis and killing o f the bacteria. The erythrocytes are not lysed or phagocytosed during this transfer reaction, but both heteropolymer and CR1 are removed fro m the erythrocytes along with the E. coli. These findings parallel obs ervations made in previous in vivo experiments in which heteropolymers were used to facilitate clearance of innocuous prototype pathogens in a monkey model. It should now be possible to extend the heteropolymer paradigm to a live pathogen in a primate model.