MONOCLONAL-ANTIBODY NIMP-R10 DIRECTED AGAINST THE CD11B CHAIN OF THE TYPE-3 COMPLEMENT RECEPTOR CAN SUBSTITUTE FOR MONOCLONAL-ANTIBODY 5C6 TO EXACERBATE LISTERIOSIS BY PREVENTING THE FOCUSING OF MYELOMONOCYTIC CELLS AT INFECTIOUS FOCI IN THE LIVER

Treatment of mice with a monoclonal antibody (mAb) designated NIMP-RIO, directed against the CD11b polypeptide -of the CD18/CD11b heterodimeric type 3 complement receptor (CR3), exacerbates listeriosis by preventing myelomonocytic cells from focusing at sites of infected hepatocytes in the liver. Under these conditions an otherwise sublethal Listeria inoculum grows unrestrictedly within hepatocytes and causes death in 3 days. The results obtained with NIMP-R10 are similar to those previously obtained with a different anti-CD11b mAb (5C6), although mAb NIMP-RIO is more effective at enhancing infection. Therefore, both mAbs can be used to analyze host antibacterial defenses in vivo.