Nonopsonic phagocytosis of Pseudomonas aeruginosa: Insights from an infantwith leukocyte adhesion deficiency

Children with leukocyte adhesion deficiency type I are at risk for overwhel ming infection because their neutrophils lack surface beta 2 integrins (CD1 8/CD11) that normally interact with endothelial cell adhesion molecules and mediate migration to sites of bacterial invasion. In vitro studies of phag ocytic cells from an infant with leukocyte adhesion deficiency type I demon strated that complement receptor 3 (CD18/CD11b) mediates nonopsonic phagocy tosis of some Pseudomonas aeruginosa strains and might play a control role in the control of Pseudomonas infections at sites where there are low level s of opsonins.