INTERACTION BETWEEN GRANULOCYTES AND ANTIBODIES IN THE ENHANCEMENT OFLUNG DEFENSES AGAINST STAPHYLOCOCCUS-AUREUS AFTER INTRANASAL IMMUNIZATION OF MICE WITH LIVE-ATTENUATED BACTERIA

Immunization with live-attenuated Staphylococcus aureus induced measur able levels of specific IgG and IgA in the lungs, but the pulmonary cl earance of S. aureus in immunized mice did not differ from that of con trol mice. Aerosol exposure of mice to Pseudomonas aeruginosa induced a significant recruitment of polymorphonuclear leukocytes (PMNL) to th e lungs in both immunized and control mice, whereas S. aureus challeng e did not. However, challenge with a mixture of P. aeruginosa-S. aureu s or exposure to an aerosol of Escherichia coli lipopolysaccharide (LP S) before S. aureus challenge induced PMNL migration and a significant enhancement of pulmonary clearance of S. aureus in immunized mice. Th e presence of both antibodies and PMNL was required for enhancement of S. aureus pulmonary clearance.