BORDETELLA-PERTUSSIS INFECTION OF HUMAN MONOCYTES INHIBITS ANTIGEN-DEPENDENT CD4 T-CELL PROLIFERATION

Human monocytes and macrophages bind Bordetella pertussis through mult iple specific receptor-ligand interactions; however, the effect of the se interactions on monocyte and macrophage function is not well unders tood. In an in vitro system, B. pertussis infection of human monocytes significantly impaired T cell proliferation to exogenous antigen at M OIs as low as 1.0. B. pertussis isogenic mutant strains deficient in f ilamentous hemagglutinin or adenylate cyclase toxin were incapable of proliferation inhibition, suggesting that these virulence-associated f actors are essential for this activity. B. pertussis-induced monocyte death alone did not explain these results, nor did differences in intr acellular survival. In addition, B. pertussis infection did not signif icantly alter monocyte phagocytosis of complement-opsonized latex part icles, indicating that B. pertussis infection does not globally impair monocyte functions in this system. These results suggest that B. pert ussis may be capable of subverting cellular immune defenses in an infe cted host.