Adaptive responses of human monocytes infected by Bordetella pertussis: The role of adenylate cyclase hemolysin

The activation/adaptive responses of human monocytes exposed to Bordetella pertussis parental or mutant strains were evaluated and correlated to the e xpression of two bacterial toxins: adenylate cyclase-hemolysin and pertussi s toxin. The marked rise in intracellular cyclic adenosine monophosphate (c AMP) observed in monocytes infected by B. pertussis parental strain, invers ely correlated with (1) the production of tumor necrosis factor alpha; (2) the release of superoxide anion; and (3) the expression of the 72-kDa heat shock/stress protein, Hsp70. Experiments performed with mutants deficient i n adenylate cyclase-hemolysin or with purified bacterial toxins confirmed t he key role of adenylate cyclase-hemolysin in the control of monocytes' res ponse to infection by B. pertussis. This bacterial strategy primarily invol ves evasion from antimicrobial defenses and, eventually, the sacrifice of t he host cell. (C) 2000 Wiley-Liss, Inc.