To investigate intoxication of host cells by B. bronchiseptica, we infected J774A.1 murine macrophage-like (CR3+) cells, Chinese hamster ovary cells carrying an empty vector (CHO-mock, CR3–), and CHO cells carrying the vector encoding human CD18 and CD11b (CHO-CR3hu+ (35)) with wild-type, ∆cyaA, and ∆fhaB B. bronchiseptica strains at a multiplicity of infection (MOI) of 100 and measured 3′−5′-cyclic AMP (cAMP) levels using a competitive ELISA. The gene discussed is ITGB2; the disease is infection.