Treatment with Bordetella PTx abrogates HIV inhibition by CCR6 ligands hBD2 and MIP-3α. PBMCs were infected with HIV–luciferase pseudotype virus (AMLV envelope) as described in “Infectivity assays.” Three hours after infection, virus was washed 3 times with PBS, and cells were incubated 3 days in complete RPMI, with or without PTx, and with or without hBD2 (20 μg/mL) or MIP-3α (1 and 5 μg/mL). Subsequently, cells were washed and lysed with cell lysis reagent from Promega. Luciferase activity in cytoplasmic lysates was measured with a Turner luminometer. The percentage of inhibition was calculated in reference to luciferase activity as measured in untreated control infections. Shown here are averages (± SEMs) of 3 experiments. Treatment of single-cycle infections with PTx alone resulted in enhancement of infection (4.8 ± 1.9) over control, untreated infection.