FIG 6.

Primary human monocytes also secrete IL-1β in response to hemolysin and CT during V. cholerae infection. Shown is the IL-1β (A) and TNF-α (B) secretion from PBMCs treated at an MOI of 25 with a wild-type V. cholerae El Tor strain or a mutant with a deletion in hlyA. Also shown is the IL-1β (D) and TNF-α (E) secretion from PBMCs treated at an MOI of 25 with wild-type V. cholerae classical strain O395 and its isogenic ΔctxAB mutant O395NT and ΔctxA mutant O395N1 for 3 h. (C, F) Percent lysis of PBMCs after 3 h as measured by LDH release. Data are presented as the mean ± the standard deviation of triplicate samples. *, P < 0.05; ns, not statistically significant; <d. l., below the limit of detection of the assay.