TLR4 and vibrio infectious disease: V. cholerae colonizes in the small intestine, and in our previous studies of secreted proteins from biopsy specimens of human duodenal mucosa during cholera, we found that major modulators of innate immune responses, including Toll-like receptor 4 (TLR4), NF-κB, and caspase-dependent inflammasomes, were differentially abundant during acute disease (16).