Figure 3.

A model for the role of the T6SS in persistence and virulence of V. cholerae. (1) The small intestine colonized with commensal bacteria is (2) invaded by V. cholerae cells that passed the gastric acid barrier. (3) Upon descent into the ducts between adjacent villi of the small intestine, V. cholerae assembles the T6SS on its surface (indicated by black spikes) in order to kill commensal microorganisms. (4) The sterile patches generated allow V. cholerae to colonize and multiply. (5) Incoming immune cells that ingest V. cholerae are killed by the T6SS-mediated toxicity, allowing the infection to proceed. (6) Secretion of cholera toxin results in massive water efflux into the host lumen, and V. cholerae cells leave the human host during diarrheal purges. (7) V. cholerae exiting the body maintain T6SS activation in preparation for bacterial and eukaryotic predators in the environment.