Effects of the adjuvant cholera toxin on dendritic cells: stimulatory and inhibitory signals that result in the amplification of immune responses.

Cholera toxin (CT) is a potent mucosal adjuvant. When administered through the mucosal route CT amplifies B and T lymphocyte responses to co-administered antigens. Since the discovery of CT as a mucosal adjuvant, other bacterial enterotoxins have been found to have this property. These molecules or their detoxified derivatives are all important for the development of mucosal vaccines for human use, and it is thus necessary to understand their mechanism of action. CT has immunomodulatory effects on different cell types, however, the interaction of CT with dendritic cells (DCs), which have a primary role in the priming of immune responses, may be crucial for its adjuvant activity.