The expression of Class II major histocompatability antigens in the murine small intestine is not influenced by the oral administration of cholera toxin

Abstract

Feeding cholera toxin (CT) induces a strong mucosal IgG and IgA response. In addition CT can act as an adjuvant inducing a strong IgA response to an unrelated protein fed simultaneously. [1] Furthermore the normal oral tolerance induced by feeding proteins is abrogated by CT [2]. There is considerable variation between mouse strains in their ability to respond to different proteins fed with CT,and no correlation between antibody response to CT and that to the second protein [3]. This has led to the proposal that CT acts as a pharmacological mediator of the mucosal immune system [3] a view supported by the observation that CT but not its B subunit has this effect [4]. The mechanism whereby CT exerts its effect is not understood. However the necessity to feed CT simultaneously with KLH indicates that it acts locally within the intestine.