FIG. 1.

Cholera toxin induces a blockade on the induction of oral tolerance. (A) Table displaying immunization strategy. (B) Endpoint titers of OVA-specific IgG in total serum are shown. Five mice per group were immunized as outlined in panel A and detailed in Materials and Methods. Blood was collected from the tail vein at the indicated time point, and an equal volume from each mouse within a group was pooled before isolating the sera. Endpoint titers were determined by serial dilutions by using IgG ELISA with OVA-coated plates.