Persistence of oral tolerance in mice fed ovalbumin is different for humoral and cell-mediated immune responses.

The duration of oral tolerance after a single feed of OVA at the age of 6 weeks was studied in BDF1 mice. Significant suppression of systemic antibody responses was present 3 months later, but not at 6.5 months; in contrast, at all times studied from 2 weeks to 17 months after an OVA feed there was suppression of systemic CMI to OVA as measured by an in vivo skin test. This indicates that the two limbs of the immune response differ in the factors responsible for the maintenance of oral tolerance.