Migration inhibition of lymph node lymphocytes as an assay for regional cell-mediated immunity in the intestinal lymphoid tissues of mice immunized orally with ovalbumin.

A migration inhibition assay, using lymph node lymphocytes, has been used as an in vitro assay for cell-mediated immunity (CMI) to ovalbumin in the mesenteric lymph nodes of mice fed ovalbumin. Migration inhibition developed only if an ovalbumin feed was preceded by cyclophosphamide administration; sensitization developed within 24 hr of a single ovalbumin feed, persisted for 14 days and could be recalled on secondary oral challenge with ovalbumin. The intestinal CMI occurred in the absence of detectable systemic immunity and was found only in mice given cyclophosphamide before oral immunization. These results confirm earlier reports on induction of CMI to ovalbumin in the intestinal mucosa, and support the hypothesis that abrogation of a gut-associated suppressor system is necessary to allow induction of intestinal CMI to a dietary protein.