Intranasal immunization with Taxoplasma gondii SAG1 induces protective cells into both NALT and GALT compartments

Intranasal (i.n.) immunization with the SAG1 protein of Toxoplasma gondii p lus cholera toxin (CT) provides protective immunity. The aim of this study was to analyze the cellular activation of several mucosal compartments afte r i.n. immunization. Cervical and mesenteric lymph node (CLN and MLN, respe ctively) lymphoid cell and intraepithelial lymphocyte (IEL) passive transfe r experiments were performed with CBA/J mice immunized i.n. with SAG1 plus CT. CLN and MLN cells and IEL isolated 42 days after immunization conferred protective immunity on naive recipient mice challenged with strain 76K T.g ondii, as assessed by the reduction in the number of brain cysts. There wer e proliferative specific responses in nose-associated lymphoid tissue and t he CLN and MLN cells from mice immunized,vith SAG1 plus CT, but no cytokine was detectable. Thus, protective immunity is associated with a specific ce llular response in the nasal and mesenteric compartments after i.n. immuniz ation.