Adjuvants for secretory immune responses.

Salivary IgA responses of rats receiving MDP were elevated after oral GTF administration and after infection with S. mutans bearing surface GTF. Intragastric administration (but not injection) of MDP enhanced salivary IgA responses to i.g. GTF. Subcutaneous injection (but not i.g. administration) of MDP enhanced IgA responses to GTF injected in the salivary gland vicinity. Conjugation of MDP to GTF did not enhance the secretory response to the antigen. Nevertheless, s.g.v. administration of OVA in IFA dramatically enhanced the secretory and serum responses. Injection of MDP may further enhance the secretory response. The combination of routes of adjuvant and antigen administration were critical in selectively enhancing a secretory immune response.