ORAL-ADMINISTRATION OF AN ANTIGENIC SYNTHETIC LIPOPEPTIDE (MAP-P3C) EVOKES SALIVARY ANTIBODIES AND SYSTEMIC HUMORAL AND CELLULAR-RESPONSES

Parenteral immunization with a tetravalent multiple antigen peptide (M AP) containing a gp120 sequence coupled to a synthetic lipophilic moie ty (MAP-P3C) has been previously found to produce systemic antibody an d cellular responses in mice. This study demonstrates that oral admini stration of MAP-P3C induced IgA antibodies in mucosal secretions and p rotein-specific IgG in the sera of the immunized mice. Moreover, intra gastric delivery of MAP-P3C generated systemic T-lymphocyte stimulatio n and specific cytotoxic T-lymphocyte (CTL) activity. The CTL response was eliminated by treatment with CD8-specific antibody plus complemen t and was MHC class I-restricted. Therefore, presentation of lipid-lin ked synthetic peptides to the intestinal mucosal surface is effective in initiating humoral and cellular immunity both at mucosal sites and systemically.