ORAL INOCULATION OF MICE WITH LOW-DOSES OF MICROENCAPSULATED, NONINFECTIOUS ROTAVIRUS INDUCES VIRUS-SPECIFIC ANTIBODIES IN GUT-ASSOCIATED LYMPHOID-TISSUE

The capacity of an aqueous-based system of microencapsulation to enhan ce virus-specific humoral immune responses was evaluated in mice orall y inoculated with noninfectious rotavirus (simian rotavirus strain RRV ). Mice were orally inoculated with 1.75 or 0.35 mu g of inactivated R RV (iRRV) or microencapsulated iRRV. Sera, intestinal contents, and or gan cultures of gut-associated lymphoid tissues (GALT) were tested for the presence of rotavirus-specific antibodies. Virus-specific IgA was produced by small intestine lamina propria lymphocytes in animals ino culated with 1.75 or 0.35 mu g of microencapsulated virus, but not in mice inoculated with unencapsulated virus. Virus-specific IgA in sera and intestinal contents were not predictive of intestinal organ cultur e responses. Microencapsulation may be an efficient way of inducing vi rus-specific immune responses in GALT after oral inoculation with smal l quantities of viral antigen. In addition, delayed release of virus f rom microcapsules may obviate the need for booster immunizations.