EFFECT OF WATER-BASED MICROENCAPSULATION ON PROTECTION AGAINST EDIM ROTAVIRUS CHALLENGE IN MICE

We determined the capacity of microcapsules formed by the combination of sodium alginate, an aqueous anionic polymer, and spermine hydrochlo ride, an aqueous cationic amine, to enhance protection against rotavir us challenge in mice. Adult BALB/c mice were orally inoculated with ei ther free or microencapsulated rotavirus (simian rotavirus strain RRV) and challenged 6 or 1.6 weeks later with murine rotavirus strain EDIM . Virus-specific humoral immune responses were determined at the time of challenge and 4 days after challenge by intestinal fragment culture . We found that spermine-alginate microcapsules enhanced protection ag ainst challenge 16 weeks after immunization but not 6 weeks after immu nization. Quantities of virus-specific immunoglobulin A produced by sm all intestinal lamina propria lymphocytes were correlated with the deg ree of protection against challenge afforded by spermine-alginate micr ocapsules. Possible mechanisms by which microcapsules enhance protecti on against rotavirus challenge are discussed.