Immunity to rotavirus infection in mice

Recent ®ndings from our laboratory regarding the immune response of mice to rotavirus (a mucosal pathogen) show that although in most situations an acquired (T or B cell or both) response is necessary for elimination of primary rotavirus infection, unidenti®ed innate mech-anisms can also play a role in some mouse strains. Similar to what is seen with many other viruses, CD8+ T cells appear to provide the ®rst but not the exclusive mechanism that mediates clearance of a primary rotavirus infection. Antibodies are the critical mediators of prevention against rotavirus reinfection. Nonneutralizing IgA monoclonal antibodies directed against VP6 (an internal structural rotavirus protein) can mediate immunity against rotaviruses in vivo. Rotavirus-speci®c CD8+ T cells can mediate their antiviral effect in the absence of perforin, fas, or interferon-g and are preferentially represented in the subset that expresses high levels of the enteric mucosal homing receptor a4b7. Mice are susceptible to rotavirus-induced diarrhea only dur-ing the ®rst 15 days of life; thus, it is almost impossible to study the active mechanisms that mediate immunity to disease. How-ever, with selected strains of murine rotavirus, adult mice ar