PROTECTION AGAINST LETHAL LYMPHOCYTIC CHORIOMENINGITIS VIRUS (LCMV) INFECTION BY IMMUNIZATION OF MICE WITH AN INFLUENZA-VIRUS CONTAINING ANLCMV EPITOPE RECOGNIZED BY CYTOTOXIC T-LYMPHOCYTES

The reverse genetics system has made it possible to modify the influen za virus genome. By this method, we were able to assess influenza viru s as a vaccine vector for protecting BALB/c mice against otherwise let hal lymphocytic choriomeningitis virus (LCMV) infection. A single dose of influenza virus [A/WSN/33 (H1N1)] bearing a cytotoxic T-lymphocyte -specific epitope of the LCMV nucleoprotein (residues 116 to 127) in t he neuraminidase stalk protected mice against LCMV challenge for at le ast 4 months. The immunity was mediated by cytotoxic T lymphocytes and was haplotype specific, indicating that the observed protective respo nse,vas solely a consequence of prior priming with the H-2(d) LCMV nuc leoprotein epitope expressed in the recombinant influenza virus. We al so found that as many as 58 amino acids could be inserted into the neu raminidase stalk without loss of viral function. These findings demons trate the potential of influenza virus as a vaccine vector, with the n euraminidase stalk as a repository for foreign epitopes.