RT Journal Article SR Electronic T1 Protective immunity in BALB/c mice against the simian virus 40-induced mKSA tumor resulting from injection of recombinant large T antigen. Requirement of CD8+ T lymphocytes. JF The Journal of Immunology JO J. Immunol. FD American Association of Immunologists SP 3919 OP 3924 VO 156 IS 10 A1 Zerrahn, J A1 Utermöhlen, O A1 Warnecke, G A1 Deppert, W A1 Lehmann-Grube, F YR 1996 UL http://www.jimmunol.org/content/156/10/3919.abstract AB BALB/c mice are often considered "low responders" or even "nonresponders" with regard to cytolytic CD8+ T lymphocytes and SV40 large T Ag (TAg). Large TAg and fragments thereof were produced by recombinant technology and injected into BALB/c mice that were subsequently challenged by i.p. injection of syngeneic TAg-expressing mKSA tumor cells. Two portions of the TAg were found to induce protective immunity, one stretching from amino acid residues 1-272 and the other from amino acid residues 683-708. In mice thus protected, the spleens were virtually free of cytotoxic T cells but CD8+ T lymphocytes obtained from the peritoneal cavity during rejection of the mKSA cells were directly lytic for TAg-expressing target cells. Depleting immune mice of CD4+ or CD8+ T lymphocytes by treatment with mAb abolished their ability to resist tumor development. We conclude that immunity against SV40 TAg-expressing tumor cells in BALB/c mice is dependent on both CD4+ and CD8+ T lymphocytes.