RT Journal Article SR Electronic T1 Expansion of Protective CD8+ T-Cell Responses Driven by Recombinant Cytomegaloviruses JF Journal of Virology JO J. Virol. FD American Society for Microbiology SP 2255 OP 2264 DO 10.1128/JVI.78.5.2255-2264.2004 VO 78 IS 5 A1 Karrer, Urs A1 Wagner, Markus A1 Sierro, Sophie A1 Oxenius, Annette A1 Hengel, Hartmut A1 Dumrese, Tilman A1 Freigang, Stefan A1 Koszinowski, Ulrich H. A1 Phillips, Rodney E. A1 Klenerman, Paul YR 2004 UL http://jvi.asm.org/content/78/5/2255.abstract AB CD8+ T cells are critical for the control of many persistent viral infections, such as human immunodeficiency virus, hepatitis C virus, Epstein-Barr virus, and cytomegalovirus (CMV). In most infections, large CD8+-T-cell populations are induced early but then contract and are maintained thereafter at lower levels. In contrast, CD8+ T cells specific for murine CMV (MCMV) have been shown to gradually accumulate after resolution of primary infection. This unique behavior is restricted to certain epitopes, including an immunodominant epitope derived from the immediate-early 1 (IE1) gene product. To explore the mechanism behind this further, we measured CD8+-T-cell-mediated immunity induced by recombinant MCMV-expressing epitopes derived from influenza A virus or lymphocytic choriomeningitis virus placed under the control of an IE promoter. We observed that virus-specific CD8+-T-cell populations were induced and that these expanded gradually over time. Importantly, these CD8+ T cells provided long-term protection against challenge without boosting. These results demonstrate a unique pattern of accumulating T cells, which provide long-lasting immune protection, that is independent of the initial immunodominance of the epitope and indicates the potential of T-cell-inducing vaccines based on persistent vectors.