RT Journal Article SR Electronic T1 Qualitatively Different Memory CD8+ T Cells Are Generated after Lymphocytic Choriomeningitis Virus and Influenza Virus Infections JF The Journal of Immunology JO J. Immunol. FD American Association of Immunologists SP 1001142 DO 10.4049/jimmunol.1001142 A1 Mueller, Scott N. A1 Langley, William A. A1 Li, Guimei A1 García-Sastre, Adolfo A1 Webby, Richard J. A1 Ahmed, Rafi YR 2010 UL http://www.jimmunol.org/content/early/2010/07/16/jimmunol.1001142.abstract AB Viral infections often induce robust T cell responses that are long-lived and protective. However, it is unclear to what degree systemic versus mucosal infection influences the generation of effector and memory T cells. In this study, we characterized memory CD8+ T cells generated after respiratory influenza virus infection and compared the phenotypic and functional qualities of these cells with memory T cells generated after systemic infection with lymphocytic choriomeningitis virus (LCMV). Using a recombinant influenza virus expressing the LCMV gp33–41 epitope and TCR transgenic CD8+ T cells with a fixed TCR, we compared responses to the same Ag delivered by mucosal or systemic viral infection. Memory cells generated postinfection with either virus showed only a few phenotypic differences. Yet, influenza memory T cells produced lower amounts of effector cytokines upon restimulation and displayed reduced proliferation compared with LCMV-induced memory cells. Strikingly, we observed reduced expansion of spleen- and, in particular, lung-derived influenza memory cells after recall in vivo, which correlated with reduced early protection from secondary infection. These findings suggest that qualitatively different memory CD8+ T cells are generated after respiratory or systemic virus infections.