title: The development of functional CD8 T cell memory after Listeria monocytogenes infection is not dependent on CD40.
abstract: The immunologic requirements for generating long-lived protective CD8 T cell memory remain unclear. Memory CD8 populations generated in the absence of CD4 Th cells reportedly have functional defects, and at least a subset of CD8 T cells transiently express CD40 after activation, suggesting that direct CD4-CD8 T cell interactions through CD40 may influence the magnitude and functional quality of memory CD8 populations. To ascertain the role of CD40 in such direct T cell interactions, we investigated CD8 T cell responses in CD40-/- mice after infection with Listeria monocytogenes, an intracellular bacterium that induces APC activation and thus priming of CD8 T cells independently of CD4 Th cell help through CD40. In this study we show that memory CD8 T cells generated in CD40-deficient mice show in vivo cytotoxicity and cytokine production equivalent to CD8 memory T cells from wild-type mice. Upon secondary Listeria infection, CD40-/- memory CD8 T cells expand to greater numbers than seen in wild-type mice. These results indicate that CD40 ligation on CD8 T cells, although reportedly a part of CD8 T cell memory development in an H-Y-directed response, is not needed for the development of functional memory CD8 T cell populations after Listeria infection.
authors.affiliation: Department of Molecular Microbiology, Oregon Health and Science University, Portland 97239, USA.
authors.forename: Megan J
authors.initials: MJ
authors.lastname: Montfort
authors.forename: H G Archie
authors.initials: HG
authors.lastname: Bouwer
authors.forename: Cynthia R
authors.initials: CR
authors.lastname: Wagner
authors.forename: David J
authors.initials: DJ
authors.lastname: Hinrichs
mesh_terms: D000818:Animals; D019013:CD40 Antigens / Q000235:genetics / Q000502:physiology*; D023201:CD40 Ligand / Q000502:physiology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology*; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis; D003602:Cytotoxicity, Immunologic / Q000235:genetics; D007117:Immunization, Secondary; D007156:Immunologic Memory; D008089:Listeria monocytogenes / Q000276:immunology; D008088:Listeriosis / Q000235:genetics / Q000276:immunology*; D008213:Lymphocyte Activation / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology
chemical_list: D019013:CD40 Antigens; D016207:Cytokines; D023201:CD40 Ligand