title: Effector-like CD8⁺ T cells in the memory population mediate potent protective immunity.
abstract: The CD8⁺ memory T cell population is heterogeneous, and it is unclear which subset(s) optimally mediate the central goal of the immune system-protection against infection. Here we investigate the protective capacities of CD8⁺ T cell subsets present at the memory stage of the immune response. We show that a population of CD8⁺ T cells bearing markers associated with effector cells (KLRG1(hi), CD27(lo), T-bet(hi), Eomes(lo)) persisted to the memory phase and provided optimal control of Listeria monocytogenes and vaccinia virus, despite weak recall proliferative responses. After antigen-specific boosting, this population formed the predominant secondary memory subset and maintained superior pathogen control. The effector-like memory subset displayed a distinct pattern of tissue distribution and localization within the spleen, and their enhanced capacity to eliminate Listeria involved specialized utilization of cytolysis. Together, these data suggest that long-lived effector CD8⁺ T cells are optimal for protective immunity against certain pathogens.
authors.affiliation: Department of Laboratory Medicine and Pathology, Center for Immunology, University of Minnesota Medical School, Minneapolis, MN 55414, USA.
authors.forename: Janelle A
authors.initials: JA
authors.lastname: Olson
authors.forename: Cameron
authors.initials: C
authors.lastname: McDonald-Hyman
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Jameson
authors.forename: Sara E
authors.initials: SE
authors.lastname: Hamilton
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000382:microbiology / Q000821:virology; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D005260:Female; D007110:Immunity, Active; D007156:Immunologic Memory; D037181:Lectins, C-Type / Q000378:metabolism; D008089:Listeria monocytogenes / Q000276:immunology*; D008088:Listeriosis / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D011213:Poxviridae Infections / Q000276:immunology*; D011971:Receptors, Immunologic; D020825:T-Box Domain Proteins / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000382:microbiology / Q000821:virology; D015534:Trans-Activators / Q000378:metabolism; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000378:metabolism; D014616:Vaccinia virus / Q000276:immunology*; D000098815:T-bet Transcription Factor
chemical_list: C491199:EOMES protein, human; C113413:KLRG1 protein, human; D037181:Lectins, C-Type; D011971:Receptors, Immunologic; D020825:T-Box Domain Proteins; D000098815:T-bet Transcription Factor; D015534:Trans-Activators; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7