title: Innate and virtual memory T cells in man.
abstract: A hallmark of the antigen-specific B and T lymphocytes of the adaptive immune system is their capacity to "remember" pathogens long after they are first encountered, a property that forms the basis for effective vaccine development. However, studies in mice have provided strong evidence that some naive T cells can develop characteristics of memory T cells in the absence of foreign antigen encounters. Such innate memory T cells may develop in response to lymphopenia or the presence of high levels of the cytokine IL-4, and have also been identified in unmanipulated animals, a phenomenal referred to as "virtual memory." While the presence of innate memory T cells in mice is now widely accepted, their presence in humans has not yet been fully validated. In this issue of the European Journal of Immunology, Jacomet et al. [Eur. J. Immunol. 2015. 45:1926-1933] provide the best evidence to date for innate memory T cells in humans. These findings may contribute significantly to our understanding of human immunity to microbial pathogens and tumors.
authors.affiliation: Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN, USA.
authors.forename: Luc
authors.initials: L
authors.lastname: Van Kaer
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate / Q000276:immunology*; D007156:Immunologic Memory / Q000276:immunology*; D051379:Mice; D016176:T-Lymphocyte Subsets / Q000276:immunology*
keywords: CD8+ T cells; Human; Immunological memory; Innate-like T cells; Memory T cells