Hidden memories: frontline memory T cells and early pathogen interception.
Immunologic memory reflects the ability of a host to more effectively respond to a re-encounter with a particular pathogen than the first encounter, and when a vaccine mimics the first encounter, comprises the basis of vaccine efficacy. For T cells, memory is often equated with the anamnestic response, the ability of secondary lymphoid tissue-based (central) memory T cells to respond to pathogen exposure with a more rapid and higher magnitude production and infection-site delivery of pathogen-specific effector cells than observed in naive hosts. However, increasing evidence supports a fundamentally different kind of T cell memory in which differentiated, long-lived effector memory T cells, prepositioned in sites of potential pathogen invasion or rapidly mobilized to such sites from blood and marginated pools, intercept and potentially control/eliminate pathogen within hours of infection. In this article, we review the evidence for this "hidden" T cell memory and its implication for vaccine development.
Department of Microbiology, Center for Immunology, University of Minnesota, Minneapolis, MN 55455, USA.
David
D
Masopust
Louis J
LJ
Picker
D000818:Animals; D002454:Cell Differentiation / Q000276:immunology; D006801:Humans; D007156:Immunologic Memory / Q000276:immunology*; D007239:Infections / Q000276:immunology; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D014612:Vaccines / Q000276:immunology*
D014612:Vaccines