Peripheral prepositioning and local CXCL9 chemokine-mediated guidance orchestrate rapid memory CD8+ T cell responses in the lymph node.
After an infection, the immune system generates long-lived memory lymphocytes whose increased frequency and altered state of differentiation enhance host defense against reinfection. Recently, the spatial distribution of memory cells was found to contribute to their protective function. Effector memory CD8+ T cells reside in peripheral tissue sites of initial pathogen encounter, in apparent anticipation of reinfection. Here we show that within lymph nodes (LNs), memory CD8+ T cells were concentrated near peripheral entry portals of lymph-borne pathogens, promoting rapid engagement of infected sentinel macrophages. A feed-forward CXCL9-dependent circuit provided additional chemotactic cues that further increase local memory cell density. Memory CD8+ T cells also produced effector responses to local cytokine triggers, but their dynamic behavior differed from that seen after antigen recognition. These data reveal the distinct localization and dynamic behavior of naive versus memory T cells within LNs and how these differences contribute to host defense.
Lymphocyte Biology Section, Laboratory of Systems Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA. wkastenm@uni-bonn.de
Wolfgang
W
Kastenmüller
Marlene
M
Brandes
Ze
Z
Wang
Jasmin
J
Herz
Jackson G
JG
Egen
Ronald N
RN
Germain
D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002465:Cell Movement / Q000276:immunology; D054370:Chemokine CXCL9 / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D005434:Flow Cytometry; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007156:Immunologic Memory / Q000276:immunology*; D007371:Interferon-gamma / Q000276:immunology / Q000378:metabolism; D008198:Lymph Nodes / Q000276:immunology* / Q000378:metabolism / Q000821:virology; D008264:Macrophages / Q000276:immunology / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D036641:Microscopy, Fluorescence, Multiphoton; D054388:Receptors, CCR / Q000276:immunology / Q000378:metabolism; D054367:Receptors, CXCR3 / Q000276:immunology / Q000378:metabolism; D014615:Vaccinia / Q000276:immunology / Q000378:metabolism / Q000821:virology; D014616:Vaccinia virus / Q000235:genetics / Q000276:immunology / Q000378:metabolism
D054370:Chemokine CXCL9; C515188:Cxcr3 protein, mouse; D054388:Receptors, CCR; D054367:Receptors, CXCR3; D049452:Green Fluorescent Proteins; D007371:Interferon-gamma