Recirculating memory T cells are a unique subset of CD4+ T cells with a distinct phenotype and migratory pattern

SK Bromley, S Yan, M Tomura… - The Journal of …, 2013 - journals.aai.org
SK Bromley, S Yan, M Tomura, O Kanagawa, AD Luster
The Journal of immunology, 2013journals.aai.org
Several populations of memory T cells have been described that differ in their migration and
function. In this study, we have identified a unique subset of memory T cells, which we have
named recirculating memory T cells (T RCM). By exposing Kaede transgenic mouse skin to
violet light, we tracked the fate of cutaneous T cells. One population of memory CD4+ T cells
remained in the skin. A second population migrated from the skin into draining lymph nodes
(LNs) in a CCR7-dependent manner. These migrating CD4+ T cells expressed a novel cell …
Abstract
Several populations of memory T cells have been described that differ in their migration and function. In this study, we have identified a unique subset of memory T cells, which we have named recirculating memory T cells (T RCM). By exposing Kaede transgenic mouse skin to violet light, we tracked the fate of cutaneous T cells. One population of memory CD4+ T cells remained in the skin. A second population migrated from the skin into draining lymph nodes (LNs) in a CCR7-dependent manner. These migrating CD4+ T cells expressed a novel cell surface phenotype (CCR7 int/+ CD62L int CD69− CD103+/− E-selectin ligands+) that is distinct from memory T cell subsets described to date. Unlike memory T cell subsets that remain resident within tissues long-term, or that migrate either exclusively between lymphoid tissues or into peripheral nonlymphoid sites, CD4+ T RCM migrate from the skin into draining LNs. From the draining LNs, CD4+ T RCM reenter into the circulation, distal LNs, and sites of non-specific cutaneous inflammation. In addition, CD4+ T RCM upregulated CD40L and secreted IL-2 following polyclonal stimulation. Our results identify a novel subset of recirculating memory CD4+ T cells equipped to deliver help to both distal lymphoid and cutaneous tissues.
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