Dendritic Cell-Induced Memory T Cell Activation in Nonlymphoid Tissues

Abstract

Secondary lymphoid organs are dominant sites of T cell activation, although many T cells are subsequently retained within peripheral tissues. Currently, these nonlymphoid compartments are viewed as sites only of effector T cell function, without the involvement of renewed induction of immunity via the interactions with professional antigen-presenting cells. We describe a method of reactivation of herpes simplex virus to examine the stimulation of tissue-resident T cells during secondary challenge. The results revealed that memory CD8+ T cell responses can be initiated within peripheral tissues through a tripartite interaction that includes CD4+ T cells and recruited dendritic cells. These findings lend evidence for the existence of a sophisticated T cell response mechanism in extra-lymphoid tissues that can act to control localized infection.

T cell differentiation in chronic infection and cancer: functional adaptation or exhaustion?

“…The concept of tissue-resident memory CD8 + T-cells is now established for several types of tissues and infections [84][85][86][87] . Indeed, PD-1 positive CD8 + T-cells have been found to be preferentially retained in bone marrow, lymph nodes, kidney, and brain after chronic LCMV clone-13 infection 42 .…”

Cutting Edge: Local Recall Responses by Memory T Cells Newly Recruited to Peripheral Nonlymphoid Tissues

“…As a consequence of this local and disseminated distribution, it has been suggested that the nonlymphoid tissue recall response can be divided into different phases, with an immediate response by those cells already at the site of infection and a later response involving memory T cells recruited from the circulation (8). Although we have recently shown that local T cells are directly stimulated and expanded in situ on reinfection (9), it remained unclear whether this was also true of the recruited memory T cells during this second phase of the peripheral recall response. In the present study we use a transplantation model of HSV-1 reactivation to investigate the activation of memory CD8 ϩ T cells recruited from the circulation.…”

Les cellules dendritiques inflammatoires

“…Les cellules dendritiques inflammatoires peuvent également présenter des antigènes exogènes sur leurs molécules du CMH I, un processus appelé cross-presentation dans lequel sont spécialisées les cellules dendritiques résidentes CD8 + et migratoires CD103 + . En effet, les cellules dendritiques inflammatoires sont impliquées dans l'activation in vivo de lymphocytes T CD8 + spécifiques de l'antigène étudié [11,22]. De plus, les cellules dendritiques inflammatoires directement purifiées des tissus ou organes lymphoïdes peuvent également activer ex vivo des lymphocytes T CD8 + spécifiques après capture de l'antigène in vivo [7,8,14,15].…”

“…Plusieurs études ont également montré un rôle prédo-minant des cellules dendritiques inflammatoires dans la présentation d'antigènes en périphérie. Ainsi, les cellules dendritiques inflammatoires qui se différencient lors d'une réactivation du virus de l'herpès HSV-1 stimulent les lymphocytes T CD4 + et CD8 + mémoires qui sont présents dans les tissus [22]. Dans le cas d'une inflammation causée par une infection avec le virus HSV-2, la stimulation des lymphocytes T effecteurs dans les tissus est très affectée par l'absence de cellules dendritiques inflammatoires [21], suggérant que ces cellules interagissent avec les lymphocytes T effecteurs directement in situ.…”