title: Antigen-independent differentiation and maintenance of effector-like resident memory T cells in tissues.
abstract: Differentiation and maintenance of recirculating effector memory CD8 T cells (T(EM)) depends on prolonged cognate Ag stimulation. Whether similar pathways of differentiation exist for recently identified tissue-resident effector memory T cells (T(RM)), which contribute to rapid local protection upon pathogen re-exposure, is unknown. Memory CD8αβ(+) T cells within small intestine epithelium are well-characterized examples of T(RM), and they maintain a long-lived effector-like phenotype that is highly suggestive of persistent Ag stimulation. This study sought to define the sources and requirements for prolonged Ag stimulation in programming this differentiation state, including local stimulation via cognate or cross-reactive Ags derived from pathogens, microbial flora, or dietary proteins. Contrary to expectations, we found that prolonged cognate Ag stimulation was dispensable for intestinal T(RM) ontogeny. In fact, chronic antigenic stimulation skewed differentiation away from the canonical intestinal T cell phenotype. Resident memory signatures, CD69 and CD103, were expressed in many nonlymphoid tissues including intestine, stomach, kidney, reproductive tract, pancreas, brain, heart, and salivary gland and could be driven by cytokines. Moreover, TGF-β-driven CD103 expression was required for T(RM) maintenance within intestinal epithelium in vivo. Thus, induction and maintenance of long-lived effector-like intestinal T(RM) differed from classic models of T(EM) ontogeny and were programmed through a novel location-dependent pathway that was required for the persistence of local immunological memory.
authors.affiliation: Department of Microbiology, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: Kerry A
authors.initials: KA
authors.lastname: Casey
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Fraser
authors.forename: Jason M
authors.initials: JM
authors.lastname: Schenkel
authors.forename: Amy
authors.initials: A
authors.lastname: Moran
authors.forename: Michael C
authors.initials: MC
authors.lastname: Abt
authors.forename: Lalit K
authors.initials: LK
authors.lastname: Beura
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Lucas
authors.forename: David
authors.initials: D
authors.lastname: Artis
authors.forename: E John
authors.initials: EJ
authors.lastname: Wherry
authors.forename: Kristin
authors.initials: K
authors.lastname: Hogquist
authors.forename: Vaiva
authors.initials: V
authors.lastname: Vezys
authors.forename: David
authors.initials: D
authors.lastname: Masopust
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000276:immunology*; D002460:Cell Line; D018984:Epitopes, T-Lymphocyte / Q000502:physiology*; D005260:Female; D007156:Immunologic Memory / Q000276:immunology*; D016130:Immunophenotyping; D007413:Intestinal Mucosa / Q000276:immunology / Q000473:pathology / Q000821:virology; D008217:Lymphocytic choriomeningitis virus / Q000276:immunology / Q000472:pathogenicity; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D009928:Organ Specificity / Q000276:immunology; D015398:Signal Transduction / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000473:pathology / Q000821:virology; D013997:Time Factors; D014018:Tissue Distribution / Q000276:immunology
chemical_list: D018984:Epitopes, T-Lymphocyte