title: Cutting Edge: Resident Memory CD8 T Cells Express High-Affinity TCRs.
abstract: Tissue-resident memory T (TRM) cells serve as vanguards of antimicrobial host defense in nonlymphoid tissues, particularly at barrier epithelia and in organs with nonrenewable cell types (e.g., brain). In this study, we asked whether an augmented ability to sense Ag complemented their role as early alarms of pathogen invasion. Using mouse polyomavirus, we show that brain-resident mouse polyomavirus-specific CD8 T cells, unlike memory cells in the spleen, progressively increase binding to MHC class I tetramers and CD8 coreceptor expression. Using the two-dimensional micropipette adhesion-frequency assay, we show that TRM cells in brain, as well as in kidney, express TCRs with up to 20-fold higher affinity than do splenic memory T cells, whereas effector cells express TCRs of similar high affinity in all organs. Together, these data demonstrate that TRM cells retain high TCR affinity, which endows them with the high Ag sensitivity needed for front-line defense against infectious agents.
authors.affiliation: Immunology and Molecular Pathogenesis Graduate Program, Emory University, Atlanta, GA 30322;
authors.forename: Elizabeth L
authors.initials: EL
authors.lastname: Frost
authors.affiliation: Immunology and Molecular Pathogenesis Graduate Program, Emory University, Atlanta, GA 30322; Department of Microbiology and Immunology, Emory University, Atlanta, GA 30322; and.
authors.forename: Anna E
authors.initials: AE
authors.lastname: Kersh
authors.affiliation: Department of Microbiology and Immunology, Emory University, Atlanta, GA 30322; and.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Evavold
authors.affiliation: Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, PA 17033 alukacher@hmc.psu.edu.
authors.forename: Aron E
authors.identifier: http://orcid.org/0000-0002-7969-2841
authors.initials: AE
authors.lastname: Lukacher
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000473:pathology; D005260:Female; D005786:Gene Expression Regulation / Q000276:immunology*; D007156:Immunologic Memory; D051379:Mice; D009928:Organ Specificity / Q000276:immunology; D011120:Polyomavirus / Q000276:immunology*; D027601:Polyomavirus Infections / Q000276:immunology* / Q000473:pathology; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D014412:Tumor Virus Infections / Q000276:immunology* / Q000473:pathology
chemical_list: D011948:Receptors, Antigen, T-Cell