title: Human MAIT cells are xenobiotic-resistant, tissue-targeted, CD161hi IL-17-secreting T cells.
abstract: Mucosal-associated invariant T (MAIT) cells are very abundant in humans and have antimicrobial specificity, but their functions remain unclear. MAIT cells are CD161(hi)IL-18Rα(+) and either CD4(-)CD8(-) (DN) or CD8αβ(int) T cells. We now show that they display an effector-memory phenotype (CD45RA(-)CD45RO(+)CD95(hi)CD62L(lo)), and their chemokine receptor expression pattern (CCR9(int)CCR7(-)CCR5(hi)CXCR6(hi)CCR6(hi)) indicates preferential homing to tissues and particularly the intestine and the liver. MAIT cells can represent up to 45% of the liver lymphocytes. They produce interferon-γ and Granzyme-B as well as high levels of interleukin-17 after phorbol myristate acetate + ionomycin stimulation. Most MAIT cells are noncycling cells (< 1% are Ki-67(+)) and express the multidrug resistance transporter (ABCB1). As expected from this phenotype, MAIT cells are more resistant to chemotherapy than other T-cell populations. These features might also allow MAIT cells to resist the xenobiotics potentially secreted by the gut bacteria. We also show that this population does not appear to have antiviral specificity and that CD8 MAIT cells include almost all the ABCB1(+)CD161(hi) CD8 T cells. Together with their already known abundance and antimicrobial specificity, the gut-liver homing characteristics, high expression of ABCB1, and ability to secrete interleukin-17 probably participate in the antibacterial properties of MAIT cells.
authors.affiliation: Département de Biologie des Tumeurs, Institut Curie, 26 rue d'Ulm, Paris, France.
authors.forename: Mathilde
authors.initials: M
authors.lastname: Dusseaux
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Martin
authors.forename: Nacer
authors.initials: N
authors.lastname: Serriari
authors.forename: Isabelle
authors.initials: I
authors.lastname: Péguillet
authors.forename: Virginie
authors.initials: V
authors.lastname: Premel
authors.forename: Delphine
authors.initials: D
authors.lastname: Louis
authors.forename: Maud
authors.initials: M
authors.lastname: Milder
authors.forename: Lionel
authors.initials: L
authors.lastname: Le Bourhis
authors.forename: Claire
authors.initials: C
authors.lastname: Soudais
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Treiner
authors.forename: Olivier
authors.initials: O
authors.lastname: Lantz
mesh_terms: D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism* / Q000502:physiology*; D002465:Cell Movement / Q000187:drug effects / Q000276:immunology; D002478:Cells, Cultured; D002648:Child; D004351:Drug Resistance / Q000276:immunology*; D005312:Fetal Blood / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D006801:Humans; D018928:Immunity, Mucosal / Q000187:drug effects / Q000276:immunology; D007231:Infant, Newborn; D020381:Interleukin-17 / Q000378:metabolism*; D053727:Interleukin-18 Receptor alpha Subunit / Q000378:metabolism; D055651:NK Cell Lectin-Like Receptor Subfamily B / Q000378:metabolism*; D009928:Organ Specificity / Q000276:immunology; D019707:Receptors, Chemokine / Q000378:metabolism; D018417:Th1 Cells / Q000276:immunology / Q000378:metabolism; D015262:Xenobiotics / Q000494:pharmacology*
chemical_list: C508717:IL17A protein, human; C508572:IL18R1 protein, human; D020381:Interleukin-17; D053727:Interleukin-18 Receptor alpha Subunit; C527203:KLRB1 protein, human; D055651:NK Cell Lectin-Like Receptor Subfamily B; D019707:Receptors, Chemokine; D015262:Xenobiotics