Human mucosal associated invariant T cells detect bacterially infected cells.
Abstract
International audienceControl of infection with Mycobacterium tuberculosis (Mtb) requires Th1-type immunity, of which CD8+ T cells play a unique role. High frequency Mtb-reactive CD8+ T cells are present in both Mtb-infected and uninfected humans. We show by limiting dilution analysis that nonclassically restricted CD8+ T cells are universally present, but predominate in Mtb-uninfected individuals. Interestingly, these Mtb-reactive cells expressed the Valpha7.2 T-cell receptor (TCR), were restricted by the nonclassical MHC (HLA-Ib) molecule MR1, and were activated in a transporter associated with antigen processing and presentation (TAP) independent manner. These properties are all characteristics of mucosal associated invariant T cells (MAIT), an "innate" T-cell population of previously unknown function. These MAIT cells also detect cells infected with other bacteria. Direct ex vivo analysis demonstrates that Mtb-reactive MAIT cells are decreased in peripheral blood mononuclear cells (PBMCs) from individuals with active tuberculosis, are enriched in human lung, and respond to Mtb-infected MR1-expressing lung epithelial cells. Overall, these findings suggest a generalized role for MAIT cells in the detection of bacterially infected cells, and potentially in the control of bacterial infection- info:eu-repo/semantics/article
- Journal articles
- MESH: Amino Acid Sequence
- MESH: CD8-Positive T-Lymphocytes
- MESH: Receptors, Antigen, T-Cell
- MESH: Clone Cells
- MESH: Complementarity Determining Regions
- MESH: Cross Reactions
- MESH: HLA Antigens
- MESH: Humans
- MESH: Molecular Sequence Data
- MESH: Mucous Membrane
- MESH: Mycobacterium tuberculosis
- [SDV.IMM]Life Sciences [q-bio]/Immunology