Bacteria, mucosal‐associated invariant T cells and MR1

@article{Chua2010BacteriaMI,
  title={Bacteria, mucosal‐associated invariant T cells and MR1},
  author={Wei-Jen Chua and Ted. H. Hansen},
  journal={Immunology and Cell Biology},
  year={2010},
  volume={88}
}
Certain subpopulations of T lymphoctyes show innate-like properties that distinguish them from conventional T cells and thus have been collectively termed innate T cells. Two extensively studied subsets of innate T cells implicated in pathogen detection are invariant natural killer T (iNKT) cells and γδ T cells. Conventional T cells detect pathogens in a manner that is exquisitely antigen specific, based on discrimination of peptides bound to classical major histocompatibility complex (MHC… 
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TLDR
It is shown that both mouse and human MAIT cells display a high level of cross-reactivity on mammalian MR1 orthologs, but with differences consistent with limited ligand discrimination, demonstrating that the presentation pathway of MR1 toMAIT cells is highly evolutionarily conserved.
MR1 uses an endocytic pathway to activate mucosal-associated invariant T cells
TLDR
It is demonstrated that MR1 antigen presentation is not affected by either the proteasome or the class I chaperones, and the class II chaperone invariant chain, Ii, physically associates with MR1 and promotes its endosomal trafficking.
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TLDR
It is shown that T cells that express the canonical hVα7.2-Jα33 or mVα19-J α33 TCR rearrangement are preferentially located in the gut lamina propria of humans and mice, respectively, and are therefore genuine mucosal-associated invariant T (MAIT) cells.
Vα14i NKT Cells Are Innate Lymphocytes That Participate in the Immune Response to Diverse Microbes
TLDR
Recent studies have shed light on the natural antigens recognized by NKT cells and the mechanisms whereby they contribute to host defense, and they suggest that these unique T cells have evolved to jump start the immune response to microbes.
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TLDR
MAIT cells are evolutionarily conserved innate-like lymphocytes that sense and help fight off microbial infection and protect against infection by Mycobacterium abscessus or Escherichia coli.
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TLDR
Monoclonal antibodies were produced in MR1 knock-out mice immunized with recombinant MR1 protein, and a series of MR1 mutations were generated at sites previously shown to disrupt the ability of class Ia molecules to bind peptide or TCR, supporting the conclusion that MR1 has an antigen presentation function.
MR1-Restricted Vα19i Mucosal-Associated Invariant T Cells Are Innate T Cells in the Gut Lamina Propria That Provide a Rapid and Diverse Cytokine Response1
TLDR
Evidence is provided for what may be two functionally distinct MAIT cell populations, and the idea that MAIT cells contribute to the innate immune response in the gut mucosa is strongly supported.
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TLDR
MAIT cells are selected by MR1 in the thymus on a non-B non-T hematopoietic cell, and acquire a memory phenotype and expand in the periphery in a process dependent both upon B cells and the bacterial flora.
Invariant Vα19i T cells regulate autoimmune inflammation
TLDR
It is demonstrated that T cells expressing the Vα19i TCR transgene inhibited the induction and progression of experimental autoimmune encephalomyelitis (EAE) in a mouse model of multiple sclerosis, suggesting an immunoregulatory function for Vα 19i T cells.
Human Mucosal Associated Invariant T Cells Detect Bacterially Infected Cells
A first indication of the biological role of mucosal associated invariant T (MAIT) cells reveals that this discrete T cell subset is broadly reactive to bacterial infection. In particular MAIT cells
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