MHC class I-related molecule, MR1, and mucosal-associated invariant T cells.
The MHC-related 1, MR1, molecule presents a new class of microbial antigens (derivatives of the riboflavin [Vitamin B2] biosynthesis pathway) to mucosal-associated invariant T (MAIT) cells. This raises many questions regarding antigens loading and intracellular trafficking of the MR1/ligand complexes. The MR1/MAIT field is also important because MAIT cells are very abundant in humans and their frequency is modified in many infectious and non-infectious diseases. Both MR1 and the invariant TCRα chain expressed by MAIT cells are strikingly conserved among species, indicating important functions. Riboflavin is synthesized by plants and most bacteria and yeasts but not animals, and its precursor derivatives activating MAIT cells are short-lived unless bound to MR1. The recognition of MR1 loaded with these compounds is therefore an exquisite manner to detect invasive bacteria. Herein, we provide an historical perspective of the field before describing the main characteristics of MR1, its ligands, and the few available data regarding its cellular biology. We then summarize the current knowledge of MAIT cell differentiation and discuss the definition of MAIT cells in comparison to related subsets. Finally, we describe the phenotype and effector activities of MAIT cells.
Institut curie, Inserm U932, Paris, France.
Katarzyna
K
Franciszkiewicz
Institut curie, Inserm U932, Paris, France.
Marion
M
Salou
Institut curie, Inserm U932, Paris, France.
Francois
F
Legoux
Institut curie, Inserm U932, Paris, France.
Qian
Q
Zhou
Institut curie, Inserm U932, Paris, France.
Yue
Y
Cui
Institut curie, Inserm U932, Paris, France.
Stéphanie
S
Bessoles
Institut curie, Inserm U932, Paris, France.|Center of Clinical Investigations, CICBT1428 IGR/Curie, Paris, France.|Laboratoire d'Immunologie Clinique, Institut Curie, Paris, France.
Olivier
O
Lantz
D000818:Animals; D002454:Cell Differentiation; D006649:Histocompatibility Antigens / Q000378:metabolism; D015395:Histocompatibility Antigens Class I / Q000378:metabolism*; D006801:Humans; D018928:Immunity, Mucosal; D015778:Minor Histocompatibility Antigens / Q000378:metabolism*; D000072336:Mucosal-Associated Invariant T Cells / Q000276:immunology*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000378:metabolism; D012256:Riboflavin / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology*
D006649:Histocompatibility Antigens; D015395:Histocompatibility Antigens Class I; C094840:MR1 protein, human; D015778:Minor Histocompatibility Antigens; D016693:Receptors, Antigen, T-Cell, alpha-beta; D012256:Riboflavin
MAIT cells; MR1; bacterial infection; riboflavin