The diverse roles of mucosal-associated invariant T lymphocytes in hematological malignancies

The majority of studies on Novel Mucosal-associated invariant T (MAIT) cells have focused on their involvement in solid tumours; however, the role and significance of MAIT cells in hematological malignancies are not well understood and have not been thoroughly investigated. MAIT cells is a population of αβ T cells that recognize non-peptide antigens presented by the non-polymorphic MR1 molecule. They are characterized by the expression of Vα7.2 together with high expression of the CD161. MAIT cells have been linked to a variety of tumours including, solid tumours such as hepatocellular carcinoma, colorectal, lung and kidney cancers and their frequencies in the tumour sites appeared to correlate with prognosis. MAIT cells were also studied in hematological malignancies such as multiple myeloma and leukaemia. In this review we will outline our current understanding of the relationship between MAIT cells and hematological malignancies, which will underline the possibility of targeting this subset for modern immunotherapy development.