bims-maitce 2025-01-05 papers

Issue of 2025–01–05
three papers selected by
Andy E. Hogan, Maynooth University

Zhongguo Shi Yan Xue Ye Xue Za Zhi. 2024 Dec;32(6): 1644-1650

[Expression and Function of MAIT Cells in Patients with Newly Diagnosed Acute Myeloid Leukemia].

Qian Peng, Zhi-Tao Wang, Ren-Hua Huang, Hui-Ping Wang, Hao Xiao, Zhi-Min Zhai.

OBJECTIVE: To explore the changes in number and immune function of mucosal-associated invariant T (MAIT) cells in peripheral blood of patients with newly diagnosed acute myeloid leukemia (AML), and its correlation with the occurrence and development of AML.
METHODS: Seventy-five clinical samples of patients with newly diagnosed AML and 48 healthy control samples in our hospital from January 2022 to February 2023 were included. Multiparametric flow cytometry was used to detect the number of MAIT cells, membrane surface markers, effector phenotypes and functional indicators in the samples.
RESULTS: Compared with healthy controls, the percentage of MAIT cells in CD3+ T cells in peripheral blood of newly diagnosed AML patients was significantly reduced ( P < 0.001). The percentage of MAIT cells in all CD3+ T cells in bone marrow of AML patients was similar to that in peripheral blood (P >0.05). Most of MAIT cells in peripheral blood of AML patients were effector memory T cells. Compared with healthy controls, the proportion of effector memory MAIT cells decreased ( P < 0.05), while the proportion of terminally differentiated effector memory MAIT cells and PD-1+MAIT cells increased significantly (both P < 0.05). AML patients' peripheral blood MAIT cells expressed significantly higher levels of granzyme B and perforin than healthy controls (both P < 0.05), and secreted significantly lower levels of cytokines such as gamma interferon and tumor necrosis factor α than healthy controls (both P < 0.001).
CONCLUSION: Compared with healthy controls, the proportion of MAIT cells in AML patients is reduced and the expression of functional markers is abnormal, suggesting that their function is impaired and may be involved in the occurrence and development of AML.

Keywords: acute myeloid leukemia; immunocyte; mucosal-associated invariant T cell; programmed death-1; cytokine

DOI: https://doi.org/10.19746/j.cnki.issn.1009-2137.2024.06.003

J Clin Invest. 2025 Jan 02. pii: e181895. [Epub ahead of print]135(1):

The T cell antigen presentation platform MR1 consists of 6 allomorphs in humans that differ by no more than 5 amino acids. The principal function of this highly conserved molecule involves presenting microbial metabolites to the abundant mucosal-associated invariant T (MAIT) cell subset. Recent developments suggest that the role of MR1 extends to presenting antigens from cancer cells, a function dependent on the K43 residue in the MR1 antigen binding cleft. Here, we successfully cultured cancer-activated, MR1-restricted T cells from multiple donors and confirmed that they recognized a wide range of cancer types expressing the most common MR1*01 and/or MR1*02 allomorphs (over 95% of the population), while remaining inert to healthy cells including healthy B cells and monocytes. Curiously, in all but one donor these T cells were found to incorporate a conserved TCR-α chain motif, CAXYGGSQGNLIF (where X represents 3-5 amino acids), because of pairing between 10 different TRAV genes and the TRAJ42 gene segment. This semi-invariance in the TCR-α chain is reminiscent of MAIT cells and suggests recognition of a conserved antigen bound to K43.

Keywords: Cancer; Cellular immune response; Immunology; Oncology; T cells

DOI: https://doi.org/10.1172/JCI181895

Turk J Med Sci. 2024 ;54(6): 1265-1270

Evaluation of the association of mucosa-associated invariant T (MAIT) cells with childhood asthma.

Meral Ekşi, Huri Bulut, Erdem Akalin, Feyza Ustabaş Kahraman, Hakan Yazan, Mebrure Yazici, Mustafa Atilla Nursoy, Emin Özkaya, Abdürrahim Koçyiğit, Erkan Çakir.

Background/aim: Innate-like T lymphocytes are a recently defined group of T cells comprising mainly mucosa-associated invariant T (MAIT) cells. The relationship between MAIT cells and childhood asthma is controversial. In this study, we aimed to determine the role of MAIT cells in patients with allergic asthma (AA) and nonallergic asthma (NAA). This is the first study to compare the ratios of these cells in patients with AA and NAA.
Materials and methods: The study included children aged 6-18 years with AA (n = 41) or NAA (n = 30) and healthy control subjects (n = 36). The control group consisted of children who presented to the outpatient clinic without chronic disease, malnutrition, or acute or chronic infection. The proportions of MAIT, TH17, MAIT-17, and Th17-17 cells were investigated by flow cytometry and compared among the AA, NAA, and control groups.
Results: When the AA and NAA patient groups were compared, the mean MAIT cell ratio was significantly lower in NAA patients (median: 0.45, p < 0.05). MAIT cell ratios were also substantially lower in NAA patients compared to the control group (mean: 0.504, p < 0.05). TH17, MAIT-17, and TH17-17 cell values were not statistically significant among the groups.
Conclusion: Our study found that MAIT cell ratios were lower in the NAA patient group compared to the control group and AA patients. It has been predicted that MAIT cell depletion may have a role in the development of NAA. Our study is the first on this subject in the literature and further studies are needed.

Keywords: Mucosa-associated invariant T cells; T helper 17 cell; allergy; childhood asthma; innate cells; interleukin 17

DOI: https://doi.org/10.55730/1300-0144.5908