bims-maitce 2024-06-09 papers

Issue of 2024‒06‒09
three papers selected by
Andy E. Hogan, Maynooth University

Curr Opin Virol. 2024 Jun 04. pii: S1879-6257(24)00026-9. [Epub ahead of print]67 101412

Role of mucosal-associated invariant T cells in coronavirus disease 2019 vaccine immunogenicity.

Ali Amini, Paul Klenerman, Nicholas M Provine.

Mucosal-associated invariant T (MAIT) cells are an unconventional T cell population that are highly abundant in humans. They possess a semi-invariant T cell receptor (TCR) that recognises microbial metabolites formed during riboflavin biosynthesis, presented on a nonpolymorphic MHC-like molecule MR1. MAIT cells possess an array of effector functions, including type 1, type 17, and tissue repair activity. Deployment of these functions depends on the stimuli they receive through their TCR and/or cytokine receptors. Strong cytokine signalling, such as in response to vaccination, can bypass TCR triggering and provokes a strong proinflammatory response. Although data are still emerging, multiple aspects of MAIT cell biology are associated with modulation of immunity induced by the coronavirus disease 2019 mRNA and adenovirus vector vaccines. In this review, we will address how MAIT cells may play a role in immunogenicity of vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and how these cells can be harnessed as cellular adjuvants.

DOI: https://doi.org/10.1016/j.coviro.2024.101412

Front Immunol. 2024 ;15 1391280

Inflammatory activity evaluation in patients with axial spondyloarthritis using MRI relaxometry and mucosal-associated invariant T cells.

Shengsheng Yang, Yonghong Zheng, Xianyuan Chen, Mingui Lin, Xiaomin Dai, Fei Gao, Huangjing Chen, Mingping Ma, Shun Yu.

Background: Currently, there is a lack of an objective quantitative measure to comprehensively evaluate the inflammatory activity of axSpA, which poses certain challenges in accurately assessing the disease activity.Objective: To explore the value of combined-parameter models of sacroiliac joints (SIJs) MRI relaxometry and peripheral blood Mucosal-associated invariant T (MAIT) cells in evaluating the inflammatory activity of axial spondyloarthritis (axSpA).
Methods: This retrospective clinical study included 88 axSpA patients (median age 31.0 (22.0, 41.8) years, 21.6% females) and 20 controls (median age 28.0 (20.5, 49.5) years, 40.0% females). The axSpA group was classified into active subgroup (n=50) and inactive subgroup (n=38) based on ASDAS-CRP. All participants underwent SIJs MRI examination including T1 and T2* mapping, and peripheral blood flow cytometry analysis of MAIT cells (defined as CD3+Vα7.2+CD161+) and their activation markers (CD69). The T1 and T2* values, as were the percentages of MAIT cells and CD69+MAIT cells were compared between different groups. Combined-parameter models were established using logistic regression, and ROC curves were employed to evaluate the diagnostic efficacy.
Results: The T1 values of SIJs and %CD69+MAIT cells in the axSpA group and its subgroup were higher than the control group (p<0.05), while %MAIT cells were lower than the control group (p<0.05). The T1 values and %CD69+MAIT cells correlated positively, while %MAIT cells correlated negatively, with the ASDAS-CRP (r=0.555, 0.524, -0.357, p<0.001). Between the control and axSpA groups, and between the inactive and active subgroups, the combined-parameter model T1 mapping+%CD69+MAIT cells has the best efficacy (AUC=0.959, 0.879, sensibility=88.6, 70%, specificity=95.0, 94.7%, respectively).
Conclusion: The combined-parameter model T1 mapping+%CD69+MAIT cells allows a more accurate evaluation of the level of inflammatory activity.

Keywords: T1 mapping; axial spondyloarthritis; combined-parameter model; magnetic resonance; mucosal-associated invariant T cells

DOI: https://doi.org/10.3389/fimmu.2024.1391280

J Clin Immunol. 2024 Jun 01. 44(6): 139

Unconventional T Cells Influence Clinical Outcome After Allogeneic Hematopoietic Cell Transplantation.

Lama Siblany, Nicolas Stocker, Laure Ricard, Eolia Brissot, Rémy Duléry, Anne Banet, Simona Sestili, Ramdane Belhocine, Zoé Van de Wyngaert, Agnès Bonnin, Antoine Capes, Tounes Ledraa, Pauline Beurier, Karen Fadel, Mohamad Mohty, Béatrice Gaugler, Florent Malard.

We evaluated the impact of early recovery of mucosal-associated invariant T cells (MAIT) and gamma-delta (γδ) T cells, especially Vδ2+ T cells, on the clinical outcomes of 76 patients who underwent allogeneic hematopoietic cell transplantation (allo-HCT). MAIT cells were identified at day 20-30 post-transplant using flow cytometry and defined as CD3+ TCRVα7.2+CD161+. Two subsets of Vδ2+ T cells were analyzed according to the expression of CD26. The cytotoxicity profile of MAIT and Vδ2+ T cells was analyzed according to the intracellular expression of perforin and granzyme B, and intracellular IFN-γ was evaluated after in vitro activation. CD26+Vδ2+ T cells displayed higher intracellular levels of IFN-γ, whereas CD26- Vδ2+ T were found to be more cytotoxic. Moreover, MAIT cell frequency was correlated with the frequency of Vδ2+ T cells with a better correlation observed with Vδ2+CD26+ than with the Vδ2+CD26- T cell subset. By using the composite endpoint graft-versus-host disease (GvHD)-free, relapse-free survival (GRFS) as the primary endpoint, we found that patients with a higher MAIT cell frequency at day 20-30 after allo-HCT had a significantly increased GRFS and a better overall survival (OS) and disease-free survival (DFS). Moreover, patients with a low CD69 expression by MAIT cells had an increased cumulative incidence of grade 2-4 acute GvHD (aGvHD). These results suggest that MAIT cell reconstitution may provide mitigating effects early after allo-HCT depending on their activation markers and functional status. Patients with a high frequency of Vδ2+CD26+ T cells had a significantly higher GRFS, OS and DFS, but there was no impact on cumulative incidence of grade 2-4 aGVHD, non-relapse mortality and relapse. These results revealed that the impact of Vδ2+ T cells on the success of allo-HCT may vary according to the frequency of the CD26+ subset.

Keywords: Acute graft-versus-host disease; Allogeneic hematopoietic cell transplantation (allo-HCT); Mucosal-associated invariant T cells (MAIT); Vδ2+ T cells

DOI: https://doi.org/10.1007/s10875-024-01741-6