Displaying publications 41 - 43 of 43 in total

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  1. Fulltext Mucosal-associated invariant T cell alterations during the development of human type 1 diabetes
    Gazali AM, Schroderus AM, Näntö-Salonen K, Rintamäki R, Pihlajamäki J, Knip M, et al.
    Diabetologia, 2020 11;63(11):2396-2409.
    PMID: 32880687 DOI: 10.1007/s00125-020-05257-7
    AIMS/HYPOTHESIS: Mucosal-associated invariant T (MAIT) cells are innate-like T cells that recognise derivatives of bacterial riboflavin metabolites presented by MHC-Ib-related protein 1 (MR1) molecules and are important effector cells for mucosal immunity. Their development can be influenced by the intestinal microbiome. Since the development of type 1 diabetes has been associated with changes in the gut microbiome, this can be hypothesised to lead to alterations in circulating MAIT cells. Accordingly, peripheral blood MAIT cell alterations have been reported previously in patients with type 1 diabetes. However, a comprehensive analysis of the frequency and phenotype of circulating MAIT cells at different stages of type 1 diabetes progression is currently lacking.

    METHODS: We analysed the frequency, phenotype and functionality of peripheral blood MAIT cells, as well as γδ T cells, invariant natural killer T (iNKT) cells and natural killer (NK) cells with flow cytometry in a cross-sectional paediatric cohort (aged 2-15) consisting of 51 children with newly diagnosed type 1 diabetes, 27 autoantibody-positive (AAb+) at-risk children, and 113 healthy control children of similar age and HLA class II background. The frequency of MAIT cells was also assessed in a separate cross-sectional adult cohort (aged 19-39) of 33 adults with established type 1 diabetes and 37 healthy individuals of similar age.

    RESULTS: Children with newly diagnosed type 1 diabetes displayed a proportional increase of CD8-CD27- MAIT cells compared with healthy control children (median 4.6% vs 3.1% of MAIT cells, respectively, p = 0.004), which was associated with reduced expression of C-C chemokine receptor (CCR)5 (median 90.0% vs 94.3% of MAIT cells, p = 0.02) and β7 integrin (median 73.5% vs 81.7% of MAIT cells, p = 0.004), as well as decreased production of IFN-γ (median 57.1% vs 69.3% of MAIT cells, p = 0.04) by the MAIT cells. The frequency of MAIT cells was also decreased in AAb+ children who later progressed to type 1 diabetes compared with healthy control children (median 0.44% vs 0.96% of CD3+ T cells, p = 0.04), as well as in adult patients with a short duration of type 1 diabetes (less than 6 years after diagnosis) compared with control individuals (median 0.87% vs 2.19% of CD3+ T cells, p = 0.007). No alterations in γδ T cell, iNKT cell or NK cell frequencies were observed in children with type 1 diabetes or in AAb+ children, with the exception of an increased frequency of IL-17A+ γδ T cells in children with newly diagnosed diabetes compared with healthy control children (median 1.58% vs 1.09% of γδ T cells, p = 0.002).

    CONCLUSIONS/INTERPRETATION: Changes in the frequency and phenotype of circulating MAIT cells were detectable before, at the onset and after diagnosis of type 1 diabetes in cross-sectional cohorts. Our results suggest a possible temporal association between peripheral blood MAIT cell alterations and the clinical onset of type 1 diabetes. Graphical abstract.

    Matched MeSH terms: Interleukin-17
  2. The artificial loss of Runx1 reduces the expression of quiescence-associated transcription factors in CD4(+) T lymphocytes
    Wong WF, Kohu K, Nagashima T, Funayama R, Matsumoto M, Movahed E, et al.
    Mol Immunol, 2015 Dec;68(2 Pt A):223-33.
    PMID: 26350416 DOI: 10.1016/j.molimm.2015.08.012
    The Runx1 transcription factor cooperates with or antagonizes other transcription factors and plays essential roles in the differentiation and function of T lymphocytes. Previous works showed that Runx1 is expressed in peripheral CD4(+) T cells which level declines after T cell receptor (TCR) activation, and artificial deletion of Runx1 causes autoimmune lung disease in mice. The present study addresses the mechanisms by which Runx1 contributes to the maintenance of peripheral CD4(+) T cell quiescence. Microarray and quantitative RT-PCR analyses were employed to compare the transcriptome of Runx1 -/- CD4(+) T cells to those of unstimulated and TCR-stimulated Runx1 +/- cells. The results identified genes whose expression was modulated similarly by Runx1 deletion and TCR activation. Among them, genes encoding cytokines, chemokines, and Jak/STAT signaling molecules were substantially induced. In Runx1-deleted T cells, simultaneous increases in Il-17A and Rorγc, a known master gene in TH17 differentiation, were observed. In addition, we observed that the loss of Runx1 reduced the transcription of genes encoding quiescence-associated transcription factors, including Foxp1, Foxo1, and Klf2. Interestingly, we identified consensus Runx1 binding sites at the promoter regions of Foxp1, Foxo1, and Klf2 genes, which can be enriched by chromatin immunoprecipitation assay with an anti-Runx1 antibody. Therefore, we suggest that Runx1 may activate, directly or indirectly, the expression of quiescence-associated molecules and thereby contribute to the maintenance of quiescence in CD4(+) T cells.
    Matched MeSH terms: Interleukin-17/genetics; Interleukin-17/immunology
  3. Lipopolysaccharide Pre-conditioning Attenuates Pro-inflammatory Responses and Promotes Cytoprotective Effect in Differentiated PC12 Cell Lines via Pre-activation of Toll-Like Receptor-4 Signaling Pathway Leading to the Inhibition of Caspase-3/Nuclear Factor-κappa B Pathway
    Sangaran PG, Ibrahim ZA, Chik Z, Mohamed Z, Ahmadiani A
    Front Cell Neurosci, 2020;14:598453.
    PMID: 33551748 DOI: 10.3389/fncel.2020.598453
    Lipopolysacharide (LPS) pre-conditioning (PC), has been shown to exert protective effects against cytotoxic effects. Therefore, we hypothesized, the tolerance produced by LPS PC will be resulted by the alterations and modifications in gene and protein expression. With reference to the results of MTT assays, AO/PI staining, and Annexin V-FITC analyses of LPS concentration (0.7815-50 μg/mL) and time-dependent (12-72 h) experiments, the pre-exposure to 3 μg/mL LPS for 12 h protected the differentiated PC12 cells against 0.75 mg/mL LPS apoptotic concentration. LPS-treated cells secreted more inflammatory cytokines like IL-1α, IL-1β, IL-2, IL-3, IL-4, IL-6, IL-17, IFN-γ, and TNF-α than LPS-PC cells. The production of inflammatory mediators ROS and NO was also higher in the LPS-induced cells compared to LPS-PC cells. Conversely, anti-inflammatory cytokines (like IL-10, IL-13, CNTF, and IL-1Ra) were upregulated in the LPS-PC cells but not in the LPS-induced cells. Meanwhile, the LPS initiated caspase-8 which in turn activates effector caspase 3/7. When the activities of caspases in the LPS-induced cells were inhibited using z-VADfmk and z-DEVDfmk, the expressions of c-MYC and Hsp70 were increased, but p53 was reduced. The potential molecules associated with protective and destructive effect was measured by RT2 Profiler PCR array to elucidate the signaling pathways and suggested inhibition NF-κB/caspase-3 signaling pathway regulates the cytoprotective genes and proto-oncogenes. In conclusion, this study provides a basis for future research to better understand the molecular mechanism underlying LPS pre-conditioning /TLR4 pre-activation and its functional role in offering cytoprotective response in neuronal environment.
    Matched MeSH terms: Interleukin-17
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