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- Houtman, Miranda, et al.
(författare)
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T cells are influenced by a long non-coding RNA in the autoimmune associated PTPN2 locus
- 2018
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Ingår i: Journal of Autoimmunity. - : ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD. - 0896-8411 .- 1095-9157. ; 90, s. 28-38
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Tidskriftsartikel (refereegranskat)abstract
- Non-coding SNPs in the protein tyrosine phosphatase non-receptor type 2 (PTPN2) locus have been linked with several autoimmune diseases, including rheumatoid arthritis, type I diabetes, and inflammatory bowel disease. However, the functional consequences of these SNPs are poorly characterized. Herein, we show in blood cells that SNPs in the PTPN2 locus are highly correlated with DNA methylation levels at four CpG sites downstream of PTPN2 and expression levels of the long non-coding RNA (IncRNA) LINC01882 downstream of these CpG sites. We observed that LINC01882 is mainly expressed in T cells and that anti-CD3/CD28 activated naive CD4(+) T cells downregulate the expression of LINC01882. RNA sequencing analysis of LINC01882 knockdown in Jurkat T cells, using a combination of antisense oligo-nucleotides and RNA interference, revealed the upregulation of the transcription factor ZEB1 and kinase MAP2K4, both involved in IL-2 regulation. Overall, our data suggests the involvement of LINC01882 in T cell activation and hints towards an auxiliary role of these non-coding SNPs in autoimmunity associated with the PTPN2 locus.
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| 2. |
- Pieper, Jennifer, et al.
(författare)
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Memory T cells specific to citrullinated alpha-enolase are enriched in the rheumatic joint
- 2018
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Ingår i: Journal of Autoimmunity. - : ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD. - 0896-8411 .- 1095-9157. ; 92, s. 47-56
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Tidskriftsartikel (refereegranskat)abstract
- ACPA-positive rheumatoid arthritis (RA) is associated with distinct HLA-DR alleles and immune responses to many citrullinated self-antigens. Herein we investigated the T cell epitope confined within alpha-enolase(326-340) in the context of HLA-DRB1*04:01 and assessed the corresponding CD4(+) T cells in both the circulation and in the rheumatic joint. Comparative crystallographic analyses were performed for the native and citrullinated alpha-enolase(326-340) peptides in complex with HLA-DRB1*04:01. HLA-tetramers assembled with either the native or citrullinated peptide were used for ex vivo and in vitro assessment of a enolase-specific T cells in peripheral blood, synovial fluid and synovial tissue by flow cytometry. The native and modified peptides take a completely conserved structural conformation within the peptide binding cleft of HLA-DRB1*04:01. The citrulline residue-327 was located N-terminally, protruding towards TCRs. The frequencies of T cells recognizing native eno(326-340) were similar in synovial fluid and peripheral blood, while in contrast, the frequency of T cells recognizing cit-eno(326-340) was significantly elevated in synovial fluid compared to peripheral blood (3.6-fold, p = 0.0150). Additionally, citrulline-specific T cells with a memory phenotype were also significantly increased (1.6-fold, p = 0.0052) in synovial fluid compared to peripheral blood. The native T cell epitope confined within alpha-enolase(326-340) does not appear to lead to complete negative selection of cognate CD4(+) T cells. In RA patient samples, only T cells recognizing the citrullinated version of alpha-enolase(326-340) were found at elevated frequencies implicating that neo-antigen formation is critical for breach of tolerance. (C) 2018 Elsevier Ltd. All rights reserved.
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