| 1. |
- Arvidsson, Gustav, et al.
(författare)
-
Multimodal Single-Cell Sequencing of B Cells in Primary Sjögren's Syndrome
- 2024
-
Ingår i: Arthritis & Rheumatology. - 2326-5191 .- 2326-5205. ; 76:2, s. 255-267
-
Tidskriftsartikel (refereegranskat)abstract
- Objective. B cells are important in the pathogenesis of primary Sjögren's syndrome (pSS). Patients positive for Sjögren's syndrome antigen A/Sjögren syndrome antigen B (SSA/SSB) autoantibodies are more prone to systemic disease manifestations and adverse outcomes. We aimed to determine the role of B cell composition, gene expression, and B cell receptor usage in pSS subgroups stratified for SSA/SSB antibodies.Methods. Over 230,000 B cells were isolated from peripheral blood of patients with pSS (n = 6 SSA−, n = 8 SSA+ single positive and n = 10 SSA/SSB+ double positive) and four healthy controls and processed for single-cell RNA sequencing (scRNA-seq) and single-cell variable, diversity, and joining (VDJ) gene sequencing (scVDJ-seq).Results. We show that SSA/SSB+ patients present the highest and lowest proportion of naïve and memory B cells, respectively, and the highest up-regulation of interferon-induced genes across all B cell subtypes. Differential usage of IGHV showed that IGHV1-69 and IGHV4-30-4 were more often used in all pSS subgroups compared with controls. Memory B cells from SSA/SSB+ patients displayed a higher proportion of cells with unmutated VDJ transcripts compared with other pSS patient groups and controls, indicating altered somatic hypermutation processes. Comparison with previous studies revealed heterogeneous clonotype pools, with little overlap in CDR3 sequences. Joint analysis using scRNA-seq and scVDJ-seq data allowed unsupervised stratification of patients with pSS and identified novel parameters that correlated to disease manifestations and antibody status.Conclusion. We describe heterogeneity and molecular characteristics in B cells from patients with pSS, providing clues to intrinsic differences in B cells that affect the phenotype and outcome and allowing stratification of patients with pSS at improved resolution.
|
|
| 2. |
- Björk, Albin, et al.
(författare)
-
Protein and DNA methylation-based scores as surrogate markers for interferon system activation in patients with primary Sjögren's syndrome
- 2020
-
Ingår i: RMD Open. - : BMJ PUBLISHING GROUP. - 2056-5933. ; 6:1
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: Standard assessment of interferon (IFN) system activity in systemic rheumatic diseases depends on the availability of RNA samples. In this study, we describe and evaluate alternative methods using plasma, serum and DNA samples, exemplified in the IFN-driven disease primary Sjogren's syndrome (pSS).Methods: Patients with pSS seropositive or negative for anti-SSA/SSB and controls were included. Protein-based IFN (pIFN) scores were calculated from levels of PD-1, CXCL9 and CXCL10. DNA methylation-based (DNAm) IFN scores were calculated from DNAm levels at RSAD2, IFIT1 and IFI44L. Scores were compared with mRNA-based IFN scores measured by quantitative PCR (qPCR), Nanostring or RNA sequencing (RNAseq).Results: mRNA-based IFN scores displayed strong correlations between B cells and monocytes (r=0.93 and 0.95, p<0.0001) and between qPCR and Nanostring measurements (r=0.92 and 0.92, p<0.0001). The pIFN score in plasma and serum was higher in patients compared with controls (p<0.0001) and correlated well with mRNA-based IFN scores (r=0.62-0.79, p<0.0001), as well as with each other (r=0.94, p<0.0001). Concordance of classification as 'high' or 'low' IFN signature between the pIFN score and mRNA-based IFN scores ranged from 79.5% to 88.6%, and the pIFN score was effective at classifying patients and controls (area under the curve, AUC=0.89-0.93, p<0.0001). The DNAm IFN score showed strong correlation to the RNAseq IFN score (r=0.84, p<0.0001) and performed well in classifying patients and controls (AUC=0.96, p<0.0001).Conclusions: We describe novel methods of assessing IFN system activity in plasma, serum or DNA samples, which may prove particularly valuable in studies where RNA samples are not available.
|
|
| 3. |
- Bolin, Karin, et al.
(författare)
-
Variants in BANK1 are associated with lupus nephritis of European ancestry
- 2021
-
Ingår i: Genes and Immunity. - : Springer Nature. - 1466-4879 .- 1476-5470. ; 22:3, s. 194-202
-
Tidskriftsartikel (refereegranskat)abstract
- The genetic background of lupus nephritis (LN) has not been completely elucidated. We performed a case-only study of 2886 SLE patients, including 947 (33%) with LN. Renal biopsies were available from 396 patients. The discovery cohort (Sweden, n = 1091) and replication cohort 1 (US, n = 962) were genotyped on the Immunochip and replication cohort 2 (Denmark/Norway, n = 833) on a custom array. Patients with LN, proliferative nephritis, or LN with end-stage renal disease were compared with SLE without nephritis. Six loci were associated with LN (p < 1 × 10−4, NFKBIA, CACNA1S, ITGA1, BANK1, OR2Y, and ACER3) in the discovery cohort. Variants in BANK1 showed the strongest association with LN in replication cohort 1 (p = 9.5 × 10−4) and proliferative nephritis in a meta-analysis of discovery and replication cohort 1. There was a weak association between BANK1 and LN in replication cohort 2 (p = 0.052), and in the meta-analysis of all three cohorts the association was strengthened (p = 2.2 × 10−7). DNA methylation data in 180 LN patients demonstrated methylation quantitative trait loci (meQTL) effects between a CpG site and BANK1 variants. To conclude, we describe genetic variations in BANK1 associated with LN and evidence for genetic regulation of DNA methylation within the BANK1 locus. This indicates a role for BANK1 in LN pathogenesis.
|
|
| 4. |
- Imgenberg-Kreuz, Juliana, et al.
(författare)
-
DNA Methylation-Based Interferon Scores Associate With Sub-Phenotypes in Primary Sjögren's Syndrome
- 2021
-
Ingår i: Frontiers in Immunology. - : Frontiers Media S.A.. - 1664-3224. ; 12
-
Tidskriftsartikel (refereegranskat)abstract
- Primary Sjogren's syndrome (pSS) is an autoimmune inflammatory disease with profound clinical heterogeneity, where excessive activation of the type I interferon (IFN) system is considered one of the key mechanisms in disease pathogenesis. Here we present a DNA methylation-based IFN system activation score (DNAm IFN score) and investigate its potential associations with sub-phenotypes of pSS. The study comprised 100 Swedish patients with pSS and 587 Swedish controls. For replication, 48 patients with pSS from Stavanger, Norway, were included. IFN scores were calculated from DNA methylation levels at the IFN-induced genes RSAD2, IFIT1 and IFI44L. A high DNAm IFN score, defined as > mean(controls) +2SD(controls) (IFN score > 4.4), was observed in 59% of pSS patients and in 4% of controls (p=1.3x10(-35)). Patients with a high DNAm IFN score were on average seven years younger at symptom onset (p=0.017) and at diagnosis (p=3x10(-3)). The DNAm IFN score levels were significantly higher in pSS positive for both SSA and SSB antibodies compared to SSA/SSB negative patients (p(discovery)=1.9x10(-8), p(replication)=7.8x10(-4)). In patients positive for both SSA subtypes Ro52 and Ro60, an increased score was identified compared to single positive patients (p=0.022). Analyzing the discovery and replication cohorts together, elevated DNAm IFN scores were observed in pSS with hypergammaglobulinemia (p=2x10(-8)) and low C4 (p=1.5x10(-3)) compared to patients without these manifestations. Patients < 70 years with ongoing lymphoma at DNA sampling or lymphoma at follow-up (n=7), presented an increased DNAm IFN score compared to pSS without lymphoma (p=0.025). In conclusion, the DNAm-based IFN score is a promising alternative to mRNA-based scores for identification of patients with activation of the IFN system and may be applied for patient stratification guiding treatment decisions, monitoring and inclusion in clinical trials.
|
|
| 5. |
- Imgenberg-Kreuz, Juliana, et al.
(författare)
-
Genetics and epigenetics in primary Sjögren's syndrome
- 2021
-
Ingår i: Rheumatology. - : Oxford University Press. - 1462-0324 .- 1462-0332. ; 60:5, s. 2085-2098
-
Forskningsöversikt (refereegranskat)abstract
- Primary Sjögren's syndrome (pSS) is considered to be a multifactorial disease, where underlying genetic predisposition, epigenetic mechanisms and environmental factors contribute to disease development. In the last 5 years, the first genome-wide association studies in pSS have been completed. The strongest signal of association lies within the HLA genes, whereas the non-HLA genes IRF5 and STAT4 show consistent associations in multiple ethnicities but with a smaller effect size. The majority of the genetic risk variants are found at intergenic regions and their functional impact has in most cases not been elucidated. Epigenetic mechanisms such as DNA methylation, histone modifications and non-coding RNAs play a role in the pathogenesis of pSS by their modulating effects on gene expression and may constitute a dynamic link between the genome and phenotypic manifestations. This article reviews the hitherto published genetic studies and our current understanding of epigenetic mechanisms in pSS.
|
|
| 6. |
- Khatri, B., et al.
(författare)
-
Genome-wide association study identifies Sjogren's risk loci with functional implications in immune and glandular cells
- 2022
-
Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
-
Tidskriftsartikel (refereegranskat)abstract
- Sjogren's disease is a complex autoimmune disease with twelve established susceptibility loci. This genome-wide association study (GWAS) identifies ten novel genome-wide significant (GWS) regions in Sjogren's cases of European ancestry: CD247, NAB1, PTTG1-MIR146A, PRDM1-ATG5, TNFAIP3, XKR6, MAPT-CRHR1, RPTOR-CHMP6-BAIAP6, TYK2, SYNGR1. Polygenic risk scores yield predictability (AUROC = 0.71) and relative risk of 12.08. Interrogation of bioinformatics databases refine the associations, define local regulatory networks of GWS SNPs from the 95% credible set, and expand the implicated gene list to >40. Many GWS SNPs are eQTLs for genes within topologically associated domains in immune cells and/or eQTLs in the main target tissue, salivary glands. The genetic architecture underlying Sjogren's syndrome is not fully understood. Here, the authors perform a genome-wide association study to identify 10 new genetic risk regions, implicating genes involved in immune and salivary gland function.
|
|
| 7. |
- Lundtoft, Christian, et al.
(författare)
-
Function of multiple sclerosis-protective HLA class I alleles revealed by genome-wide protein-quantitative trait loci mapping of interferon signalling
- 2020
-
Ingår i: PLOS Genetics. - : Public Library of Science (PLoS). - 1553-7390 .- 1553-7404. ; 16:10
-
Tidskriftsartikel (refereegranskat)abstract
- Interferons (IFNs) are cytokines that are central to the host defence against viruses and other microorganisms. If not properly regulated, IFNs may contribute to the pathogenesis of inflammatory autoimmune, or infectious diseases. To identify genetic polymorphisms regulating the IFN system we performed an unbiased genome-wide protein-quantitative trait loci (pQTL) mapping of cell-type specific type I and type II IFN receptor levels and their responses in immune cells from 303 healthy individuals. Seven genome-wide significant (p < 5.0E-8) pQTLs were identified. Two independent SNPs that tagged the multiple sclerosis (MS)-protective HLA class I alleles A*02/A*68 and B*44, respectively, were associated with increased levels of IFNAR2 in B and T cells, with the most prominent effect in IgD–CD27+ memory B cells. The increased IFNAR2 levels in B cells were replicated in cells from an independent set of healthy individuals and in MS patients. Despite increased IFNAR2 levels, B and T cells carrying the MS-protective alleles displayed a reduced response to type I IFN stimulation. Expression and methylation-QTL analysis demonstrated increased mRNA expression of the pseudogene HLA-J in B cells carrying the MS-protective class I alleles, possibly driven via methylation-dependent transcriptional regulation. Together these data suggest that the MS-protective effects of HLA class I alleles are unrelated to their antigen-presenting function, and propose a previously unappreciated function of type I IFN signalling in B and T cells in MS immune-pathogenesis.Author summaryGenetic association studies have been very successful in identifying disease-associated single nucleotide polymorphisms (SNPs), but it has been challenging to define the molecular mechanisms underlying these associations. As interferons (IFNs) have a central role in the immune system, we hypothesized that some of the SNPs associated to immune-mediated diseases would affect the IFN system. By combining genetic data with characterization of interferon receptor levels and their responses on the protein level in immune cells from 303 genotyped healthy individuals, we show that two SNPs tagging the HLA class I alleles A*02/A*68 and B*44 are associated with a decreased response to type I IFN stimulation in B cells and T cells. Notably, both HLA-A*02 and HLA-B*44 confer protection from developing multiple sclerosis (MS), which is a chronic inflammatory neurologic disease. In addition to suggesting a pathogenic role of enhanced type I interferon signalling in B cells and T cells in MS, our data emphasize the fact that genetic associations in the HLA locus can affect functions not directly associated to antigen presentation, which conceptually may be important for other diseases genetically associated to the HLA locus.
|
|
| 8. |
- Mortensen, Anja, et al.
(författare)
-
Utilizing CD44v6 and V600EBRAF-mutation for in vitro targeted combination therapy of thyroid carcinomas
- 2023
-
Ingår i: Heliyon. - : Cell Press. - 2405-8440. ; 9:12
-
Tidskriftsartikel (refereegranskat)abstract
- Aim: The aim of this study was to assess the feasibility of targeted therapy of thyroid carcinoma, first exploring potential targets BRAF, EGFR and CD44v6 in patient material through immunohistochemistry and mutation analysis.Materials and methods: A patient cohort (n = 22) consisting of seven papillary (PTC), eight anaplastic (ATC) and seven follicular (FTC) thyroid carcinomas were evaluated. Additionally, eight thyroid carcinoma cells lines were analyzed for CD44v6-expression and sensitivity to the multi-kinase inhibitor sorafenib (Nexavar (R)), which targets numerous serine/threonine and tyrosine kinases, including the Raf family kinases. Targeted therapy using 131I-AbN44v6, a novel anti-CD44v6 antibody, and/or sorafenib was evaluated in 3D multicellular tumor spheroids. RResults: Of the two cell surface proteins, EGFR and CD44v6, the latter was overexpressed in >80 % of samples, while EGFR-expression levels were moderate at best in only a few samples. BRAF mutations were more common in PTC patient samples than in ATC samples, while FTC samples did not harbor BRAF mutations. CD44v6-expression levels in the thyroid carcinoma cell lines were more heterogenous compared to patient samples, while BRAF mutational status was in line with the original tumor type. Monotherapy in 3D multicellular ATC tumor spheroids with either 131I-AbN44v6 or sorafenib resulted in delayed spheroid growth. The combination of 131I-AbN44v6 and sorafenib was the most potent and resulted in significantly impaired spheroid growth.Conclusion: This "proof of concept" targeted therapy study in the in vitro ATC 3D multicellular tumor spheroids indicated applicability of utilizing CD44v6 for molecular radiotherapy both as a monotherapy and in combination with sorafenib.
|
|
| 9. |
- Norheim, Katrine Braekke, et al.
(författare)
-
Genetic variants at the RTP4/MASP1 locus are associated with fatigue in Scandinavian patients with primary Sjogren's syndrome
- 2021
-
Ingår i: RMD Open. - : BMJ Publishing Group Ltd. - 2056-5933. ; 7:3
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives Fatigue is common and severe in primary Sjogren's syndrome (pSS). The aim of this study was to identify genetic determinants of fatigue in pSS through a genome-wide association study. Methods Patients with pSS from Norway, Sweden, UK and USA with fatigue and genotype data available were included. After genotype imputation and quality control, 682 patients and 4 966 157 genetic markers were available. Association analysis in each cohort using linear regression with fatigue as a continuous variable and meta-analyses between the cohorts were performed. Results Meta-analysis of the Norwegian and Swedish cohorts identified five polymorphisms within the same linkage disequilibrium block at the receptor transporter protein 4 (RTP4)/MASP1 locus associated with fatigue with genome-wide significance (GWS) (p<5x10(-8)). Patients homozygous for the major allele scored 25 mm higher on the fatigue Visual Analogue Scale than patients homozygous for the minor allele. There were no variants associated with fatigue with GWS in meta-analyses of the US/UK cohorts, or all four cohorts. RTP4 expression in pSS B cells was upregulated and positively correlated with the type I interferon score. Expression quantitative trait loci effects in whole blood for fatigue-associated variants at RTP4/MASP1 and levels of RTP4 and MASP1 expression were identified. Conclusion Genetic variations at RTP4/MASP1 are associated with fatigue in Scandinavian pSS patients. RTP4 encodes a Golgi chaperone that influences opioid pain receptor function and MASP1 is involved in complement activation. These results add evidence for genetic influence over fatigue in pSS.
|
|
| 10. |
- Thorlacius, Guðný Ella, et al.
(författare)
-
Genetic and clinical basis for two distinct subtypes of primary Sjögren's syndrome
- 2021
-
Ingår i: Rheumatology. - : Oxford University Press. - 1462-0324 .- 1462-0332. ; 60:2, s. 837-848
-
Tidskriftsartikel (refereegranskat)abstract
- ObjectivesClinical presentation of primary Sjögren’s syndrome (pSS) varies considerably. A shortage of evidence-based objective markers hinders efficient drug development and most clinical trials have failed to reach primary endpoints.MethodsWe performed a multicentre study to identify patient subgroups based on clinical, immunological and genetic features. Targeted DNA sequencing of 1853 autoimmune-related loci was performed. After quality control, 918 patients with pSS, 1264 controls and 107 045 single nucleotide variants remained for analysis. Replication was performed in 177 patients with pSS and 7672 controls.ResultsWe found strong signals of association with pSS in the HLA region. Principal component analysis of clinical data distinguished two patient subgroups defined by the presence of SSA/SSB antibodies. We observed an unprecedented high risk of pSS for an association in the HLA-DQA1 locus of odds ratio 6.10 (95% CI: 4.93, 7.54, P=2.2×10−62) in the SSA/SSB-positive subgroup, while absent in the antibody negative group. Three independent signals within the MHC were observed. The two most significant variants in MHC class I and II respectively, identified patients with a higher risk of hypergammaglobulinaemia, leukopenia, anaemia, purpura, major salivary gland swelling and lymphadenopathy. Replication confirmed the association with both MHC class I and II signals confined to SSA/SSB antibody positive pSS.ConclusionTwo subgroups of patients with pSS with distinct clinical manifestations can be defined by the presence or absence of SSA/SSB antibodies and genetic markers in the HLA locus. These subgroups should be considered in clinical follow-up, drug development and trial outcomes, for the benefit of both subgroups.
|
|
