Welcome to the Autoimmunity 2021 Congress Calendar

Background and Aims

Genetic variants within/near the interferon regulatory factor 5 (IRF5) locus associate with systemic lupus erythematosus (SLE) across ancestral groups. The major IRF5-SLE risk haplotype is common across populations, yet immune functions for the risk haplotype are undefined.

Methods

Healthy donors carrying the major IRF5-SLE risk haplotype in European Caucasians (rs2004640, rs10954213, rs10488631, and rs142738614 (CGGGG indel)) were identified from the Feinstein Genotype and Phenotype (GaP) Registry after genotyping on the Illumina Human Immunochip. Participants carried either the major IRF5 homozygous risk or non-risk haplotype and had no personal/family history of autoimmune/inflammatory diseases or cancer. Immuno-phenotypes were characterized by ELISA, flow cytometry, ex vivo co-culture and RNA-sequencing.

Results

Contrary to previous studies in B lymphoblastoid cell lines and SLE immune cells, IRF5 genetic variants had little effect on IRF5 protein levels in healthy donors. Instead, we detected basal IRF5 hyper-activation in the myeloid compartment of risk donors that drives an SLE immune-phenotype. Risk donors were ANA positive with anti-Ro and -MPO specificity, had increased circulating plasma cells and plasmacytoid dendritic cells, and enhanced spontaneous NETosis. The IRF5-SLE immune-phenotype was conserved over time and probed mechanistically by ex vivo co-culture, indicating that risk neutrophils are drivers of the global immune-phenotype. RNAseq of risk neutrophils revealed increased IRF5 transcript expression, IFN pathway enrichment and decreased expression of ROS pathway genes.

Conclusions

Altogether, data support that individuals carrying the IRF5-SLE risk haplotype are more susceptible to environmental/stochastic influences that trigger chronic immune activation, predisposing to the development of autoimmune diseases, such as SLE.

Background and Aims

The pathophysiology of inflammatory bowel diseases (IBD) reflects a balance between mucosal injury and reparative mechanisms. Some regenerating gene (Reg) family members (REG Iα, REG Iβ, and REG IV) are expressed in Crohn’s disease (CD) and ulcerative colitis (UC) and involved as proliferative mucosal factors in IBD. We revealed that REG Iαand REG Iβ were induced by IL-6/IL-22 via MZF1, RTEF1/TEAD4, and STAT3 in REG Iα and HLTF/FOXN2F in REG Iβ, respectively. Although REG IV was up-regulated in IBD biopsy samples, the up-regulation of REG IV was not at all observed in cell culture system by autoimmune-related cytokines such as IL-6, IL-8, IL-17A, IL-22, TNFα, HGF, bFGF, and EGF.

Methods

Here, we analyzed REG IV expression in LS-174T and HT-29 human colonic epithelial cells by real-time RT-PCR and ELISA.

Results

REG IV expression was induced by lipopolysaccharide (LPS) in both cells. However, LPS did not activate REG IVpromoter (-1,053~+22) activity. As the LPS-induced up-regulation of REG IV was considered to be regulated post-transcriptionally, we searched targeted microRNA (miR) using the MicroRNA.org program (http://www.microrna.org/microrna/home.do), which revealed that REG IV mRNA have a potential target sequence for miR-24. We measured the miR-24 level of LPS-treated cells by RT-PCR and found that the level was significantly lower (0.0278±0.00665 fold in LS-174T cells [P=0.0368]; 0.1400±0.0618 fold in HT-29 cells [P=0.0490]).

Conclusions

The LPS-induced increase of REG IV mRNA was abolished by the introduction of miR-24 mimic but not by non-specific control RNA in both LS-174T and HT-29 cells.

Background and Aims

We have recently demonstrated that G allele of the rs4986790 polymorphism (Asp299Gly) of TLR4 Gene (AG genotype) has been associated with decreased development of clinical atherosclerosis in familiar hypercholesterolemia (FH). The aim of the study was to analyze the relationships between TLR4 polymorphism and lipid disorders in FH patients.

Methods

Methods. 67 patients with FH (50 female and 17 male) were involved into the study. Heterozygous FH was diagnosed using the Dutch Lipid Clinic Network criteria including genetic testing. The TLR4 rs4986790 polymorphism was determined by polymerase chain reaction/restriction fragment length polymorphism. Low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and Lipoprotein (a) levels were measured in all patients.

Results

Results. The presence of АА genotype rs4986790 polymorphism of TLR4 gene was found in 82% of patients with FH while AG genotype was detected in 16,4% of patients. That is, the frequency of AG polymorphism of the TLRs gene in FH is at least threefold exceeds that in the general population. Lipid levels were 6.36+0,27 mmol/l vs 6,40+0,21 mmol/l LDL-C in AA genotype vs AG genotype and 1,75+0,17 mmol/l vs 1,62 mmol/l +0,20 HDL-C in AA genotype vs AG genotype correspondingly. Nevertheless in patients with the AA genotype, the frequency of increased levels of atherogenic Lipoprotein (a) was significantly higher than in patients with the AG genotype (38% and 11%, respectively).

Conclusions

Conclusion. The AG allele of rs4986790 polymorphism of TLR4 Gene could be bound with diminished risk of atherosclerosis via its association with decreased levels of Lipoprotein (a).

Background and Aims

Sarcoidosis and tuberculosis have several similar clinical and pathogenetic characteristics, what makes some researchers consider a common pathogenesis for these diseases. HLA-genotypes are known as a genetic predisposition factor for many diseases and are studied for sarcoidosis and tuberculosis patients. However there is no comparative study of genetic predisposition for sarcoidosis or tuberculosis development.

The aim of this study was to analyze the relationship between HLA genotypes and the development of sarcoidosis and tuberculosis.

Methods

Original (n=19) and review articles (n=14) published in various online databases from 1960 to 2019 were studied. The papers were selected according to key words: sarcoidosis, tuberculosis, HLA-genotype, genetic predisposition.

Results

The study results showed opposite effects of the HLA genotypes associated with a predisposition to the development of sarcoidosis or tuberculosis. It was revealed, the genotypes predisposing to the development of sarcoidosis (HLA-DRB1*03/07/15) have protective properties against the development of tuberculosis. Moreover, genotypes causing its development (HLA-DRB1*04) have a protective effect on the development of sarcoidosis. Some of these results might be explained by the weak affinity of MHC molecules for mycobacterial antigens in patients with HLA-DRB1*04 genotype and the strong affinity of MHC proteins for bacterial antigens in individuals with HLA-DRB1*03: 01 genotype

Conclusions

The HLA system may determine the development of the immune response in contact with mycobacteria. It was shown that HLA-DRB1*04 genotype predispose to tuberculosis development, while the HLA-DRB1*03/07/15 genotypes to sarcoidosis. Determining the HLA genotypes may result in assessing a risk degree for developing tuberculosis or sarcoidosis in the foci of mycobacterial infection.

Background and Aims

Immune aggregates organized as tertiary lymphoid structures (TLS) are observed within kidneys of systemic lupus erythematosus (SLE) patients with lupus nephritis (LN). The gene profile of kidney specific TLS compared to the kidney and lymph node (LyN) during LN progression has not yet been studied.

Methods

We characterized renal TLS in lupus-prone (NZBxNZW) F1 mice with respect to cell composition and vessel formation. Ribonucleic acid (RNA) sequencing was performed on transcriptomes isolated from LyN, macro-dissected TLS from kidneys, and total kidneys of mice at different disease stages by using Ion Torrent Personal Genome Machine (Ion PGM) and RNAseq from Illumina.

Results

Formation of TLS was found in anti-dsDNA antibody positive mice and the structures were organized as interconnected large networks with distinct T and B cell zones with adjacent dendritic cells, macrophages, plasma cells, high endothelial venules, supporting follicular dendritic cells network, and functional germinal centers. Comparison of gene profiles of whole kidney, renal TLS and LyN revealed a similar gene signature of TLS and LyN. The upregulated genes within the kidneys of lupus-prone mice during the development of LN reflected the TLS formation, while the downregulated genes were involved in metabolic processes of the kidney cells. A comparison with human LN gene expression revealed similar upregulated genes as observed during the development of murine LN and TLS.

Conclusions

We conclude that kidney TLS have a similar cell composition, structure and gene signature as LyN, and therefore may function as a kidney specific type of LyN.

Background and Aims

Rheumatoid Arthritis (RA) is a chronic inflammatory disease, affecting women more than men, with a more aggressive course in women.

Methods

A prospective study that recruited 58 patients (46 women aged 56 ± 12 years) with active long-standing RA disease (>12 months). Our goals were to measure their endothelial function, part of the cardiovascular risk assessment. The Brachial Artery method measured endothelial function (the flow mediated percent change [FMD percentage] of the brachial artery diameter). A senior Rheumatologist clinically evaluated all subjects. Mann Whitney rank sum test estimated gender differences among the RA patients.

Results

Median FMD% change for men was -6.07%, while median FMD% change for women was 0.44% (Z = 2.38, P = 0.01). Baseline Brachial artery diameter was larger in men (Z = 2.52, P = 0.01); however, tender joints count and BMI were greater in women (Z=-2.24, P = 0.01; Z=-3.99, P = 0.001), respectively.

Conclusions

Women with RA have significantly better endothelial function than men with RA. It means that even though RA is 3-fold more prevalent in women, women are more protected from atherosclerotic coronary artery disease and cardiac events.

Background and Aims

We tested the hypothesis that autoinflammatory disease and non-specific autoinflammatory features were common in myelodysplastic syndrome (MDS) cohorts and we further theorised that MDS with somatic mutations and karyotypic abnormalities were associated with autoinflammation/autoimmune disorders.

Methods

160 MDS patients recruited between 2012-2018 were evaluated for autoinflammation and its link with karyotypes and somatic mutations status. Patients with autoinflammation were classified as well-defined autoinflammatory diseases or undifferentiated “autoinflammatory state”(UAS) (non-specific symptomatology and non-infection related elevated CRP over 10.0 mg/L on 5 consecutive occasions) and were compared in terms of demographic, clinical, laboratory, cytogenetics charts, and outcomes.

Results

The average age was 75.3±11.7 years (median 77 years), with (n=99, 61.9%) male. 78 (48.8%) patients had an autoinflammatory state, were younger (73.4±11.9 years versus 77±11.2 years, borderline significant), and had more frequently arthritis (n=25, 32.1%, versus n=12, 14.6%, p=0.014), arthralgia (n=32, 41.0%, versus n=18, 22.0%, p=0.0108), skin rash (n=22, 28.2%, versus n=10, 12.2%, p=0.0169), pleuritis (16, 20.5%, versus n=3, 3.7%, p=0.0011) and unexplained fever (n=18, 23.1% versus n=0, 0.0%, p<0.0001). 24.4% of autoinflammatory MDS patients had well-defined autoinflammatory disorders (neutrophilic dermatosis, and polymyalgia rheumatic being the commonest). Mutations affecting the transcription factor pathway (NPM1, RUNX1, BCOR, WTI, TP53) (OR 3.22 [95%CI 1.05-9.36], p=0.0402) and deletion of chromosome 5 (OR 3.37 [95%CI 1.01-11.30], p=0.0485) were associated with autoinflammation.

Conclusions

Both well-defined and UAS are common in MDS. Transcription factor pathway somatic mutations and abnormal karyotype are associated with the risk of autoinflammation which is also linked to malignant transformation and worse prognosis.

Background and Aims

Chemokine ligand 18 (CCL18) is wieldy found elevated in synovial fluid (500ng/mL) in rheumatoid arthritis (RA) patients. Enriched CCL18 promotes fibroblast-like-synoviocytes in RA (RA-FLS) migration and facilities RA progression. To explore mechanism of CCL18 regulatory role in synoviocyte migration and associated pathway in RA-FLS would be benefit to RA disease investigation.

Methods

RA-FLS were obtained from Parker-Pearson needle biopsy of RA-patients. Primary normal fibroblast-like synoviocytes (HFLS) were purchased from CellApplications Inc. Total RNA was isolated from HFLS treated with CCL18 (500ng/mL) or vehicle, and five clinical RA-FLS cases. RNA-Sequencing and DESeq2 were implemented to extract differentiation expression genes (DEGs). Kyoto Encyclopedia of Genes and Genomes Gene Set Enrichment Analysis (KEGG-GSEA) on DEGs identified significant pathway involvement. In vitro Oris migration assay confirmed CCL18-stimulated HFLS migration.

Results

at 60h posted stopper-removal in Oris migration assay, the stopper-removal areas were filled with more migrated cells in the HFLS treated with CCL18 than with vehicle (p<0.001) (Fig 1A). Multiple pathways were activated in HFLS treated with CCL18 by KEGG-GSEA (p<0.05) (Fig 1B) and in RA-FLS (data not-shown). Toll-like receptor signaling pathway and NF-kappa B signaling pathway were activated in both HFLS+CCL18 and RA-FLS when compared with HFLS. In GSEA, these two pathways shared similar leading-edge subset with upregulated genes (Fig 1C and Fig 1D). Most upregulated genes shared in both HFLS+CCL18 and RA-FLS were characterized as RA-associated inflammation and pathogenesis factors, such as TRL4, TRL5, NFKB1 and RELA.

Conclusions

CCL18 increase synoviocyte migration by activation of NF-kappa-B and Toll-like-receptor signaling pathways similar in rheumatoid arthritis pathogenesis.