Antibody-based gene expression profiling of peripheral blood from patients with idiopathic inflammatory myopathy / 中华风湿病学杂志

Objective:To elucidate the pathophysiological mechanisms of idiopathic inflammatory myopathy subtypes by analyzing the gene expression profiles of peripheral blood mononuclear cells (PBMCs) from anti-MDA5 antibody-positive and anti-Jo-1 antibody-positive myositis patients.Methods:Gene expression profiling screening and analysis of PBMCs from 12 anti-MDA5 positive, 16 anti-Jo-1 positive myositis patients and 43 healthy controls were performed using Illumina HT-12 v4 expression profiling microarrays. Applying the unpaired t test with Benjamini-Hochberg correction, the genes with the absolute value of fold change (FC) in gene expression signal ≥2 and adjusted P<0.05 were selected as differentially expressed genes. Differential gene sets were subjected to Gene Ontology (GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, with P<0.05 as the threshold for being significantly enriched. Validation of differentially expressed genes by real time-PCR. The Kolmogorov-Smirnov test was used to test the normality of continuous variables. If the distribution was normal and the variance was homogeneous, analysis of variance (one-way ANOVA) was used.If the distribution was not normal, Kruskal-Wallis test was used, and P<0.05 was regarded as statistically significant difference. Results:Analysis of gene expression profiles of PBMCs from patients with positive anti-MDA5 and anti-Jo-1 antibody revealed significant differences in gene expression of PBMCs from patients with the two myositis subtypes. The number of differentially expressed genes that specifically up-regulated in anti-MDA5 antibody positive patients was 407, and the GO functional enrichment analysis was mainly enriched in biological processes such as innate immune response ( P<0.001), response to virus ( P<0.001) and type Ⅰ interferon signaling pathway ( P<0.001), and the KEGG pathway enrichment analysis was mainly enriched in the viral infection-associated pathway ( P<0.001), RIG-Ⅰ like receptor signaling pathway ( P<0.001) and Toll-like receptor signaling pathway ( P=0.002), etc. The 259 differential genes specifically down-regulated in the anti-MDA5 antibody positive group were mainly enriched in biological processes such as immune response ( P=0.006), TGF-β receptor signaling pathway ( P=0.010) and natural killer cell mediated immunity ( P=0.015) in GO functional enrichment analysis. There were 162 differentially expressed genes up-regulated specifically in anti-Jo-1 antibody positive patients, and GO functional enrichment analysis was mainly enriched in biological processes such as nucleosome assembly ( P<0.001), negative regulation of cell growth ( P=0.001), negative regulation of apoptotic process P=0.004), and innate immune response in mucosa ( P=0.012), and the KEGG pathway enrichment analysis mainly enriched in metabolic-related signaling pathways ( P<0.001) and immune-related pathways ( P<0.001), etc. Real-time PCR confirmed that IFIH1 ( P=0.037), ISG15 ( P=0.003), and DDX58 ( P=0.032) in the RIG-Ⅰ-like receptor pathway as well as chemokines MCP-1 ( P=0.003), MCP-2 ( P<0.001), and transcription factor BATF2 ( P=0.002), and inflammatory signaling pathway-associated MYD88 ( P<0.001) were highly expressed in PBMCs from anti-MDA5 antibody-positive myositis patients. Conclusion:The gene expression profile of PBMCs in anti-MDA5 antibody-positive patients suggests that the pathogenesis of patients with anti-MDA 5 antibody positive is closely related to biological processes such as innate immune response, viral infection, and interferon response.

Alpha-synuclein dynamics bridge Type-I Interferon response and SARS-CoV-2 replication in peripheral cells

BACKGROUND: Increasing evidence suggests a double-faceted role of alpha-synuclein (α-syn) following infection by a variety of viruses, including SARS-CoV-2. Although α-syn accumulation is known to contribute to cell toxicity and the development and/or exacerbation of neuropathological manifestations, it is also a key to sustaining anti-viral innate immunity. Consistently with α-syn aggregation as a hallmark of Parkinson's disease, most studies investigating the biological function of α-syn focused on neural cells, while reports on the role of α-syn in periphery are limited, especially in SARS-CoV-2 infection. RESULTS: Results herein obtained by real time qPCR, immunofluorescence and western blot indicate that α-syn upregulation in peripheral cells occurs as a Type-I Interferon (IFN)-related response against SARS-CoV-2 infection. Noteworthy, this effect mostly involves α-syn multimers, and the dynamic α-syn multimer:monomer ratio. Administration of excess α-syn monomers promoted SARS-CoV-2 replication along with downregulation of IFN-Stimulated Genes (ISGs) in epithelial lung cells, which was associated with reduced α-syn multimers and α-syn multimer:monomer ratio. These effects were prevented by combined administration of IFN-ß, which hindered virus replication and upregulated ISGs, meanwhile increasing both α-syn multimers and α-syn multimer:monomer ratio in the absence of cell toxicity. Finally, in endothelial cells displaying abortive SARS-CoV-2 replication, α-syn multimers, and multimer:monomer ratio were not reduced following exposure to the virus and exogenous α-syn, suggesting that only productive viral infection impairs α-syn multimerization and multimer:monomer equilibrium. CONCLUSIONS: Our study provides novel insights into the biology of α-syn, showing that its dynamic conformations are implicated in the innate immune response against SARS-CoV-2 infection in peripheral cells. In particular, our results suggest that promotion of non-toxic α-syn multimers likely occurs as a Type-I IFN-related biological response which partakes in the suppression of viral replication. Further studies are needed to replicate our findings in neuronal cells as well as animal models, and to ascertain the nature of such α-syn conformations.

Establishment and application of detection method for interferon stimulated genes expression in children / 中华检验医学杂志

Objective:To establish the detection method for the interferon stimulated genes(ISGs), calculate the cut-off value and test it in clinical practice.Methods:Patients with type I interferonopathies who were admitted to Peking Union Medical College Hospital from November 2017 to September 2021 were chosen as the disease group, and healthy children were included as the control group. A total of 18 children were in the disease group, including 8 males and 10 females, with a median age of 8.5 years for the first test. From them 25 blood specimens were collected. A total of 28 healthy children, aged 1 to 18 years, with a median age of 10.5 years, including 15 males and 13 females, were included in the control group. Blood samples of 34 controls and 18 interferonopathies patients were collected, then total RNA extraction and cDNA synthesis were performed. Real-time quantitative polymerase chain reaction assays were run in duplicate to measure the expression of six ISGs: interferon induced protein with tetratricopeptide repeats 1 (IFIT1), interferon α inducible protein 27 (IFI27), interferon induced protein 44 like (IFI44L), interferon stimulated genes 15 (ISG15), sialic acid binding Ig like lectin 1 (SIGLEC1), and radical S-adenosyl methionine domain containing 2 (RSAD2). The relative abundances of each target transcript was normalized to the expression level of β-Actin and OAZ. The median fold change of the six ISGs was used to create an interferon score (IS) for each individual. Samples with abnormal expressions were removed and the cDNA mix of the remaining samples was used as a calibrator to calculate the IS. We define an abnormal IS as being greater than+2 standard deviations above the mean of controls. Differences in IS between groups were compared using t-test or Mann-Whitney U-test. Results:The mean IS of controls was 1.046, standard 0.755, and the cut-off value was 2.556. A total of 25 samples from 18 interferonopathies patients were tested. The mean value was 27.010 with a 15/18 abnormality rate. Compared with the control group, IS in patients was significantly higher, t=4.247( P=0.000 1). The accuracy, precision, sensitivity, and specificity were 91.30% (42/46), 7.47%(0.084/1.124), 15/18, and 96.43% (27/28), respectively. Conclusion:This study provides a new and reliable method for clinical screening and dynamic monitoring of type Ⅰ interferonopathies by detecting ISGs expression and creating an IS.

Identification of new type I interferon-stimulated genes and investigation of their involvement in IFN-β activation

Virus infection induces the production of type I interferons (IFNs). IFNs bind to their heterodimeric receptors to initiate downstream cascade of signaling, leading to the up-regulation of interferon-stimulated genes (ISGs). ISGs play very important roles in innate immunity through a variety of mechanisms. Although hundreds of ISGs have been identified, it is commonly recognized that more ISGs await to be discovered. The aim of this study was to identify new ISGs and to probe their roles in regulating virus-induced type I IFN production. We used consensus interferon (Con-IFN), an artificial alpha IFN that was shown to be more potent than naturally existing type I IFN, to treat three human immune cell lines, CEM, U937 and Daudi cells. Microarray analysis was employed to identify those genes whose expressions were up-regulated. Six hundred and seventeen genes were up-regulated more than 3-fold. Out of these 617 genes, 138 were not previously reported as ISGs and thus were further pursued. Validation of these 138 genes using quantitative reverse transcription PCR (qRT-PCR) confirmed 91 genes. We screened 89 genes for those involved in Sendai virus (SeV)-induced IFN-β promoter activation, and PIM1 was identified as one whose expression inhibited SeV-mediated IFN-β activation. We provide evidence indicating that PIM1 specifically inhibits RIG-I- and MDA5-mediated IFN-β signaling. Our results expand the ISG library and identify PIM1 as an ISG that participates in the regulation of virus-induced type I interferon production.

Research progress towards interferon stimulated genes and its clinical signifi-cance / 中国免疫学杂志

Interferon (IFN) acts on the surface of the target cell receptors and activate the expression of interferon stimulated genes(interferon stimulated genes,ISGs) through a series of signal transduction.ISGs have antiviral and immunomodulation and other biological functions,indicating ISGs are important molecules for interferon to function and have some potential clinical significance.A large number of research results showed that ISGs may predict the antiviral effect of IFN-α;specific expression of ISGs in patients with autoimmune diseases in vivo may be used as a new biomarker for clinical diagnosis of the diseases;ISGs may act as a new target for cancer treatment and have other potential applications.This review mainly focuses on the induction,the biological functions like antiviral effects and the potential clinical significance of ISGs.