Immunological pathogenesis and treatment of systemic lupus erythematosus

Genomic sequencing and functional analyses identify MAP4K3/GLK germline and somatic variants associated with systemic lupus erythematosus

OBJECTIVES

MAP4K3 (GLK) overexpression in T cells induces interleukin (IL)-17A production and autoimmune responses. GLK overexpressing T-cell population is correlated with severity of human systemic lupus erythematosus (SLE); however, it is unclear how GLK is upregulated in patients with SLE.

METHODS

We enrolled 181 patients with SLE and 250 individuals without SLE (93 healthy controls and 157 family members of patients with SLE) in two independent cohorts from different hospitals/cities. Genomic DNAs of peripheral blood mononuclear cells were subjected to next-generation sequencing to identify GLK gene variants. The functional consequences of the identified GLK germline or somatic variants were investigated using site-directed mutagenesis and cell transfection, followed by reporter assays, mass spectrometry, immunoblotting, coimmunoprecipitation, and in situ proximity ligation assays.

RESULTS

We identified 58 patients with SLE from Cohort #1 and #2 with higher frequencies of a somatic variant (chr2:39 477 124 A>G) in GLK 3'-untranslated region (UTR); these patients with SLE showed increased serum anti-double-stranded DNA levels and decreased serum C3/C4 levels. This somatic variant in 3'-UTR enhanced GLK mRNA levels in T cells. In addition, we identified five patients with SLE with GLK (A410T) germline variant in Cohort #1 and #2, as well as two other patients with SLE with GLK (K650R) germline variant in Cohort #1. Another GLK germline variant, A579T, was also detected in one patient with SLE from Cohort #2. Both GLK (A410T) and GLK (K650R) mutants inhibited GLK ubiquitination induced by the novel E3 ligase makorin ring-finger protein 4 (MKRN4), leading to GLK protein stabilisation.

CONCLUSIONS

Multiple GLK germline and somatic variants cause GLK induction by increasing mRNA or protein stability in patients with SLE.

A Review of Neutrophil Extracellular Traps (NETs) in Disease: Potential Anti-NETs Therapeutics

Activated neutrophils release neutrophil extracellular traps (NETs) in response to a variety of stimuli. NETosis is driven by protein-arginine deiminase type 4, with the release of intracellular granule components that function by capturing and destroying microbes, including viral, fungal, bacterial, and protozoal pathogens. The positive effects of pathogen control are countered by pro-inflammatory effects as demonstrated in a variety of diseases. Components of NETS are non-specific, and other than controlling microbes, they cause injury to surrounding tissue by themselves or by increasing the pro-inflammatory response. NETs can play a role in enhancement of the inflammation seen in autoimmune diseases including psoriasis, rheumatoid arthritis, and systemic lupus erythematosis. In addition, autoinflammatory diseases such as gout have been associated with NETosis. Inhibition of NETs may decrease the severity of many diseases improving survival. Herein, we describe NETosis in different diseases focusing on the detrimental effect of NETs and outline possible therapeutics that can be used to mitigate netosis. There is a need for more studies and clinical trials on these and other compounds that could prevent or destroy NETs, thereby decreasing damage to patients.

Exploring Macrophage Activation Syndrome Secondary to Systemic Lupus Erythematosus in Adults: A Systematic Review of the Literature

Among the autoimmune (AI) diseases, systemic lupus erythematosus (SLE) is known to mimic various disease processes and this can lead to under-diagnosis of macrophage activation syndrome (a dire complication). We aimed at performing a systematic review to identify trigger factors that could lead to the development of macrophage activation syndrome (MAS) in patients with SLE as well as identify factors that can affect mortality. We searched the following databases to extract relevant articles: PubMed, ScienceDirect, Cochrane library, Pro-Quest, and Google Scholar. We used search terms including but not limited to hemophagocytic syndromes OR hemophagocytic lymphohistiocytosis OR macrophage activation syndrome OR HLH OR secondary hemophagocytic lymphohistiocytosis AND systemic lupus erythematosus OR SLE. We screened the articles first by titles and abstracts and later by full text. After the application of our eligibility criteria, we identified eight studies to include in our final synthesis. The studies showed that lupus flare itself, as well as, time to onset and high systemic lupus erythematosus disease activity index (SLEDAI) scores, were major risk factors that led to the development of MAS. In addition, infections followed by drugs, underlying malignancy, and pregnancy were other potential trigger factors identified. Studies also detected that MAS development led to high intensive care unit (ICU) admissions and in-hospital mortalities with C-reactive protein (CRP) levels, age, presence of infection, leukopenia, thrombocytopenia, MAS throughout the hospital stay, and high liver function tests (LFTs) as signs of poor prognosis. Additionally, ferritin levels, LFTs, and triglyceride levels formed an important part of diagnostic criteria. However, our review was limited due to the absence of prospective studies and heterogeneity in the studies seen. More studies need to be done to identify various factors leading to hemophagocytic lymphohistiocytosis (HLH) in autoimmune diseases with validated criteria for MAS secondary to autoimmune diseases.

The Kynurenine Pathway-New Linkage between Innate and Adaptive Immunity in Autoimmune Endocrinopathies

The kynurenine pathway (KP) is highly regulated in the immune system, where it promotes immunosuppression in response to infection or inflammation. Indoleamine 2,3-dioxygenase 1 (IDO1), the main enzyme of KP, has a broad spectrum of activity on immune cells regulation, controlling the balance between stimulation and suppression of the immune system at sites of local inflammation, relevant to a wide range of autoimmune and inflammatory diseases. Various autoimmune diseases, among them endocrinopathies, have been identified to date, but despite significant progress in their diagnosis and treatment, they are still associated with significant complications, morbidity, and mortality. The precise cellular and molecular mechanisms leading to the onset and development of autoimmune disease remain poorly clarified so far. In breaking of tolerance, the cells of the innate immunity provide a decisive microenvironment that regulates immune cells' differentiation, leading to activation of adaptive immunity. The current review provided a comprehensive presentation of the known role of IDO1 and KP activation in the regulation of the innate and adaptive arms of the immune system. Significant attention has been paid to the immunoregulatory role of IDO1 in the most prevalent, organ-specific autoimmune endocrinopathies-type 1 diabetes mellitus (T1DM) and autoimmune thyroiditis.

Telitacicept: First Approval

Telitacicept (Tai'ai^®) is fusion protein comprising a recombinant transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI) receptor fused to the fragment crystallizable (Fc) domain of human immunoglobulin G (IgG). Telitacicept is being developed by Yantai Rongchang Pharmaceutical through its subsidiary RemeGen for the treatment of B cell-mediated autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and multiple sclerosis (MS). Telitacicept binds to and neutralizes the activity of two cell-signalling molecules, B-lymphocyte stimulator (BLyS) and a proliferation-inducing ligand (APRIL), thereby suppressing the development and survival of plasma cells and mature B cells. In March 2021, telitacicept received its first approval in China for the treatment of patients with active SLE. Clinical studies of telitacicept in several other indications, including IgA nephropathy, MS, myasthenia gravis, neuromyelitis optica spectrum disorders, RA and Sjögren's syndrome are underway in China. This article summarizes the milestones in the development of telitacicept leading to this first approval for SLE.

Modulation of T-Cell Activation Markers Expression by the Adipose Tissue-Derived Mesenchymal Stem Cells of Patients with Rheumatic Diseases

Background:

Activated T lymphocytes play an important role in the pathogenesis of rheumatic diseases (RD). Mesenchymal stem cells (MSCs) possess immunoregulatory activities but such functions of MSCs from bone marrow of systemic lupus erythematosus (SLE), systemic sclerosis (SSc), and ankylosing spondylitis (AS) patients are impaired. Adipose tissue–derived MSCs (ASCs) are an optional pool of therapeutically useful MSCs, but biology of these cells in RD is poorly known. This study aimed at investigating the effect of ASCs from RD patients and healthy donors (HD) on the expression of the key T-cell activation markers.

Methods:

ASCs were isolated from subcutaneous abdominal fat from SLE (n = 16), SSc (n = 18), and AS (n = 16) patients, while five human ASCs lines from HD were used as a control. Untreated and cytokine (tumor necrosis factor α + interferon γ)-treated ASCs were co-cultured with allogenic, mitogen (phytohemagglutinin)-stimulated peripheral blood mononuclear cells (PBMCs) or purified anti-CD3/CD28-activated CD4⁺ T lymphocytes. Contacting and noncontacting ASCs-PBMCs co-cultures were performed. RD/ASCs were analyzed in co-cultures with both allogeneic and autologous PBMCs. Flow cytometry analysis was used to evaluate expression of CD25, HLA-DR, and CD69 molecules on CD4⁺ and CD8⁺ cells.

Results:

In co-cultures with allogeneic, activated CD4⁺ T cells and PBMCs, HD/ASCs and RD/ASCs downregulated CD25 and HLA-DR, while upregulated CD69 molecules expression on both CD4⁺ and CD8⁺ cells with comparable potency. This modulatory effect was similar in contacting and noncontacting co-cultures. RD/ASCs exerted weaker inhibitory effect on CD25 expression on autologous than allogeneic CD4⁺ and CD8⁺ T cells.

Conclusion:

RD/ASCs retain normal capability to regulate expression of activation markers on allogeneic T cells. Both HD/ASCs and RD/ASCs exert this effect independently of their activation status, mostly through the indirect pathway and soluble factors. However, autologous CD4⁺ and CD8⁺ T cells are partially resistant to RD/ASCs inhibition of CD25 expression, suggesting weaker control of T-cell activation in vivo.

TYK2 as a therapeutic target in the treatment of autoimmune and inflammatory diseases

JAKs are intracellular protein tyrosine kinases that, through activation of STATs, are responsible for signal transduction pathways that regulate cellular responses to numerous cytokines, growth factors and hormones in many different cells. JAK-STAT signaling plays a key role in regulating immune function, and cytokines - such as IL-23, IL-12 and type I interferons - are central to the pathogenesis of autoimmune diseases, including psoriasis, inflammatory bowel disease and systemic lupus erythematosus. Here the authors review the evidence for targeting TYK2 as a more specific approach to treating these conditions. TYK2 inhibitors are clinically effective in autoimmune and inflammatory diseases and may avoid some of the complications reported with nonselective JAK inhibitors.

ECP Overexpression in T Cells and Exosomes Induces IFN-γ Production and Tissue Inflammation

Objective

T cells play a critical role in the pathogenesis of systemic lupus erythematosus (SLE). Serum‐derived exosomes are increased in SLE patients and are correlated with disease severity. This study was undertaken to investigate whether T cell–derived exosomal proteins play a role in SLE pathogenesis.

Methods

We characterized proteins in T cell–derived exosomes from SLE patients and healthy controls by MACSPlex exosome analysis and proteomics. To study the potential pathogenic functions of the exosomal protein identified, we generated and characterized T cell–specific transgenic mice that overexpressed that protein in T cells.

Results

We identified eosinophil cationic protein (ECP, also called human RNase III) as overexpressed in SLE T cell–derived exosomes. T cell–specific ECP–transgenic mice (n = 5 per group) displayed early induction of serum interferon‐γ (IFNγ) levels (P = 0.062) and inflammation of multiple tissue types. Older T cell–specific ECP–transgenic mice (n = 3 per group) also displayed an increase in follicular helper T cell and plasma B cell numbers, and in autoantibody levels (P < 0.01). Single‐cell RNA sequencing showed the induction of IFNγ messenger RNA (P = 2.2 × 10^‐13) and inflammatory pathways in ECP‐transgenic mouse T cells. Notably, adoptively transferred ECP‐containing exosomes stimulated serum autoantibody levels (P < 0.01) and tissue IFNγ levels in the recipient mice (n = 3 per group). The transferred exosomes infiltrated into multiple tissues of the recipient mice, resulting in hepatitis, nephritis, and arthritis.

Conclusion

Our findings indicate that ECP overexpression in T cells or T cell–derived exosomes may be a biomarker and pathogenic factor for nephritis, hepatitis, and arthritis associated with SLE.

The immunoregulatory axis (programmed death-1/programmed death ligand-1) on CD4+ T cells in lupus nephritis: association with vitamin D and chemokine C-X-C motif ligand 12

Lupus nephritis (LN) is one of the most serious complications of systemic lupus erythematosus (SLE). Multiple immunomodulatory mechanisms contribute to the pathogenesis of LN. A deep understanding of the immunopathogenesis of LN is essential to identify optimal molecular targets, as most immunotherapeutic algorithms are still based on unselective drugs. The study aimed to elucidate the possible association of vitamin D deficiency with the programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1) axis and inflammatory response in patients with LN, as well as the relationship between the PD-1/PD-L1 axis and chemokine C-X-C motif ligand 12 (CXCL12). Flow cytometry was used to determine the frequencies of CD279 (PD-1) and CD274 (PD-L1) in the peripheral CD3+CD4+ cell population of persons with LN. Furthermore, ELISA was used to detect serum CXCL12 and vitamin D concentrations. A distinct decrease of PD-1 and a significant increase of PD-L1 was demonstrated in patients with LN compared with either SLE patients with no LN or healthy controls. The PD-1/PD-L1 axis was negatively correlated with different disease parameters. Vitamin D deficiency and insufficiency were more prevalent in patients with LN than in controls, being significantly associated with disease activity and inversely associated with the PD-1/PD-L1 expression. Moreover, CXCL12 was negatively correlated with the PD-1/PD-L1 axis and vitamin D concentration. The findings suggest an involvement of the PD-1/PD-L1 axis in lupus nephritis, which might serve as a potential highly selective therapeutic target that is more effective but less toxic. In addition, restoring adequate vitamin D levels in lupus nephritis could be a possible simple measure to control inflammatory immune responses.

Systemic Lupus Erythematosus Disease: An Overview of the Clinical Approach to Pathogenesis, Diagnosis, and Treatment

The systemic lupus erythematosus (SLE), commonly known as Lupus, is a rare and complex multisystem autoimmune disease where one’s immune system is overactive, and the body attacks its organ systems. SLE is a historically old disease described already in antiquity; it is an example of a chronic disease with physical, psychological, financial, and social implications for individuals diagnosed. It has inspired medical and basic biological scientists that focus on molecular biology, basic immunology, immunopathology, clinical science, genetics, and epidemiology. The syndrome is real in its existence-although hidden behind obstacles, cumbersome for patients and clinicians, and rebellious for scientists. There is currently no cure for SLE. The goal of treatment is to ease symptoms. This article will review information on the general approach to SLE therapy, focusing on currently approved therapies and novel approaches that might be used in the future.

Comparative Analysis on Abnormal Methylome of Differentially Expressed Genes and Disease Pathways in the Immune Cells of RA and SLE

We identified abnormally methylated, differentially expressed genes (DEGs) and pathogenic mechanisms in different immune cells of RA and SLE by comprehensive bioinformatics analysis. Six microarray data sets of each immune cell (CD19⁺ B cells, CD4⁺ T cells and CD14⁺ monocytes) were integrated to screen DEGs and differentially methylated genes by using R package “limma.” Gene ontology annotations and KEGG analysis of aberrant methylome of DEGs were done using DAVID online database. Protein-protein interaction (PPI) network was generated to detect the hub genes and their methylation levels were compared using DiseaseMeth 2.0 database. Aberrantly methylated DEGs in CD19⁺ B cells (173 and 180), CD4⁺ T cells (184 and 417) and CD14⁺ monocytes (193 and 392) of RA and SLE patients were identified. We detected 30 hub genes in different immune cells of RA and SLE and confirmed their expression using FACS sorted immune cells by qPCR. Among them, 12 genes (BPTF, PHC2, JUN, KRAS, PTEN, FGFR2, ALB, SERB-1, SKP2, TUBA1A, IMP3, and SMAD4) of RA and 12 genes (OAS1, RSAD2, OASL, IFIT3, OAS2, IFIH1, CENPE, TOP2A, PBK, KIF11, IFIT1, and ISG15) of SLE are proposed as potential biomarker genes based on receiver operating curve analysis. Our study suggests that MAPK signaling pathway could potentially differentiate the mechanisms affecting T- and B- cells in RA, whereas PI3K pathway may be used for exploring common disease pathways between RA and SLE. Compared to individual data analyses, more dependable and precise filtering of results can be achieved by integrating several relevant data sets.

Change of serum B-cell activating factor level in patients with positive antiphospholipid antibodies and previous adverse pregnancy outcomes and its significance

Background:

B-cell activating factor (BAFF) is vital for B cell survival. Serum BAFF levels are elevated in thrombotic antiphospholipid syndrome, but little is known about levels in patients with positive antiphospholipid antibodies (aPLs) and previous adverse pregnancy outcomes (APOs). We aimed to analyze serum BAFF concentrations of these patients in early pregnancy along with different pregnancy outcomes.

Methods:

Thirty-six pregnant patients positive for aPLs and previous APOs (patient group), 25 healthy pregnant females (HP group) and 35 healthy non-pregnant females (HNP group) from the Peking University Third Hospital, between October 2018 and March 2019, were enrolled in this study. Serum of HNP and serum of patients as well as HP in the first gestational trimester were collected. Enzyme-linked immunosorbent assay kits were used to measure serum BAFF and interferon-alpha (IFN-α) concentrations. Cytometric bead array analysis was used to measure serum concentrations of cytokines. The patient group was further divided into APOs and non-APOs (NAPOs) group, fetal loss and live birth group according to pregnancy outcomes. The Mann-Whitney U-test was used to assess significance between and within groups. Spearman rank-order was used to evaluate correlation coefficients between BAFF and related cytokines.

Results:

The serum BAFF level in HP group was significantly lower than HNP group (245.24 [218.80, 265.90] vs. 326.94 [267.31, 414.80] pg/mL, Z = −3.966, P < 0.001). The BAFF level was obviously elevated in patient group compared to that in HP group (307.77 [219.86, 415.65] vs. 245.24 [218.80, 265.90] pg/mL, Z = −2.464, P = 0.013). BAFF levels in APOs group tended to be higher than that in NAPOs group (416.52 [307.07, 511.12] vs. 259.37 [203.59, 375.81] pg/mL, Z = −2.718, P = 0.006). Compared to HP group, concentrations of IFN-α, interleukin (IL-6) and tumor necrosis factor were higher in patient group (33.37 [18.85, 48.12] vs. 13.10 [6.85, 25.47] pg/mL, Z = −2.023, P = 0.043; 39.16 [4.41, 195.87] vs. 3.37 [2.92, 3.90] pg/mL, Z = −3.650, P < 0.001; 8.23 [2.27, 64.46] vs. 1.53 [1.25, 2.31] pg/mL, Z = −3.604, P < 0.001, respectively). Serum BAFF levels had a positive correlation with the concentrations of both IL-6 and IL-10 (IL-6: r = 0.525, P = 0.002; IL-10: r = 0.438, P = 0.012).

Conclusions:

Serum BAFF levels are increased in patients with positive aPLs and previous APOs as compared to healthy pregnant females and tend to be higher in individuals with current APOs. The BAFF levels have a positive correlation with serum IL-6 and IL-10.

Immune evolution from preneoplasia to invasive lung adenocarcinomas and underlying molecular features

The mechanism by which anti-cancer immunity shapes early carcinogenesis of lung adenocarcinoma (ADC) is unknown. In this study, we characterize the immune contexture of invasive lung ADC and its precursors by transcriptomic immune profiling, T cell receptor (TCR) sequencing and multiplex immunofluorescence (mIF). Our results demonstrate that anti-tumor immunity evolved as a continuum from lung preneoplasia, to preinvasive ADC, minimally-invasive ADC and frankly invasive lung ADC with a gradually less effective and more intensively regulated immune response including down-regulation of immune-activation pathways, up-regulation of immunosuppressive pathways, lower infiltration of cytotoxic T cells (CTLs) and anti-tumor helper T cells (Th), higher infiltration of regulatory T cells (Tregs), decreased T cell clonality, and lower frequencies of top T cell clones in later-stages. Driver mutations, chromosomal copy number aberrations (CNAs) and aberrant DNA methylation may collectively impinge host immune responses and facilitate immune evasion, promoting the outgrowth of fit subclones in preneoplasia into dominant clones in invasive ADC.

Three functional variants in the NLRP3 gene are associated with susceptibility and clinical characteristics of systemic lupus erythematosus

OBJECTIVE

Nod-like receptor pyrin domain containing 3 (NLRP3) gene encodes an intracellular receptor whose dysregulation in systemic lupus erythematosus (SLE) has been reported in multiple studies. Activation of NLRP3 inflammasome leads to the induction of inflammatory response via cleaving and producing of specific cytokines. In the present study, we assessed the possible association between three functional polymorphisms in this gene and SLE risk in the Iranian population. These variants include two gain of function (rs4612666 and rs10754558) and one loss of function (rs6672995) which are correlated with modulation of expression of NLRP3.

METHODS

A case-control study involving 110 SLE patients and 116 control subjects was undertaken to estimate the frequency of rs4612666, rs10754558, and rs6672995 genotypes using real-time PCR high resolution melting method (HRM).

RESULTS

Our findings revealed significant associations between GG genotype and G allele of rs10754558 with increased risk of SLE (OR _{for GG genotype}= 2.82; 95%CI [1.45-5.46]/OR _{for G allele}= 1.97; 95%CI [1.36-2.87]). Although, no significant associations were recognized between allele and genotype frequencies of rs4612666 and rs6672995 polymorphisms with SLE risk (P > 0.05). Also, our analysis revealed that the C allele in rs4612666 and G allele in rs10754558 was correlated with the severity of disease activity (P < 0.001). Moreover, these common variants were associated with lower age of onset and some clinical symptoms in the patient group, such as skin manifestation, neurological symptom and, renal involvement (P < 0.05).

CONCLUSION

This study demonstrates a substantial association between NLRP3 polymorphisms with increased risk, clinical symptoms, and the severity of disease activity of SLE.

The Normal Ratio of Th17 and Th1 Post-mesenchymal Stem Cells Coculture with PBMCs of Systemic Lupus Erythematosus Patients

BACKGROUND: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by altered T-cell population homeostasis, including Th1 and Th17 populations. Mesenchymal stem cell (MSC)-induced i-Treg in SLE milieu can suppress Th17 cell populations; however, Th1 cell population status as a response to the Th17 decrease remains unclear. Therefore, improving SLE flare by suppressing Th17 and constantly controlling Th1 under normal level through MSCs administration is crucial. AIM: This study aimed to investigate the role of MSCs in suppressing Th17 cell populations and controlling Th1 to a normal level by in vitro coculturing MSCs with PBMC from SLE patients.. METHODS: This study used a post-test control group design. MSCs were obtained from human umbilical cord blood and characterized according to their surface antigen expression and multilineage differentiation capacities. PBMCs isolated from SLE patients were divided into five groups: Sham, control, and three treatment groups. The treatment groups were treated by coculturing MSCs to PBMCs with a ratio of 1:10, 1:25, and 1:40 for 72 h incubation. Th1 and Th17 cells were analyzed by flow cytometry. RESULTS: This study showed that there was no significance difference of the percentages of Th1 cells on all treatment groups. On the other hand, the percentages of Th17 were significantly decreased on T1 group. Interestingly, there was also significant decrease of Th1-like Th17 cells population on T1 group. CONCLUSIONS: MSCs may suppress Th17 and control Th1 to a normal level by in vitro coculturing MSCs with PBMC from SLE.

Understanding Accelerated Atherosclerosis in Systemic Lupus Erythematosus: Toward Better Treatment and Prevention

Systemic lupus erythematosus (SLE) carries a significant risk of cardiovascular disease (CVD). The prevalence of premature CVD is especially noteworthy because it occurs in premenopausal women with SLE who would otherwise have very low rates of CVD. While traditional risk factors likely play a role in development of CVD in the setting of SLE, they do not fully explain the excess risk. The pathogenesis of CVD in SLE is not fully understood, but the inflammatory nature of SLE is believed to be a key factor in accelerating atherosclerosis. Systemic inflammation may lead to an abnormal lipid profile with elevated triglycerides, total cholesterol, and low-density lipoprotein cholesterol and dysfunctional high-density lipoprotein cholesterol. Additionally, the inflammatory milieu of SLE plasma promotes endothelial dysfunction and vascular injury, early steps in the progression of atherosclerotic CVD. Despite the overall headway that has been achieved in treating lupus, innovative therapeutics specifically targeting the progression of atherosclerosis within the lupus population are currently lacking. However, there have been advancements in the development of promising modalities for diagnosis of subclinical atherosclerosis and detection of high CVD risk patients. Due to the significant impact of CVD on morbidity and mortality, research addressing prevention and treatment of CVD in SLE needs to be prioritized. This review explores the intricate interplay of SLE-specific properties that contribute to atherosclerosis and CVD within this population, as well as screening methods and possible therapies.

LINC00176 facilitates CD4+T cell adhesion in systemic lupus erythematosus via the WNT5a signaling pathway by regulating WIF1

Accruing research shows the implications of long non-coding RNAs (lncRNAs) in the progression of various autoimmune diseases including systemic lupus erythematosus (SLE). The present study aimed to identify the expression pattern of LINC00176 in SLE and to explore its effects on CD4⁺T cell adhesion in this context. The biological functions of LINC00176, WIF1 and WNT5a on CD4⁺T cells in SLE were evaluated via gain- and loss-of-function experiments, following delivery of pcDNA3-LINC00176, siRNA-LINC00176, pcDNA3-WIF1 and WNT-sFRP5 (an inhibitor for the WNT5a signaling pathway). High LINC00176 expression was evident in the CD4⁺T cells of SLE patients. Additionally, WIF1 was identified as a potential target gene of LINC00176, and was negatively regulated by LINC00176. The overexpression of LINC00176 could promote proliferation and adhesion of CD4⁺T cells in SLE. Such alternations were reversed following up-regulation of WIF1 or inhibition of the WNT5a signaling pathway. Taken together, the key findings of our study highlight the ability of LINC00176 to potentially promote the proliferation and adhesion of CD4⁺T cells in SLE by down-regulating WIF1 and activating the WNT5a signaling pathway, providing new insight and a theoretical basis for translation in SLE therapy.

Potential role of viral infection and B cells as a linker between innate and adaptive immune response in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease that involves several organ systems. Although B cells play a key role in SLE pathogenesis, the mechanisms behind B cell dysregulation in SLE development remained controversial. Finding the modules containing highly co-expressed genes in B cells could explain biological pathways involved in the pathogenesis of SLE, which may further support the reasons for the altered function of B cells in SLE disease. A total of three microarray gene expression datasets were downloaded from Gene Expression Omnibus. SLE samples were prepared from the purified B lymphocyte cells of the patients who have not received immunosuppressive drugs as well as high dose immunocytotoxic therapies or steroids. A weighted gene co-expression network was then constructed to find the relevant modules implicated in the SLE progression. Among 17 identified modules, 3 modules were selected through mapping to STRING and finding the ones that had highly connection at the protein level. These modules clearly indicate the involvement of several pathways in the pathogenesis of SLE including viral infection, adaptive immune response, and innate immune response in B lymphocytes. The WGCN analysis further revealed the co-expressed genes involved in both innate and adaptive immune systems. Mix infections and primary immunodeficiency might also dysregulate B lymphocytes, which may facilitate SLE development. As such, identifying novel biomarkers and pathways in lupus would be of importance.

Mesenchymal stem/stromal cells as a valuable source for the treatment of immune-mediated disorders

Over recent years, mesenchymal stem/stromal cells (MSCs) and their potential biomedical applications have received much attention from the global scientific community in an increasing manner. Firstly, MSCs were successfully isolated from human bone marrow (BM), but in the next steps, they were also extracted from other sources, mostly from the umbilical cord (UC) and adipose tissue (AT). The International Society for Cellular Therapy (ISCT) has suggested minimum criteria to identify and characterize MSCs as follows: plastic adherence, surface expression of CD73, D90, CD105 in the lack of expression of CD14, CD34, CD45, and human leucocyte antigen-DR (HLA-DR), and also the capability to differentiate to multiple cell types including adipocyte, chondrocyte, or osteoblast in vitro depends on culture conditions. However, these distinct properties, including self-renewability, multipotency, and easy accessibility are just one side of the coin; another side is their huge secretome which is comprised of hundreds of mediators, cytokines, and signaling molecules and can effectively modulate the inflammatory responses and control the infiltration process that finally leads to a regulated tissue repair/healing or regeneration process. MSC-mediated immunomodulation is a direct result of a harmonic synergy of MSC-released signaling molecules (i.e., mediators, cytokines, and chemokines), the reaction of immune cells and other target cells to those molecules, and also feedback in the MSC-molecule-target cell axis. These features make MSCs a respectable and eligible therapeutic candidate to be evaluated in immune-mediated disorders, such as graft versus host diseases (GVHD), multiple sclerosis (MS), Crohn's disease (CD), and osteoarthritis (OA), and even in immune-dysregulating infectious diseases such as the novel coronavirus disease 2019 (COVID-19). This paper discussed the therapeutic applications of MSC secretome and its biomedical aspects related to immune-mediated conditions. Sources for MSC extraction, their migration and homing properties, therapeutic molecules released by MSCs, and the pathways and molecular mechanisms possibly involved in the exceptional immunoregulatory competence of MSCs were discussed. Besides, the novel discoveries and recent findings on immunomodulatory plasticity of MSCs, clinical applications, and the methods required for their use as an effective therapeutic option in patients with immune-mediated/immune-dysregulating diseases were highlighted.

Regulation of Toll-like receptor-mediated inflammatory response by microRNA-152-3p-mediated demethylation of MyD88 in systemic lupus erythematosus

OBJECTIVE

microRNAs (miRNAs) play critical roles in embryogenesis, cell differentiation and the pathogenesis of several human diseases, including systemic lupus erythematosus (SLE). Toll-like receptors (TLRs) are also known to exert crucial functions in the immune response activation occurring in the pathogenesis of autoimmune diseases like SLE. Herein, the current study aimed to explore the potential role of miR-152-3p in TLR-mediated inflammatory response in SLE.

METHODS

We determined the miR-152-3p expression profiles in CD4+ T cells and peripheral blood mononuclear cells (PBMCs) harvested from patients with SLE and healthy controls, and analyzed the correlation between miR-152-3p expression and clinicopathological parameters. CD70 and CD40L expression patterns in CD4+ T cells were assessed by RT-qPCR and flow cytometry. ChIP was adopted to determine the enrichment of DNA methyltransferase 1 (DNMT1) in the promoter region of myeloid differentiation factor 88 (MyD88).

RESULTS

The obtained findings revealed that miR-152-3p was highly-expressed in CD4+ T cells and PBMCs of patients with SLE, and this high expression was associated with facial erythema, joint pain, double-stranded DNA, and IgG antibody. DNMT1 could be enriched in the MyD88 promoter, and miR-152-3p inhibited the methylation of MyD88 by targeting DNMT1. We also found that silencing miR-152-3p inhibited MyD88 expression not only to repress the autoreactivity of CD4+ T cells and but also to restrain their cellular inflammation, which were also validated in vivo.

CONCLUSION

Our study suggests that miR-152-3p promotes TLR-mediated inflammatory response in CD4+ T cells by regulating the DNMT1/MyD88 signaling pathway, which highlights novel anti-inflammatory target for SLE treatment.

Abnormal thymic B cell activation and impaired T cell differentiation in pristane-induced lupus mice

Changes in the thymus and potential mechanisms underlying the pathogenesis in pristane-induced lupus (PIL) mice are poorly understood. This study aimed to systematically and specifically examine changes in the thymus and the potential mechanisms responsible for immunological abnormalities in PIL mice. The results showed that PIL mice exhibit serious thymic hyperplasia, an elevated thymus index, a damaged histopathological structure and increased thymocyte apoptosis. We found that thymic T cell differentiation was impaired as the CD4⁺ CD8⁺ double-positive (DP) thymocyte frequency significantly decreased, becoming almost absent at 28 weeks after induction, while CD4 CD8^- double-negative (DN) thymocytes and CD4⁺ CD8^- single-positive (CD4⁺ SP) and CD4 CD8⁺ single-positive (CD8⁺ SP) cells were increased. This phenomenon might be explained by an inhibition of the DN-to-DP-cell transition and stimulation of DP cell conversion into CD4⁺ /CD8⁺ SP thymocytes. Moreover, we discovered a dramatic and abnormal increase in thymic B cells, that was associated with CD19, Irf8, Ebf1, Pax5, Irf4, Blk, CXCL13, CXCR5, CD79a, CD79b, Lyn, Syk, Btk, and BLNK gene accumulation, which exhibited positive interactions. We further verified that the mRNA expression of these genes was significantly upregulated and consistent with the RNA-seq results. These results suggest a role of these genes in the increase of B cells in the thymus of PIL mice. In summary, our results showed the changes in the thymus in PIL and elucidated the immunologic abnormalities of increased B cells, potentially providing insight into the associated molecular mechanisms and facilitating further research.

Aberrant Non-Coding RNA Expression in Patients with Systemic Lupus Erythematosus: Consequences for Immune Dysfunctions and Tissue Damage

Systemic lupus erythematosus (SLE) is a complex systemic autoimmune disease with heterogeneous clinical manifestations. A diverse innate and adaptive immune dysregulation is involved in the immunopathogenesis of SLE. The dysregulation of immune-related cells may derive from the intricate interactions among genetic, epigenetic, environmental, and immunological factors. Of these contributing factors, non-coding RNAs (ncRNAs), including microRNAs (miRNAs, miRs), and long non-coding RNAs (lncRNAs) play critical roles in the post-transcriptional mRNA expression of cytokines, chemokines, and growth factors, which are essential for immune modulation. In the present review, we emphasize the roles of ncRNA expression in the immune-related cells and cell-free plasma, urine, and tissues contributing to the immunopathogenesis and tissue damage in SLE. In addition, the circular RNAs (circRNA) and their post-translational regulation of protein synthesis in SLE are also briefly described. We wish these critical reviews would be useful in the search for biomarkers/biosignatures and novel therapeutic strategies for SLE patients in the future.

Sphingolipids and Diagnosis, Prognosis, and Organ Damage in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that involves multiple organs and disproportionality affects females, especially African Americans from 15 to 44 years of age. SLE can lead to end organ damage including kidneys, lungs, cardiovascular and neuropsychiatric systems, with cardiovascular complications being the primary cause of death. Usually, SLE is diagnosed and its activity is assessed using the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), Systemic Lupus International Collaborating Clinics Damage Index (SLICC/ACR), and British Isles Lupus Assessment Group (BILAG) Scales, which unfortunately often occurs after a certain degree of systemic involvements, disease activity or organ damage already exists. There is certainly a need for the identification of early biomarkers to diagnose and assess disease activity as well as to evaluate disease prognosis and response to treatment earlier in the course of the disease. Here we review advancements made in the area of sphingolipidomics as a diagnostic/prognostic tool for SLE and its co-morbidities. We also discuss recent reports on differential sphingolipid metabolism and blood sphingolipid profiles in SLE-prone animal models as well as in diverse cohorts of SLE patients. In addition, we address targeting sphingolipids and their metabolism as a method of treating SLE and some of its complications. Although such treatments have already shown promise in preventing organ-specific pathology caused by SLE, further investigational studies and clinical trials are warranted.

Type I interferon antagonists in clinical development for lupus

INTRODUCTION

Systemic lupus erythematosus (SLE) is a severe chronic and incurable autoimmune disease. Treatment includes glucocorticoids and immunosuppressants which typically result in partial responses, and hence there is a great need for new therapies. The type I interferon (IFN) pathway is activated in more than 50% of SLE patients, and it is strongly implicated as a pathogenic factor in SLE.

AREAS COVERED

We searched the literature using 'SLE and interferon antagonists' as search terms. This identified a number of therapeutics that have entered clinical development targeting type I IFN in SLE. These include monoclonal antibodies against type I IFN cytokines and a kinoid vaccination strategy to induce anti-IFN antibodies.

EXPERT OPINION

Type I IFN antagonists have had some success, but many molecules have not progressed to phase III. These varied results are likely attributed to the multiple concurrent cytokine abnormalities present in SLE, the imprecise nature of the IFN signature as a readout for type I IFN and difficulties with clinical trials such as background medication use and diffuse composite disease activity measures. Despite these challenges, it seems likely that a type I IFN antagonist will come to clinical utility for SLE given the large unmet need and the recent phase III success with anifrolumab.

Natural Killer Cell Dysfunction and Its Role in COVID-19

When facing an acute viral infection, our immune systems need to function with finite precision to enable the elimination of the pathogen, whilst protecting our bodies from immune-related damage. In many instances however this "perfect balance" is not achieved, factors such as ageing, cancer, autoimmunity and cardiovascular disease all skew the immune response which is then further distorted by viral infection. In SARS-CoV-2, although the vast majority of COVID-19 cases are mild, as of 24 August 2020, over 800,000 people have died, many from the severe inflammatory cytokine release resulting in extreme clinical manifestations such as acute respiratory distress syndrome (ARDS) and hemophagocytic lymphohistiocytosis (HLH). Severe complications are more common in elderly patients and patients with cardiovascular diseases. Natural killer (NK) cells play a critical role in modulating the immune response and in both of these patient groups, NK cell effector functions are blunted. Preliminary studies in COVID-19 patients with severe disease suggests a reduction in NK cell number and function, resulting in decreased clearance of infected and activated cells, and unchecked elevation of tissue-damaging inflammation markers. SARS-CoV-2 infection skews the immune response towards an overwhelmingly inflammatory phenotype. Restoration of NK cell effector functions has the potential to correct the delicate immune balance required to effectively overcome SARS-CoV-2 infection.

Correlation between C-reactive Protein with Malondialdehyde in Systemic Lupus Erythematosus Patients

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by an inflammatory process. One of the inflammation markers that can be measured is C-reactive protein (CRP). Another indicator of inflammation is malondialdehyde (MDA), though it is still uncommon to be analyzed in SLE patients. The study looked for the MDA value and found a correlation with CRP. A cross-sectional study design with a correlative analytical was performed. CRP level data was taken from Hasan Sadikin lupus registry data, and MDA levels were analyzed from a bioarchive patient's serum. We collected the patients' data who had CRP level from Hasan Sadikin lupus registry and analysed MDA levels from the serum sample. MDA levels were analyzed using an ELISA method. The data obtained were analyzed using the Pearson correlation and Eta correlation test. The study involved 78 data patients as subjects. It was found that the median of CRP and MDA was 0.85 mg/l and 153.10 ng/ml, respectively. These results indicate that the CRP levels in SLE patients are still within normal limits. Statistical analysis showed no correlation between CRP and MDA level (r = 0.2, P > 0.05). Additionally, the correlation between CRP and MDA with organ involvement, such as lupus nephritis (LN), lupus cutaneous (LC), and lupus musculoskeletal (LM), showed no correlation (F_h < F_t). There is no correlation between CRP and MDA levels in SLE patients, and specific organ involvement of the disease does not affect the correlation.

Mechanistic Paradigms of Natural Plant Metabolites as Remedial Candidates for Systemic Lupus Erythromatosus

Systemic lupus erythematosus (SLE) is a complex autoimmune disorder involving a dysregulated immune response which ultimately leads to multiple organ failure. Several immunological and cellular checkpoints are available as drug targets. However, the available chemosynthetic drugs such as non-steroidal anti-inflammatory drugs and corticosteroids provide limited therapy with extreme toxicities. Moreover, the disease heterogeneity in SLE is very difficult to manage by a single drug component. Hence, it is imperative to utilize the holistic capabilities of natural plant products as immunomodulators and intracellular signaling regulators, thereby providing an auxiliary option of treatment. Additionally, the herbal drugs also serve as symptomatic relief providers, thereby serving as a prophylactic remedy in case of cerebrovascular, hepatic, nephropathological, hematological, cardiopulmonary, mucocutaneous and musculoskeletal manifestations of SLE. The present review attempts to showcase the current state of knowledge regarding the utility of plant-derived phyto-metabolites with their probable mechanistic roles in treating SLE, by means of targeting the signaling cascade, proinflammatory cytokine production and B–T cell co-stimulation. It is hoped that further preclinical and clinical studies will be embarked upon in order to understand the underlying therapeutic and mechanistic aspects of these medicinal herbs.

Lipid-based Vehicles for siRNA Delivery in Biomedical Field

BACKGROUND

Genetic drugs have aroused much attention in the past twenty years. RNA interference (RNAi) offers novel insights into discovering potential gene functions and therapies targeting genetic diseases. Small interference RNA (siRNA), typically 21-23 nucleotides in length, can specifically degrade complementary mRNA. However, targeted delivery and controlled release of siRNA remain a great challenge.

METHODS

Different types of lipid-based delivery vehicles have been synthesized, such as liposomes, lipidoids, micelles, lipoplexes and lipid nanoparticles. These carriers commonly have a core-shell structure. For active targeting, ligands may be conjugated to the surface of lipid particles.

RESULTS

Lipid-based drug delivery vehicles can be utilized in anti-viral or anti-tumor therapies. They can also be used to tackle genetic diseases or discover novel druggable genes.

CONCLUSION

In this review, the structures of lipid-based vehicles and possible surface modifications are described, and applications of delivery vehicles in biomedical field are discussed.

The Phenotype and Secretory Activity of Adipose-Derived Mesenchymal Stem Cells (ASCs) of Patients with Rheumatic Diseases

Mesenchymal stem/stromal cells (MSCs) have immunosuppressive and regenerative properties. Adipose tissue is an alternative source of MSCs, named adipose-derived mesenchymal stem cells (ASCs). Because the biology of ASCs in rheumatic diseases (RD) is poorly understood, we performed a basic characterization of RD/ASCs. The phenotype and expression of adhesion molecules (intracellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1) on commercially available healthy donors (HD), ASC lines (n = 5) and on ASCs isolated from patients with systemic lupus erythematosus (SLE, n = 16), systemic sclerosis (SSc, n = 17) and ankylosing spondylitis (AS, n = 16) were analyzed by flow cytometry. The secretion of immunomodulatory factors by untreated and cytokine-treated ASCs was measured by ELISA. RD/ASCs have reduced basal levels of CD90 and ICAM-1 expression, correlated with interleukin (IL)-6 and transforming growth factor (TGF)-β1 release, respectively. Compared with HD/ASCs, untreated and tumour necrosis factor (TNF) + interferon (IFN)-γ (TI)-treated RD/ASCs produced similar amounts of prostaglandin E2 (PGE2), IL-6, leukemia inhibiting factor (LIF), and TGF-β1, more IL-1Ra, soluble human leukocyte antigen G (sHLA-G) and tumor necrosis factor-inducible gene (TSG)-6, but less kynurenines and galectin-3. Basal secretion of galectin-3 was inversely correlated with the patient's erythrocyte sedimentation rate (ESR) value. IFN-α and IL-23 slightly raised galectin-3 release from SLE/ASCs and AS/ASCs, respectively. TGF-β1 up-regulated PGE2 secretion by SSc/ASCs. In conclusion, RD/ASCs are characterized by low basal levels of CD90 and ICAM-1 expression, upregulated secretion of IL-1Ra, TSG-6 and sHLA-G, but impaired release of kynurenines and galectin-3. These abnormalities may modify biological activities of RD/ASCs.

Neutrophils-Important Communicators in Systemic Lupus Erythematosus and Antiphospholipid Syndrome

Systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS) are two autoimmune diseases that can occur together or separately. Insights into the pathogenesis have revealed similarities, such as development of autoantibodies targeting subcellular antigens as well as a shared increased risk of cardiovascular morbidity, potentially due to mutual pathologic mechanisms. In this review, we will address the evidence implicating neutrophils in the pathogenesis of these conditions, highlighting their shared features. The neutrophil is the most abundant leukocyte, recognized for its role in infectious and inflammatory diseases, but dysregulation of neutrophil effector functions, including phagocytosis, oxidative burst and formation of neutrophil extracellular traps (NETs) may also contribute to an autoimmune process. The phenotype of neutrophils in SLE and APS differs from neutrophils of healthy individuals, where neutrophils in SLE and APS are activated and prone to aggregate. A specific subset of low-density neutrophils with different function compared to normal-density neutrophils can also be found within the peripheral blood mononuclear cell (PBMC) fraction after density gradient centrifugation of whole blood. Neutrophil phagocytosis is required for regular clearance of cell remnants and nuclear material. Reactive oxygen species (ROS) released by neutrophils during oxidative burst are important for immune suppression and impairment of ROS production is seen in SLE. NETs mediate pathology in both SLE and APS via several mechanisms, including exposure of autoantigens, priming of T-cells and activation of autoreactive B-cells. NETs are also involved in cardiovascular events by forming a pro-thrombotic scaffolding surface. Lastly, neutrophils communicate with other cells by producing cytokines, such as Interferon (IFN) -α, and via direct cell-cell contact. Physiological neutrophil effector functions are necessary to prevent autoimmunity, but in SLE and APS these are altered.

A rare case of Rhupus syndrome with Hashimoto's thyroiditis, associated adverse effect of drugs and incidental findings

The term Rhupus is coded for the individuals who have rheumatoid like arthritis with erosions and fulfil the criteria for both rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Abnormal Th2 cell plays a central role in SLE while Th1 participate in RA. Thus the overlap of SLE and RA has a very low incidence (0.01%-0.2%) in patient with arthritis. This 40-year-old male patient presented with complains of severe multiple joint pain with progressive deformities, diminished vision from last 2 months, redness on back, headache and swelling over scalp. As this patient had history of severe trauma that was considered as a precipitating factor for ongoing chronic inflammatory disorder. Posterior subcapsular cataract was explained by prolong use of systemic steroid and rashes on the lower back due to sulfasalazine. Radioimaging study revealed arachnoid cyst and calcified projection arising from outer table of skull, which was kept under observation.