Autoimmune Response Research Articles

The atypical chemokine receptor 2 reduces T cell expansion and tertiary lymphoid tissue but does not limit autoimmune organ injury in lupus-prone B6lpr mice

IntroductionThe atypical chemokine receptor 2 (ACKR2) is a chemokine scavenger receptor, which limits inflammation and organ damage in several experimental disease models including kidney diseases. However, potential roles of ACKR2 in reducing inflammation and tissue injury in autoimmune disorders like systemic lupus erythematosus (SLE) and lupus nephritis are unknown, as well as its effects on systemic autoimmunity. MethodsTo characterize functional roles of ACKR2 in SLE, genetic Ackr2 deficiency was introduced into lupus-prone C57BL/6lpr (Ackr2-/- B6lpr) mice. ResultsUpon inflammatory stimulation in vitro, secreted chemokine levels increased in Ackr2 deficient tubulointerstitial tissue but not glomeruli. Moreover, Ackr2 expression was induced in kidneys and lungs of female C57BL/6lpr mice developing SLE. However, female Ackr2-/- B6lpr mice at 28 weeks of age showed similar renal functional parameters as wildtype (WT)-B6lpr mice. Consistently, assessment of activity and chronicity indices for lupus nephritis revealed comparable renal injury. Interestingly, Ackr2-/- B6lpr mice showed significantly increased renal infiltrates of CD3+ T and B cells, but not neutrophils, macrophages or dendritic cells, with T cells predominantly accumulating in the tubulointerstitial compartment of Ackr2-/- B6lpr mice. In addition, histology demonstrated significantly increased peribronchial lung infiltrates of CD3+ T cells in Ackr2-/- B6lpr mice. Despite this, protein levels of pro-inflammatory chemokines and mRNA expression of inflammatory mediators were not different in kidneys and lungs of WT- and Ackr2-/- B6lpr mice. This data suggests compensatory mechanisms for sufficient chemokine clearance in Ackr2-deficient B6lpr mice in vivo. Analysis of systemic autoimmune responses revealed comparable levels of circulating lupus-associated autoantibodies and glomerular immunoglobulin deposition in the two genotypes. Interestingly, similar to kidney and lung CD4+ T cell numbers and activation were significantly increased in spleens of Ackr2-deficient B6lpr mice. In lymph nodes of Ackr2-/- B6lpr mice abundance of activated dendritic cells decreased, but CD4+ T cell numbers were comparable to WT. Moreover, increased plasma levels of CCL2 were present in Ackr2-/- B6lpr mice, which may facilitate T cell mobilization into spleens and peripheral organs. DiscussionIn summary, we show that ACKR2 prevents expansion of T cells and formation of tertiary lymphoid tissue, but is not essential to limit autoimmune tissue injury in lupus-prone B6lpr mice.

Human endogenous retrovirus W in multiple sclerosis: transcriptional activity is associated with decline in oligodendrocyte proportions in the white matter of the brain.

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease. One of the basic mechanisms in this disease is the autoimmune response against the myelin sheet leading to axonal damage. There is strong evidence showing that this response is regulated by both genetic and environmental factors. In addition, the role of viruses has been extensively studied, especially in the case of human endogenous retroviruses (HERVs). However, although several associations with MS susceptibility, especially in the case of HERV-W family have been observed, the pathogenic mechanisms have remained enigmatic. To clarify these HERV-mediated mechanisms as well as the responsible HERV-W loci, we utilized RNA sequencing data obtained from the white matter of the brain of individuals with and without MS. CIBERSORTx tool was applied to estimate the proportions of neuronal, glial, and endothelial cells in the brain. In addition, the transcriptional activity of 215 HERV-W loci were analyzed. The results indicated that 65 HERV-W loci had detectable expression, of which 14 were differentially expressed between MS and control samples. Of these, 12 HERV-W loci were upregulated in MS. Expression levels of the 8 upregulated HERV-W loci had significant negative correlation with estimated oligodendrocyte proportions, suggesting that they are associated with the dynamics of oligodendrocyte generation and/or maintenance. Furthermore, Gene Set Enrichment Analysis (GSEA) results indicated that expression levels of three upregulated HERV-W loci: 2p16.2, 2q13, and Xq13.3, are associated with suppression of oligodendrocyte development and myelination. Taken together, these data suggest new HERV-W loci candidates that might take part in MS pathogenesis.

Enhancing tuberculosis vaccine development: a deconvolution neural network approach for multi-epitope prediction

Tuberculosis (TB) a disease caused by Mycobacterium tuberculosis (Mtb) poses a significant threat to human life, and current BCG vaccinations only provide sporadic protection, therefore there is a need for developing efficient vaccines. Numerous immunoinformatic methods have been utilized previously, here for the first time a deep learning framework based on Deconvolutional Neural Networks (DCNN) and Bidirectional Long Short-Term Memory (DCNN-BiLSTM) was used to predict Mtb Multiepitope vaccine (MtbMEV) subunits against six Mtb H37Rv proteins. The trained model was used to design MEV within a few minutes against TB better than other machine learning models with 99.5% accuracy. The MEV has good antigenicity, and physiochemical properties, and is thermostable, soluble, and hydrophilic. The vaccine's BLAST search ruled out the possibility of autoimmune reactions. The secondary structure analysis revealed 87% coil, 10% beta, and 2% alpha helix, while the tertiary structure was highly upgraded after refinement. Molecular docking with TLR3 and TLR4 receptors showed good binding, indicating high immune reactions. Immune response simulation confirmed the generation of innate and adaptive responses. In-silico cloning revealed the vaccine is highly expressed in E. coli. The results can be further experimentally verified using various analyses to establish a candidate vaccine for future clinical trials.

Vitiligo Causes and Treatment: A Review

Vitiligo is a chronic autoimmune disorder characterized by patches of skin losing pigment due to the destruction of melanocytes, the cells responsible for producing pigment. The condition can affect people of all ages and ethnicities, with symptoms including milky-white patches on the skin, premature graying of hair, and color loss in mucous membranes like the mouth or nose. Among the main causes of vitiligo are; Autoimmune Response: Vitiligo is primarily an autoimmune disease where the immune system mistakenly attacks melanocytes, leading to depigmentation. Factors like family history, genetic predisposition, and immune system disorders contribute to its development, Triggers: Events such as sunburn, emotional distress, or exposure to certain chemicals can trigger or exacerbate vitiligo. The treatment options are; Medications: Treatments include light therapy (phototherapy), oral medications like psoralen combined with UVA light (PUVA), and depigmentation therapy using monobenzone to match skin tones Surgery: Surgical options are available for some cases of vitiligo and Psychological Support: Counseling and mental health services can help individuals cope with the emotional impact of vitiligo, in conclusion, v is a multifaceted skin condition lacking a conclusive remedy, many types of vitiligo, but the most common one is Non-segmental Vitiligo (NSV), honmental and genetic are the most important causes of vitiligo. Important symptoms of vitiligo are; depigmented patches, hair discoloration, sensitivity to sunlight, treatment of vitiligo have many approach, among them are; topical Corticosteroids, phototherapy and Cosmetic Camouflage.

Dangers of the chronic stress response in the context of the microbiota-gut-immune-brain axis and mental health: a narrative review

More than 20% of American adults live with a mental disorder, many of whom are treatment resistant or continue to experience symptoms. Other approaches are needed to improve mental health care, including prevention. The role of the microbiome has emerged as a central tenet in mental and physical health and their interconnectedness (well-being). Under normal conditions, a healthy microbiome promotes homeostasis within the host by maintaining intestinal and brain barrier integrity, thereby facilitating host well-being. Owing to the multidirectional crosstalk between the microbiome and neuro-endocrine-immune systems, dysbiosis within the microbiome is a main driver of immune-mediated systemic and neural inflammation that can promote disease progression and is detrimental to well-being broadly and mental health in particular. In predisposed individuals, immune dysregulation can shift to autoimmunity, especially in the presence of physical or psychological triggers. The chronic stress response involves the immune system, which is intimately involved with the gut microbiome, particularly in the process of immune education. This interconnection forms the microbiota-gut-immune-brain axis and promotes mental health or disorders. In this brief review, we aim to highlight the relationships between stress, mental health, and the gut microbiome, along with the ways in which dysbiosis and a dysregulated immune system can shift to an autoimmune response with concomitant neuropsychological consequences in the context of the microbiota-gut-immune-brain axis. Finally, we aim to review evidenced-based prevention strategies and potential therapeutic targets.

Stat5b/Ezh2 axis governs high PD-L1 expressing tolerogenic dendritic cell subset in autoimmune diabetes

Dendritic cells (DCs) are specialized antigen-presenting cells that play an important role in inducing and maintaining immune tolerance. The altered distribution and/or function of DCs contributes to defective tolerance in autoimmune diseases such as type 1 diabetes (T1D). In human T1D and in NOD mouse models, DCs share some defects and are often described as less tolerogenic and excessively immunogenic. In the NOD mouse model, the autoimmune response is associated with a defect in the Stat5b signaling pathway. We have reported that expressing a constitutively active form of Stat5b in DCs of transgenic NOD mice (NOD.Stat5b-CA), re-established their tolerogenic function, restored autoimmune tolerance and conferred protection from diabetes. However, the role and molecular mechanisms of Stat5b signaling in regulating splenic conventional DCs tolerogenic signature remained unclear. In this study, we reported that, compared to immunogenic splenic DCs of NOD, splenic DCs of NOD.Stat5b-CA mice exhibited a tolerogenic profile marked by elevated PD-L1 and PD-L2 expression, reduced pro-inflammatory cytokine production, increased frequency of the cDC2 subset and decreased frequency of the cDC1 subset. This tolerogenic profile was associated with increased Ezh2 and IRF4 but decreased IRF8 expression. We also found an upregulation of PD-L1 in the cDC1 subset and high PD-L1 and PD-L2 expression in cDC2 of NOD.Stat5b-CA mice. Mechanistically, we demonstrated that Ezh2 plays an important role in the maintenance of high PD-L1 expression in cDC1 and cDC2 subsets and that Ezh2 inhibition resulted in PD-L1 but not PD-L2 downregulation which was more drastic in the cDC2 subset. Additionally, Ezh2 inhibition severely reduced the cDC2 subset and increased the cDC1 subset and Stat5b-CA.DC pro-inflammatory cytokine production. Together our data suggest that the Stat5b-Ezh2 axis is critical for the maintenance of tolerogenic high PD-L1-expressing cDC2 and autoimmune tolerance in NOD.Stat5b-CA mice.

Current Vaccination Practice in Diabetic (Diabetes I) Patients.

The worldwide prevalence of diabetes, an endocrine condition, is rising quickly. The alarming rise of diabetes in recent years has emerged as a major contributor to premature death and illness among persons of working age. The potential use of immunomodulatory drugs to prevent diabetes has been a source of worry in light of recent advances in our understanding of the role of autoimmune responses in the development of diabetes. Vaccines can work in a variety of ways, including by eliminating autoreactive T-cells or by blocking the connections between immune cells. Most diabetes vaccines that have been created so far have only been evaluated in animal models, with just a small number having undergone successful human trials. In this article, the authors also look at the clinical trial research that are currently being conducted to create a prototype diabetes vaccine.

The effect of single nucleotide polymorphisms on depression in combination with coronary diseases: a systematic review and meta-analysis

BackgroundDepression and coronary heart disease (CHD) have common risk mechanisms. Common single nucleotide polymorphisms (SNPs) may be associated with the risk of depression combined with coronary heart disease.MethodsThis study was designed according to the PRISMA-P guidelines. We will include case-control studies and cohort studies investigating the relationship between gene SNPs and depression and coronary heart disease comorbidities. The Newcastle-Ottawa Scale (NOS) will be used to assess the risk of bias. When measuring dichotomous outcomes, we will use the odds ratio (OR) and 95% confidence interval (95%CIs) in a case-control study. Five genetic models (allele model, homozygous model, co-dominant model, dominant model, and recessive model) will be evaluated for each included study. Subgroup analysis by ethnicity will be performed. If necessary, post hoc analysis will be made according to different types.ResultsA total of 13 studies were included in this study, and the types of genes included are FKBP5 and SGK1 genes that act on glucocorticoid; miR-146a, IL-4-589, IL-6-174, TNF-α-308, CRP-717 genes that act on inflammatory mechanisms; eNOS genes from endothelial cells; HSP70 genes that act on the autoimmune response; ACE2 and MAS1 genes that act to mediate Ang(1-7) in the RAS system; 5-HTTLPR gene responsible for the transport of serotonin 5-HT and neurotrophic factor BDNF gene. There were three studies on 5-HTTLPR and BDNF genes, respectively, while there was only one study targeting FKBP5, SGK1, miR-146a, IL-4-589, IL-6-174, TNF-alpha-308, CRP-717, eNOS, HSP70, ACE2, and MAS1 genes. We did not perform a meta-analysis for genes reported in a single study, and meta-analysis was performed separately for studies exploring the 5-HTTLPR and BDNF genes. The results showed that for the 5-HTTLPR gene, there was a statistically significant association between 5-HTTLPR gene polymorphisms and depression in combination with coronary diseases (CHD-D) under the co-dominant model (LS vs LL: OR 1.76, 95%CI 1.20-2.59; SS vs LL: OR 2.80, 95%CI 1.45 to 5.41), the dominant model (LS+SS vs LL: OR 2.06, 95%CI 1.44 to 2.96), and the homozygous model (SS vs LL: OR 2.80 95%CI 1.45 to 5.5.41) were statistically significant for CHD-D, demonstrating that polymorphisms in the 5-HTTLPR gene are associated with the development of CHD-D and that the S allele in the 5-HTTLPR gene is likely to be a risk factor for CHD-D. For the BDNF gene, there were no significant differences between one of the co-dominant gene models (AA vs GG: OR 6.63, 95%CI 1.44 to 30.64), the homozygous gene model (AA vs GG: OR 6.63,95% CI 1.44 to 30.64), the dominant gene model (GA+AA vs GG: OR4.29, 95%CI 1.05 to 17.45), recessive gene model (AA vs GG+GA: OR 2.71, 95%CI 1.16 to 6.31), and allele model (A vs G: OR 2.59, 95%CI 1.18 to 5.67) were statistically significant for CHD-D, demonstrating that BDNFrs6265 gene polymorphisms are associated with the CHD-D development and that the A allele in the BDNFrs6265 gene is likely to be a risk factor for CHD-D. We analyzed the allele frequencies of SNPs reported in a single study and found that the SNPs in the microRNA146a gene rs2910164, the SNPs in the ACE2 gene rs2285666 and the SNPs in the SGK1 gene rs1743963 and rs1763509 were risk factors for the development of CHD-D. We performed a subgroup analysis of three studies involving the BDNFrs6265 gene. The results showed that European populations were more at risk of developing CHD-D than Asian populations in both dominant model (GA+AA vs GG: OR 10.47, 95%CI 3.53 to 31.08) and co-dominant model (GA vs GG: OR 6.40, 95%CI 1.98 to 20.73), with statistically significant differences. In contrast, the studies involving the 5-HTTLPR gene were all Asian populations, so subgroup analyses were not performed. We performed sensitivity analyses of studies exploring the 5-HTTLPR and BDNF rs6265 genes. The results showed that the results of the allele model, the dominant model, the recessive model, the homozygous model and the co-dominant model for both 5-HTTLPR and BDNF rs6265 genes were stable. Due to the limited number of studies of the 5-HTTLPR and BDNF genes, it was not possible to determine the symmetry of the funnel plot using Begg’s funnel plot and Egger’s test. Therefore, we did not assess publication bias.DiscussionSNPs of the microRNA146a gene at rs2910164, the ACE2 gene at the rs2285666 and the SGK1 gene at rs1743963 and rs1763509, and the SNPs at the 5-HTTLPR and BDNF gene loci are associated with the onset of comorbid depression in coronary heart disease. We recommend that future research focus on studying SNPs’ impact on comorbid depression in coronary heart disease, specifically targeting the 5-HTTLPR and BDNF gene at rs6265.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/, identifier CRD42021229371.

Mycobacterium avium paratuberculosis Infection Suppresses Vitamin D Activation and Cathelicidin Production in Macrophages through Modulation of the TLR2-Dependent p38/MAPK-CYP27B1-VDR-CAMP Axis.

Vitamin D plays a vital role in modulating both innate and adaptive immune systems. Therefore, vitamin D deficiency has been associated with higher levels of autoimmune response and increased susceptibility to infections. CYP27B1 encodes a member of the cytochrome P450 superfamily of enzymes. It is instrumental in the conversion of circulating vitamin D (calcifediol) to active vitamin D (calcitriol). This is a crucial step for macrophages to express Cathelicidin Anti-microbial Peptide (CAMP), an anti-bacterial factor released during the immune response. Our recent study indicated that a Crohn's disease (CD)-associated pathogen known as Mycobacterium avium paratuberculosis (MAP) decreases vitamin D activation in macrophages, thereby impeding cathelicidin production and MAP infection clearance. The mechanism by which MAP infection exerts these effects on the vitamin D metabolic axis remains elusive. We used two cell culture models of THP-1 macrophages and Caco-2 monolayers to establish the effects of MAP infection on the vitamin D metabolic axis. We also tested the effects of Calcifediol, Calcitriol, and SB203580 treatments on the relative expression of the vitamin D metabolic genes, oxidative stress biomarkers, and inflammatory cytokines profile. In this study, we found that MAP infection interferes with vitamin D activation inside THP-1 macrophages by reducing levels of CYP27B1 and vitamin D receptor (VDR) gene expression via interaction with the TLR2-dependent p38/MAPK pathway. MAP infection exerts its effects in a time-dependent manner, with the maximal inhibition observed at 24 h post-infection. We also demonstrated the necessity to have toll-like receptor 2 (TLR2) for MAP infection to influence CYP27B1 and CAMP expression, as TLR2 gene knockdown resulted in an average increase of 7.78 ± 0.88 and 13.90 ± 3.5 folds in their expression, respectively. MAP infection also clearly decreased the levels of p38 phosphorylation and showed dependency on the p38/MAPK pathway to influence the expression of CYP27B1, VDR, and CAMP which was evident by the average fold increase of 1.93 ± 0.28, 1.86 ± 0.27, and 6.34 ± 0.51 in their expression, respectively, following p38 antagonism. Finally, we showed that calcitriol treatment and p38/MAPK blockade reduce cellular oxidative stress and inflammatory markers in Caco-2 monolayers following macrophage-mediated MAP infection. This study characterized the primary mechanism by which MAP infection leads to diminished levels of active vitamin D and cathelicidin in CD patients, which may explain the exacerbated vitamin D deficiency state in these cases.

IgG4-related autoimmune pancreatitis and sclerosing cholangitis: A case report and literature review.

Immunoglobulin G4-related disease (IgG4-RD) can involve various organs throughout the body, primarily manifesting as endocrine dysfunction, visual impairment, jaundice, and limited sexual function. IgG4-related autoimmune pancreatitis is triggered by autoimmune reactions and characterized by structural changes in the pancreas and pancreatic ducts. The disease mainly affects middle-aged and elderly males, typically presenting as progressive painless jaundice and misdiagnosed as cholangiocarcinoma or pancreatic cancer. This study reports a 54-year-old male who consulted with different institutions multiple times due to diabetes, pancreatitis, elevated liver enzymes, and jaundice. Magnetic resonance imaging revealed swollen head of the pancreas and atrophic tail. Liver and pancreatic tissue pathology showed IgG4 plasma cell infiltration, while liver biopsy indicated interface hepatitis, liver fibrosis, and pseudolobule formation, with no evidence of bile duct damage. Following hormone therapy, the patient's serum IgG4 levels and liver enzyme levels returned to normal. The disease relapsed 2 years after maintaining hormone therapy, and the patient underwent additional hormone-induced remission therapy combined with azathioprine. The purpose of this research report is to enhance the awareness and understanding of IgG4-RD, emphasizing the necessity for personalized treatment strategies that take into account its recurrence, associations, and imaging features. This report provides valuable insights and guidance for clinicians in managing and diagnosing patients with IgG4-RD.

Rare presentations of Sjogren syndrome

Sjögren’s syndrome is a chronic systemic autoimmune disease characterized by lymphocytic infiltration of exocrine glands. It most commonly presenting with sicca symptoms. Sicca refers to dryness most often involving the eyes and mouth due to inflammation and resultant pathology of the lacrimal and salivary glands. Up to one-half of affected individuals also develop extra-glandular involvement in organs such as the joints, skin, lungs, gastrointestinal (GI) tract, nervous system, and kidneys. This condition is frequently associated with other autoimmune disorders including rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) - called the secondary Sjogrens syndrome. Evaluation of a patient with suspected Sjogren syndrome should include an evaluation of oral and ocular dryness and function. In addition to the history, this may include the performance of a Schirmer test, slit-lamp exam with vital dye staining, salivary flow rate, and/or nuclear scintigraphic evaluation of the salivary glandular function. Assessment of autoantibodies (ANA, RF, SS-A, and SS-B) should also be performed. Of these, SS-A is probably the most sensitive and specific antibody for Sjogren's but alone is not diagnostic since it may be present in other autoimmune disorders and may be absent in up to a third of Sjogren cases. The most specific single test is a minor salivary gland (lip) biopsy which will demonstrate focal lymphocytic sialadenitis (FLS). Therapies are directed toward replacing moisture at affected glandular sites and suppressing the autoimmune response locally as well as systemically. This activity reviews the evaluation and management of Sjogren syndrome and explains the different rare presentations in which it can present.  

Mobilizing endogenous neuroprotection: the mechanism of the protective effect of acupuncture on the brain after stroke.

Given its high morbidity, disability, and mortality rates, ischemic stroke (IS) is a severe disease posing a substantial public health threat. Although early thrombolytic therapy is effective in IS treatment, the limited time frame for its administration presents a formidable challenge. Upon occurrence, IS triggers an ischemic cascade response, inducing the brain to generate endogenous protective mechanisms against excitotoxicity and inflammation, among other pathological processes. Stroke patients often experience limited recovery stages. As a result, activating their innate self-protective capacity [endogenous brain protection (EBP)] is essential for neurological function recovery. Acupuncture has exhibited clinical efficacy in cerebral ischemic stroke (CIS) treatment by promoting the human body's self-preservation and "Zheng Qi" (a term in traditional Chinese medicine (TCM) describing positive capabilities such as self-immunity, self-recovery, and disease prevention). According to research, acupuncture can modulate astrocyte activity, decrease oxidative stress (OS), and protect neurons by inhibiting excitotoxicity, inflammation, and apoptosis via activating endogenous protective mechanisms within the brain. Furthermore, acupuncture was found to modulate microglia transformation, thereby reducing inflammation and autoimmune responses, as well as promoting blood flow restoration by regulating the vasculature or the blood-brain barrier (BBB). However, the precise mechanism underlying these processes remains unclear. Consequently, this review aims to shed light on the potential acupuncture-induced endogenous neuroprotective mechanisms by critically examining experimental evidence on the preventive and therapeutic effects exerted by acupuncture on CIS. This review offers a theoretical foundation for acupuncture-based stroke treatment.

Unraveling the Complexities of Severe Acute Respiratory Syndrome Coronavirus 2: A Comprehensive Ophthalmic and Systemic Perspective.

The editorial explores the profound implications of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic, which emerged in December 2019 and rapidly evolved into a global health crisis. Despite initial focus on respiratory symptoms, the virus revealed significant ocular implications, prompting a reevaluation of the eye's role in its transmission, diagnosis, and systemic effects. The paradoxical nature of SARS-CoV-2-simultaneously novel and familiar within the coronavirus family-has been central to guiding the global medical response, including the swift development of vaccines. The pandemic has intensified research into the eye's susceptibility to viral infections, enhancing our understanding of virus-host interactions and the systemic impacts of viral diseases. The editorial delves into the pathophysiology of SARS-CoV-2, highlighting its potential to trigger autoinflammatory and autoimmune reactions with significant ocular repercussions. It examines the rapid vaccine development and deployment, the associated ocular side effects, and the ongoing research necessary to mitigate these outcomes. As the World Health Organization declared the end of COVID-19 as a public health emergency, the focus has shifted toward understanding the virus's long-term implications, including its effects on ocular health. This work underscores the critical role of interdisciplinary collaboration in addressing the systemic impacts of viral infections. It emphasizes the importance of ophthalmology in the broader context of public health and highlights the need for continued vigilance, research, and adaptation in a postpandemic world. The editorial calls for an integrated approach to health care, emphasizing the lessons learned from the SARS-CoV-2 pandemic to prepare for future health challenges, with a particular focus on the intersection of virology, immunology, and ophthalmology.

Correlation analysis between HLA-DQA1*0102/DQB1*0602 genotypes and narcolepsy patients in China.

At present, the etiology of narcolepsy is not fully understood, and it is generally believed to be an autoimmune reaction caused by interactions between environmental and genetic factors. Human leukocyte antigen (HLA) class II genes are strongly associated with this gene, especially HLA-DQB1*0602/DQA1*0102. In this study, we mainly analyzed the correlation between different genotypes of HLA-DQB1*0602/DQA1*0102 and clinical manifestations in Chinese patients with narcolepsy. Narcolepsy patients who were treated at the Department of Neurology, The First Affiliated Hospital of Shandong First Medical University from January 2021 to September 2023 were selected. General information, sleep monitoring data, cerebrospinal fluid (CSF) orexin levels, and human leukocyte antigen gene typing data were collected. The statistical analysis was performed using SPSS 26.0, and the graphs were drawn using GraphPad Prism 9.5. A total of 78 patients were included in this study. The DQA1 and DQB1 gene loci were detected in 54 patients, and only the DQB1 gene locus was detected in 24 narcoleptic patients. The most common allele at the HLA-DQB1 locus was *0602 (89.7%), and the most common genotype at this locus was *0602*0301 (19.2%), followed by *0602*0602 (17.9%). The most common phenotype of the HLA-DQA1 locus is *0102 (92.6%), and the most common genotype of this locus is *0102*0102 (27.8%), followed by *0102*0505 (14.8%). There were significant differences (p < 0.05) between HLA-DQB1*0602-positive and HLA-DQB1*0602-negative patients in terms of orexin-A levels, presence or absence of cataplexy, UNS, PSG sleep latency, REM sleep latency, N1 sleep percentage, oxygen depletion index, and average REM latency on the MSLT. The HLA-DQA1*0102-positive and HLA-DQA1*0102-negative patients showed significant differences (p < 0.05) in disease course, presence or absence of sudden onset, PSG REM sleep latency, N1 sleep percentage, and average REM latency on the MSLT. There were significant differences in the average REM latency of the MSLT between HLA-DQB1*0602/DQA1*0102 homozygous and heterozygous patients p < 0.05, and no differences were found in the baseline data, orexin-A levels, scale scores, or other sleep parameters. Different genotypes of HLA-DQA1*0102/DQB1*0602 are associated with symptoms of cataplexy in Chinese narcoleptic patients. Homozygous individuals have a shorter mean REM latency in the MSLT, greater genetic susceptibility, and relatively more severe sleepiness.

A mouse model of autoimmune inner ear disease without endolymphatic hydrops

Autoimmune inner ear disease (AIED) is an organ-specific disease characterized by irreversible, prolonged, and progressive hearing and equilibrium dysfunctions. The primary symptoms of AIED include asymmetric sensorineural hearing loss accompanied by vertigo, aural fullness, and tinnitus. AIED is divided into primary and secondary types. Research has been conducted using animal models of rheumatoid arthritis (RA), a cause of secondary AIED. However, current models are insufficient to accurately analyze vestibular function, and the mechanism underlying the onset of AIED has not yet been fully elucidated. Elucidation of the mechanism of AIED onset is urgently needed to develop effective treatments. In the present study, we analyzed the pathogenesis of vertigo in autoimmune diseases using a mouse model of type II collagen-induced RA. Auditory brain stem response analysis demonstrated that the RA mouse models exhibited hearing loss, which is the primary symptom of AIED. In addition, our vestibulo-oculomotor reflex analysis, which is an excellent vestibular function test, accurately captured vertigo symptoms in the RA mouse models. Moreover, our results revealed that the cause of hearing loss and vestibular dysfunction was not endolymphatic hydrops, but rather structural destruction of the organ of Corti and the lateral semicircular canal ampulla due to an autoimmune reaction against type II collagen. Overall, we were able to establish a mouse model of AIED without endolymphatic hydrops. Our findings will help elucidate the mechanisms of hearing loss and vertigo associated with AIED and facilitate the development of new therapeutic methods.

Evaluation of the Role of Oral Microbes in Pathogenesis of Oral Lichen Planus

ABSTRACT Background: The pathophysiology and etiology of oral lichen planus (OLP) are still unknown, despite the fact that the condition’s progression has been connected to a T-cell-based immune response. Research has focused on variables, such as oral bacteria, that may cause an autoimmune reaction with conflicting results. Aim: This study was conducted to evaluate the role of oral microorganisms in the pathogenesis of OLP. Materials and Methods: In this study, 82 formalin-fixed paraffin-embedded specimens of histopathologically confirmed cases of OLP and 20 such specimens of normal healthy subjects were obtained. Immunohistochemistry was carried out for the identification of microorganisms. Results: Candida albicans was observed in 47.12% of OLP cases and 9.43% of healthy controls. Helicobacter pylori was discovered in 45.21% of OLP cases and 13.46% of healthy controls. Periodontopathogenic bacteria was found in 33.14% of OLP cases and 13.45% of healthy controls. Human papillomavirus (HPV)-16 was noticed in 38.12% of OLP cases and 11.24% in the control group. HPV-18 was found in 32.43% of OLP patients and 11.43% in the control group. Mycoplasma salivarium was found in 46.47% of OLP patients and 6.45% in control. Conclusion: It was observed that several microorganisms like H. pylori, C. albicans, M. salivarium, periodontopathogenic bacteria, HPV-16, and HPV-18 were found to be related to OLP.

P140 IgG Autoantibodies with Increased Affinity for Epithelial Cells in Severe Systemic Sclerosis

Abstract Background/Aims In health IgG immunoglobulins form a network through interaction with cell surface proteins and controlled by regulatory cells, whereas in autoimmune diseases IgG responses become skewed towards higher affinity and potentially damaging responses against self-antigens. Moreover, recent studies have demonstrated activation of the epithelial layer of skin in systemic sclerosis (SSc), implicating keratinocytes as a target of the autoimmune process. We investigated the presence of plasma IgG autoantibodies directed against keratinocytes and sought correlation with clinical parameters in well-characterized patients. Methods Diffuse SSc (dcSSc), limited SSc (lcSSc) and healthy control (HC) plasma samples (each n = 30), were assayed in an anti-epithelial cell antibody assay (AEpCA), using fixed keratinocytes to evaluate binding of IgG . Clinical characteristics of patients with positive versus negative AEpCA were compared. The capacity for SSc IgG to activate epithelial cells was assessed using keratinocytes in vitro. Results Preliminary serial dilution assay of SSc and HC plasma (n = 10) showed enhanced affinity of SSc IgG for keratinocytes (ANOVA p &amp;lt; 0.001 for overall effect SSc vs HC IgG p &amp;lt; 0.0048 for dose effect)(Figure 1A). Dilution of 1/80 gave optimal differential binding in the AEpCA assay (corrected p &amp;lt; 0.027 for SSc vs HC at 1/80). Further HC, dcSSc, and lcSSc plasma samples (each n = 30) were screened, demonstrating increased AEpCA titre in SSc (Figure 1B) (Kruskall-Wallace test p &amp;lt; 0.014 for lcSSc vs HC, p &amp;lt; 0.041 for dcSSc vs HC). SSc patients with positive AEpCA had higher skin scores (mRSS) (AEPCA neg 5(0-24); AEpCA pos 9(0-40) p &amp;lt; 0.0032), higher frequency of ATA antibody (AEpCA neg ATA pos 6/30; AEpCA pos ATA pos 13/30, chi squared p = 0.052) more interstitial lung disease (AEPCA neg 7/30, AEpCA pos 13/30, p NS)(Figure 1C) and trend towards higher use of immunosuppression. SSc but not HC IgG activated keratinocytes in vitro, triggering IL-1α release. Conclusion In this study, we have shown evidence of IgG autoantibodies with increased affinity for keratinocytes in the plasma of SSc patients. Positive testing for the AEpCA was associated with more severe skin disease and lung involvement. The perturbed IgG network in such patients could be activating through common epithelial cells antigens in the skin and lung. Disclosure C. Moezinia: None. V. Wong: None. J. Watson: None. L. Nagib: None. S. Lopez Garces: None. H. Lopez: None. G. Martin: None. S. Zhang: None. B. Ahmed Abdi: None. C. Denton: None. D. Abraham: None. R.J. Stratton: None.

E024 A pregnant woman with vasculitis and a new rash

Abstract Background/Aims A 41-year-old pregnant woman at 16 weeks of gestation was followed-up in the combined obstetric and rheumatology clinic as she had a history of eosinophilic granulomatosis with polyangiitis (EGPA) and two previous miscarriages at first trimester. Her vasculitis was well-controlled with a baseline daily dose of prednisolone 7.5mg. Methods During her pregnancy, she started on vaginal progesterone by the IVF (In Vitro Fertilization) team for pregnancy support following a vaginal bleed. During her second review in clinic, she complained about a widespread pruritic rash for the last 3 weeks. She had already been seen by her GP who prescribed her emollients without any improvement. On examination, the active lesions looked urticarial and were tender. There was also residual hyperpigmentation. The lesions persisted for more than 24 hours before spontaneous resolution. Cutaneous vasculitis was suspected based on the duration of the rash more than 24 hours, the hyperpigmentation, tenderness, and the history of EGPA. Otherwise, she was well in herself with no symptoms of active vasculitis and no recent infections. Therefore, prednisolone was increased to 15mg daily and loratadine was given for the pruritus. Her repeat blood tests were reassuring with negative ANCA, normal C3 and C4, CRP, and eGFR. Results During her early follow-up, the rash was the same despite the higher dose of steroids and she volunteered that the rash is worse in the morning and at night. Autoimmune progesterone dermatitis (AIPD) was considered then. AIPD is a rare autoimmune hypersensitivity reaction to endogenous or exogenous progesterone. AIPD varies greatly from patient to patient and can present as urticaria, eczema or vesiculobullous eruptions. Urticarial or EGPA vasculitis, and urticaria would have improved with steroids. Furthermore, she did not have any symptoms suggestive of systemic vasculitis and the relevant blood tests were also normal. Of note, the rash was worse in the morning and at night, which corresponded to the time of vaginal exposure to progesterone. The patient stopped the progesterone pessaries after discussion with the obstetrician. The rash improved gradually and resolved in five days, confirming the diagnosis of AIPD. Conclusion The rash could have been mistaken for urticaria or vasculitis. Consequently, the patient may have had unnecessarily antihistamines and steroids during pregnancy with all relevant side effects, such as gestational diabetes. In November 2021, NICE recommended vaginal progesterone in women who experience bleeding in early pregnancy and have a history of miscarriage as it slightly reduces the risk of a further miscarriage. The new guidelines suggest that more pregnant women will use topical progesterone during pregnancy who may develop AIPD. This means that we are going to see more pregnant women in the rheumatology clinic with AIPD and the rheumatology community should be aware of this entity. Disclosure A. Madenidou: Grants/research support; Janssen. H. Kither: None. I. Bruce: Consultancies; AstraZeneca, GSK, Eli Lilly, and UCB. Honoraria; AstraZeneca, GSK, and UCB. Grants/research support; AstraZeneca, GSK, and Janssen.

P124 Elucidating the role of risk variants in the BIM gene enhancer in T-Cell dysregulation and rheumatoid arthritis pathogenesis

Abstract Background/Aims The balance governing T-cell responses is pivotal for immune homeostasis. Disruptions to this balance may lead to aberrant behaviours, potentially resulting in autoimmunity. Rheumatoid Arthritis (RA), an autoimmune disorder primarily manifesting in the joints, is characterised by a defective immune response, resulting in chronic inflammation. Enhanced T-cell apoptosis resistance in this context can contribute to sustained activation and abnormal proliferation in a pro-inflammatory environment. Understanding these disease mechanisms could lead to improvements in clinical care. Genome-wide association studies (GWAS) have identified hundreds of single nucleotide polymorphisms (SNPs) associated with RA, preferentially enriched in non-coding, T-cell-specific putative enhancers. Enhancers are DNA elements that can regulate the transcription of specific genes, often from many kilobases away. Our previous work identified BCL2L11, or BIM, as the probable causal gene within the RA locus rs13396472, despite the GWAS variants' intronic positioning relative to ACOXL. The RA risk variant disrupts a distant enhancer regulating the BIM gene, pivotal for apoptosis. Given the role of apoptosis in immune tolerance, disruption of this pathway driven by RA risk variants could pave the way for autoimmune responses. Our aim was to investigate the effect of this enhancer on T-cell proliferation and function in an in vivo model. Methods We mapped the human RA-locus to the mouse genome and utilised CRISPR-Cas9 to delete this putative RA enhancer in mice. Two sgRNAs, combined with Cas9, were microinjected into C57BL6/J zygote pronuclei, followed by embryo transfer to pseudo-pregnant mice. PCR and Sanger sequencing confirmed enhancer deletion in pups, establishing an RA-enhancer deletion colony. To gauge cell proportion differences, murine splenocytes or thymocytes were stained with specific fluorochrome markers and analysed via a flow cytometer. For the antigen-induced arthritis (AIA) model, wildtype and RA-enhancer deletion mice were subjected to arthritis induction via intra-articular injection of methylated bovine serum albumin, following prior immunisation, and monitored for arthritis signs. Results We observed an increased CD4+CD8+ double positive (DP) T-cell population in aged mice homozygous and heterozygous for the RA-enhancer deletion, but not in younger and wild-type controls. Knockout mice exhibited visibly enlarged spleens in response to the immunisation step prior to AIA induction. Further work will establish the mechanisms underlying this and disease progression after arthritis induction. These observations underscore a potential impact this enhancer might have on immune responses and survival upon immune system alteration. Conclusion Our research indicates that perturbing mouse non-coding sequences syntenic to human GWAS loci can provide a physiological model to elucidate novel mechanisms underlying RA, potentially suggesting therapeutic targets. Future research will explore the mechanism by which the enhancer deletion leads to an increase in DP T-cells and the altered phenotype, and the implications of such a change for T- and B-cell biology and RA. Disclosure S. Rossi: None. E. Richards: None. J. Ding: None. C. Shi: None. M. Menon: None. J. Gibbs: None. R. Grencis: None. A. Adamson: None. G. Orozco: None.

A Novel DNase Assay Reveals Low DNase Activity in Severe Asthma.

Secreted deoxyribonucleases (DNases), such as DNase-1 and DNase-IL3, degrade extracellular DNA, and endogenous DNases have roles in resolving airway inflammation and guarding against autoimmune responses to nucleotides. Subsets of patients with asthma have high airway DNA levels, but information about DNase activity in health and in asthma is lacking. To characterize DNase activity in health and in asthma, we developed a novel kinetic assay using a Taqman probe sequence that is quickly cleaved by DNase-I to produce a large product signal. We used this kinetic assay to measure DNase activity in sputum from participants in the Severe Asthma Research Program (SARP)-3 (n=439) and from healthy controls (n=89). We found that DNase activity was lower than normal in asthma (78.7 RFU/min vs 120.4 RFU/min, p<0.0001). Compared to asthma patients with sputum DNase activity levels in the upper tertile activity levels, those in the lower tertile of sputum DNase activity were characterized clinically by more severe disease and pathologically by airway eosinophilia and airway mucus plugging. Carbamylation of DNase-I, a post translational modification that can be mediated by eosinophil peroxidase, inactivated DNase-I. In summary, a Taqman probe-based DNase activity assay uncovers low DNase activity in the asthma airway which is associated with more severe disease and airway mucus plugging and may be caused, at least in part, by eosinophil-mediated carbamylation.