Nuclear Antigens Research Articles

Toll-like receptors 7 and 9 regulate the proliferation and differentiation of B cells in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune illness marked by the loss of immune tolerance and the production of autoantibodies against nucleic acids and other nuclear antigens (Ags). B lymphocytes are important in the immunopathogenesis of SLE. Multiple receptors control abnormal B-cell activation in SLE patients, including intrinsic Toll-like receptors (TLRs), B-cell receptors (BCRs), and cytokine receptors. The role of TLRs, notably TLR7 and TLR9, in the pathophysiology of SLE has been extensively explored in recent years. When endogenous or exogenous nucleic acid ligands are recognized by BCRs and internalized into B cells, they bind TLR7 or TLR9 to activate related signalling pathways and thus govern the proliferation and differentiation of B cells. Surprisingly, TLR7 and TLR9 appear to play opposing roles in SLE B cells, and the interaction between them is still poorly understood. In addition, other cells can enhance TLR signalling in B cells of SLE patients by releasing cytokines that accelerate the differentiation of B cells into plasma cells. Therefore, the delineation of how TLR7 and TLR9 regulate the abnormal activation of B cells in SLE may aid the understanding of the mechanisms of SLE and provide directions for TLR-targeted therapies for SLE.

Epstein Barr virus nuclear antigens among University Students in Port Harcourt, Nigeria

Several diseases are associated with Epstein Barr virus (EBV) and they can be life threatening especially in immunocompromised individuals. Moreover, there is no well-established EBV prevention and control strategies in Nigeria. Therefore, this study was carried out to assess the prevalence of Epstein Barr Nuclear Antigen (EBNA) IgM antibody among university students in Port Harcourt, Nigeria. A hospital based cross-sectional survey was adopted to randomly analyze 91 students attending lectures in University of Port Harcourt, Rivers State, Nigeria. Enzyme Linked Immunosorbent Assay (ELISA) was used to analyze EBNA IgM antibody in the samples obtained. Chi-square analysis was used to determine the association of the infection with socio-demographic factors. Of the 91 subjects, 3(3.2%) were seropositive for EBNA IgM antibody while 88(96.7%) were observed to be seronegative for EBNA IgM antibody. Sera EBNA IgM positivity was highest in age group 20-25 years (4.7%), single (3.2%), male (3.8%), students (3.9), sexually inactive (4.0%), oral sex (2.4%), non-Anal sex (3.4%), never using condoms (5.0%), dry kissing (11.1%), Non-smokers (4.0%), no history of blood transfusion (3.3%), no history of tissue transplant (3.2%), no history of surgery (3.2%). This study confirms the presence of Epstein Barr virus primary infection among university students in Port Harcourt, and an onward risk of Infectious mononucleosis. This comes with the responsibility of establishing surveillance programs for detection, treatment and control of EBV in Port Harcourt and Nigeria at large.

Determination of specific autoantibodies in patients with systemic lupus erythematosus by Line immunoassay, ELISA and CLIF assay.

Detection of specific antinuclear-antibodies is very importance in term of diagnosis, prognosis and management of patients with systemic lupus erythematosus (SLE). To date, Line immunoassay (LIA), enzyme-linked immunosorbent assay (ELISA) and Crithidia luciliae indirect immunofluorescence (CLIF) assay are commonly used for detection of specific antinuclear-antibodies. To determine the performance of LIA, ELISA and CLIF for the detection of anti-double-stranded DNA (dsDNA), anti-nucleosome, and anti-extractable nuclear antigens (ENA) antibodies in patients with SLE. A total 100 sera from 50 patients with SLE, 25 patients with disease control and 25 healthy control subjects were tested for anti-dsDNA, anti-nucleosome, and anti-ENA antibodies by LIA, ELISA, and CLIF assay. Agreement and diagnostic performance of each assay were analyzed using Cohen's kappa coefficient and receiver operating characteristic curve analysis. For the detection of anti-dsDNA antibody, ELISA had a substantial agreement with CLIF assay (? = 0.74) but LIA had a fair agreement with ELISA and CLIF assay (? = 0.37, and 0.35 respectively). For the detection of anti-nucleosome, anti-nRNP/Sm, anti-Sm, anti-SSA, and anti-SSB antibodies, LIA had a substantial to perfect agreement with ELISA (? = 0.64, 0.78, 0.68, 0.91, and 0.74, respectively). Anti-dsDNA-NcX ELISA and anti-dsDNA CLIF assay had equally diagnostic performance (sensitivity, 66% vs. 68%, and specificity, 96% vs. 94%, respectively) whereas, anti-dsDNA LIA has low sensitivity (22%) but high specificity (100%). LIA, ELISA, and CLIF demonstrated comparable performance for the detection of specific antinuclear-antibodies. However, there were some discrepancy between assays particularly in the detection of anti-dsDNA antibody.

An autoantigen-ome from HS-Sultan B-Lymphoblasts offers a molecular map for investigating autoimmune sequelae of COVID-19

To understand how COVID-19 may induce autoimmune diseases, we have been compiling an atlas of COVID autoantigens (autoAgs). Using dermatan sulfate (DS) affinity enrichment of autoantigenic proteins extracted from HS-Sultan lymphoblasts, we identified 362 DS-affinity proteins, of which at least 201 (56%) are confirmed autoAgs. Comparison with available multi-omic COVID data shows that 315 (87%) of the 362 proteins are affected in SARS-CoV-2 infection via altered expression, interaction with viral components, or modification by phosphorylation or ubiquitination, at least 186 (59%) of which are known autoAgs. These proteins are associated with gene expression, mRNA processing, mRNA splicing, translation, protein folding, vesicles, and chromosome organization. Numerous nuclear autoAgs were identified, including both classical antinuclear antibodies (ANAs) and extractable nuclear antigens (ENAs) of systemic autoimmune diseases and unique autoAgs involved in the DNA replication fork, mitotic cell cycle, or telomerase maintenance. We also identified many uncommon autoAgs involved in nucleic acid and peptide biosynthesis and nucleocytoplasmic transport, such as aminoacyl-tRNA synthetases. In addition, this study found autoAgs that potentially interact with multiple SARS-CoV-2 Nsp and Orf components, including CCT/TriC chaperonin, insulin degrading enzyme, platelet-activating factor acetylhydrolase, and the ezrin-moesin-radixin family. Furthermore, B-cell-specific IgM-associated endoplasmic reticulum (ER) complex (including MBZ1, BiP, heat shock proteins, and protein disulfide-isomerases) is enriched by DS-affinity and up-regulated in B-cells of COVID-19 patients, and a similar IgH-associated ER complex was also identified in autoreactive pre-B1 cells in our previous study, which suggests a role of autoreactive B1 cells in COVID-19 that merits further investigation. In summary, this study demonstrates that virally infected cells are characterized by alterations of proteins with propensity to become autoAgs, thereby providing a possible explanation for infection-induced autoimmunity. The COVID autoantigen-ome provides a valuable molecular resource and map for investigation of COVID-related autoimmune sequelae and considerations for vaccine design.

Immunological aspects of ozone in rheumatoid arthritis and its role in patients with chronic pain syndrome, fibromyalgia, positive tested for antinuclear antibody (ANA).

Fibromyalgia is a long-term or chronic disorder. It is associated with widespread pain in the muscles and bones, areas of tenderness, and general fatigue.
 Symptoms like these are considered subjective, meaning they cannot be determined or measured by tests. Because its symptoms are subjective and there is no clear known cause, fibromyalgia is often misdiagnosed. Antinuclear Antibodies (ANA’s) directed against a variety of nuclear antigens have been detected in the serum of patients with many rheumatic and non rheumatic diseases. The lack of reproducible, objective tests for this disorder plays a role in some doctors questioning the disorder all together. Although it is more widely accepted in medical circles now than previously, some doctors and researchers do not consider fibromyalgia a real condition.
 According to our clinical studies, this can increase your risk of depression, with stems from a struggle in gaining acceptance for painful symptoms.

Current issues of standardization of antinuclear antibodies’ detection by indirect immunofluorescence on HEp-2 cells

Background. Antinuclear antibodies (ANA) are a group of antibodies that target nuclear and cytoplasmic antigens. Testing for ANA using an immunofluorescence assay (IFA) on HЕp-2 cell (IFA-HEp-2) is a screening test for the diagnosis of systemic autoimmune rheumatic diseases, druginduced lupus erythematosus, autoimmune liver diseases, juvenile idiopathic arthritis. In routine ANA testing final report forms bears important, but unstandardized variables (e. g., screening and final titers of ANA, coding of glow types, the procedure for performing confirmatory tests). Aim of the study. Develop a standard report form for IFA-HEp-2 testing results.Material and methods. Survey of 10 immunological and clinical diagnostic laboratories using the ICAP questionnaire adapted by the Working Group on Standardization of the definition of ANA by the IFA-HEp-2 method (Committee on Immunology of the Association ‘Federation of Laboratory Medicine’).Results. According to the results of a survey: most of the participants use a screening dilution of serum 1:160; indicates the maximum end titer of antinuclear factor (ANF), cytoplasmic staining; identifies staining types (including AC encoding); considers it mandatory to make confirmatory tests to detect ANA to individual nuclear antigens in ANF-positive patients, but does not provide a list of this tests in the results form; describes ANF titer for each of the detected glows separately; designates ANF titers using a colon and does not give a clinical interpretation of the results. Based on interlaboratory consensus, ICAP recommendations and the requirements of ISO 15189, the standard report form for IFA-HEp-2 testing results was developed.Conclusions. To achieve high quality of interaction between clinical diagnostic/immunological laboratories and clinical departments of health care facilities, it’s necessary to introduce into practice a standard form for IFA-HEp-2 testing results, developed relying on modern clinical recommendations and interlaboratory consensus.

EBV infection mediated BDNF expression is associated with bladder inflammation in interstitial cystitis/bladder pain syndrome with Hunner's lesion.

Interstitial cystitis/bladder pain syndrome with Hunner's lesion (HIC) is characterized by chronic inflammation and nerve hyperplasia; however, the pathogenesis of HIC remains a mystery. In this study, we detected both Epstein-Barr virus (EBV) latency infection genes EBNA-1 and LMP-1 and EBV lytic infection BZLF-1 and BRLF-1 expression in the HIC bladders, indicating the coexistence of EBV persistence and reactivation in the B cells in HIC bladders. Upregulation of EBV-associated inflammatory genes in HIC bladders, such as TNF-α and IL-6, suggests EBV infection is implicated in the pathogenesis of bladder inflammation. Nerve hyperplasia and upregulation of brain-derived neurotrophic factor (BDNF) were noted in the HIC bladders. Double immunochemical staining and flow cytometry revealed the origin of BDNF to be EBV-infected B cells. Inducible BDNF expression was noted in B cells upon EBV infection, but not in the T cells. A chromatin immunoprecipitation study revealed BDNF transcription could be promoted by cooperation between EBV nuclear antigens, chromatin modifiers, and B-cell-specific transcription. Knockdown of BDNF in EBV-infected B cells resulted in the inhibition of cell proliferation and viability. Downregulation of phosphorylated SMAD2 and STAT3 after BDNF knockdown may play a role in the mechanism. Implantation of latent EBV-infected B cells into rat bladder walls resulted in a higher expression level of CD45 and PGP9.5, suggesting tissue inflammation and nerve hyperplasia. In contrast, implantation of BDNF depleted EBV-infected B cells abrogated these effects. This is the first study to provide insights into the mechanisms underlying the involvement of EBV-infected B cells in HIC pathogenesis. © 2022 The Pathological Society of Great Britain and Ireland.

Unraveling the Link between Interferon-α and Systemic Lupus Erythematosus: From the Molecular Mechanisms to Target Therapies.

Systemic lupus erythematosus (SLE) is a chronic, systemic autoimmune disease with a wide range of clinical expressions. The kidney is often affected, usually within 5 years of the onset of SLE, and lupus nephropathy (LN) carries a high risk for increased morbidity. The clinical heterogeneity of the disease is accompanied by complex disturbances affecting the immune system with inflammation and tissue damage due to loss of tolerance to nuclear antigens and the deposition of immune complexes in tissues. Several studies have reported that in human SLE, there is an important role of the Type-I-interferons (INF) system suggested by the upregulation of INF-inducible genes observed in serial gene expression microarray studies. This review aims to describe the transduction pathways of Type-I-interferons, in particular INFα, and its immune-regulatory function in the pathogenesis of SLE and, in particular, in LN. In addition, recent novelties concerning biologic therapy in LN will be discussed.

Regulation of B cell receptor signalling by Epstein-Barr virus nuclear antigens.

The cancer-associated Epstein-Barr virus (EBV) latently infects and immortalises B lymphocytes. EBV latent membrane protein 2A and EBV-encoded microRNAs are known to manipulate B cell receptor signalling to control cell growth and survival and suppress lytic replication. Here, we show that the EBV transcription factors EBNA2, 3A, 3B and 3C bind to genomic sites around multiple B cell receptor (BCR) pathway genes, regulate their expression and affect BCR signalling. EBNA2 regulates the majority of BCR pathway genes associated with binding sites, where EBNA3 proteins regulate only 42% of targets predicted by binding. Both EBNA2 and 3 proteins predominantly repress BCR pathway gene expression and target some common genes. EBNA2 and at least one EBNA3 protein repress the central BCR components CD79A and CD79B and the downstream genes BLNK, CD22, CD72, NFATC1, PIK3CG and RASGRP3. Studying repression of CD79B, we show that EBNA2 decreases transcription by disrupting binding of Early B cell Factor-1 to the CD79B promoter. Consistent with repression of BCR signalling, we demonstrate that EBNA2 and EBNA3 proteins suppress the basal or active BCR signalling that culminates in NFAT activation. Additionally, we show that EBNA2, EBNA3A and EBNA3C expression can result in reductions in the active serine 473 phosphorylated form of Akt in certain cell contexts, consistent with transcriptional repression of the PI3K-Akt BCR signalling arm. Overall, we identify EBNA2, EBNA3A and EBNA3C-mediated transcription control of BCR signalling as an additional strategy through which EBV may control the growth and survival of infected B cells and maintain viral latency.

ASSOCIATION OF EPSTEIN-BARR VIRUS WITH SYSTEMIC LUPUS ERYTHEMATOSUS BY LIMITED MATERIALS: PATIENT CHARACTERISTICS AND CLINICAL MANIFESTATIONS IN YEMEN

Background and aims: Systemic lupus erythematosus (SLE) is an autoimmune chronic inflammatory disease with damage to many organs due to the production of auto-antibodies, including auto-antibodies to renal antigen, vascular tissue antigens, brain antigens, ribosomes, nuclear antigens, and phospholipids. This study was conducted to determine patient characteristics and clinical manifestations of systemic lupus erythematosus and to find out the association of positive IgG with high titer of EBV-VCA with clinical features of SLE patients. Materials and Methods: In this cross-sectional study, 142 patients with SLE diagnosed based on American College of Rheumatology criteria were selected. All were included in the study after obtaining informed consent for participation. Whole blood samples were taken and serum was separated to determine anti-EBV IgG antibodies using the ELISA method and assessment with the SLE. Results: Female represent 81% of the total patients, while male represent only 19%, with ratio male: female equal to 1: 4.3, most of the patients were adults over 20 years old, with mean age ± SD was 35.8 ± 13.7 years. The most common signs were joint pain (95.1%), fever (92.3%), persistent fatigue (83.8%), followed by joint swelling (69.7%), photosensitivity (54.4%), renal involvement (52.8%), weigh loss (49.3%) and alopecia (49.3%), while other SLE signs were less frequent. Conclusion: EBV may have an important role in SLE pathogenesis and activity, SLE male: female ratio equals 1:4.3, most patients were adults over 20 years of age, and the most common signs of SLE were joint pain, fever and persistent fatigue. Peer Review History: Received: 2 September 2022; Revised: 11 October; Accepted: 15 November, Available online: 15 November 2022 Academic Editor: Dr. Iman Muhammad Higazy, National Research Center, Egypt, imane.higazy@hotmail.com Received file: Reviewer's Comments: Average Peer review marks at initial stage: 5.5/10 Average Peer review marks at publication stage: 7.0/10 Reviewers: Dr. Rima Benatoui,Laboratory of Applied Neuroendocrinology, Department of Biology, Faculty of Science, Badji Mokhtar University Annaba, Algeria. benattouiryma@gmail.com Similar Articles: THE ASSOCIATION OF EPSTEIN-BARR VIRUS ANTIBODIES WITH RHEUMATOID ARTHRITIS AMONG YEMENI PATIENTS IN SANA’A CITY

Evaluation of Interferon Alpha (IFN-α) in Women with Systemic Lupus Erythematosus in Iraq

Systemic Lupus Erythematosus (SLE) is a multifactorial chronic systemic autoimmune disease. It is characterized by a lack of immune tolerance to autoantigens such as nuclear antigens. The aim of the study is to assess the interferon-alpha (IFN-α) serum level in Iraqi patients with SLE and determine its potential relation to different clinical and laboratory parameters and disease activity. 100 SLE patients were all females and with a mean of age 31.3 ± 10 years (16-63years) and disease duration of 5.8 ± 3.7years (1 month to 15 years). The average of SLEDAI score ranged from 2 to 22 with a mean of (8.53 ±3.42). Proteinuria, ESR, creatinine and AST were significantly higher (65% vs. 10% and 0.62±0.11 vs. 0.70±0.14 mg/dl respectively) while the PLT was significantly lower (231.9±88.8 vs. 282.3±67.3 103/mL) (p< 0.001) among SLE patients as compared to control. Serum levels of IFN-α were increased in the SLE patients compared to control, and no significant difference has been observed (208.7±530.0 vs. 63.7±34.8 pg/ml) respectively (P=0.245). Interferon-alpha showed a significant negative correlation with the SLE Disease Activity Index (SLEDAI) in the active and inactive groups. There were no significant variations in all study parameters across IFN-α serum levels (p greater than 0.05). In conclusion, the results suggest a risk effect for female gender and age in etiology of SLE. IFN-α could not be considered as biomarker or to have a risk effect in SLE patients or perpetuate the disease activity. No evidence for any correlation between the IFN-α serum level and any clinical manifestations or laboratory investigation of the disease in current study except for age and disease duration, which suggests them as a risk factor for increasing the IFN-α serum level.

Detection of Antinuclear Antibodies Targeting Intracellular Signal Transduction, Metabolism, Apoptotic Processes and Cell Death in Critical COVID-19 Patients.

The heterogeneity of the coronavirus disease of 2019 (COVID-19) lies within its diverse symptoms and severity, ranging from mild to lethal. Acute respiratory distress syndrome (ARDS) is a leading cause of mortality in COVID-19 patients, characterized by a hyper cytokine storm. Autoimmunity is proposed to occur as a result of COVID-19, given the high similarity of the immune responses observed in COVID-19 and autoimmune diseases. Here, we investigate the level of autoimmune antibodies in COVID-19 patients with different severities. Initial screening for antinuclear antibodies (ANA) IgG using ELISA revealed that 1.58% (2/126) and 4% (5/126) of intensive care unit (ICU) COVID-19 cases expressed strong and moderate ANA levels, respectively. An additional sample was positive with immunofluorescence assays (IFA) screening. However, all the non-ICU cases (n=273) were ANA negative using both assays. Samples positive for ANA were further confirmed with large-scale autoantibody screening by phage immunoprecipitation-sequencing (PhIP-Seq). The majority of the ANA-positive samples showed "speckled" ANA pattern by microscopy and revealed autoantibody specificities that targeted proteins involved in intracellular signal transduction, metabolism, apoptotic processes, and cell death by PhIP-Seq; further denoting reactivity to nuclear and cytoplasmic antigens. Our results further support the notion of routine screening for autoimmune responses in COVID-19 patients, which might help improve disease prognosis and patient management. Further, results provide compelling evidence that ANA-positive individuals should be excluded from being donors for convalescent plasma therapy in the context of COVID-19.

Presence of autoantibodies and epidemiological characteristics of systemic sclerosis patients in western Paraná

Systemic sclerosis (SSc) is a systemic autoimmune disease of the connective tissue with unknown etiology, characterized by abnormal collagen deposition in the skin. The changes in patients result in the obliteration of microvessels and fibrosis, leading to damage to the skin, gastrointestinal tract, kidneys, lungs, heart, and oral cavity. Brazil has insufficient data about the epidemiological and laboratory aspects of SSc. This study aimed to identify and characterize the patients in treatment for SSc in Cascavel/PR, a city in the south of Brazil. Data were collected from March 2019 to September 2020 from all health services of Cascavel that provide care in rheumatology: a university-affiliated hospital, two public outpatient clinics, and six private clinics. Data about age, sex, residence, time to diagnosis, the form of the disease, and the results of tests for antinuclear (ANA) and anti-extractable nuclear antigens (ENA) antibodies were obtained. The study identified 57 patients; 82.5% were female with a mean age of 50.4 years, and the predominant disease form was diffuse (52.6%). The ANA test was positive in 87.7% of the patients, of which 49.2% showed high titers and a predominance of the centromeric pattern. Anti-Scl-70, anti-centromere (ACA), and anti-RNA polymerase III antibodies were positive in 28.1%, 25%, and 5% of the patients. The characteristics of the patients diagnosed with SSc in Cascavel/PR are similar to those reported in the literature. This study contributed to the scarce Brazilian data about the disease.

Systemic Lupus in males – clinical-laboratory, immunological and histological characteristics.

Systemic lupus erythematosus is a chronic, systemic, non-organ-specific autoimmune disease that affects all organs and systems of the human body and is characterized by the production of autoantibodies against nuclear antigens. Its prevalence in Europe reaches 1:2500. It affects mostly women (female : male ratio=9 : 1) in fertile age group (15-45 years). The clinical course of lupus in males is characterized by more aggressive clinical course and the development of serious complications, such as vasculitis, central nervous system involvement, antiphospholipid syndrome, etc. For the period of 7 years (2012-2019) we observed overall 18 male patients with systemic lupus, 11 with biopsy-proven renal involvement and 7 without clinically significant renal disease (proteinuria < 0.5 g/24 h., no erythrocyturia/cylindruria, normal renal function), mean age at the diagnosis 39.6 +/- 12.3 years. All patients received pathogenetic treatment (corticosteroids + cytotoxic agents). Three had secondary antiphospholipid syndrome, 1 – inflammatory bowel disease, 1 – seronegative spondyloarthropathy. Three had type 2 diabetes. The authors discuss the clinical, immunological and histological characteristics and the therapeutic approach in males with systemic lupus.

Immunocytochemical Reactivity Comparison between Formalin-Fixed and Liquid-Based Cytology-Fixed Specimens

Introduction: Liquid-based cytology (LBC)-fixed samples can be used for preparing multiple specimens of the same quality and for immunocytochemistry (ICC); however, LBC fixing solutions affect immunoreactivity. Therefore, in this study, we examined the effect of LBC fixing solutions on immunoreactivity. Methods: Samples were cell lines, and specimens were prepared from cell blocks of 10% neutral buffered formalin (NBF)-fixed samples and the four types of LBC-fixed samples: PreservCyt®, CytoRich™ Red, CytoRich™ Blue, and TACAS™ Ruby, which were post-fixed with NBF. ICC was performed using 24 different antibodies, and immunocytochemically stained specimens were analyzed for the percentage of positive cells. Results: Immunoreactivity differed according to the type of antigen detected. For nuclear antigens, the highest percentage of positive cells of Ki-67, WT-1, ER, and p63 was observed in the NBF-fixed samples, and the highest percentage of positive cells of p53, TTF-1, and PgR was observed in the TACAS™ Ruby samples. For cytoplasmic antigens, the percentage of positive cells of CK5/6, Vimentin, and IMP3 in LBC-fixed samples was higher than or similar to that in NBF-fixed samples. The percentage of positive cells of CEA was significantly lower in CytoRich™ Red and CytoRich™ Blue samples than in the NBF-fixed sample (p < 0.01). Among the cell membrane antigens, the percentage of positive cells of Ber-EP4, CD10, and D2-40 was the highest in NBF-fixed samples and significantly lower in CytoRich™ Red and CytoRich™ Blue samples than that in NBF-fixed samples (p < 0.01). The NBF-fixed and LBC-fixed samples showed no significant differences in the percentage of positive cells of CA125 and EMA. Discussion/Conclusion: ICC using LBC-fixed samples showed the same immunoreactivity as NBF-fixed samples when performed on cell block specimens post-fixed with NBF. The percentage of positive cells increased or decreased based on the type of fixing solution depending on the amount of antigen in the cells. Further, the detection rate of ICC with LBC-fixed samples varied according to the type of antibody and the amount of antigen in the cells. Therefore, we propose that ICC using LBC-fixed samples, including detection methods, should be carefully performed.

P40 Dry eyes and a dry mouth: is it Sjögren’s syndrome?

P40 Dry eyes and a dry mouth: is it Sjögren’s syndrome?

Origins and history of autoimmunity—A brief review

AbstractIt was not widely recognized, until the 1950s, that an immune response could be developed not only against “foreign” but also “self” antigens from the studies of chronic thyroiditis leading to the acceptance of autoimmune diseases. Paul Ehrlich coined the term “horror autotoxicus” to emphasize the pathogenesis of autoimmunity and how the immune system distinguishes “foreign” from “self”. The process led to the concept of immune tolerance. The discoveries of allergy and anaphylaxis were the first signs that the immune system was capable of self‐damage. The first autoantibodies were discovered in the 1940s, when antinuclear antibodies and rheumatoid factors were described as serum factors that could bind nuclear antigens and immunoglobulins, respectively. It has now becoming increasingly understandable that autoantibodies play a pivotal role in the pathogenesis of several diseases and mediate systemic inflammation and tissue injury. The purpose of this review article is to elucidate, explain, and emphasize the origins and history of autoimmunity.

Frequency of ANA/DFS70 autoantibodies in Colombian patients with undifferentiated connective tissue disease.

The objective was to describe the clinical characteristics and the frequency of the ANA/DFS70 autoantibodies in patients affected by undifferentiated connective tissue disease (UCTD) in a tertiary hospital in Colombia. This descriptive cross-sectional study enrolled patients who fulfilled the classification criteria for UCTD. ANAHEp- 2 test and the modified assay for ANA/DFS70 autoantibodies were performed through the indirect immunofluorescence technique. Erythrocyte sedimentation rate, C-reactive protein, rheumatoid factor, and the antibodies to anti-extractable nuclear antigens, DNA, phospholipids (IgG, IgM, IgA), and cyclic citrullinated peptide were also evaluated. Fifty-three patients were studied; 42/53 (79%) tested positive for ANA and 5/42 (11.9%) for ANA/DFS70 antibodies with a dense fine speckled fluorescent pattern (AC-2) in ANA HEp-2 test that was confirmed by a modified HEp-2-DFS70 assay. Patients had arthralgia (87%, n=47), non-erosive arthritis (66%, n=34), xerostomia (64%, n=34), xerophthalmia (42%, n=22), and Raynaud's phenomenon (17%, n=9). Arthralgia, xerophthalmia, xeroderma, and absence of disease evolution to a specific disease over five years were more frequent in patients with a positive result for the anti-DFS70 antibodies. The ANA/DFS70 autoantibodies were more frequent in patients with UCTD compared to other rheumatic diseases for which they were initially evaluated. More studies are required to support the predictive role of this antibody to the absence of progression to a well-defined connective tissue disease.

The Epstein-Barr Virus Enhancer Interaction Landscapes in Virus-Associated Cancer Cell Lines.

Epstein-Barr virus (EBV) persists in human cells as episomes. EBV episomes are chromatinized and their 3D conformation varies greatly in cells expressing different latency genes. We used HiChIP, an assay which combines genome-wide chromatin conformation capture followed by deep sequencing (Hi-C) and chromatin immunoprecipitation (ChIP), to interrogate the EBV episome 3D conformation in different cancer cell lines. In an EBV-transformed lymphoblastoid cell line (LCL) GM12878 expressing type III EBV latency genes, abundant genomic interactions were identified by H3K27ac HiChIP. A strong enhancer was located near the BILF2 gene and looped to multiple genes around BALFs loci. Perturbation of the BILF2 enhancer by CRISPR interference (CRISPRi) and CRISPR activation (CRISPRa) altered the expression of BILF2 enhancer-linked genes, including BARF0 and BALF2, suggesting that this enhancer regulates the expression of linked genes. H3K27ac ChIP followed by deep sequencing (ChIP-seq) identified several strong EBV enhancers in T/NK (natural killer) lymphoma cells that express type II EBV latency genes. Extensive intragenomic interactions were also found which linked enhancers to target genes. A strong enhancer at BILF2 also looped to the BALF loci. CRISPRi also validated the functional connection between BILF2 enhancer and BARF1 gene. In contrast, H3K27ac HiChIP found significantly fewer intragenomic interactions in type I EBV latency gene-expressing primary effusion lymphoma (PEL) cell lines. These data provided new insight into the regulation of EBV latency gene expression in different EBV-associated tumors. IMPORTANCE EBV is the first human DNA tumor virus identified, discovered over 50 years ago. EBV causes ~200,000 cases of various cancers each year. EBV-encoded oncogenes, noncoding RNAs, and microRNAs (miRNAs) can promote cell growth and survival and suppress senescence. Regulation of EBV gene expression is very complex. The viral C promoter regulates the expression of all EBV nuclear antigens (EBNAs), some of which are very far away from the C promoter. Another way by which the virus activates remote gene expression is through DNA looping. In this study, we describe the viral genome looping patterns in various EBV-associated cancer cell lines and identify important EBV enhancers in these cells. This study also identified novel opportunities to perturb and eventually control EBV gene expression in these cancer cells.

Dysregulated naive B cells and de novo autoreactivity in severe COVID-19

Severe SARS-CoV-2 infection1 has been associated with highly inflammatory immune activation since the earliest days of the COVID-19 pandemic2–5. More recently, these responses have been associated with the emergence of self-reactive antibodies with pathologic potential6–10, although their origins and resolution have remained unclear11. Previously, we and others have identified extrafollicular B cell activation, a pathway associated with the formation of new autoreactive antibodies in chronic autoimmunity12,13, as a dominant feature of severe and critical COVID-19 (refs. 14–18). Here, using single-cell B cell repertoire analysis of patients with mild and severe disease, we identify the expansion of a naive-derived, low-mutation IgG1 population of antibody-secreting cells (ASCs) reflecting features of low selective pressure. These features correlate with progressive, broad, clinically relevant autoreactivity, particularly directed against nuclear antigens and carbamylated proteins, emerging 10–15 days after the onset of symptoms. Detailed analysis of the low-selection compartment shows a high frequency of clonotypes specific for both SARS-CoV-2 and autoantigens, including pathogenic autoantibodies against the glomerular basement membrane. We further identify the contraction of this pathway on recovery, re-establishment of tolerance standards and concomitant loss of acute-derived ASCs irrespective of antigen specificity. However, serological autoreactivity persists in a subset of patients with postacute sequelae, raising important questions as to the contribution of emerging autoreactivity to continuing symptomology on recovery. In summary, this study demonstrates the origins, breadth and resolution of autoreactivity in severe COVID-19, with implications for early intervention and the treatment of patients with post-COVID sequelae.