Murine BAFF expression is up-regulated by estrogen and interferons: implications for sex bias in the development of autoimmunity

Insights into neuromyelitis optica spectrum disorder and pregnancy from a single-center study in Thailand

Our study focused on assessing disease and pregnancy outcomes in Thai patients with Neuromyelitis Optica Spectrum Disorder (NMOSD), a condition that disproportionately affects women of childbearing age and poses risks to both mother and fetus. We retrospectively analyzed eight NMOSD patients with a total of 10 pregnancies from our central nervous system inflammatory demyelinating diseases (CNS-IDDs) registry. Over a 12-months spanning from before pregnancy to 12 months postpartum, we observed 13 relapses, with a notable 76.92% occurring postpartum. The mean annualized relapse rate (ARR) peaked at 1.2 (SD ± 1.93) during specific postpartum intervals (0-3 and 6-9 months postpartum), significantly increasing from 0.20 (SD ± 0.42) in the 12 months before pregnancy (BP) to 1.00 (SD ± 1.49) during the 12 months postpartum (PP). Disability, assessed using the Expanded Disability Status Scale (EDSS) scores, worsened from 1.56 (SD ± 2.18) before pregnancy to 2.1 (SD ± 2.63) at six months postpartum. Maternal and fetal complications were prevalent, with six out of nine pregnancies experiencing adverse outcomes such as false labor, premature rupture of membranes, postpartum hemorrhage, intrauterine growth restriction, preterm birth, stillbirth, and low birth weight. Based on our findings, azathioprine and rituximab may be suitable treatment options for maintaining therapy throughout pregnancy, particularly in cases of high disease activity. Our study highlights the critical need for comprehensive management strategies for NMOSD patients of childbearing age. Preconception planning and counselling, along with early obstetrical consultation and closely monitored treatments during pregnancy and postpartum, are vital to mitigating pregnancy-related relapses and adverse fetal outcomes in this vulnerable patient population.

The effect of the number of endometrial CD138+ cells on the pregnancy outcomes of infertile patients in the proliferative phase

Objective

This study was conducted to determine the influence of the number of CD138+ cells in the proliferative endometrium on pregnancy outcomes.

Methods

This retrospective cohort study was conducted from January to August 2018. A total of 664 infertile women who were not diagnosed with chronic endometritis (CE) and who had not received the respective antibiotic treatment were studied. Immunostaining was performed for the plasmacyte marker CD138. The number of CD138+ cells was compared in the proliferative and mid-luteal phases of the same patients without antibiotic therapy. Infertile patients were separated into three groups based on the number of positive lesions [the number of high power fields (HPFs) containing no less than five CD138+ cells]: 0 (n = 474), 1-2 (n = 125), and ≥3 positive lesions (n = 104). The pregnancy outcomes of the infertile women undergoing in vitro fertilization-embryo transfer (IVF-ET) among the three groups were then compared.

Results

There was a much higher level of CD138+ cells during proliferation than during the mid-luteal phase (P <0.0001). Pregnancy outcomes did not differ between the groups with 0 and 1-2 positive lesions. However, the ≥3 positive lesions group (P =0.006, P =0.029) had significantly lower ongoing pregnancy and live birth rates compared with the no positive lesion group. Although the 0 and ≥3 positive lesions groups showed a trend toward higher rates of clinical pregnancy (P =0.132), these differences failed to reach statistical significance. After age, body mass index (BMI), and clinical features were adjusted for, the ≥3 positive lesions group showed significantly lower live birth rates (aOR, 1.84; 95%CI, 1.08-3.15; P =0.026), clinical pregnancy (adjusted odds ratio (aOR), 1.78; 95% CI, 1.06-2.95; P =0.028), and ongoing pregnancy (aOR, 1.85; 95% CI, 1.09-3.15; P =0.024). The analysis demonstrated that the smallest number of stromal CD138+ cells suggestive of CE patients requiring treatment was defined as ≥ 3 positive lesions during the proliferation.

Conclusions

Different diagnostic criteria for CE should be created for the proliferative and mid-luteal phases. The analysis demonstrated that the smallest number of stromal CD138+ cells suggestive of CE patients was defined as ≥ 3 positive lesions during the proliferative phase.

Sex difference in human diseases: mechanistic insights and clinical implications

Sex characteristics exhibit significant disparities in various human diseases, including prevalent cardiovascular diseases, cancers, metabolic disorders, autoimmune diseases, and neurodegenerative diseases. Risk profiles and pathological manifestations of these diseases exhibit notable variations between sexes. The underlying reasons for these sex disparities encompass multifactorial elements, such as physiology, genetics, and environment. Recent studies have shown that human body systems demonstrate sex-specific gene expression during critical developmental stages and gene editing processes. These genes, differentially expressed based on different sex, may be regulated by androgen or estrogen-responsive elements, thereby influencing the incidence and presentation of cardiovascular, oncological, metabolic, immune, and neurological diseases across sexes. However, despite the existence of sex differences in patients with human diseases, treatment guidelines predominantly rely on male data due to the underrepresentation of women in clinical trials. At present, there exists a substantial knowledge gap concerning sex-specific mechanisms and clinical treatments for diverse diseases. Therefore, this review aims to elucidate the advances of sex differences on human diseases by examining epidemiological factors, pathogenesis, and innovative progress of clinical treatments in accordance with the distinctive risk characteristics of each disease and provide a new theoretical and practical basis for further optimizing individualized treatment and improving patient prognosis.

Decoding the connection between SLE and DNA Sensors: A comprehensive review

Systemic lupus erythematosus (SLE) is recognized as a prevalent autoimmune disorder characterized by a multifaceted pathogenesis potentially influenced by a combination of environmental factors, genetic predisposition, and hormonal regulation. The continuous study of immune system activation is especially intriguing. Analysis of blood samples from individuals with SLE reveals an abnormal increase in interferon levels, along with the existence of anti-double-stranded DNA antibodies. This evidence suggests that the development of SLE may be initiated by innate immunity. The presence of abnormal dsDNA fragments can activate DNA sensors within cells, particularly immune cells, leading to the initiation of downstream signaling cascades that result in the upregulation of relevant cytokines and the subsequent initiation of adaptive immune responses, such as B cell differentiation and T cell activation. The intricate pathogenesis of SLE results in DNA sensors exhibiting a wide range of functions in innate immune responses that are subject to variation based on cell types, developmental processes, downstream effector signaling pathways and other factors. The review aims to reorganize how DNA sensors influence signaling pathways and contribute to the development of SLE according to current studies, with the aspiration of furnishing valuable insights for future investigations into the pathological mechanisms of SLE and potential treatment approaches.

Impact of sex differences on the clinical presentation, pathogenesis, treatment and prognosis of Sjögren's syndrome

Sjögren's syndrome is a common chronic autoimmune disease that manifests as dry mouth, dry eyes and systemic complications. There are sex differences in the clinical manifestations between men and women, with the average age of onset being around 55 years and the majority of female patients developing the disease during the menopausal years. Understanding the impact of sex differences on SS may help in the treatment and prognosis of patients. Studies have confirmed that a number of factors are associated with the onset of SS, but the exact mechanisms are not fully understood. Sex hormones (especially oestrogens and androgens) play a very important role, and the balance of sex hormone levels in the body is crucial for maintaining homeostasis in the acinar cells of the lacrimal and salivary glands. In addition, chromosomes play a very important role in the sex differences in SS. The gut microbiota also has some influence on sex differences in SS. In this review, we focus on oestrogens and androgens, which are important in the pathogenesis of SS, and summarize the progress of non-clinical studies. Sex differences may influence differences in individualized treatment regimens and further studies are needed.

Mechanisms and consequences of sex differences in immune responses

Biological sex differences refer to differences between males and females caused by the sex chromosome complement (that is, XY or XX), reproductive tissues (that is, the presence of testes or ovaries), and concentrations of sex steroids (that is, testosterone or oestrogens and progesterone). Although these sex differences are binary for most human individuals and mice, transgender individuals receiving hormone therapy, individuals with genetic syndromes (for example, Klinefelter and Turner syndromes) and people with disorders of sexual development reflect the diversity in sex-based biology. The broad distribution of sex steroid hormone receptors across diverse cell types and the differential expression of X-linked and autosomal genes means that sex is a biological variable that can affect the function of all physiological systems, including the immune system. Sex differences in immune cell function and immune responses to foreign and self antigens affect the development and outcome of diverse diseases and immune responses.

Inflammatory immune profiles associated with disease severity in pulmonary tuberculosis patients with moderate to severe clinical TB or anemia

Background

Immune control of Mycobacterium tuberculosis (Mtb) infection is largely influenced by the extensive disease heterogeneity that is typical for tuberculosis (TB). In this study, the peripheral inflammatory immune profile of different sub-groups of pulmonary TB patients was explored based on clinical disease severity, anemia of chronic disease, or the radiological extent of lung disease.

Methods

Plasma samples were obtained from n=107 patients with active pulmonary TB at the time of diagnosis and after start of standard chemotherapy. A composite clinical TB symptoms score, blood hemoglobin status and chest X-ray imaging were used to sub-group TB patients into 1.) mild and moderate-severe clinical TB, 2.) anemic and non-anemic TB, or 3.) limited and extensive lung involvement. Plasma levels of biomarkers associated with inflammation pathways were assessed using a Bio-Plex Magpix 37-multiplex assay. In parallel, Th1/Th2 cytokines were quantified with a 27-multiplex in matched plasma and cell culture supernatants from whole blood stimulated with M. tuberculosis-antigens using the QuantiFERON-TB Gold assay.

Results

Clinical TB disease severity correlated with low blood hemoglobin levels and anemia but not with radiological findings in this study cohort. Multiplex protein analyses revealed that distinct clusters of inflammation markers and cytokines separated the different TB disease sub-groups with variable efficacy. Several top-ranked markers overlapped, while other markers were unique with regards to their importance to differentiate the TB disease severity groups. A distinct immune response profile defined by elevated levels of BAFF, LIGHT, sTNF-R1 and 2, IP-10, osteopontin, chitinase-3-like protein 1, and IFNα2 and IL-8, were most effective in separating TB patients with different clinical disease severity and were also promising candidates for treatment monitoring. TB patients with mild disease displayed immune polarization towards mixed Th1/Th2 responses, while pro-inflammatory and B cell stimulating cytokines as well as immunomodulatory mediators predominated in moderate-severe TB disease and anemia of TB.

Conclusions

Our data demonstrated that clinical disease severity in TB is associated with anemia and distinct inflammatory immune profiles. These results contribute to the understanding of immunopathology in pulmonary TB and define top-ranked inflammatory mediators as biomarkers of disease severity and treatment prognosis.

Advances in the management of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a severe multisystem autoimmune disease that can cause injury in almost every body system. While considered a classic example of autoimmunity, it is still relatively poorly understood. Treatment with immunosuppressive agents is challenging, as many agents are relatively non-specific, and the underlying disease is characterized by unpredictable flares and remissions. This State of The Art Review provides a comprehensive current summary of systemic lupus erythematosus based on recent literature. In basic and translational science, this summary includes the current state of genetics, epigenetics, differences by ancestry, and updates about the molecular and immunological pathogenesis of systemic lupus erythematosus. In clinical science, the summary includes updates in diagnosis and classification, clinical features and subphenotypes, and current guidelines and strategies for treatment. The paper also provides a comprehensive review of the large number of recent clinical trials in systemic lupus erythematosus. Current knowns and unknowns are presented, and potential directions for the future are suggested. Improved knowledge of immunological pathogenesis and the molecular differences that exist between patients should help to personalize treatment, minimize side effects, and achieve better outcomes in this difficult disease.

Role of Sex Hormones in Prevalent Kidney Diseases

Chronic kidney disease (CKD) is a constantly growing global health burden, with more than 840 million people affected worldwide. CKD presents sex disparities in the pathophysiology of the disease, as well as in the epidemiology, clinical manifestations, and disease progression. Overall, while CKD is more frequent in females, males have a higher risk to progress to end-stage kidney disease. In recent years, numerous studies have highlighted the role of sex hormones in the health and diseases of several organs, including the kidney. In this review, we present a clinical overview of the sex-differences in CKD and a selection of prominent kidney diseases causing CKD: lupus nephritis, diabetic kidney disease, IgA nephropathy, and autosomal dominant polycystic kidney disease. We report clinical and experimental findings on the role of sex hormones in the development of the disease and its progression to end-stage kidney disease.

Sex hormone-dependent and -independent regulation of serum BAFF and TNF in cohorts of transgender and cisgender men and women

Background

The risk of inflammatory diseases is sex-dependent, but it remains unknown whether this is due to the impact of sex hormones or sex chromosomes. Transgender individuals represent a unique cohort for studying the relative influence of endocrine and chromosomal factors. Here we compared serum levels of B-cell activating-factor (BAFF) and tumor necrosis factor (TNF) in transgender men (TM), transgender women (TW), cisgender women (CW) and cisgender men (CM).

Methods

BAFF and TNF were measured in the serum of 26 CW, 30 CM, 27 TM and 16 TW individuals. To determine the responsiveness of immune cells, TNF was measured in bacterial lipopolysaccharide (LPS)-treated peripheral leukocytes.

Results

BAFF was higher in CF (998 pg/mL) and TW (973 pg/mL) compared to CM (551 pg/mL) (P < 0.0001) and TM (726 pg/mL) (P < 0.0001). No difference in BAFF levels was shown between subjects grouped according to the number of X chromosomes. TNF was higher in CM (174 pg/mL) than TW (2.3 pg/mL) (P = 0.027) and TM (27.4 pg/mL) (P = 0.028). LPS-induced TNF was higher in CM (2524 pg/mL) and TM (2078 pg/mL) than in CW (1332 pg/mL) (both P < 0.0001) and TW (1602 pg/mL) (both P = 0.009).

Discussion

Sex hormones and sex chromosomes have different impacts on cytokines involved in the sex-dependent inflammatory response. The concentration of BAFF and LPS-stimulated TNF secretion depended on sex hormone levels, whereas basal TNF was regulated by both sex hormone-dependent and -independent factors.

Sex bias in lymphocytes: Implications for autoimmune diseases

Autoimmune diseases are characterized by a significant sex dimorphism, with women showing increased susceptibility to disease. This is, at least in part, due to sex-dependent differences in the immune system that are influenced by the complex interplay between sex hormones and sex chromosomes, with contribution from sociological factors, diet and gut microbiota. Sex differences are evident in the number and function of lymphocyte populations. Women mount a stronger pro-inflammatory response than males, with increased lymphocyte proliferation, activation and pro-inflammatory cytokine production, whereas men display expanded regulatory cell subsets. Ageing alters the immune landscape of men and women in differing ways, resulting in changes in autoimmune disease susceptibility. Here we review the current literature on sex differences in lymphocyte function, the factors that influence this, and the implications for autoimmune disease. We propose that improved understanding of sex bias in lymphocyte function can provide sex-specific tailoring of treatment strategies for better management of autoimmune diseases.

Sex hormones affect the pathogenesis and clinical characteristics of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) affects women more frequently than men, similar to the female predilection for other autoimmune diseases. Moreover, male patients with SLE exhibit different clinical features than female patients. Sex-associated differences in SLE required special considerations for disease management such as during pregnancy or hormone replacement therapy (HRT). Sex hormones, namely, estrogen and testosterone, are known to affect immune responses and autoimmunity. While estrogen and progesterone promote type I immune response, and testosterone enhances T-helper 1 response. Sex hormones also influence Toll-like receptor pathways, and estrogen receptor signaling is involved in the activation and tolerance of immune cells. Further, the clinical features of SLE vary according to hormonal changes in female patients. Alterations in sex hormones during pregnancy can alter the disease activity of SLE, which is associated with pregnancy outcomes. Additionally, HRT may change SLE status. Sex hormones affect the pathogenesis, clinical features, and management of SLE; thus, understanding the occurrence and exacerbation of disease caused by sex hormones is necessary to improve its management.

LncRNA Expression Profiles in Systemic Lupus Erythematosus and Rheumatoid Arthritis: Emerging Biomarkers and Therapeutic Targets

Systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) are two common multisystem autoimmune diseases that share, among others, many clinical manifestations and serological features. The role of long non-coding RNAs (lncRNAs) has been of particular interest in the pathogenesis of autoimmune diseases. Here, we aimed to summarize the roles of lncRNAs as emerging novel biomarkers and therapeutic targets in SLE and RA. We conducted a narrative review summarizing original articles on lncRNAs associated with SLE and RA, published until November 1, 2021. Based on the studies on lncRNA expression profiles in samples (including PBMCs, serum, and exosomes), it was noted that most of the current research is focused on investigating the regulatory mechanisms of these lncRNAs in SLE and/or RA. Several lncRNAs have been hypothesized to play key roles in these diseases. In SLE, lncRNAs such as GAS5, NEAT1, TUG1, linc0949, and linc0597 are dysregulated and may serve as emerging novel biomarkers and therapeutic targets. In RA, many validated lncRNAs, such as HOTAIR, GAS5, and HIX003209, have been identified as promising novel biomarkers for both diagnosis and treatment. The shared lncRNAs, for example, GAS5, may participate in SLE pathogenesis through the mitogen-activated protein kinase pathway and trigger the AMP-activated protein kinase pathway in RA. Here, we summarize the data on key lncRNAs that may drive the pathogenesis of SLE and RA and could potentially serve as emerging novel biomarkers and therapeutic targets in the coming future.

Differential serum interferon-β levels in autoimmune thyroid diseases

INTRODUCTION

Interferon (IFN)-β is known as an environmental trigger for the occurrence of autoimmune thyroid disease (AITD). However, the association of another type-1 IFN, IFN-β, with AITD is unknown.

MATERIAL AND METHODS

In the study, we explored the association of serum IFN-β levels with AITD in an ethnic Chinese (i.e., Taiwanese) population. We enrolled 160 patients with Graves' disease (GD), 47 patients with Hashimoto's thyroiditis (HT), and 119 healthy controls. Serum IFN-β and B-cell activating factor (BAFF) levels were quantified in healthy controls at the baseline and in patients with AITD either prior to receiving medication or while under medication. Thyroid function and thyroid-stimulating hormone receptor antibody (TSHRAb) levels were measured at the time of serum collection.

RESULTS

Serum IFN-β levels were lower in the HT group than in the control group (p = 0.031). A significant inverse correlation was observed between IFN-β and TSHRAb levels in men with GD (r = -0.433, p = 0.044). Serum IFN-β levels were also negatively associated with BAFF levels in men with GD, HT, and AITD (r = -0.320, p = 0.032; r = -0.817, p = 0.047; and r = -0.354, p = 0.011, respectively), but not in women with GD, HT, or AITD.

CONCLUSIONS

Serum IFN-β levels were lower in HT patients. Correlations of serum IFN-β with TSHRAb and BAFF levels were found to be gender-specific. Further well-designed studies with larger sample sizes are required to confirm our findings.

Immunopathological events surrounding IL-6 and IFN-α: A bridge for anti-lupus erythematosus drugs used to treat COVID-19

With the outbreak and rapid spread of COVID-19, the world health situation is unprecedentedly severe. Systemic lupus erythematosus (SLE) is a common autoimmune disease, which can cause multiple organ damage. Numerous studies have shown that immune factors have important roles in the pathogenesis of both COVID-19 and SLE. In the early stages of COVID-19 and SLE pathogenesis, IFN-α expression is frequently increased, which aggravates the virus infection and promotes SLE development. In addition, increased IL-6 levels, caused by different mechanisms, are observed in the peripheral blood of patients with severe COVID-19 and SLE, stimulating a series of immune cascades that lead to a cytokine storm, as well as causing B cell hyperfunction and production of numerous of antibodies, aggravating both COVID-19 and SLE. In this review, we explore the background immunopathological mechanisms in COVID-19 and SLE and analyze the advantages and disadvantages of commonly used SLE drugs for patients with COVID-19, to optimize treatment plans for patients with SLE who develop COVID-19.

The complex role of AIM2 in autoimmune diseases and cancers

Absent in melanoma 2 (AIM2) is a novel member of interferon (IFN)-inducible PYHIN proteins. In innate immune cells, AIM2 servers as a cytoplasmic double-stranded DNA sensor, playing a crucial role in the initiation of the innate immune response as a component of the inflammasome. AIM2 expression is increased in patients with systemic lupus erythematosus (SLE), psoriasis, and primary Sjogren's syndrome, indicating that AIM2 might be involved in the pathogenesis of autoimmune diseases. Meanwhile, AIM2 also plays an antitumorigenesis role in an inflammasome independent-manner. In melanoma, AIM2 is initially identified as a tumor suppressor factor. However, AIM2 is also found to contribute to lung tumorigenesis via the inflammasome-dependent release of interleukin 1β and regulation of mitochondrial dynamics. Additionally, AIM2 reciprocally dampening the cGAS-STING pathway causes immunosuppression of macrophages and evasion of antitumor immunity during antibody treatment. To summarize the complicated effect and role of AIM2 in autoimmune diseases and cancers, herein, we provide an overview of the emerging research progress on the function and regulatory pathway of AIM2 in innate and adaptive immune cells, as well as tumor cells, and discuss its pathogenic role in autoimmune diseases, such as SLE, psoriasis, primary Sjogren's syndrome, and cancers, such as melanomas, non-small-cell lung cancer, colon cancer, hepatocellular carcinoma, renal carcinoma, and so on, hopefully providing potential therapeutic and diagnostic strategies for clinical use.

Sex Bias and Autoimmune Diseases

Sex bias in immune function has been well-described, and women have been shown to counter immunologically stimulating phenomena such as infection, malignancy, and trauma with more protective responses than men. Heightened immunity in women may also result in a predisposition for loss of self-tolerance and development of autoimmunity, reflected by the overwhelming female sex bias of patients with autoimmune diseases. In this review, we discuss the postulated evolutionary etiologies for sexual dimorphism in immunity. We also review the molecular mechanisms underlying divergent immune responses in men and women, including sex hormone effects, X chromosome dosage, and autosomal sex-biased genes. With increasing evidence that autoimmune disease susceptibility is influenced by numerous hormonal and genetic factors, a comprehensive understanding of these topics may facilitate the development of much-needed targeted therapeutics.

Lower BAFF Levels in Myasthenic Patients Treated with Glucocorticoids

B-cell activating factor (BAFF), a member of tumor necrosis factor family, activates B cells, promotes their survival and proliferation. BAFF is considered to have an influence on development of autoimmune diseases including myasthenia gravis (MG). We aimed to evaluate BAFF serum levels in MG patients, their potential connection with therapy and course of MG. Cross-sectional study. Two hundred eighteen adult patients with MG (67% women, age: 18-89 years, 82.6% AChR antibody seropositive (AChRAb(+)). Serum BAFF levels, their relationship with severity of clinical symptoms, therapy conducted, clinical and demographic features and other factors were analyzed. Patients with AChRAb(+) MG demonstrated significantly higher BAFF levels than MuSK-MG patients (831.2 ± 285.4 pg/ml vs. 745.6 ± 633.4 pg/ml, respectively; p = 0.030). Serum BAFF levels in women were significantly higher than in men (855.9 ± 302.5 vs. 756.6 ± 289.4, respectively; p = 0.017). Mean serum BAFF level was significantly decreased in patients who were ever treated with corticosteroids (CS) (770.4 ± 327.8 pg/ml vs. 891.3 ± 246.1 pg/ml, respectively; p = 0.001). Thymoma-MG patients demonstrated significantly lower BAFF levels (671.2 ± 244.9 vs. 833.5 ± 302.4, respectively; p = 0.044). Thymectomized patients did not differ in BAFF levels from the MG patients who had not undergone thymectomy. In multiple linear regression model, recent CS therapy and male sex were found to be independent predictors of lower BAFF levels. Serum BAFF level is decreased in patients treated with CS, which may suggest inhibiting influence of CS on BAFF-a potential mechanism contributing to the effectiveness of such therapy.

The gene silencing of IRF5 and BLYSS effectively modulates the outcome of experimental lupus nephritis

Systemic lupus erythematosus is a highly complex and heterogeneous autoimmune disease mostly mediated by B cells. It is characterized by circulating self-reactive antibodies that deposit and form immune complexes in kidney, leading to irreparable tissue damage and resulting in lupus nephritis. In a New Zealand Black X New Zealand White F1 mouse model, we tested two different small interfering RNA (siRNA) silencing treatments against interferon regulatory factor 5 (IRF5) and B cell-activating factor (BLYSS) expression and their combination in a second set of animals. The administration of these two siRNAs separately prevented the progression of proteinuria and albuminuria at similar levels to that in cyclophosphamide animals. These treatments effectively resulted in a reduction of serum anti-double-stranded DNA (dsDNA) antibodies and histopathological renal score compared with non-treated group. Treated groups showed macrophage, T cell, and B cell infiltrate reduction in renal tissue. Moreover, kidney gene expression analysis revealed that siRNA treatments modulated very few pathways in contrast to cyclophosphamide, despite showing similar therapeutic effects. Additionally, the combined therapy tested in a second set of animals, in which the disease appeared more virulent, exhibited better results than monotherapies in the disease progression, delaying the disease onset and ameliorating the disease outcome. Herein, we provide the potential therapeutic effect of both selective IRF5 and BLYSS silencing as an effective and potential treatment, particularly in early phases of the disease.

Association of FOXP3 and GAGE10 promoter polymorphisms and decreased FOXP3 expression in regulatory T cells with susceptibility to generalized vitiligo in Gujarat population

Alterations in regulatory T (Treg) cells have been observed in generalized vitiligo (GV) patients and decreased Forkhead Box P3 (FOXP3) has been implicated in the disease pathogenesis. The present study examined FOXP3 rs3761547(A > G), rs3761548(C > A), rs2232365(A > G) and GAGE10 rs11798415(A > T) promoter single nucleotide polymorphisms (SNPs) in 419 GV patients and 429 controls from Gujarat population using PCR-RFLP and ARMS-PCR. Real-time PCR and flow cytometry were used for assessment of FOXP3 mRNA and protein levels respectively in 96 GV patients and 90 controls. The frequency of genotypes (p < 0.001) and alleles (p = 0.012 & p = 0.040) for rs3761547(A > G) and rs11798415(A > T) SNPs significantly differed between GV patients and controls. FOXP3 mRNA and protein levels were significantly decreased (p < 0.001) in GV Tregs compared to controls. Active vitiligo (AV) Tregs showed significantly reduced FOXP3 mRNA and protein levels compared to that of stable vitiligo (SV) (p = 0.02 & p = 0.039). The correlation of genotype-phenotype of FOXP3 SNPs suggested reduced FOXP3 mRNA (p = 0.019, p < 0.001 & p < 0.001) and protein (p = 0.028, p < 0.001 & p = 0.022) levels in patients with susceptible GG, AA and GG genotypes respectively. The GAGT, GCGT & ACGT haplotypes were prevalent in GV patients (p = 0.004, p = 0.004 & p = 0.016); however, GAGT & GCGT were overrepresented in patients with AV (p = 0.044 & p = 0.024). The susceptible GAGT and GCGT haplotypes in patients exhibited reduction in FOXP3 mRNA (p = 0.014 & p = 0.019) and protein (p = 0.024 & p = 0.028). DNA-protein docking analysis revealed reduced binding for transcription factor C/EBP to the susceptible allele 'G' (rs3761547) compared to A allele. For the first time, the study suggests significant association of FOXP3 rs3761547(A > G) & GAGE10 rs11798415(A > T) SNPs with susceptibility to GV in Gujarat population. In addition, the likely role of these SNPs in altered FOXP3 expression of Tregs may possibly affect Treg suppressive function in GV.

Human pregnancy levels of estrogen and progesterone contribute to humoral immunity by activating TFH /B cell axis

Circulating T_FH (cT_FH ) cells express CXCR5, PD-1, and, when activated, ICOS, and release IL-21. According to the production of IFN-γ, IL-4, and IL-17 and expression of FoxP3, these cells are also classified as cT_FH 1, cT_FH 2, cT_FH 17, and cT_FR cells, respectively. This CD4⁺ T-cell subset is pivotal to efficient humoral immunity, and pregnancy appears to favor IgG production. Here, not only pregnancy amplified the in vivo production of anti-HBsAg IgG in HBV immunized women, but the frequency of cT_FH cells was directly correlated with estradiol levels. In vitro, pregnancy-related dose of 17-β-estradiol (E2) directly increased the percentage of different cT_FH subsets. While E2 and progesterone (P4) increased the proportion of differentiated T_FH cells derived from naïve CD4⁺ T-cells, only E2 amplified the release of IL-21 in those cell cultures. In addition, E2 and P4 increased the proportion of memory B cells and plasma cells, respectively. In SEB-activated B/T_FH cell co-cultures, E2, in the presence of P4, increased the production of total IgG. Finally, among the hormones, P4 was stronger in upregulating the percentage of IL-10⁺ T_FR cells. Collectively, our findings suggested that E2 and P4 cooperate in the humoral immune response by favoring the expansion of different cT_FH and B cell subsets.

Abundance and nuclear antigen reactivity of intestinal and fecal Immunoglobulin A in lupus-prone mice at younger ages correlate with the onset of eventual systemic autoimmunity

Our recent studies, using (SWRxNZB)F1 (SNF1) mice, showed a potential contribution of the gut microbiota and pro-inflammatory immune responses of the gut mucosa to systemic autoimmunity in lupus. Here, using this mouse model, we determined the abundance and the nAg reactivity of IgA antibody produced in the intestine under lupus susceptibility. Intestinal lymphoid tissues from SNF1 mice, females particularly, showed significantly higher frequencies of nAg (dsDNA and nucleohistone) reactive IgA producing B cells compared to B6 females. Most importantly, younger age fecal IgA -abundance and -nAg reactivity of lupus-prone mice showed a positive correlation with eventual systemic autoimmunity and proteinuria onset. Depletion of gut microbiota in SNF1 mice resulted in the diminished production of IgA in the intestine and the nAg reactivity of these antibodies. Overall, these observations show that fecal IgA features, nuclear antigen reactivity particularly, at preclinical stages/in at-risk subjects could be predictive of autoimmune progression.

What's Sex Got to Do With COVID-19? Gender-Based Differences in the Host Immune Response to Coronaviruses

The novel severe acute respiratory syndrome coronavirus 2, the cause of the coronavirus disease 2019 (COVID-19) pandemic, has ravaged the world, with over 22 million total cases and over 770,000 deaths worldwide as of August 18, 2020. While the elderly are most severely affected, implicating an age bias, a striking factor in the demographics of this deadly disease is the gender bias, with higher numbers of cases, greater disease severity, and higher death rates among men than women across the lifespan. While pre-existing comorbidities and social, behavioral, and lifestyle factors contribute to this bias, biological factors underlying the host immune response may be crucial contributors. Women mount stronger immune responses to infections and vaccinations and outlive men. Sex-based biological factors underlying the immune response are therefore important determinants of susceptibility to infections, disease outcomes, and mortality. Despite this, gender is a profoundly understudied and often overlooked variable in research related to the immune response and infectious diseases, and it is largely ignored in drug and vaccine clinical trials. Understanding these factors will not only help better understand the pathogenesis of COVID-19, but it will also guide the design of effective therapies and vaccine strategies for gender-based personalized medicine. This review focuses on sex-based differences in genes, sex hormones, and the microbiome underlying the host immune response and their relevance to infections with a focus on coronaviruses.

Regulating the Polarization of Macrophages: A Promising Approach to Vascular Dermatosis

Macrophages, a kind of innate immune cells, derive from monocytes in circulation and play a crucial role in the innate and adaptive immunity. Under the stimulation of the signals from local microenvironment, macrophages generally tend to differentiate into two main functional phenotypes depending on their high plasticity and heterogeneity, namely, classically activated macrophage (M1) and alternatively activated macrophage (M2). This phenomenon is often called macrophage polarization. In pathological conditions, chronic persistent inflammation could induce an aberrant response of macrophage and cause a shift in their phenotypes. Moreover, this shift would result in the alteration of macrophage polarization in some vascular dermatoses; e.g., an increase in proinflammatory M1 emerges from Behcet's disease (BD), psoriasis, and systemic lupus erythematosus (SLE), whereas an enhancement in anti-inflammatory M2 appears in infantile hemangioma (IH). Individual polarized phenotypes and their complicated cytokine networks may crucially mediate in the pathological processes of some vascular diseases (vascular dermatosis in particular) by activation of T cell subsets (such as Th1, Th2, Th17, and Treg cells), deterioration of oxidative stress damage, and induction of angiogenesis, but the specific mechanism remains ambiguous. Therefore, in this review, we discuss the possible role of macrophage polarization in the pathological processes of vascular skin diseases. In addition, it is proposed that regulation of macrophage polarization may become a potential strategy for controlling these disorders.

Sex differences in lymphoid follicles in COPD airways

Background

Female smokers have increased risk for chronic obstructive pulmonary disease (COPD) compared with male smokers who have a similar history of cigarette smoke exposure. Tertiary lymphoid follicles are often found in the lungs of patients with severe COPD but sex-related differences have not been previously investigated. We determined the impact of female sex hormones on chronic cigarette smoke-induced expression of lymphoid aggregates in mice with COPD-like pathologies.

Methods

Lymphoid aggregate counts, total aggregate cross-sectional area and foamy macrophage counts were determined morphometrically in male, female, and ovariectomized mice exposed to air or cigarette smoke for 6 months. B-cell activating factor (BAFF) protein expression and markers of oxidative stress were evaluated in mouse lung tissues by immunofluorescence staining and gene expression analyses. Quantitative histology was performed on lung tissue sections of human COPD lungs to evaluate follicle formation.

Results

Lymphoid follicle and foamy macrophage counts as well as the total follicle cross-sectional area were differentially increased in lung tissues of female mice compared to male mice, and these differences were abolished by ovariectomy. These lymphoid aggregates were positive for CD45, CD20, CD21 and BAFF expression. Differential increases in Mmp12 and Cxcl2 gene expression correlated with an increase in foamy macrophages in parenchymal tissues of female but not male mice after smoke exposure. Parenchymal tissues from female mice failed to induce antioxidant-related genes in response to smoke exposure, and this effect was restored by ovariectomy. 3-nitrotyrosine, a stable marker of oxidative stress, positively correlated with Mmp12 and Cxcl2 gene expression. Hydrogen peroxide induced BAFF protein in mouse macrophage cell line. In human lung tissues, female smokers with severe COPD demonstrated increased numbers of lymphoid follicles compared with males.

Conclusions

Chronic smoke exposure increases the risk of lymphoid aggregate formation in female mice compared with male mice, which is mediated female sex hormones and BAFF expression in an oxidative environment.

Gut microbiota differently contributes to intestinal immune phenotype and systemic autoimmune progression in female and male lupus-prone mice

The risk of developing systemic lupus erythematosus (SLE) is about 9 times higher in women as compared to men. Our recent report, which used (SWRxNZB) F1 (SNF1) mouse model of spontaneous lupus, showed a potential link between immune response initiated in the gut mucosa at juvenile age (sex hormone independent) and SLE susceptibility. Here, using this mouse model, we show that gut microbiota contributes differently to pro-inflammatory immune response in the intestine and autoimmune progression in lupus-prone males and females. We found that gut microbiota composition in male and female littermates are significantly different only at adult ages. However, depletion of gut microbes causes suppression of autoimmune progression only in females. In agreement, microbiota depletion suppressed the pro-inflammatory cytokine response of gut mucosa in juvenile and adult females. Nevertheless, microbiota from females and males showed, upon cross-transfer, contrasting abilities to modulate disease progression. Furthermore, orchidectomy (castration) not only caused changes in the composition of gut microbiota, but also a modest acceleration of autoimmune progression. Overall, our work shows that microbiota-dependent pro-inflammatory immune response in the gut mucosa of females initiated at juvenile ages and androgen-dependent protection of males contribute to gender differences in the intestinal immune phenotype and systemic autoimmune progression.

Estrogen, estrogen-like molecules and autoimmune diseases

In western countries, the slope of autoimmune disease (AD) incidence is increasing and affects 5-8% of the population. Mainly prevalent in women, these pathologies are due to thymic tolerance processes breakdown. The female sex hormone, estrogen, is involved in this AD female susceptibility. However, predisposition factors have to act in concert with unknown triggering environmental factors (virus, microbiota, pollution) to initiate AD. Individuals are exposed to various environmental compounds that display endocrine disruption abilities. The cellular effects of some of these molecules may be mediated through the aryl hydrocarbon receptor (AhR). Here, we review the effects of these molecules on the homeostasis of the thymic cells, the immune tolerance intrinsic factors (transcription factors, epigenetic marks) and on the immune tolerance extrinsic factors (microbiota, virus sensibility). This review highlights the contribution of estrogen and endocrine disruptors on the dysregulation of mechanisms sustaining AD development.

Neuroimmunologic disorders in pregnancy

Pregnancy influences the course of neuroimmunologic conditions, which include multiple sclerosis (MS), neuromyelitis optica spectrum disorder, and autoimmune encephalitis. The outcomes differ significantly for each disorder, reflecting the impact of hormonal changes, T-cell subsets, and placental factors on disease pathogenesis. In recent years, numerous data have emerged regarding MS activity throughout pregnancy and postpartum. Historically, the misconception that pregnancy worsens MS outcomes led patients to abstain from childbearing. Now, more women with these disorders, empowered by up-to-date information and better baseline disease control, are choosing to conceive. Nevertheless, the management of MS and related disorders in the pregnancy and postpartum period is complicated and requires a nuanced approach. Since standardized treatment guidelines around pregnancy are currently lacking, neurologists, together with obstetricians, must engage patients in a shared decision-making process that weighs the benefits to the mother and risks to the fetus. This chapter outlines the pathophysiology of neuroimmunologic disorders during pregnancy and postpartum, the impact of these diseases on childbearing, including fertility, pregnancy, delivery, and peurperium, as well as existing recommendations for treatment.

Correlations of Expression Levels of a Panel of Genes (IRF5, STAT4, TNFSF4, MECP2, and TLR7) and Cytokine Levels (IL-2, IL-6, IL-10, IL-12, IFN-γ, and TNF-α) with Systemic Lupus Erythematosus Outcomes in Jordanian Patients

Systemic lupus erythematosus (SLE) is characterized by systemic end-organ damage. We investigated the involvement of IRF5, TLR-7, MECP2, STAT4, and TNFSF4 genes and TNF-α, IFN-γ, IL-2, IL-12, IL-6, and IL-10 cytokines in SLE pathogenesis and in organ damage in Jordanian patients. Blood was collected from 51 patients and 50 controls. Expression levels of SLE genes in PBMCs and cytokine levels were determined using RT-PCR and ELISA, respectively. Expression levels of all genes and levels of TNF-α, IL-12, IL-6, and IL-10 were higher in SLE patients than those in controls (p < 0.05), whereas IL-2 level was lower. High STAT4 (α), TNFSF4, and IL-10 levels correlated with cardiovascular damage, and high MECP2 (α) and TNF-α correlated with renal damage. Pulmonary and musculoskeletal damages correlated with high levels of TNFSF4. We concluded that STAT4 and TNFSF4 genes with TNF-α and IL-10 cytokines could be used as biomarkers to assess SLE activity and manage treatment.

Associations of BAFF rs2893321 polymorphisms with myasthenia gravis susceptibility

Background

Myasthenia gravis (MG) is an autoimmune diseases characterized by fatigue and weakness of skeletal muscles. B-lymphocyte-activating factor (BAFF), an essential factor for B cell differentiation and development, is important in the progression of MG. The current study aimed to investigate the association between single nucleotide polymorphism rs2893321 in BAFF with MG susceptibility in Chinese Han population.

Methods

One hundred forty-nine patients with MG and 148 healthy controls were recruited. Using improved multiple ligase detection reaction technology, the polymorphisms of rs2893321 between groups and among MG subgroups have been compared.

Results

A significant differences between the MG group and the healthy control group was observed. Additionally, rs2893321 was found to be associated with gender and age in patients with MG.

Conclusion

Genetic variations of rs2893321 in BAFF might be associated with susceptibility to MG in the Chinese Han population.

Updated advances of linking psychosocial factors and sex hormones with systemic lupus erythematosus susceptibility and development

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease that primarily affects women, especially those of reproductive age. Genetics, environment, and gene-environment interactions play key roles in the development of SLE. Despite the numerous susceptibility genes of SLE identified to date, gene therapy is far from a clinical reality. Thus, more attention should be paid to the risk factors and underlying mechanisms of SLE. Currently, it is reported that psychosocial factors and sex hormones play vital roles in patients with SLE, which still need further investigated. The purpose of this review is to update the roles and mechanisms of psychosocial factors and sex hormones in the susceptibility and development of SLE. Based on review articles and reports in reputable peer-reviewed journals and government websites, this paper summarized psychosocial factors (e.g., alexithymia, depression, anxiety, negative emotions, and perceived stress) and sex hormones (e.g., estrogens, progesterone, androgens, and prolactin) involved in SLE. We further explore the mechanisms linking these factors with SLE susceptibility and development, which can guide the establishment of practical measures to benefit SLE patients and offer new ideas for therapeutic strategies.

Curcumin attenuates lupus nephritis in MRL/lpr mice by suppressing macrophage-secreted B cell activating factor (BAFF)

This study aimed to investigate the therapeutic effects and mechanism of action of curcumin against a MRL/lpr lupus model. Eight-week-old female MRL/lpr mice were used to establish the lupus nephritis model. Histologic and immunohistochemical analysis was conducted for lupus nephritis. Anti-dsDNA IgG and BAFF level were detected by ELISA. Cells directly isolated from the spleen were used to detect macrophage subsets and activation status by FACS. Curcumin reduced the total IgG and anti-dsDNA IgG levels in blood and reduced the activation of B cells in MRL/lpr mice. Moreover, curcumin prevented activation of macrophages in MRL/lpr mice. Levels of BAFF in serum, spleens and kidneys were also reduced in curcumin-treated MRL/lpr mice. In vitro experiments showed that curcumin reduced the activation of macrophage and leaded to the decrease of BAFF from them upon toll like receptor (TLR) 4 stimulation. Curcumin attenuates lupus nephritis in MRL/lpr mice by inhibiting macrophages activation and their secreting BAFF, which may be a potential therapeutic candidate for the treatment of SLE.

Interferon (IFN)-inducible Absent in Melanoma 2 proteins in the negative regulation of the type I IFN response: Implications for lupus nephritis

Systemic lupus erythematosus (SLE) is a complex autoimmune disease that exhibits a strong female bias (female-to-male ratio 9:1) in patients. Further, 40-60% SLE patients develop lupus nephritis (LN), which significantly increases the mortality rates. The failure of current therapies to adequately treat LN in patients reflects an incomplete understanding of the disease pathogenesis. Notably, a chronic increase in serum interferon-α (IFN-α) activity is a heritable risk factor to develop SLE. Accordingly, blood cells from most SLE patients with an active disease exhibit an increase in the expression of the type I IFN (IFN-α/β)-stimulated genes (ISGs, also referred to as "IFN-signature"), a type I IFN response. Further, LN patients during renal flares also exhibit an "IFN-signature" in renal biopsies. Therefore, an improved understanding of the regulation of type I IFNs expression is needed. Basal levels of the IFN-β through "priming" of IFN-α producing cells augment the expression of the IFN-α genes. Of interest, recent studies have indicated a role for the type I IFN-inducible Absent in Melanoma 2 proteins (the murine Aim2 and human AIM2) in the negative regulation of the type I IFN response through inflammasome-dependent and independent mechanisms. Further, an increase in the expression of Aim2 and AIM2 proteins in kidney and renal macrophages associated with the development of nephritis. Therefore, we discuss the role of Aim2/AIM2 proteins in the regulation of type I IFNs and LN. An improved understanding of the mechanisms by which the Absent in Melanoma 2 proteins suppress the type I IFN response and modulate nephritis is key to identify novel therapeutic targets to treat a group of LN patients.

Serum markers of B-cell activation in pregnancy during late gestation, delivery, and the postpartum period

PROBLEM

B cells are vital for the normal evolution of pregnancy due to their humoral and possible regulatory activities. Our group and others have documented that circulating B-cell subsets undergo changes from normal late pregnancy to the postpartum period. However, the underlying mechanisms are poorly understood. Therefore, this study examined the degree of B-cell activation in normal pregnancy by analyzing the levels of serum markers in healthy pregnant women during the third trimester of pregnancy, the day of delivery, and the postpartum period.

METHOD OF STUDY

A prospective study including pregnant and non-pregnant women attending routine care was undertaken at a hospital clinic. Sociodemographic and clinical data were collected, along with peripheral blood samples. The serum levels of soluble CD23 (sCD23), B-cell-activating factor (BAFF), kappa (κ) and lambda (λ) free light chains (FLC), IgA, IgG, and IgM were quantified.

RESULTS

Our study included 43 third trimester pregnant and 35 non-pregnant women. In the pregnant women, the median levels of sCD23, BAFF, IgG, and κ FLC were significantly higher during the postpartum period than during the third trimester of pregnancy. Compared to the non-pregnant women, the third trimester pregnant women had higher median BAFF levels and lower sCD23, IgA, IgG, and FLC levels.

CONCLUSION

Changes in serum markers of B-cell kinetics that occur during pregnancy often persist into the postpartum period and affect the secretion of immunoglobulins from different classes. Further studies are needed to clarify the biological significance of our observations.

17β-Estradiol and 17α-Ethinyl Estradiol Exhibit Immunologic and Epigenetic Regulatory Effects in NZB/WF1 Female Mice

17α-Ethinyl estradiol (EE), a synthetic analog of natural estrogen 17β-estradiol (E2), is extensively used in hormonal contraceptives and estrogen replacement therapy, and it has also been found in sewage effluents. Given that E2 is a well-known immunomodulator, surprisingly there has been only limited information on the cellular and molecular immunologic consequences of exposure to EE. To address this fundamental gap, we directly compared the effects of EE with E2 on splenic leukocytes of New Zealand Black × New Zealand White F1 progeny (NZB/WF1) mice during the preautoimmune period. We found that EE and E2 have common, as well as distinctive, immunologic effects, with EE exposure resulting in more profound effects. Both EE and E2 increased numbers of splenic neutrophils, enhanced neutrophil serine proteases and myeloperoxidase expression, promoted the production of nitric oxide and monocyte chemoattractant protein-1, and altered adaptive immune T cell subsets. However, activation of splenic leukocytes through the T cell receptor or Toll-like receptor (TLR)4 revealed not only common (IL-10), but also hormone-specific alterations of cytokines (IFNγ, IL-1β, ΤΝFα, IL-2). Furthermore, in EE-exposed mice, TLR9 stimulation suppressed IFNα, in contrast to increased IFNα from E2-exposed mice. EE and E2 regulated common and hormone-specific expression of immune-related genes. Furthermore, EE exposure resulted in more marked alterations in miRNA expression levels than for E2. Only EE was able to reduce global DNA methylation significantly in splenic leukocytes. Taken together, our novel data revealed that EE and E2 exposure confers more similar effects in innate immune system-related cell development and responses, but has more differential regulatory effects in adaptive immune-related cell development and responses.

Sex Hormones in Acquired Immunity and Autoimmune Disease

Women have stronger immune responses to infections and vaccination than men. Paradoxically, the stronger immune response comes at a steep price, which is the high incidence of autoimmune diseases in women. The reasons why women have stronger immunity and higher incidence of autoimmunity are not clear. Besides gender, sex hormones contribute to the development and activity of the immune system, accounting for differences in gender-related immune responses. Both innate and adaptive immune systems bear receptors for sex hormones and respond to hormonal cues. This review focuses on the role of sex hormones particularly estrogen, in the adaptive immune response, in health, and autoimmune disease with an emphasis on systemic lupus erythematosus.

Our Environment Shapes Us: The Importance of Environment and Sex Differences in Regulation of Autoantibody Production

Consequential differences exist between the male and female immune systems’ ability to respond to pathogens, environmental insults or self-antigens, and subsequent effects on immunoregulation. In general, females when compared with their male counterparts, respond to pathogenic stimuli and vaccines more robustly, with heightened production of antibodies, pro-inflammatory cytokines, and chemokines. While the precise reasons for sex differences in immune response to different stimuli are not yet well understood, females are more resistant to infectious diseases and much more likely to develop autoimmune diseases. Intrinsic (i.e., sex hormones, sex chromosomes, etc.) and extrinsic (microbiome composition, external triggers, and immune modulators) factors appear to impact the overall outcome of immune responses between sexes. Evidence suggests that interactions between environmental contaminants [e.g., endocrine disrupting chemicals (EDCs)] and host leukocytes affect the ability of the immune system to mount a response to exogenous and endogenous insults, and/or return to normal activity following clearance of the threat. Inherently, males and females have differential immune response to external triggers. In this review, we describe how environmental chemicals, including EDCs, may have sex differential influence on the outcome of immune responses through alterations in epigenetic status (such as modulation of microRNA expression, gene methylation, or histone modification status), direct and indirect activation of the estrogen receptors to drive hormonal effects, and differential modulation of microbial sensing and composition of host microbiota. Taken together, an intriguing question develops as to how an individual’s environment directly and indirectly contributes to an altered immune response, dysregulation of autoantibody production, and influence autoimmune disease development. Few studies exist utilizing well-controlled cohorts of both sexes to explore the sex differences in response to EDC exposure and the effects on autoimmune disease development. Translational studies incorporating multiple environmental factors in animal models of autoimmune disease are necessary to determine the interrelationships that occur between potential etiopathological factors. The presence or absence of autoantibodies is not a reliable predictor of disease. Therefore, future studies should incorporate all the susceptibility/influencing factors, coupled with individual genomics, epigenomics, and proteomics, to develop a model that better predicts, diagnoses, and treats autoimmune diseases in a personalized-medicine fashion.

Neuromyelitis optica spectrum disorders and pregnancy: Interactions and management

Neuromyelitis optica spectrum disorders (NMOSD) predominantly affect women who are of childbearing age. Understanding the interactions between pregnancy and NMOSD is important for clinical management. Aquaporin-4 (AQP4), the most common target antigen in NMOSD, is expressed on placenta in early pregnancy. A variety of immune and cytokine changes in pregnancy may impact pregnancy outcomes in NMOSD patients. Relapses continue during pregnancy and increase in frequency postpartum. Preeclampsia and fetal loss are more frequent in NMOSD than in controls. Transfer of AQP4-immunoglobulin G (IgG) from mother to baby occurs but appears not to cause disease. Several treatment options are relatively safe and mitigate the risk of relapse during pregnancy and postpartum. For patients with active NMOSD, it may be advisable to continue immunotherapy during pregnancy.

Balance between Estrogens and Proinflammatory Cytokines Regulates Chemokine Production Involved in Thymic Germinal Center Formation

The early-onset form of Myasthenia Gravis (MG) is prevalent in women and associates with ectopic germinal centers (GCs) development and inflammation in the thymus. we aimed to investigate the contribution of estrogens in the molecular processes involved in thymic GCs formation. We examined expression of genes involved in anti-acetylcholine receptor (AChR) response in MG, MHC class II and α-AChR subunit as well as chemokines involved in GC development (CXCL13, CCL21and CXCL12). In resting conditions, estrogens have strong regulatory effects on thymic epithelial cells (TECs), inducing a decreased protein expression of the above molecules. In knockout mouse models for estrogen receptor or aromatase, we observed that perturbation in estrogen transduction pathway altered MHC Class II, α-AChR, and CXCL13 expression. However, in inflammatory conditions, estrogen effects were partially overwhelmed by pro-inflammatory cytokines. Interestingly, estrogens were able to control production of type I interferon and therefore play dual roles during inflammatory events. In conclusion, we showed that estrogens inhibited expression of α-AChR and HLA-DR in TECs, suggesting that estrogens may alter the tolerization process and favor environment for an autoimmune response. By contrast, under inflammatory conditions, estrogen effects depend upon strength of the partner molecules with which it is confronted to.

Enhanced Inflammasome Activity in Systemic Lupus Erythematosus Is Mediated via Type I Interferon-Induced Up-Regulation of Interferon Regulatory Factor 1

OBJECTIVE

The inflammasome complex is a driver of organ damage in patients with systemic lupus erythematosus (SLE). Although type I interferons (IFNs) are well established as mediators of SLE pathogenesis, their role in inflammasome activation in SLE has not been assessed. The aim of this study was to examine type I IFNs as regulators of the inflammasome.

METHODS

SLE patients fulfilled ≥4 American College of Rheumatology criteria and were recruited from the University of Michigan Lupus Cohort. Primary monocytes were isolated from SLE patients or healthy controls by negative selection, treated with inflammasome activators in the presence or absence of IFNα, and IL-1β secretion was measured by enzyme-linked immunosorbent assay. Expression levels of IFN and inflammasome-related molecules were assessed by real-time polymerase chain reaction and Western blotting. IFN regulatory factor 1 (IRF-1) expression was specifically down-regulated by small interfering RNA (siRNA) transfection and a chemical inhibitor.

RESULTS

Monocytes from patients with SLE exhibited increased expression and enhanced activation of the inflammasome by ATP when compared with control monocytes. Expression of inflammasome and IFN-regulated genes was significantly correlated in monocytes from SLE patients but not in control monocytes. Inflammasome activity was increased after prolonged exposure to IFNα. Reduction of IRF-1 expression via siRNA blocked caspase 1 up-regulation after treatment with IFNα. Importantly, hyperactivity of the inflammasome in the monocytes of SLE patients was significantly reduced after knockdown or inhibition of IRF-1.

CONCLUSION

Prolonged type I IFN exposure, as seen in SLE patients, primes monocytes for robust inflammasome activation in an IRF-1-dependent manner. IRF-1 inhibition may serve as a novel target for treatment of SLE-associated inflammation and organ damage.

Crosstalk between signals initiated from TLR4 and cell surface BAFF results in synergistic induction of proinflammatory mediators in THP-1 cells

Cellular response to stimulation is mediated by meshwork of signaling pathways that may share common signaling adaptors. Here, we present data demonstrating that signaling pathways initiated from the membrane-bound form of B-cell activating factor (BAFF) can crosstalk with lipopolysaccharide (LPS)-induced signaling for synergistic expression of proinflammatory mediators in the human macrophage-like cell line THP-1. Co-treatment of the cells with BAFF-specific monoclonal antibody and LPS resulted in enhanced mitogen-activated protein kinase (MAPK)/mitogen- and stress-activated protein kinase (MSK)-mediated phosphorylation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) p65 subunit (Ser276), which then interacts with CREB binding protein (CBP) for subsequent acetylation. Simultaneously, the phosphorylation of cyclic AMP-response element binding protein (CREB) was enhanced through the combined action of phosphatidylinositol-3-kinase (PI3K)/AKT and MAPK/MSK pathways, and the resulting phospho-CREB interacted with the NF-κB/CBP complex. Transfection of CREB-specific siRNA inhibited the BAFF-mediated enhancing effect indicating that the formation of the CREB/NF-κB/CBP complex is required for the synergistic induction of the proinflammatory genes. These findings indicate that BAFF-mediated reverse signaling can modulate LPS-induced inflammatory activation through regulation of NF-κB and CREB activity and point out the necessity to re-evaluate the role of BAFF in diseases where its expression is high in macrophages.

Spotlight on blisibimod and its potential in the treatment of systemic lupus erythematosus: evidence to date

B cells in general and BAFF (B cell activating factor of the tumor necrosis factor [TNF] family) in particular have been primary targets of recent clinical trials in systemic lupus erythematosus (SLE). In 2011, belimumab, a monoclonal antibody against BAFF, became the first biologic agent approved for the treatment of SLE. Follow-up studies have shown excellent long-term safety and tolerability of belimumab. In this review, we critically analyze blisibimod, a novel BAFF-neutralizing agent. In contrast to belimumab that only blocks soluble BAFF trimer but not soluble 60-mer or membrane BAFF, blisibimod blocks with high affinity all three forms of BAFF. Furthermore, blisibimod has a unique structure built on four high-affinity BAFF-binding peptides fused to the IgG1-Fc carrier. It was tested in phase I and II trials in SLE where it showed safety and tolerability. While it failed to reach the primary endpoint in a recent phase II trial, post hoc analysis demonstrated its efficacy in SLE patients with higher disease activity. Based on these results, blisibimod is currently undergoing phase III trials targeting this responder subpopulation of SLE patients. The advantage of blisibimod, compared to its competitors, lies in its higher avidity for BAFF, but a possible drawback may come from its immunogenic potential and the anticipated loss of efficacy over time.

Thymic Germinal Centers and Corticosteroids in Myasthenia Gravis: an Immunopathological Study in 1035 Cases and a Critical Review

The most common form of Myasthenia gravis (MG) is due to anti-acetylcholine receptor (AChR) antibodies and is frequently associated with thymic pathology. In this review, we discuss the immunopathological characteristics and molecular mechanisms of thymic follicular hyperplasia, the effects of corticosteroids on this thymic pathology, and the role of thymic epithelial cells (TEC), a key player in the inflammatory thymic mechanisms. This review is based not only on the literature data but also on thymic transcriptome results and analyses of pathological and immunological correlations in a vast cohort of 1035 MG patients without thymoma. We show that among patients presenting a thymic hyperplasia with germinal centers (GC), 80 % are females, indicating that thymic follicular hyperplasia is mainly a disease of women. The presence of anti-AChR antibodies is correlated with the degree of follicular hyperplasia, suggesting that the thymus is a source of anti-AChR antibodies. The degree of hyperplasia is not dependent upon the time from the onset, implying that either the antigen is chronically expressed and/or that the mechanisms of the resolution of the GC are not efficiently controlled. Glucocorticoids, a conventional therapy in MG, induce a significant reduction in the GC number, together with changes in the expression of chemokines and angiogenesis. These changes are likely related to the acetylation molecular process, overrepresented in corticosteroid-treated patients, and essential for gene regulation. Altogether, based on the pathological and molecular thymic abnormalities found in MG patients, this review provides some explanations for the benefit of thymectomy in early-onset MG patients.

Absent in Melanoma 2 proteins in SLE

Type I interferons (IFN-α/β)-inducible PYRIN and HIN domain-containing protein family includes Absent in Melanoma 2 (murine Aim2 and human AIM2), murine p202, and human PYRIN-only protein 3 (POP3). The generation of Aim2-deficient mice indicated that the Aim2 protein is essential for inflammasome activation, resulting in the secretion of interleukin-1β (IL-1β) and IL-18 and cell death by pyroptosis. Further, Aim2-deficiency also increased constitutive expression of the IFN-β and expression of the p202 protein. Notably, an increased expression of p202 protein in female mice associated with the development of systemic lupus erythematosus (SLE). SLE in patients is characterized by a constitutive increase in serum levels of IFN-α and an increase in the expression IFN-stimulated genes. Recent studies indicate that p202 and POP3 proteins inhibit activation of the Aim2/AIM2 inflammasome and promote IFN-β expression. Therefore, we discuss the role of Aim2/AIM2 proteins in the suppression of type I IFNs production and lupus susceptibility.

Gender-Specific Mechanisms Underlying the Amelioration of High-Fat Diet-Induced Glucose Intolerance in B-Cell-Activating Factor Deficient Mice

It has recently been found that B cell activating factor (BAFF) plays an important role in the regulation of energy homeostasis. We also have previously reported that BAFF deficiency reverses high-fat (HF) diet-induced glucose intolerance by potentiating adipose tissue function. In the present study, we found that BAFF deficient (BAFF^-/-) mice exhibit gender-specific differences in protection against diet-induced glucose intolerance, and aimed to characterize the gender-dependent molecular alterations in energy metabolism. Under HF feeding conditions, serum BAFF level of female wild-type (WT) mice was considerably higher than that of male mice. Despite increased body weight gain, both male and female BAFF^-/- mice showed significantly improved glucose tolerance compared to their WT counterparts. Expressions of genes involved in glucose transport, thermogenesis and lipid oxidation were up-regulated in brown adipose tissues of both male and female BAFF^-/- mice. Interestingly, the expression of thermogenic genes in subcutaneous adipose tissue was significantly enhanced in female BAFF^-/- compared to WT mice, but the difference was not observed between male BAFF^-/- and WT mice. The enhanced thermogenic program was confirmed by higher protein levels of UCP1 and irisin in female BAFF^-/- than in WT mice. Additionally, adiponectin production in white adipose tissues and AMPK phosphorylation in subcutaneous adipose tissue were also significantly elevated in female BAFF^-/- compared to WT mice, but not in male BAFF^-/- mice. Our findings define a comprehensive scenario for the enhancing effect of BAFF depletion on glucose tolerance wherein the underlying mechanism is, at least in part, gender-specific, and suggest that gender difference should be considered as an important factor in the use of BAFF blockade as a therapeutic approach for the prevention and treatment of type 2 diabetes.

Serum BAFF and thyroid autoantibodies in autoimmune thyroid disease

BACKGROUND

This study investigated the association of serum B-lymphocyte activating factor (BAFF) levels with autoimmune thyroid disease (AITD) in a Chinese population.

MATERIALS AND METHODS

We enrolled 221 patients with AITD [170 patients with Graves' disease (GD), 51 patients with Hashimoto's thyroiditis (HT)], and 124 healthy controls. Serum BAFF levels, thyroid function and thyroid autoantibody (TAb) levels, including of thyroid-stimulating hormone receptor antibody (TSHRAb), anti-thyroid peroxidase antibody (Anti-TPO Ab), and antithyroglobulin antibody (ATA), were measured at baseline.

RESULTS

Serum BAFF levels were higher in the GD, HT, and AITD groups than in the control group. Significant correlations were observed between BAFF and TSHRAb levels (r=0.238, p=0.018), between BAFF and Anti-TPO Ab levels (p=0.038), and between BAFF and ATA titers (p=0.025) in women but not in men. In addition, serum BAFF levels were significantly associated with free thyroxine (r=0.430, p=0.004) and TSHRAb (r=0.495, p=0.001) levels in women with active GD but not in those with inactive GD.

CONCLUSIONS

Serum BAFF levels are increased in GD, HT, and AITD. The correlation between serum BAFF and TAb levels exhibits a dimorphic pattern, particularly in active GD.

Blisibimod for treatment of systemic lupus erythematosus: with trials you become wiser

INTRODUCTION

Blisibimod is a potent and selective inhibitor of B cell activating factor (BAFF), a mediator of differentiation, maturation and survival of B cells. It has a unique tetravalent, 'peptibody' structure and resulting high potency, and is currently in clinical evaluation for the treatment of SLE. The importance of BAFF in the pathogenesis of systemic lupus erythematosus (SLE) is under intense investigation. The anti BAFF monoclonal antibody belimumab was approved by the FDA for the treatment of SLE.

AREAS COVERED

The general properties of blisibimod are reviewed including pharmacokinetic and pharmacodynamic properties in patients with SLE, efficacy and safety in the phase 2 PEARL-SC and open-label extension trials, and the focus in the ongoing phase 3 trial (CHABLIS-SC1) on the hypothesized 'responder' population. In addition, the rationale for evaluating blisibimod in patients with IgA nephropathy, a common nephritic disease for which there is no approved therapy, is presented.

EXPERT OPINION

Blisibimod's unique tetravalent, peptibody structure and resulting high potency, and the deliberate focus of the Phase 3 clinical development program on the 'responder populations' identified in completed trials in SLE raise the possibility that blisibimod will become an important medication for treatment of SLE and IgA nephropathy.

Hormonal Modulation of Dendritic Cells Differentiation, Maturation and Function: Implications for the Initiation and Progress of Systemic Autoimmunity

Hormonal homeostasis is crucial for keeping a competent and healthy immune function. Several hormones can modulate the function of various immune cells such as dendritic cells (DCs) by influencing the initiation of the immune response and the maintenance of peripheral tolerance to self-antigens. Hormones, such as estrogens, prolactin, progesterone and glucocorticoids may profoundly affect DCs differentiation, maturation and function leading to either a pro-inflammatory or an anti-inflammatory (or tolerogenic) phenotype. If not properly regulated, these processes can contribute to the pathogenesis of autoimmune disease. An unbalanced hormonal status may affect the production of pro-inflammatory cytokines, the expression of activating/inhibitory receptors and co-stimulatory molecules on conventional and plasmacytoid DCs (pDCs), conferring susceptibility to develop autoimmunity. Estrogen receptor (ER)-α signaling in conventional DCs can promote IFN-α and IL-6 production and induce the expression of CD40, CD86 and MHCII molecules. Furthermore, estrogen modulates the pDCs response to Toll-like receptor ligands enhancing T cell priming. During lupus pathogenesis, ER-α deficiency decreased the expression of MHC II on pDCs from the spleen. In contrast, estradiol administration to lupus-prone female mice increased the expression of co-stimulatory molecules, enhanced the immunogenicity and produced large amounts of IL-6, IL-12 and TNF-α by bone marrow-derived DCs. These data suggest that estradiol/ER signaling may play an active role during lupus pathology. Similarly, understanding hormonal modulation of DCs may favor the design of new therapeutic strategies based on autologous tolerogenic DCs transfer, especially in sex-biased systemic autoimmune diseases. In this review, we discuss recent data relative to the role of different hormones (estrogen, prolactin, progesterone and glucocorticoids) in DC function during systemic autoimmune pathogenesis.

BAFF Expression is Modulated by Female Hormones in Human Immune Cells

Among several autoimmune diseases, one of the main risk factors is the female gender, and much consideration has been given to the involvement of female hormones in their etiology. B-cell activating factor (BAFF) is a key factor in survival and maturation of B cells and is overexpressed in several autoimmune patients although the mechanism behind this feature is unclear. In murine models, BAFF expression could be upregulated by exogenous estrogen treatment in splenocytes; however, no evidence of this relationship was available in humans. Here, leukocytes from healthy male and female individuals were collected and cultivated in the presence or absence of estrogen or progesterone. BAFF gene expression was accessed by quantitative PCR and compared between treated and untreated group of cells. In the presence of estrogen, BAFF expression was upregulated by more than 5 times in both genders. When exposed to progesterone, the female-originated cells showed increased expression, while the cells of male origin a significant downregulation of BAFF. Our results suggest that female hormones can modulate the expression of BAFF, a key cytokine in autoimmune pathways, in human immune cells. These data might contribute to the understanding of the etiology as well as the gender bias featured by several autoimmune disorders.