IL-10 producing regulatory and helper T-cells in systemic lupus erythematosus

Type 2 hypersensitivity disorders, including systemic lupus erythematosus, Sjögren's syndrome, Graves' disease, myasthenia gravis, immune thrombocytopenia, autoimmune hemolytic anemia, dermatomyositis, and graft-versus-host disease, are THαβ-dominant autoimmune diseases

The THαβ host immunological pathway contributes to the response to infectious particles (viruses and prions). Furthermore, there is increasing evidence for associations between autoimmune diseases, and particularly type 2 hypersensitivity disorders, and the THαβ immune response. For example, patients with systemic lupus erythematosus often produce anti-double stranded DNA antibodies and anti-nuclear antibodies and show elevated levels of type 1 interferons, type 3 interferons, interleukin-10, IgG1, and IgA1 throughout the disease course. These cytokines and antibody isotypes are associated with the THαβ host immunological pathway. Similarly, the type 2 hypersensitivity disorders myasthenia gravis, Graves' disease, graft-versus-host disease, autoimmune hemolytic anemia, immune thrombocytopenia, dermatomyositis, and Sjögren's syndrome have also been linked to the THαβ pathway. Considering the potential associations between these diseases and dysregulated THαβ immune responses, therapeutic strategies such as anti-interleukin-10 or anti-interferon α/β could be explored for effective management.

IL-10: A Key Regulator and potential therapeutic target in uveitis

Uveitis is a prevalent inflammatory eye disease that primarily affects working-age individuals and can lead to blindness if untreated. Interleukin-10 (IL-10) is a multifunctional cytokine with broad immunosuppressive properties and plays a significant role in various pathological and physiological processes. However, its specific role and underlying mechanisms in uveitis remain incompletely understood. This review aims to shed light on the biological characteristics of IL-10, its involvement in the uveitis pathophysiology, and its potential as a novel therapeutic target. By examining existing literature, the review analyzes IL-10 expression levels and regulatory mechanisms in different types of uveitis, discussing its role in immune regulation. Despite IL-10 being expressed variably across various forms of autoimmune uveitis, studies consistently highlight its protective role, prompting research into ways to enhance its bioavailability in the eye. IL-10 is often upregulated in infectious uveitis, contributing to pathogen immune evasion. Furthermore, primary intraocular lymphoma (PIOL), which shares clinical similarities with uveitis, also shows upregulated IL-10 levels, whereas IL-6 is more commonly elevated in uveitis. This differential expression suggests that IL-6 and IL-10 could be diagnostic markers to distinguish between PIOL and uveitis. Future research should continue to focus on elucidating the molecular mechanisms of IL-10 in uveitis, exploring its potential therapeutic applications, and developing targeted treatments that leverage the immunomodulatory effects of IL-10 to prevent and manage this sight-threatening condition.

Characterization of Tissue Immunity Defense Factors of the Lip in Primary Dentition Children with Bilateral Cleft Lip Palate

BACKGROUND

Bilateral cleft lip palate is a severe congenital birth defect of the mouth and face. Immunity factors modulate immune response, inflammation, and healing; therefore, they are vital in the assessment of the immunological status of the patient. The aim of this study is to assess the distribution of Gal-10, CD-163, IL-4, IL-6, IL-10, HBD-2, HBD-3, and HBD-4 in tissue of the bilateral cleft lip palate in primary dentition children.

METHODS

Five patients underwent cheiloplasty surgery, where five tissue samples of lip were obtained. Immunohistochemical staining, semi-quantitative evaluation, and non-parametric statistical analysis were used.

RESULTS

A statistically significant increase in HBD-2, HBD-3, and HBD-4 was found in skin and mucosal epithelium, hair follicles, and blood vessels. A notable increase was also noted in IL-4, IL-6, and IL-10 in the mucosal epithelium and CD163 in blood vessels. The connective tissue of patients presented with a statistically significant decrease in Gal-10, IL-10, and HBD-3. Spearman's rank correlation revealed multiple significant positive and negative correlations between the factors.

CONCLUSIONS

Upregulation of CD163 points to increased angiogenesis but the increase in IL-4 and IL-10 as well as the decrease in Gal-10 points to suppression of excessive inflammatory damage. Decreased connective tissue healing and excessive scarring are suggested by the decrease in HBD-3 and IL-10 and the increase in IL-6.

Gene profiling of Epstein-Barr Virus and human endogenous retrovirus in peripheral blood mononuclear cells of SLE patients: immune response implications

Systemic lupus erythematosus (SLE) is a multifactorial disease characterized by the convergence of genetic, immunological, and viral elements resulting in a complex interaction of both internal and external factors. The role of the Epstein-Barr virus (EBV) and human endogenous retroviruses (HERV-E) as triggers and maintenance elements in the pathogenesis of SLE has been widely recognized. Previous studies have independently evaluated the effects of EBV and HERV-E in this disease. In this work, for the first time, these viral factors are jointly investigated in SLE patients. This study aimed at assessing the differential expression of immune regulatory genes and the incidence of specific viral pathogens (EBV and HERV-E), alongside the detailed characterization of surface markers in T- and B-lymphocytes in patients with SLE and control participants. A comparative analysis between patients with SLE and control participants was performed, evaluating the expression of phenotypic markers and genes involved in the immune response (TNF-α, IL-2, IL-6, IL-10, IFNG, TLR3), as well as HERV-E gag and EBV viral genes (LMP1 and BZLF1).A significant association between SLE and EBV was found in this study. A notable increase in EBV LMP1 gene expression was observed in patients with SLE . Also, a significant overexpression of HERV-E was observed, in addition to a considerable increase in the distribution of the cell surface marker CD27 + on T- and B-lymphocytes, observed in individuals with SLE compared to the control group. This study provides evidence regarding the role that EBV virus plays in lymphocytes in the context of SLE, highlighting how both the virus and the host gene expression may influence disease pathogenesis by altering immune regulatory pathways mediated by TNF-α, IFN-γ, and IL-10, as well as parallel overexpression of HERV-E gag. The decrease in TLR3 could indicate a compromised antiviral response, which could facilitate viral reactivation and contribute to disease activity.

Small extracellular vesicle-based delivery of interleukin-10 improves treatment of experimental autoimmune uveitis

Non-infectious uveitis is an intraocular autoimmune disease mainly characterized by immune dysregulation of the eye, which may cause blindness if not well treated. Interleukin 10 (IL-10) is a potent cytokine with multiple immunoregulatory functions. However, it's in vivo activity is unstable owing to its inherent protein instability and short plasma half-life. Therefore, our previous research tried to establish IL-10-overexpressing MSC-sEVs (sEVs-IL10) using lentiviral transfection. While this approach indeed improved drug delivery, it also suffered from tedious procedures and limited loading efficiency. Accordingly, we constructed a novel MSC-sEVs-based delivery system for IL-10 (IL-10@sEVs) by sonication. The obtained formulation (IL-10@sEVs) had relatively higher loading efficiency and exerted a more profound immunomodulatory effect than sEVs-IL10 in vitro. Furthermore, IL-10@sEVs had significant therapeutic effects in a mouse model of experimental autoimmune uveitis (EAU) by decreasing the percentage of Th17 cells, increasing regulatory T cells in the eye, and draining lymph nodes. In summary, sonication outperforms conventional transfection methods for loading IL-10 into MSC-sEVs.

The Role of TLR7 and TLR9 in the Pathogenesis of Systemic Sclerosis

The bleomycin-induced scleroderma model is a well-established and dependable method for creating a mouse model of SSc (systemic sclerosis). In the field of skin connective tissue diseases, increasing evidence from clinical and animal experiments suggests that TLRs (Toll-like receptors) play an important role in several diseases. This study aimed to determine the role of TLR7 (Toll-like receptor 7) and TLR9 (Toll-like receptor 9) in the mechanisms of immune abnormalities and fibrosis in SSc. This study used TLR7-KO mice (TLR7-knockout mice with a balb/c background) and TLR9-KO mice (TLR9-knockout mice with a balb/c background) as well as WT mice (wild-type balb/c mice). All three kinds of mice were induced by BLM (bleomycin) in a scleroderma model as the experimental group; meanwhile, WT mice treated with PBS (phosphate-buffered saline) were used as the control group. We analyzed the fibrotic phenotype and the immunological abnormality phenotype of TLR7-deficient and TLR9-deficient mice in the SSc disease model using flow cytometry, RT-PCR (reverse transcription-polymerase chain reaction), a histological examination, and IHC (immunohistochemical staining). In a mouse model of SSc disease, the deletion of TLR7 attenuated skin and lung fibrosis, while the deletion of TLR9 exacerbated skin and lung fibrosis. The deletion of TLR7 resulted in a relative decrease in the infiltration and expression of various pro-inflammatory and fibrotic cells and cytokines in the skin. On the other hand, the deletion of TLR9 resulted in a relative increase in the infiltration and expression of various pro-inflammatory and cytokine-inhibiting cells and cytokines in the skin. Under the influence of pDCs (plasmacytoid dendritic cells), the balances of Beff/Breg (IL-6 + CD19 + B cell/IL-10 + CD19 + B cell), Th17/Treg (IL-17A + CD4 + T cell/Foxp3 + CD25 + CD4 + T cell), M1/M2 (CD86 + macrophage/CD206 + macrophage), and Th1/Th2 (TNFα + CD3 + CD4 + T cell/IL-4 + CD3 + CD4 + T cell) were biased towards the suppression of inflammation and fibrosis as a result of the TLR7 deletion. Comparatively, the balance was biased towards promoting inflammation and fibrosis due to the TLR9 deletion. In the SSc model, TLR7 promoted inflammation and fibrosis progression, while TLR9 played a protective role. These results suggest that TLR7 and TLR9 play opposite roles in triggering SSc to produce immune system abnormalities and skin fibrosis.

Deciphering disulfidptosis: Uncovering a lncRNA-based signature for prognostic assessment, personalized immunotherapy, and therapeutic agent selection in lung adenocarcinoma patients

BACKGROUND

Disulfidptosis, a recently identified type of regulated cell death, plays critical roles in various biological processes of cancer; however, whether they can impact the prognosis of lung adenocarcinoma (LUAD) remains to be fully elucidated. We aimed to adopt this concept to develop and validate a lncRNA signature for LUAD prognostic prediction.

METHODS

For this study, the TCGA-LUAD dataset was used as the training cohort, and multiple datasets from the GEO database were pooled as the validation cohort. Disulfidptosis regulated genes were obtained from published studies, and various statistical methods, including Kaplan-Meier (KM), Cox, and LASSO, were used to train our gene signature DISULncSig. We utilized KM analysis, COX analysis, receiver operating characteristic analysis, time-dependent AUC analysis, principal component analysis, nomogram predictor analysis, and functional assays in our validation process. We also compared DISULncSig with previous studies. We performed analyses to evaluate DISULncSig's immunotherapeutic ability, focusing on eight immune algorithms, TMB, and TIDE. Additionally, we investigated potential drugs that could be effective in treating patients with high-risk scores. Additionally qRT-PCR examined the expression patterns of DISULncSig lncRNAs, and the ability of DISULncSig in pan-cancer was also assessed.

RESULTS

DISULncSig containing twelve lncRNAs was trained and showed strong predictive ability in the validation cohort. Compared with previous similar studies, DISULncSig had more prognostic ability advantages. DISULncSig was closely related to the immune status of LUAD, and its tight relationship with checkpoints KIR2DL3, IL10, IL2, CD40LG, SELP, BTLA, and CD28 may be the key to its potential immunotherapeutic ability. For the high DISULncSig score population, we found ten drug candidates, among which epothilone-b may have the most potential. The pan-cancer analysis found that DISULncSig was a risk factor in multiple cancers. Additionally, we discovered that some of the DISULncSig lncRNAs could play crucial roles in specific cancer types.

CONCLUSION

The current study established a powerful prognostic DISULncSig signature for LUAD that was also valid for most pan-cancers. This signature could serve as a potential target for immunotherapy and might help the more efficient application of drugs to specific populations.

Dietary tryptophan and genetic susceptibility expand gut microbiota that promote systemic autoimmune activation

Tryptophan modulates disease activity and the composition of microbiota in the B6.Sle1.Sle2.Sle3 (TC) mouse model of lupus. To directly test the effect of tryptophan on the gut microbiome, we transplanted fecal samples from TC and B6 control mice into germ-free or antibiotic-treated non-autoimmune B6 mice that were fed with a high or low tryptophan diet. The recipient mice with TC microbiota and high tryptophan diet had higher levels of immune activation, autoantibody production and intestinal inflammation. A bloom of Ruminococcus gnavus (Rg), a bacterium associated with disease flares in lupus patients, only emerged in the recipients of TC microbiota fed with high tryptophan. Rg depletion in TC mice decreased autoantibody production and increased the frequency of regulatory T cells. Conversely, TC mice colonized with Rg showed higher autoimmune activation. Overall, these results suggest that the interplay of genetic and tryptophan can influence the pathogenesis of lupus through the gut microbiota.

Vitamin D3 mitigates autoimmune inflammation caused by activation of myeloid dendritic cells in SLE

Systemic lupus erythematosus (SLE) is an autoimmune disease in which defective T cells, immune complex deposition and other immune system alterations contribute to pathological changes of multiple organ systems. The vitamin D metabolite c is a critical immunomodulator playing pivotal roles in the immune system. Epidemiological evidence indicates that vitamin D deficiency is correlated with the severity of SLE. Our aim is to investigate the effects of 1,25(OH)2D3 (VitD3) on the activation of myeloid dendritic cells (mDCs) by autologous DNA-containing immune complex (DNA-ICs), and the effects of VitD3 on immune system balance during SLE. We purified DNA-ICs from the serum of SLE patients and isolated mDCs from normal subjects. In vitro studies showed that DNA-ICs were internalized and consumed by mDCs. VitD3 blocked the effects of DNA-ICs on RelB, IL-10 and TNF-α in mDCs. Further analysis indicated that DNA-ICs stimulated histone acetylation in the RelB promoter region, which was inhibited by VitD3. Knockdown of the histone deacetylase 3 gene (HDAC3) blocked these VitD3-mediated effects. Co-culture of mDCs and CD4+ T cells showed that VitD3 inhibited multiple processes mediated by DNA-ICs, including proliferation, downregulation of IL-10, TGF-β and upregulation of TNF-α. Moreover, VitD3 could also reverse the effects of DNA-IC-induced imbalance of CD4+  CD127-  Foxp3+ T cells and CD4+  IL17+ T cells. Taken together, our results indicated that autologous DNA-ICs stimulate the activation of mDCs in the pathogenesis of SLE, and VitD3 inhibits this stimulatory effects of DNA-ICs by negative transcriptional regulation of RelB gene and maintaining the Treg/Th17 immune cell balance. These results suggest that vitamin D may have therapeutic value for the treatment of SLE.

Regulation of the STAT3 pathway by lupus susceptibility gene Pbx1 in T cells

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease in which poorly characterized genetic factors lead to the production of proinflammatory or autoreactive T cells. Pre-B cell leukemia homeobox 1 (PBX1) is a transcription factor whose dominant negative isoform (PBX1-D) is overexpressed in the CD4+ T cells of SLE patients and lupus-prone mice. Pbx1-D overexpression favors the expansion of proinflammatory T cells and impairs regulatory T (Treg) cell development. Here we show that Pbx1 deficiency and Pbx1-D overexpression decreased STAT3 expression and activation in T cells. Accordingly, Pbx1 deficiency in T cells and Pbx1-D overexpression reduced STAT3-dependent TH17 cell polarization in vitro, but it had no effect in vivo at steady state. STAT3-dependent follicular helper T (TFH) cell polarization in vitro and splenic TFH cell frequency were not affected by either Pbx1 deficiency or Pbx1-D overexpression. Pbx1 deficiency also increased the expression of cell cycle arrest and pro-apoptotic genes, with an increased apoptosis in T cells. Our results suggest a complex interplay between PBX1 and STAT3, which may contribute to lupus pathogenesis through dysregulation of the cell cycle and apoptosis.

The effects of Lactobacillus delbrueckii and Lactobacillus rhamnosus on cytokines and their related molecules: An ex vivo study on patients with systemic lupus erythematosus

Objectives

This study aimed to assess the ex vivo impact of Lactobacillus delbrueckii (L. delbrueckii) and Lactobacillus rhamnosus (L. rhamnosus) on inflammatory and anti-inflammatory cytokines as well as their related molecules on the peripheral blood mononuclear cells (PBMCs) of systemic lupus erythematosus (SLE) patients.

Patients and methods

This study was conducted with 20 newly diagnosed SLE patients (18 females, 2 males; mean age: 33.3±12.4 years; range, 18 to 68 years) between September 2017 and September 2018. Extracted PBMCs from each patient were divided into 4 cell groups in our study. Three cell groups act as treatment groups receiving L. rhamnosus (107 CFU/mL), L. delbrueckii (105 CFU/mL) or a mixture of both, and one group act as our untreated control group in the absence of any probiotic agents. All cell groups were cultured in RPMI 1460 medium for 48 h. Then, total RNA was extracted, and cDNA was synthesized.

Results

The gene expression levels of forkhead box P3 (FOXP3), transforming growth factor beta (TGF-β), interleukin (IL)-6, IL-10, and IL-2 were evaluated by a quantitative real-time polymerase chain reaction. The results revealed that expression levels of FOXP3, TGF-β, IL-10, and IL-2 increased and the level of IL-6 decreased in probiotics-receiving groups compared to the control group. Lactobacillus delbrueckii and L. rhamnosus enhanced the expression of regulatory T cell-related molecules such as FOXP3 and IL-2 and also increased the expression of IL-10. These probiotics also reduced the expression of IL-6 as proinflammatory cytokines in the PBMCs of SLE patients.

Conclusion

The results of the present study show that these probiotics could be effective in regulating the balance of cytokine gene expression ex vivo , and due to their beneficial effects, they can be an intriguing option in the production of new complement drugs for SLE.

Crosstalk between copper homeostasis and cuproptosis reveals a lncRNA signature to prognosis prediction, immunotherapy personalization, and agent selection for patients with lung adenocarcinoma

BACKGROUND

Copper homeostasis and cuproptosis play critical roles in various biological processes of cancer; however, whether they can impact the prognosis of lung adenocarcinoma (LUAD) remain to be fully elucidated. We aimed to adopt these concepts to create and validate a lncRNA signature for LUAD prognostic prediction.

METHODS

For this study, the TCGA-LUAD dataset was used as the training cohort, and multiple datasets from the GEO database were pooled as the validation cohort. Copper homeostasis and cuproptosis regulated genes were obtained from published studies, and various statistical methods, including Kaplan-Meier (KM), Cox, and LASSO, were used to train our gene signature CoCuLncSig. We utilized KM analysis, COX analysis, receiver operating characteristic analysis, time-dependent AUC analysis, principal component analysis, and nomogram predictor analysis in our validation process. We also compared CoCuLncSig with previous studies. We performed analyses using R software to evaluate CoCuLncSig's immunotherapeutic ability, focusing on eight immune algorithms, TMB, and TIDE. Additionally, we investigated potential drugs that could be effective in treating patients with high-risk scores. Additionally qRT-PCR examined the expression patterns of CoCuLncSig lncRNAs, and the ability of CoCuLncSig in pan-cancer was also assessed.

RESULTS

CoCuLncSig containing eight lncRNAs was trained and showed strong predictive ability in the validation cohort. Compared with previous similar studies, CoCuLncSig had more prognostic ability advantages. CoCuLncSig was closely related to the immune status of LUAD, and its tight relationship with checkpoints IL10, IL2, CD40LG, SELP, BTLA, and CD28 may be the key to its potential immunotherapeutic ability. For the high CoCuLncSig score population, we found 16 drug candidates, among which epothilone-b and gemcitabine may have the most potential. The pan-cancer analysis found that CoCuLncSig was a risk factor in multiple cancers. Additionally, we discovered that some of the CoCuLncSig lncRNAs could play crucial roles in specific cancer types.

CONCLUSION

The current study established a powerful prognostic CoCuLncSig signature for LUAD that was also valid for most pan-cancers. This signature could serve as a potential target for immunotherapy and might help the more efficient application of drugs to specific populations.

Extranodal lymphoma: pathogenesis, diagnosis and treatment

Approximately 30% of lymphomas occur outside the lymph nodes, spleen, or bone marrow, and the incidence of extranodal lymphoma has been rising in the past decade. While traditional chemotherapy and radiation therapy can improve survival outcomes for certain patients, the prognosis for extranodal lymphoma patients remains unsatisfactory. Extranodal lymphomas in different anatomical sites often have distinct cellular origins, pathogenic mechanisms, and clinical manifestations, significantly influencing their diagnosis and treatment. Therefore, it is necessary to provide a comprehensive summary of the pathogenesis, diagnosis, and treatment progress of extranodal lymphoma overall and specifically for different anatomical sites. This review summarizes the current progress in the common key signaling pathways in the development of extranodal lymphomas and intervention therapy. Furthermore, it provides insights into the pathogenesis, diagnosis, and treatment strategies of common extranodal lymphomas, including gastric mucosa-associated lymphoid tissue (MALT) lymphoma, mycosis fungoides (MF), natural killer/T-cell lymphoma (nasal type, NKTCL-NT), and primary central nervous system lymphoma (PCNSL). Additionally, as PCNSL is one of the extranodal lymphomas with the worst prognosis, this review specifically summarizes prognostic indicators and discusses the challenges and opportunities related to its clinical applications. The aim of this review is to assist clinical physicians and researchers in understanding the current status of extranodal lymphomas, enabling them to make informed clinical decisions that contribute to improving patient prognosis.

Elevation of Metrnβ and Its Association with Disease Activity in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an auto-immune disease, the pathogenesis of which remains to be fully addressed. Metrnβ is a novel cytokine involved in the pathogenesis of inflammatory disease, but its regulatory roles in SLE are unclear. We aimed to comprehensively investigate the clinical value of Metrnβ in SLE. A massive elevation of circulating Metrnβ levels was observed in SLE, and patients with an active phase displayed higher Metrnβ concentrations than those with inactive phases. Additionally, we found that Metrnβ expression was positively correlated with clinical indicators of SLE. Longitudinal cytokine and chemokine profiles revealed a disturbed immune response in SLE, with high activity profiles displayed severe pathogenic inflammation, and a positive correlation of the serum Metrnβ with CXCL9, IL10, IL18 and IL1RA was observed as well. Moreover, Metrnβ expressions exhibited an inverse correlation with Treg and B10. Of note, a significant decrease of ILC2 was found in SLE, and there was a negative correlation of Metrnβ with ILC2 as well. Further ROC analysis showed that the area under the curve (AUC) for Metrnβ was 0.8250 (95% CI: 0.7379-0.9121), with a cutoff value of 1131 pg/mL to effectively distinguish SLE patients from healthy controls. Our study herein demonstrated for the first time that Metrnβ values were increased and were immunologically correlated with SLE activity, which could be utilized as an alternative biomarker for the early identification and predicting of the immuno-response of SLE.

Circulating miR-21 Overexpression Correlates with PDCD4 and IL-10 in Systemic Lupus Erythematosus (SLE): A Promising Diagnostic and Prognostic Biomarker

Background

Systemic Lupus Erythematosus (SLE) is a chronic autoimmune condition that affects multiple organs significantly impacts morbidity and mortality. The development of SLE is influenced by genetic predisposition and dysregulated immune response. Our objective was to investigate miR-21, IL-10, and PDCD4 expression in SLE patient plasma and analyze their correlations and potential diagnostic and prognostic values.

Methods

The study included 100 healthy subjects, 50 newly diagnosed (ND), and 50 under-treatment (UT) SLE patients. The patients were observed for 24 weeks to track relapses. miR-21 and PDCD4 gene expression levels were measured using real-time RT-PCR, and IL-10 production was measured using ELISA.

Results

miR-21 and IL-10 expression levels were significantly greater in SLE patients than in healthy subjects, with the highest levels observed in ND patients. PDCD4 expression was also significantly greater in SLE patients than in subjects, with the highest levels observed in UT patients. ROC curve analyses and Cox-Mantel Log-rank tests indicated miR-21, PDCD4, and IL-10 as proper diagnostic and prognostic biomarkers for SLE. The study also revealed a significant positive correlation between miR-21 and PDCD4 and IL-10 levels in SLE patients.

Conclusions

The studies suggest that dysregulation of miR-21, PDCD4, and IL-10 in patients with SLE may contribute to disease development and provides new diagnostic and prognostic markers. Additionally, the observed correlation between miR-21, PDCD4, and IL-10 levels in SLE patients signifies a potential interplay between these molecules.

Innate and Adaptive Immunity during SARS-CoV-2 Infection: Biomolecular Cellular Markers and Mechanisms

The coronavirus 2019 (COVID-19) pandemic was caused by a positive sense single-stranded RNA (ssRNA) severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, other human coronaviruses (hCoVs) exist. Historical pandemics include smallpox and influenza, with efficacious therapeutics utilized to reduce overall disease burden through effectively targeting a competent host immune system response. The immune system is composed of primary/secondary lymphoid structures with initially eight types of immune cell types, and many other subtypes, traversing cell membranes utilizing cell signaling cascades that contribute towards clearance of pathogenic proteins. Other proteins discussed include cluster of differentiation (CD) markers, major histocompatibility complexes (MHC), pleiotropic interleukins (IL), and chemokines (CXC). The historical concepts of host immunity are the innate and adaptive immune systems. The adaptive immune system is represented by T cells, B cells, and antibodies. The innate immune system is represented by macrophages, neutrophils, dendritic cells, and the complement system. Other viruses can affect and regulate cell cycle progression for example, in cancers that include human papillomavirus (HPV: cervical carcinoma), Epstein-Barr virus (EBV: lymphoma), Hepatitis B and C (HB/HC: hepatocellular carcinoma) and human T cell Leukemia Virus-1 (T cell leukemia). Bacterial infections also increase the risk of developing cancer (e.g., Helicobacter pylori). Viral and bacterial factors can cause both morbidity and mortality alongside being transmitted within clinical and community settings through affecting a host immune response. Therefore, it is appropriate to contextualize advances in single cell sequencing in conjunction with other laboratory techniques allowing insights into immune cell characterization. These developments offer improved clarity and understanding that overlap with autoimmune conditions that could be affected by innate B cells (B1+ or marginal zone cells) or adaptive T cell responses to SARS-CoV-2 infection and other pathologies. Thus, this review starts with an introduction into host respiratory infection before examining invaluable cellular messenger proteins and then individual immune cell markers.

Interrelation of T cell cytokines and autoantibodies in systemic lupus erythematosus: A cross-sectional study

T-helper cytokines interferon gamma (IFNɣ), interleukin 17 (IL-17) and IL-10 impact systemic lupus erythematosus (SLE) directly and indirectly via modulation of autoAb production. We determined the separate and combined effects on clinical manifestations of SLE (N = 62). IFNɣ, IL-17 but not IL-10 were significantly elevated in patients with SLE. IFNɣ positively correlated with anti-DNA and anti-SSA. IL-17 positively correlated with anti-SSA and was significantly higher in patients with discoid rash and class V LN. IL-10 did not correlate with circulating autoantibodies but was significantly elevated in patients with LN. Patients with LN had elevated plasma levels of anti-DNA and anti-Sm/ribonuclear protein (RNP). Anti-Sm/RNP levels were decreased in patients with acute mucocutaneous manifestations, including photosensitivity and/or malar rash. The study provides critical insights into pathological mechanisms of LN, which could help guide future diagnoses and therapies.

Updated insight into the role of Th2-associated immunity in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease with multiple organs involvement, abundant autoantibodies, complement activation, and immune complexes depositions. By regulating inflammation and immune homeostasis, cytokines have been well documented to participate in the pathogenesis of SLE. A number of studies have shown that T helper 2 (Th2)-associated immunity plays an important role in autoimmune diseases, including SLE. Key molecules underlying Th2-related immunity are expected to serve as promising targets for the diagnosis and targeted treatment of SLE. Current progress in SLE pathogenesis and biological treatment strategies has been reviewed, focusing on the latest development in Th2-associated immunity.

Safe Introduction of Hydroxychloroquine Focusing on Early Intolerance Due to Adverse Drug Reactions in Patients with Systemic Lupus Erythematosus

Objective This study explored the predictors of hydroxychloroquine intolerance and propose appropriate methods to initiate hydroxychloroquine in patients with systemic lupus erythematosus. Methods This retrospective study registered consecutive patients who were diagnosed with systemic lupus erythematosus and started treatment with hydroxychloroquine between 2015 and 2021. Any adverse events that required dose reduction or cessation of hydroxychloroquine, indicating intolerance to the drug, were recorded for up to 26 weeks after initiation of hydroxychloroquine. Results A total of 130 patients were included. Hydroxychloroquine intolerance due to adverse drug reactions was observed in 28 patients (21.5%), including gastrointestinal symptoms in 15 (11.5%) and cutaneous reactions in 7 (5.4%). Furthermore, the intolerance was observed more frequently in the maintenance group (patients treated daily with <20 mg prednisolone) than in the induction group (7.1% vs. 25.5%, p=0.04), and none of the patients in the induction group developed cutaneous reactions. The initial dose of hydroxychloroquine per ideal body weight was associated with hydroxychloroquine intolerance in a dose-dependent manner. Multivariable analyses revealed that the hydroxychloroquine dose per ideal body weight and higher levels of C4 predicted hydroxychloroquine intolerance. In particular, C4 levels were positively correlated with cutaneous reactions, whereas the dose of prednisolone was negatively correlated with gastrointestinal reactions. Conclusion Low-dose hydroxychloroquine may be optimal for induction in patients with systemic lupus erythematosus who have high C4 levels or are taking low doses of steroids.

IL-10 revisited in systemic lupus erythematosus

IL-10 is a cytokine with pleiotropic functions, particularly known for its suppressive effects on various immune cells. Consequently, it can limit the pathogenesis of inflammatory diseases, such as multiple sclerosis (MS), inflammatory bowel disease, Crohn’s disease, and Epidermolysis bullosa acquisita, among others. Recent evidence however indicates that it plays dual roles in Systemic lupus Erythematosus (SLE) where it may inhibit pro-inflammatory effector functions but seems to be also a main driver of the extrafollicular antibody response, outside of germinal centers (GC). In line, IL-10 promotes direct differentiation of activated B cells into plasma cells rather than stimulating a GC response. IL-10 is produced by B cells, myeloid cells, and certain T cell subsets, including extrafollicular T helper cells, which are phenotypically distinct from follicular helper T cells that are relevant for GC formation. In SLE patients and murine lupus models extrafollicular T helper cells have been reported to support ongoing extrafollicular formation of autoreactive plasma cells, despite the presence of GCs. Here, we discuss the role of IL-10 as driver of B cell responses, its impact on B cell proliferation, class switch, and plasma cells.

Comparison of Peripheral Blood Regulatory T Cells and Functional Subsets Between Ocular and Generalized Myasthenia Gravis

Purpose

This study aims to discuss the function mechanism of regulatory T cells and its subsets in the pathogenic process of myasthenia gravis by contracting the activation levels of those cells in peripheral blood among healthy people, patients with ocular myasthenia gravis (oMG) and patients with generalized myasthenia gravis (gMG).

Method

Healthy people, newly diagnosed oMG patients, and gMG patients were enrolled in this study. The percentage of the CD3⁺CD4⁺CD25⁺ Treg cells, CD3⁺CD4⁺CD25⁺Foxp3⁺ Treg cells, CD3⁺CD4⁺CD25⁺Foxp3^hi CD45RA^–aTreg cells, CD3⁺CD4⁺CD25⁺Foxp3^loCD45RA^–n-sTreg cells, and CD3⁺CD4⁺CD25⁺ Foxp3^loCD45RA⁺rTreg cells in the peripheral blood were examined by flow cytometry. And then analyzed the differences of Treg cells and its subsets among the study members.

Results

The percentage of the CD4⁺CD25⁺Treg cells in the peripheral blood of oMG patients and gMG patients were both lower than that of healthy people (p < 0.05), the percentage of patients with oMG had no distinct difference with that of patients with gMG (p = 0.475), however. Also, the percentage of CD3⁺CD4⁺CD25⁺Foxp3⁺Treg cells in the oMG and gMG patients’ group were both lower than that of healthy group. And the percentage of CD25⁺Foxp3⁺Treg cells in the peripheral blood of patients with oMG and healthy people were both higher than that of patients with gMG (p < 0.05). The percentage of rTreg in the CD3⁺CD4⁺CD25⁺Treg of the peripheral blood for both gMG and oMG patients’ group were lower than healthy group (p < 0.05), but there was no statistical significance between the oMG and gMG patients’ group (p = 0.232). The percentage of the aTreg cells in the CD3⁺CD4⁺CD25⁺Treg cells of the peripheral blood for the oMG patients was higher than that of gMG patients (p < 0.05), but both of them were lower than healthy group (p < 0.05). The percentage of n-sTreg cells in the peripheral blood descended among the gMG patients’ group, oMG patients’ group, and healthy group (p < 0.05).

Conclusion

The changes in the number and function of Treg cells and its subsets can cause the impairment of negative immune regulation, which may mediate the triggering of oMG and its progression to gMG.

Deep Phenotyping of T-Cells Derived From the Aneurysm Wall in a Pediatric Case of Subarachnoid Hemorrhage

Intracranial aneurysms (IAs) are very rare in children, and the characteristics of the T-cells in the IA wall are largely unknown. A comatose 7-years-old child was admitted to our center because of a subarachnoid hemorrhage due to a ruptured giant aneurysm of the right middle cerebral artery. Two days after the aneurysm clipping the patient was fully awake with left hemiparesis. T-cells from the IA wall and from peripheral blood of this patient were analyzed by multi-dimensional flow cytometry. Unbiased analysis, based on the use of FlowSOM clustering and dimensionality reduction technique UMAP, indicated that there was virtually no overlap between circulating and tissue-infiltrating T-cells. Thus, naïve T-cells and canonical memory T-cells were largely restricted to peripheral blood, while CD4^-CD8^-T-cells were strongly enriched in the IA wall. The unique CD4⁺, CD8⁺ and CD4^-CD8^-T-cell clusters from the IA wall expressed high levels of CCR5, Granzyme B and CD69, displaying thus characteristics of cytotoxic and tissue-resident effector cells. Low Ki67 expression indicated that they were nevertheless in a resting state. Among regulatory T-cell subsets, Eomes⁺Tr1-like cells were strongly enriched in the IA wall. Finally, analysis of cytokine producing capacities unveiled that the IA wall contained poly-functional T-cells, which expressed predominantly IFN-γ, TNF and IL-2. CD4⁺T-cells co-expressed also CD40L, and produced some IL-17, GM-CSF and IL-10. This report provides to our knowledge the first detailed characterization of the human T-cell compartment in the IA wall.

Potential role of interleukin-33 in systemic lupus erythematosus by regulating toll like receptor 4

Introduction

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by immune activation and multi-immunologic phenotypes. Interleukin-33 (IL-33) has been shown to be a critical and pleiotropic immunoregulatory mediator in the pathogenesis of many autoimmune diseases. At present, there are conflicting findings in the research of IL-33 in SLE. The purpose of this study was to investigate whether and how IL-33 is involved in the occurrence and development of SLE.

Methods

43 SLE patients and 43 healthy volunteers were recruited for this study. Serum levels of IL-33, IL-4, IL-6, IL-10 and IL-21 were measured by ELISA. The expression of IL-33 was investigated in kidney sections by immunohistochemistry in lupus nephritis patients ( n = 5) and controls ( n = 3). The mRNA expressions of Toll like receptor 4 (TLR4), TLR2, and tumorigenicity 2 (ST2)L were quantified in peripheral blood mononuclear cells (PBMCs) by real-time PCR. The surface expression of TLR4 on T cells, B cells, monocytes, and neutrophils was assessed by flow cytometry ( n = 22). Mann–Whitney U-test and Spearman’s test were used for statistical analysis.

Results

Serum concentrations of IL-33 were significantly higher in SLE patients than in healthy controls ( p < 0.0001). IL-33 expressions were positively correlated with IL-4 and IL-6 levels in SLE patients, which play pivotal roles in the autoantibody production. In addition, TLR4 and TLR2 mRNA were markedly increased in PBMCs from SLE patients ( p < 0.05). TLR4 was positively associated with IL-33, while TLR2 was not.

Conclusions

These results imply that upregulated expression of serum IL-33 together with increased TLR4 in PBMCs may contribute to the pathogenesis of SLE via promotion of inflammatory cytokines production.

Amelioration of Lupus Serum-Induced Skin Inflammation in CD64-Deficient Mice

Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disorder characterized by high autoantibodies levels and multiorgan tissue damage. The current study investigated the role of CD64 in SLE patients and animal models. According to a flow cytometry study, SLE patients showed an increase in CD64 expression in circulating monocytes. There was a correlation between CD64 and SLEDAI, blood urea nitrogen levels, and anti-Sm antibodies. In skin lesions of lupus MRL/lpr mice, there was high IgG deposition and CD64 expression. In vitro, cytokines IL-10 and IFN-γ upregulated CD64 expression in monocytes/macrophages that was inhibited by glucocorticoids. In CD64-deficient mice, skin inflammation induced by lupus serum was reduced. Furthermore, activation of spleen tyrosine kinase (Syk), Akt, and extracellular signal-regulated kinase (Erk) was inhibited in CD64-deficient monocytes. The results suggest that CD64 could be a biomarker for observing SLE progression, as well as a mechanistic checkpoint in lupus pathogenesis.

Biological impact of iberdomide in patients with active systemic lupus erythematosus

OBJECTIVES

Iberdomide is a high-affinity cereblon ligand that promotes proteasomal degradation of transcription factors Ikaros (IKZF1) and Aiolos (IKZF3). Pharmacodynamics and pharmacokinetics of oral iberdomide were evaluated in a phase 2b study of patients with active systemic lupus erythematosus (SLE).

METHODS

Adults with autoantibody-positive SLE were randomised to placebo (n=83) or once daily iberdomide 0.15 mg (n=42), 0.3 mg (n=82) or 0.45 mg (n=81). Pharmacodynamic changes in whole blood leucocytes were measured by flow cytometry, regulatory T cells (Tregs) by epigenetic assay, plasma cytokines by ultrasensitive cytokine assay and gene expression by Modular Immune Profiling.

RESULTS

Iberdomide exhibited linear pharmacokinetics and dose-dependently modulated leucocytes and cytokines. Compared with placebo at week 24, iberdomide 0.45 mg significantly (p<0.001) reduced B cells, including those expressing CD268 (TNFRSF13C) (-58.3%), and plasmacytoid dendritic cells (-73.9%), and increased Tregs (+104.9%) and interleukin 2 (IL-2) (+144.1%). Clinical efficacy was previously reported in patients with high IKZF3 expression and high type I interferon (IFN) signature at baseline and confirmed here in those with an especially high IFN signature. Iberdomide decreased the type I IFN gene signature only in patients with high expression at baseline (-81.5%; p<0.001) but decreased other gene signatures in all patients.

CONCLUSION

Iberdomide significantly reduced activity of type I IFN and B cell pathways, and increased IL-2 and Tregs, suggesting a selective rebalancing of immune abnormalities in SLE. Clinical efficacy corresponded to reduction of the type I IFN gene signature.

TRIAL REGISTRATION NUMBER

NCT03161483.

Serum cytokines are associated with n-3 polyunsaturated fatty acids and not with methylmercury measured in infant cord blood in the Seychelles child development study

BACKGROUND

Maternal fish consumption increases infant methylmercury (MeHg) exposure and polyunsaturated fatty acid (PUFA) concentrations. The n-3 PUFA are regulators of inflammation while MeHg may impact the cord cytokine profile and, subsequently, contribute to immune mediated outcomes. This study aimed to investigate associations between infant MeHg exposure and cord cytokine concentrations while adjusting for cord PUFA.

METHODS

We studied participants in the Seychelles Child Development Study (SCDS) Nutrition Cohort 2 (NC2), a large birth cohort in a high fish-eating population. Whole blood MeHg, serum PUFA and serum cytokine concentrations (IFN-γ, IL-1β, IL-2, IL-12p70, TNF-α, IL-4, IL-10, IL-13, IL-6 and IL-8) were measured in cord blood collected at delivery (n = 878). Linear regression examined associations between infant MeHg exposure and cord cytokines concentrations, with and without adjustment for cord PUFA. An interaction model examined cord MeHg, cytokines and tertiles of the n-6:n-3 ratio (low/medium/high).

RESULTS

There was no overall association between cord MeHg (34.08 ± 19.98 μg/L) and cytokine concentrations, with or without adjustment for PUFA. Increased total n-3 PUFA (DHA, EPA and ALA) was significantly associated with lower IL-10 (β = -0.667; p = 0.007) and lower total Th2 (IL-4, IL-10 and IL-13) (β = -0.715; p = 0.036). In the interaction model, MeHg and IL-1β was positive and significantly different from zero in the lowest n-6:n-3 ratio tertile (β = 0.002, p = 0.03).

CONCLUSION

Methylmercury exposure from fish consumption does not appear to impact markers of inflammation in cord blood. The association of cord n-3 PUFA with lower IL-10 and total Th2 cytokines suggests that they may have a beneficial influence on the regulation of the inflammatory milieu. These findings are important for public health advice and deserve to be investigated in follow up studies.

Molecular Mechanisms of Immunosenescene and Inflammaging: Relevance to the Immunopathogenesis and Treatment of Multiple Sclerosis

Aging is characterized, amongst other features, by a complex process of cellular senescence involving both innate and adaptive immunity, called immunosenescence and associated to inflammaging, a low-grade chronic inflammation. Both processes fuel each other and partially explain increasing incidence of cancers, infections, age-related autoimmunity, and vascular disease as well as a reduced response to vaccination. Multiple sclerosis (MS) is a lifelong disease, for which considerable progress in disease-modifying therapies (DMTs) and management has improved long-term survival. However, disability progression, increasing with age and disease duration, remains. Neurologists are now involved in caring for elderly MS patients, with increasing comorbidities. Aging of the immune system therefore has relevant implications for MS pathogenesis, response to DMTs and the risks mediated by these treatments. We propose to review current evidence regarding markers and molecular mechanisms of immunosenescence and their relevance to understanding MS pathogenesis. We will focus on age-related changes in the innate and adaptive immune system in MS and other auto-immune diseases, such as systemic lupus erythematosus and rheumatoid arthritis. The consequences of these immune changes on MS pathology, in interaction with the intrinsic aging process of central nervous system resident cells will be discussed. Finally, the impact of immunosenescence on disease evolution and on the safety and efficacy of current DMTs will be presented.

SCARF1-Induced Efferocytosis Plays an Immunomodulatory Role in Humans, and Autoantibodies Targeting SCARF1 Are Produced in Patients with Systemic Lupus Erythematosus

Deficiency in the clearance of cellular debris is a major pathogenic factor in the emergence of autoimmune diseases. We previously demonstrated that mice deficient for scavenger receptor class F member 1 (SCARF1) develop a lupus-like autoimmune disease with symptoms similar to human systemic lupus erythematosus (SLE), including a pronounced accumulation of apoptotic cells (ACs). Therefore, we hypothesized that SCARF1 will be important for clearance of ACs and maintenance of self-tolerance in humans, and that dysregulation of this process could contribute to SLE. In this article, we show that SCARF1 is highly expressed on phagocytic cells, where it functions as an efferocytosis receptor. In healthy individuals, we discovered that engagement of SCARF1 by ACs on BDCA1+ dendritic cells initiates an IL-10 anti-inflammatory response mediated by the phosphorylation of STAT1 and STAT3. Unexpectedly, there was no significant difference in SCARF1 expression in samples of patients with SLE compared with healthy donor samples. However, we detected anti-SCARF1 autoantibodies in 26% of patients with SLE, which was associated with dsDNA Ab positivity. Furthermore, our data show a direct correlation of the levels of anti-SCARF1 in the serum and defects in the removal of ACs. Depletion of Ig restores efferocytosis in SLE serum, suggesting that defects in the removal of ACs are partially mediated by SCARF1 pathogenic autoantibodies. Our data demonstrate that human SCARF1 is an AC receptor in dendritic cells and plays a role in maintaining tolerance and homeostasis.

The small heat shock protein HSPB5 attenuates the severity of lupus nephritis in lupus-prone mice

Lupus nephritis (LN) is a common and serious complication of systemic lupus erythematosus. The current treatments for LN are accompanied with severe immunotoxicity and have limits of effectiveness. Since our in vitro experiments demonstrated that a small heat shock protein (HSP), alpha-B crystallin (HSPB5; CRYAB), selectively modulates myeloid cells towards anti-inflammatory and tolerogenic phenotypes, the aim of this study was to investigate whether HSPB5 can attenuate the severity of LN. MRL/lpr mice were treated intravenously with HSPB5 at 2.5 or 10 μg/dose twice per week after disease onset, from 11 to 21 weeks of age. Disease progression was monitored by weekly measurements of proteinuria, and sera, spleens, and kidneys were collected for assessment at the terminal time point. Treatment with 10 μg HSPB5 substantially reduced endocapillary proliferation and tubular atrophy, which significantly reduced proteinuria and blood urea nitrogen (BUN). Compared to vehicle, 10 μg HSPB5 treatment substantially decreased activation/proliferation of splenocytes, increased IL-10+ macrophages, T and B regulatory cells (Treg, Breg), increased serum IL-10, and lowered expression of IL-6 in kidneys, which correlated with improved kidney function and pathology. This study demonstrated the utility of exogenous human HSPB5 to attenuate severe nephropathy in MRL/lpr mice and provides evidence in favour of a novel therapeutic approach for lupus nephritis.

Impact and Possible Mechanism(s) of Adipose Tissue-Derived Mesenchymal Stem Cells on T-Cell Proliferation in Patients With Rheumatic Disease

Objectives: Systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) are chronic wasting, incurable rheumatic diseases of autoimmune background, in which T cells play a critical pathogenic role. Autologous adipose tissue-derived mesenchymal stem cells (ASCs) may represent an alternative therapeutic option for SLE and SSc patients, but the biology of these cells is poorly understood. Methods: Herein, we evaluated the anti-proliferative impact of ASCs of healthy donors (HD/ASCs, 5 reference cell lines), SLE patients (n = 20), and SSc patients (n = 20) on T lymphocytes. To assess the direct and indirect pathway of ASCs action, peripheral blood mononuclear cells (PBMCs) and purified CD4+ T cells of HD were activated and co-cultured in cell-to-cell contact (C-C) and transwell (T-W) conditions with untreated or cytokine (TNF + IFNΥ, TI)-licensed ASCs, then analyzed by flow cytometry to rate the proliferation response of CD8+ and/or CD4+ T cells. The concentrations of kynurenines, prostaglandin E2 (PGE2), interleukin 10 (IL-10), and transforming growth factor β (TGFβ) were measured from culture supernatants. Specific inhibitors of these factors (1-MT, indomethacin, and cytokine-neutralizing antibody) were used to assess their contribution to anti-proliferative ASCs action. Results: All tested ASCs significantly decreased the number of proliferating CD4+ and CD8+ T cells, the number of division/proliferating cell (PI), and fold expansion (RI), and similarly upregulated kynurenines and PGE2, but not cytokine levels, in the co-cultures with both types of target cells. However, TI-treated SLE/ASCs and SSc/ASCs exerted a slightly weaker inhibitory effect on CD4+ T-cell replication than their respective HD/ASCs. All ASCs acted mainly via soluble factors. Their anti-proliferative effect was stronger, and kynurenine levels were higher in the T-W condition than the C-C condition. Blocking experiments indicated an involvement of kynurenine pathway in inhibiting the number of proliferating cells, PI, and RI values as well as PGE2 role in decreasing the number of proliferating cells. TGFβ did not contribute to ASCs anti-proliferative capabilities, while IL-10 seems to be involved in such activity of only SLE/ASCs. Conclusion: The results indicate that SLE/ASCs and SSc/ASCs retain their capability to restrain the expansion of allogeneic CD4+ and CD8+ T cells and act by similar mechanisms as ASCs of healthy donors and thus may have therapeutic value.

The Framework for Human Host Immune Responses to Four Types of Parasitic Infections and Relevant Key JAK/STAT Signaling

The human host immune responses to parasitic infections are complex. They can be categorized into four immunological pathways mounted against four types of parasitic infections. For intracellular protozoa, the eradicable host immunological pathway is TH1 immunity involving macrophages (M1), interferon gamma (IFNγ) CD4 T cells, innate lymphoid cells 1 (NKp44+ ILC1), CD8 T cells (Effector-Memory4, EM4), invariant natural killer T cells 1 (iNKT1) cells, and immunoglobulin G3 (IgG3) B cells. For intracellular protozoa, the tolerable host immunological pathway is TH1-like immunity involving macrophages (M2), interferon gamma (IFNγ)/TGFβ CD4 T cells, innate lymphoid cells 1 (NKp44- ILC1), CD8 T cells (EM3), invariant natural killer T 1 (iNKT1) cells, and immunoglobulin A1 (IgA1) B cells. For free-living extracellular protozoa, the eradicable host immunological pathway is TH22 immunity involving neutrophils (N1), interleukin-22 CD4 T cells, innate lymphoid cells 3 (NCR+ ILC3), iNKT17 cells, and IgG2 B cells. For free-living extracellular protozoa, the tolerable host immunological pathway is TH17 immunity involving neutrophils (N2), interleukin-17 CD4 T cells, innate lymphoid cells 3 (NCR- ILC3), iNKT17 cells, and IgA2 B cells. For endoparasites (helminths), the eradicable host immunological pathway is TH2a immunity with inflammatory eosinophils (iEOS), interleukin-5/interleukin-4 CD4 T cells, interleukin-25 induced inflammatory innate lymphoid cells 2 (iILC2), tryptase-positive mast cells (MCt), iNKT2 cells, and IgG4 B cells. For ectoparasites (parasitic insects and arachnids), the eradicable host immunological pathway is TH2b immunity with inflammatory basophils, chymase- and tryptase-positive mast cells (MCct), interleukin-3/interleukin-4 CD4 T cells, interleukin-33 induced nature innate lymphoid cells 2 (nILC2), iNKT2 cells, and immunoglobulin E (IgE) B cells. The tolerable host immunity against ectoparasites and endoparasites is TH9 immunity with regulatory eosinophils, regulatory basophils, interleukin-9 mast cells (MMC9), thymic stromal lymphopoietin induced innate lymphoid cells 2, interleukin-9 CD4 T cells, iNKT2 cells, and IgA2 B cells. In addition, specific transcription factors important for specific immune responses were listed. This JAK/STAT signaling is key to controlling or inducing different immunological pathways. In sum, Tfh is related to STAT5β, and BCL6 expression. Treg is related to STAT5α, STAT5β, and FOXP3. TH1 immunity is related to STAT1α, STAT4, and T-bet. TH2a immunity is related to STAT6, STAT1α, GATA1, and GATA3. TH2b immunity is related to STAT6, STAT3, GATA2, and GATA3. TH22 immunity is associated with both STAT3α and AHR. THαβ immunity is related to STAT1α, STAT1β, STAT2, STAT3β, and ISGF. TH1-like immunity is related to STAT1α, STAT4, STAT5α, and STAT5β. TH9 immunity is related to STAT6, STAT5α, STAT5β, and PU.1. TH17 immunity is related to STAT3α, STAT5α, STAT5β, and RORG. TH3 immunity is related to STAT1α, STAT1β, STAT2, STAT3β, STAT5α, STAT5β, and ISGF. This categorization provides a complete framework of immunological pathways against four types of parasitic infections. This framework as well as relevant JAK/STAT signaling can provide useful knowledge to control allergic hypersensitivities and parasitic infections via development of vaccines or drugs in the near future.

Guidelines for the use of flow cytometry and cell sorting in immunological studies (third edition)

The third edition of Flow Cytometry Guidelines provides the key aspects to consider when performing flow cytometry experiments and includes comprehensive sections describing phenotypes and functional assays of all major human and murine immune cell subsets. Notably, the Guidelines contain helpful tables highlighting phenotypes and key differences between human and murine cells. Another useful feature of this edition is the flow cytometry analysis of clinical samples with examples of flow cytometry applications in the context of autoimmune diseases, cancers as well as acute and chronic infectious diseases. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid. All sections are written and peer-reviewed by leading flow cytometry experts and immunologists, making this edition an essential and state-of-the-art handbook for basic and clinical researchers.

Prioritization of Diagnostic and Prognostic Biomarkers for Lupus Nephritis Based on Integrated Bioinformatics Analyses

Lupus nephritis (LN) is an important driver of end-stage renal disease (ESRD). However, few biomarkers are available for evaluating the diagnosis and prognosis of LN. For this study, we downloaded microarray data of multiple LN expression profiles from the GEO database. We used the WGCNA and R limma packages to identify LN hub genes and differentially-expressed genes (DEGs). We identified nine co-DEGs in the intersection with LN-related genes from the Genecards database. We found DEGs that are primarily associated with immune-related functions and pathways (including with the complement pathway, primary immunodeficiency markers, and MHC-like protein complexes) through our comprehensive GSEA, GO, and KEGG enrichment analyses. We used other LN and SLE validation datasets and discovered six explicitly expressed co-DEGs: HLA-DMA, HLA-DPA1, HLA-DPB1, HLA-DRA, IL10RA, and IRF8 in the LN set; ROC and Precision-Recall curve analyses revealed that these six genes have a good diagnostic efficacy. The correlation analysis with prognostic data from the Nephroseq database indicates that the differential expression of these co-DEGs is associated with a low glomerular filtration rate in that cohort. Additionally, we used a single-cell LN database of immune cells (for the first time) and discovered these co-DEGs to be predominantly distributed in different types of macrophages and B cells. In conclusion, by integrating multiple approaches for DEGs discovery, we identified six valuable biomarkers that are strongly correlated with the diagnosis and prognosis of LN. These markers can help clarify the pathogenesis and improve the clinical management of LN.

Roles of IL-1 and IL-10 family cytokines in the progression of systemic lupus erythematosus: Friends or foes?

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease of unknown etiology that can affect nearly every organ system in the body. Besides genetic and environmental factors, unbalanced pro-inflammatory and anti-inflammatory cytokines contribute to immune dysregulation, trigger an inflammatory response, and induce tissue and organ damage. Inflammatory responses in SLE can be promoted and/or maintained by the availability of cytokines that are overproduced systemically and/or in local tissues. Several key cytokines have been considered potential targets for the reduction of chronic inflammation in SLE. Recent studies indicated that dysregulated production of several cytokines, including those of the IL-1 family and IL-10 family, orchestrate immune activation and self-tolerance, play critical roles in the pathogenesis of SLE. Among IL-1 family cytokines, IL-1, IL-18, IL-33, IL-36, IL-37, and IL-38 had been the most thoroughly investigated in SLE. Additionally, IL-10 family cytokines, IL-10, IL-20, IL-22, IL-26, IL-28, and IL-29 are dysregulated in SLE. Therefore, a better understanding of the initiation and progression of SLE may provide suitable novel targets for therapeutic intervention. In this review, we discuss the involvement of inflammation in the pathogenesis of SLE, with a focus on IL-1 family and IL-10 family cytokines, and highlight pathophysiological approaches and therapeutic potential for treating SLE.

Interleukin-10-592 polymorphism: impact on relapse and survival after allogeneic hematopoietic stem cell transplantation in children with hematological malignancies

Purpose

Interleukin-10 (IL-10) potentially can promote the development of alloimmunity. The aim of this study was to investigate if the IL-10-592 CC genotype in the donor reduces the risk of relapse after hematopoietic stem cell transplantation (HSCT) and if that has an impact on event-free survival (EFS) and overall survival (OS).

Methods

A cohort of 211 children with acute lymphoblastic leukemia (n = 99), acute myeloid leukemia (n = 69), myelodysplastic syndrome (n = 31) or chronic myeloid leukemia (n = 12) who underwent hematopoietic stem cell transplantation (HSCT) in a single center and their respective donors were genotyped of IL-10 gene for rs1800872 using TaqMan real-time polymerase chain reaction.

Results

The IL-10-592 CC genotype was detected in 107 of the 211 donors (50.7%) and in 106 of the 211 patients (50.2%). Genotype AC was found in 95 donors (45.0%) and in 90 patients (42.7%). Nine donors (4.3%) and 15 patients (7.1%) were homozygous for AA. Ultimately, we observed a significantly reduced incidence of relapse rate (RR) in patients who were transplanted from a donor with the IL-10-592 CC genotype (19% versus 43% (AC) versus 49% (AA); P = 0.0007). In addition, a significant increase of EFS (P = 0.004) and OS (P = 0.006) was detected if the IL-10-592 CC genotype is present in the donor. The occurrence of the IL-10-592 CC genotype, in either donors or recipients, had no significant impact on acute and chronic graft-versus-host disease. In addition, the IL-10-592 genotype of the recipients was not relevant for the RR (P = 0.47434), the EFS (P = 0.840), and the OS (P = 0.535).

Conclusion

The IL-10-592 CC genotype in the donor was associated with a significant decrease of RR which led to a significant increase of EFS and OS after HSCT. This is the first study to describe an association of the IL-10 gene polymorphism with RR, EFS, and OS after HSCT. Selecting a donor with the IL-10-592 CC genotype could be a useful therapeutic strategy for improving the outcome after allogeneic HSCT.

Harnessing Tolerogenic Histone Peptide Epitopes From Nucleosomes for Selective Down-Regulation of Pathogenic Autoimmune Response in Lupus (Past, Present, and Future)

Autoantigen-directed tolerance can be induced by certain nucleosomal histone peptide epitope/s in nanomolar dosage leading to sustained remission of disease in mice with spontaneous SLE. By contrast, lupus is accelerated by administration of intact (whole) histones, or whole nucleosomes in microparticles from apoptotic cells, or by post-translationally acetylated histone-peptides. Low-dose therapy with the histone-peptide epitopes simultaneously induces TGFβ and inhibits IL-6 production by DC in vivo, especially pDC, which then induce CD4+CD25+ Treg and CD8+ Treg cells that suppress pathogenic autoimmune response. Both types of induced Treg cells are FoxP3+ and act by producing TGFβ at close cell-to-cell range. No anaphylactic adverse reactions, or generalized immunosuppression have been detected in mice injected with the peptides, because the epitopes are derived from evolutionarily conserved histones in the chromatin; and the peptides are expressed in the thymus during ontogeny, and their native sequences have not been altered. The peptide-induced Treg cells can block severe lupus on adoptive transfer reducing inflammatory cell reaction and infiltration in the kidney. In Humans, similar potent Treg cells are generated by the histone peptide epitopes in vitro in lupus patients’ PBMC, inhibiting anti-dsDNA autoantibody and interferon production. Furthermore, the same types of Treg cells are generated in lupus patients who are in very long-term remission (2-8 years) after undergoing autologous hematopoietic stem cell transplantation. These Treg cells are not found in lupus patients treated conventionally into clinical remission (SLEDAI of 0); and consequently they still harbor pathogenic autoimmune cells, causing subclinical damage. Although antigen-specific therapy with pinpoint accuracy is suitable for straight-forward organ-specific autoimmune diseases, Systemic Lupus is much more complex. The histone peptide epitopes have unique tolerogenic properties for inhibiting Innate immune cells (DC), T cells and B cell populations that are both antigen-specifically and cross-reactively involved in the pathogenic autoimmune response in lupus. The histone peptide tolerance is a natural and non-toxic therapy suitable for treating early lupus, and also maintaining lupus patients after toxic drug therapy. The experimental steps, challenges and possible solutions for successful therapy with these peptide epitopes are discussed in this highly focused review on Systemic Lupus.

Coronavirus disease 2019 (COVID-19) and autoimmunity

The coronavirus 2019 pandemic (coronavirus disease, COVID-19), etiologically related to the SARS-CoV-2 virus (severe acute respiratory syndrome coronavirus-2), has once again reawakened healthcare professionals’ interest towards new clinical and conceptual issues of human immunology and immunopathology. An unprecedented number of clinical trials and fundamental studies of epidemiology, virology, immunology and molecular biology, of the COVID-19 clinical course polymorphism and pharmacotherapy have been conducted within one year since the outbreak of 2019 pandemic, bringing together scientists of almost all biological and physicians of almost all medical specialties. Their joint efforts have resulted in elaboration of several types of vaccines against SARS-CoV-2 infection and, in general, fashioning of more rational approaches to patient management. Also important for COVID-19 management were all clinical trials of biologics and “targeted” anti-inflammatory drugs modulating intracellular cytokine signaling, which have been specifically developed for treatment immune-mediated inflammatory rheumatic disease (IMIRDs) over the past 20 years. It became obvious after a comprehensive analysis of the entire spectrum of clinical manifestations and immunopathological disorders in COVID-19 is accompanied by a wide range of extrapulmonary clinical and laboratory disorders, some of which are characteristic of IMIRDs and other autoimmune and auto-in-flammatory human diseases. All these phenomena substantiated the practice of anti-inflammatory drugs repurposing with off-label use of specific antirheumatic agents for treatment of COVID-19. This paper discusses potential use of glucocorticoids, biologics, JAK inhibitors, etc., blocking the effects of pro-inflammatory cytokines for treatment of COVID-19.

Dual Role of Interleukin-10 in Murine NZB/W F1 Lupus

As a key anti-inflammatory cytokine, IL-10 is crucial in preventing inflammatory and autoimmune diseases. However, in human and murine lupus, its role remains controversial. Our aim was to understand regulation and immunologic effects of IL-10 on different immune functions in the setting of lupus. This was explored in lupus-prone NZB/W F1 mice in vitro and vivo to understand IL-10 effects on individual immune cells as well as in the complex in vivo setting. We found pleiotropic IL-10 expression that largely increased with progressing lupus, while IL-10 receptor (IL-10R) levels remained relatively stable. In vitro experiments revealed pro- and anti-inflammatory IL-10 effects. Particularly, IL-10 decreased pro-inflammatory cytokines and slowed B cell proliferation, thereby triggering plasma cell differentiation. The frequent co-expression of ICOS, IL-21 and cMAF suggests that IL-10-producing CD4 T cells are important B cell helpers in this context. In vitro and in vivo effects of IL-10 were not fully concordant. In vivo IL-10R blockade slightly accelerated clinical lupus manifestations and immune dysregulation. Altogether, our side-by-side in vitro and in vivo comparison of the influence of IL-10 on different aspects of immunity shows that IL-10 has dual effects. Our results further reveal that the overall outcome may depend on the interplay of different factors such as target cell, inflammatory and stimulatory microenvironment, disease model and state. A comprehensive understanding of such influences is important to exploit IL-10 as a therapeutic target.

HDAC1 potentiates CD4 + T cell activation by inhibiting miR-124 and promoting IRF1 in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease leading to considerable morbidity worldwide, which can be developed from a breakdown in immunological tolerance, resulting in T cell hyperactivation. T cell hyperactivation has been implicated in the tissue damage associated with many diseases. Although many researchers have identified the involvement of T-cell receptor-associated signaling molecules in T-cell activation, the mechanisms underlying this process are yet to be elaborated. In the current study, we set out to reveal a novel transcriptional mechanism required for CD4 + T cell immunoactivity involved in SLE. First of all, miR-124 was experimentally determined to be under-expressed in peripheral blood samples of SLE patients relative to healthy individuals. We further isolated CD4 + T cells from the peripheral blood samples of SLE patients and healthy individuals, and found that miR-124 was poorly expressed in peripheral blood-derived CD4 + T cells of SLE patients. Subsequent experiments demonstrated that re-expression of miR-124 inhibited the immunoactivity of CD4 + T cells from SLE patients, which was achieved through the down-regulation of IRF1 since dual-luciferase reporter gene assay findings indicated that miR-124 could target IRF1. In addition, HDAC1 was found to be enriched at the miR-124 promoter resulting in inhibition of miR-124 expression, thereby promoting the immunoactivity of CD4 + T cells. In conclusion, we identify that as a stimulator of CD4 + T cell immunoactivity, HDAC1 may be implicated in the immunopathology of SLE. The study will open up new avenues to explore future immunotherapy strategies for SLE.

The Potential Role of Regulatory B Cells in Idiopathic Membranous Nephropathy

Regulatory B cells (Breg) are widely regarded as immunomodulatory cells which play an immunosuppressive role. Breg inhibits pathological autoimmune response by secreting interleukin-10 (IL-10), transforming growth factor-β (TGF-β), and adenosine and through other ways to prevent T cells and other immune cells from expanding. Recent studies have shown that different inflammatory environments induce different types of Breg cells, and these different Breg cells have different functions. For example, Br1 cells can secrete IgG4 to block autoantigens. Idiopathic membranous nephropathy (IMN) is an autoimmune disease in which the humoral immune response is dominant and the cellular immune response is impaired. However, only a handful of studies have been done on the role of Bregs in this regard. In this review, we provide a brief overview of the types and functions of Breg found in human body, as well as the abnormal pathological and immunological phenomena in IMN, and propose the hypothesis that Breg is activated in IMN patients and the proportion of Br1 can be increased. Our review aims at highlighting the correlation between Breg and IMN and proposes potential mechanisms, which can provide a new direction for the discovery of the pathogenesis of IMN, thus providing a new strategy for the prevention and early treatment of IMN.

Cutting Edge: NOX2 NADPH Oxidase Controls Infection by an Intracellular Bacterial Pathogen through Limiting the Type 1 IFN Response

The NOX2 NADPH oxidase (NOX2) produces reactive oxygen species to kill phagosome-confined bacteria. However, we previously showed that Listeria monocytogenes is able to avoid the NOX2 activity in phagosomes and escape to the cytosol. Thus, despite the established role of NOX2 limiting L. monocytogenes infection in mice, the underlying mechanisms of this antibacterial activity remain unclear. In this article, we report that NOX2 controls systemic L. monocytogenes spread through modulation of the type I IFN response, which is known to be exploited by L. monocytogenes during infection. NOX2 deficiency results in increased expression of IFN-stimulated genes in response to type I IFN and leads to 1) promotion of cell-to-cell spread by L. monocytogenes, 2) defective leukocyte recruitment to infection foci, and 3) production of anti-inflammatory effectors IL-10 and thioredoxin 1. Our findings report a novel antimicrobial role for NOX2 through modulation of type I IFN responses to control bacterial dissemination.

Evidence for a pathogenic role of extrafollicular, IL-10-producing CCR6+B helper T cells in systemic lupus erythematosus

Interleukin 10 (IL-10) is an antiinflammatory cytokine, but also promotes B cell responses and plays a pathogenic role in systemic lupus erythematosus (SLE). CD4⁺CCR6⁺IL-7R⁺T cells from human tonsils produced IL-10 following stimulation by naïve B cells, which promoted B cell immunoglobulin G (IgG) production. These tonsillar CCR6⁺B helper T cells were phenotypically distinct from follicular helper T (T_FH) cells and lacked BCL6 expression. In peripheral blood, a CCR6⁺T cell population with similar characteristics was identified, which lacked Th17- and T_FH-associated gene signatures and differentiation-associated surface markers. CD4⁺CCR6⁺T cells expressing IL-10, but not IL-17, were also detectable in the spleens of cytokine reporter mice. They provided help for IgG production in vivo, and expanded systemically in pristane-induced lupus-like disease. In SLE patients, CD4⁺CCR6⁺IL-7R⁺T cells were associated with the presence of pathogenic anti-dsDNA (double-stranded DNA) antibodies, and provided spontaneous help for autoantibody production ex vivo. Strikingly, IL-10-producing CCR6⁺T cells were highly abundant in lymph nodes of SLE patients, and colocalized with B cells at the margins of follicles. In conclusion, we identified a previously uncharacterized population of extrafollicular B helper T cells, which produced IL-10 and could play a prominent pathogenic role in SLE.