Hyperactivation of NLRP3 inflammasome contributes to the neuroinflammation in autoimmune disorders, but the underlying regulating mechanism remains to be elucidated. We here demonstrate that mice lacking thymic stromal lymphopoietin receptor gene (Tslpr-/-) exhibit significant decreases in experimental autoimmune encephalitis (EAE) score, reduced CD4+ T cells infiltration, and restored expression of myelin basic protein (MBP) in the brain after induction of EAE by injection of myelin oligodendrocyte glycoprotein35-55 (MOG35-55) . TSLPR signals through Janus Kinase 2 (JAK2) to activate NLRP3. Tslpr-/- mice of EAE show decreased phosphorylation of JAK2 and expression of NLRP3 in the brain. In wild type (WT) mice after induction of EAE, inhibition of JAK2 by ruxolitinib inflammatory and CD4+ cell infiltration, decreased expression of NLRP3, and restored BMP expression in the brain. Ruxolitinib also decreased levels of IL-1β and TSLP in brain of EAE mouse when compared to that without ruxolitinib treatment. Further results with NLRP3 inhibitor MCC950 in EAE mouse of WT verified the proinflammatory role of NLRP3 by showing decreased inflammatory cells and CD4+ T cells, restored MBP expression, and declined levels of IL-1β and TSLP in the brain. In patients with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis we found increased level of NLRP3 and IL-1β in CSF when compared to that in control subjects. These findings highlight TSLP as a prospective target for treating JAK2-NLRP3 axis-associated autoimmune inflammatory disorders.

Brain tumors and brain metastases induce changes in brain tissue remodelling that lead to immunosuppression and trigger an inflammatory response within the tumor microenvironment. These immune and inflammatory changes can influence invasion and metastasis. Other neuroinflammatory and necrotic lesions may occur in patients with brain cancer or brain metastases as sequelae from treatment with radiotherapy. Glioblastoma (GBM) is the most aggressive primary malignant brain cancer in adults. Imaging methods such as positron-emission tomography (PET) and different magnetic resonance imaging (MRI) techniques are highly valuable for the diagnosis and therapeutic evaluation of GBM and other malignant brain tumors. However, differentiating between tumor tissue and inflamed brain tissue with imaging protocols remains a challenge. Here, we review recent advances in imaging methods that have helped to improve the specificity of primary tumor diagnosis versus evaluation of inflamed and necrotic brain lesions. We also comment on advances in differentiating metastasis from neuroinflammation processes. Recent advances include the radiosynthesis of 18F-FIMP, an L-type amino acid transporter 1 (LAT1)-specific PET probe that allows better differentiation between tumor tissue and inflammation compared to previous probes; and the combination different advanced imaging protocols with the inclusion of radiomics and machine learning algorithms.

Recent studies have shown that T cell metabolism has become a key regulator of T cell function and even can determine T cell function at last. Naïve T cells use fatty acid oxidation (FAO) to meet their energetic demands. Effector T cells mainly rely on aerobic glycolysis to supply energy and synthesize intermediate products. Similar to naïve T cells, memory T cells primarily utilize FAO for energy. Exhausted T cells, which can be induced by continuous activation of T cells upon persistently chronic infections such as tuberculosis, mainly rely on glycolysis for energy. The prevention and treatment of T cell exhaustion is facing great challenges. Interfering T cell metabolism may achieve the goal of prevention and treatment of T cell exhaustion. In this review, we compiled the researches related to exhausted T cell metabolism and put forward the metabolic intervention strategies to reverse T cell exhaustion at different stages to achieve the purpose of preventing and treating T cell exhaustion.

Healthy pregnancy is accompanied by various immunological and metabolic adaptations. Maternal obesity has been implicated in adverse pregnancy outcomes such as miscarriage, preeclampsia, and gestational diabetes mellitus (GDM), while posing a risk to the neonate. There is a lack of knowledge surrounding obesity and the maternal immune system. The objective of this study was to consider if immunological changes in pregnancy are sabotaged by maternal obesity. Peripheral blood was collected from fasted GDM-negative pregnant women at 26-28 weeks of gestation. Analysis was done using immunoassay, flow cytometry, bioenergetics analysis and cell culture. The plasma profile was significantly altered with increasing BMI, specifically leptin (r=0.7635), MCP-1 (r=0.3024) and IL-6 (r=0.4985). Circulating leukocyte populations were also affected with changes in the relative abundance of intermediate monocytes (r=-0.2394), CD4:CD8 T cell ratios (r=0.2789), and NKT cells (r=-0.2842). Monocytes analysed in more detail revealed elevated CCR2 expression and decreased mitochondrial content. However, LPS-stimulated cytokine production and bioenergetic profile of MNCs was not affected by maternal BMI. The Th profile skews towards Th17 with increasing BMI; Th2 (r=-0.3202) and Th9 (r=-0.3205) cells were diminished in maternal obesity, and CytoStimTM-stimulation exacerbates IL-6 (r=0.4166), IL-17A (r=0.2753), IL-17F (r=0.2973) and IL-22 (r=0.2257) production with BMI, while decreasing IL-4 (r=-0.2806). Maternal obesity during pregnancy creates an inflammatory microenvironment. Successful pregnancy requires Th2-biased responses yet increasing maternal BMI favours a Th17 response that could be detrimental to pregnancy. Further research should investigate key populations of cells identified here to further understand the immunological challenges that beset pregnant women with obesity.

Objective: Behçet’s syndrome (BS) is a systemic vasculitis with several clinical manifestations. Neutrophils hyperactivation mediates vascular BS involvement, via a massive production of reactive oxygen species (ROS) and the release of neutrophil extracellular traps (NETs). We investigated neutrophil-mediated mechanisms of damage in non-vascular BS manifestations and explored in vitro the effects of colchicine in counteracting these mechanisms. Methods: NETs and intracellular ROS production was assessed in blood samples from 80 BS patients (46 with active non-vascular BS, 34 with inactive disease) and 80 healthy controls. Moreover, isolated neutrophils were incubated for 1 hour with an oxidating agent (2,2′-azobis (2-amidinopropane) dihydrochloride; 250nM), and the ability of pure colchicine pre-treatment (100ng/ml) to counteract oxidation-induced damage was assessed. Results: Patients with active non-vascular BS had remarkably increased NET levels [21.2 (IQR 18.3-25.9) mU/ml] compared to patients with inactive disease [16.8 (13.3-20.2) mU/ml] and to controls [7.1 (5.1-8.7) mU/ml], p<0.001]. Also, intracellular ROS tended to be increased in active BS, although not significantly. In active non-vascular BS, NETs correlated with neutrophils ROS production (p<0.001) and were particularly increased in patients with active mucosal (p<0.001), articular (p=0.004), and gastrointestinal symptoms (p=0.006). On isolated neutrophils, colchicine significantly reduced oxidation-induced NET production and cell apoptosis, though not via an antioxidant activity. Conclusion: Neutrophil-mediated mechanisms might be directly involved in non-vascular BS, and NETs, more than ROS, might drive the pathogenesis of mucosal, articular and intestinal manifestations. Colchicine might be effective to counteract neutrophils-mediated damage in BS, although further studies are needed.

Endometriosis is a chronic inflammatory disorder resulting in pelvic pain and infertility. The role of T helper 17 (Th17) cells in endometriosis remains elusive. In this study, through detecting CXCR3, CCR4, CCR10, CCR6, interleukin-17 Receptor E (IL-17RE), and CD27, live RORγt-and-IL-17A-expressing Th17 cells were distinguished and sorted from peritoneal fluid (PF) of patients with stage III and IV endometriosis. Furthermore, we found that IL-17RE and CD27 were the labels of heterogeneous PF Th17 subsets, i.e. IL-17RE-CD27- subset, IL-17RE+CD27- subset, and IL-17RE+CD27+ subset. The former two subsets expressed higher IL-17A, GM-CSF, and IL-22 and were more proliferative than the latter subset. RNA-Seq analysis on IL-17RE+ Th17 subset and IL-17RE- Th17 subset revealed up-regulation of genes involved in oxidative phosphorylation and electron transport chain in IL-17RE+ Th17 subset relative to IL-17RE- Th17 subset. Consistently, the IL-17RE+ Th17 subset produced more adenosine triphosphate (ATP) and reactive oxygen species (ROS) than IL-17RE- Th17 subset. In conclusion, this study provides a novel method to detect and isolate live PF Th17 cells from endometriosis patients and unveils the functional and metabolic heterogeneity of PF Th17 subsets. Therefore, it sheds light on the elucidation of molecular mechanisms that modulate the function of pathological Th17 cells in endometriosis.

This non-randomized controlled study aimed to assess the efficacy of tofacitinib in reducing the risk of invasive mechanical ventilation or death in patients with COVID-19. Patients with COVID-19 associated with reduced oxygen saturation, increased C-reactive protein (≥50 mg/L), and/or persisting fever were recruited. Tofacitinib was administered in addition to standard of care therapy. Study outcomes were evaluated separately in the groups of patients with oxygen saturation at rest ≤93% and >93%. Hazard ratios (HR) with 95% confidence intervals (CI) were calculated using Cox regression analysis adjusted for inverse propensity score weighting. Overall, 384 patients with COVID-19 (212 males; median age 60 years) were included in our study and were treated with tofactinib (n=131) or standard of care alone (n=253). The percentages of patients who started mechanical ventilation or died during hospitalization in the tofacitinib and control groups were 12.5% (9/72) vs. 14.1% (26/185) among patients who required respiratory support (HR 0.92, 95% CI 0.33-2.56), and 1.7% (1/59) vs. 4.4% (3/68) in those with normal oxygen saturation (HR 0.83; 95 CI 0.07-9.44). Tofacitinib did not reduce the risk of invasive mechanical ventilation or death in patients with COVID-19, although the analysis of these outcomes favored tofacitinib.

RORγt+Foxp3+ regulatory T (Treg) cells, known as T regulatory 17 cells (Tr17 cells), are a novel subset of Treg cells, which have the potential to regulate the development of experimental autoimmune encephalomyelitis (EAE) thorough a specific repression of T helper 17 (Th17) cell mediated inflammation. However, the function of Tr17 cells the development of other autoimmune diseases such as autoimmune arthritis remains unclear. Collagen induced arthritis (CIA) was found to be prolonged in Foxp3creRORγtfl/fl mice, in which Tr17 cells were deleted, compared with Foxp3wtRORγtfl/fl mice. Tr17 cells were significantly increased in ankle joints compared with draining lymph nodes after the onset of arthritis. CC chemokine receptor 6 (CCR6) was up-regulated on Tr17 cells compared to RORγt negative Treg cells. CD25, cytotoxic T-lymphocyte antigen 4 (CTLA-4), glucocorticoid-induced TNF-receptor (GITR), and inducible T-cell co-stimulator (ICOS) expression was also up-regulated on Tr17 cells compared to RORγt negative Treg cells. IL-10-producing cells and Blimp-1+ cells were increased in Tr17 cells compared to RORγt-Treg cells. Tr17-enriched Treg cells significantly suppressed proliferation of conventional T cells compared with CCR6-Treg cells. Tr17 cells increased during the clinical course of CIA and accumulated in inflamed joints. These cells expressed CD25, CTLA4, GITR, and ICOS molecules and up-regulated Blimp-1 and over-produced IL-10. Moreover, CCR6+ Treg cells significantly suppressed cell proliferation. Taken together, it appears that Tr17 cells play a crucial role in the regulation of autoimmune arthritis.

Abstract: Background： Naïve T and T memory cell subsets can provide important information for the diagnosis and treatment of immunological and hematological disorders. Lymphocyte compartment undergo dramatic changes during adulthood; age-related reference values derived from healthy individuals are crucial. However, extensively detailed immunophenotyping reference values of peripheral blood lymphocytes in whole spectrum of adulthood performed by flow cytometry-based single-platform method are rare. Methods: 309 healthy adult volunteers were recruited from Tianjin in China. The absolute counts and percentages of CD3+CD4+ T cells, CD3+CD8+ T cells, naïve T cells (Tn), T memory stem cells (Tscm), central memory T cells (Tcm), effector memory T cells (Tem), terminal effector T cells (Tte) were determined by flow cytometry with single platform technologies. Results: Reference range of absolute counts and percentage of lymphocyte subsets were formulated by different age and gender. We also find out the changing regularity of them: the cells which have stem cell properties, Tn and Tscm cells, decrease with aging; memory cell subsets, Tcm and Tem increase with aging, which increase from 18 to 64 years old and present no significant change over the 65 years old. Gender have influence on the fluctuation of lymphocyte subsets, absolute count of CD3+CD8+, CD8+ Tcm, CD8+ Tem in male are higher than that in female. Conclusion: The reference values of percentages and absolute numbers of naïve T and T memory cell subsets can help doctors to understand the immune state of patients and to evaluate conditions of prognosis then adjust treatment for patients.

Epidermal melanocyte loss in vitiligo, triggered by stresses ranging from trauma to emo-tional stress, chemical exposure or metabolite imbalance, to the unknown, can stimulate oxidative stress in pigment cells which secrete damage-associated molecular patterns that then initiate innate immune responses. Antigen presentation to melanocytes leads to stim-ulation of autoreactive T cell responses, with further targeting of pigment cell. Studies show a pathogenic basis for cellular stress, innate immune responses and adaptive immun-ity in vitiligo. Improved understanding of the aetiological mechanisms in vitiligo has already resulted in successful use of the Jak-1 inhibitors in vitiligo. In this review we outline the cur-rent understanding of the pathological mechanisms in vitiligo, and locate loci to which therapeutic attack might be directed.

The aim of the study was to examine the in vitro effects of the slow-releasing H2S donor GYY4137 on immune cells involved in the pathogenesis of the central nervous system (CNS) autoimmune disease, multiple sclerosis (MS). GYY4137 specifically potentiated TGF-beta expression and production in dendritic cells and significantly reduced IFN-γ and IL-17 production in the lymph node and spinal cord T cells obtained from mice immunized with CNS antigens. Both the proportion of FoxP3+ regulatory CD4+ T cells in the lymph node cells, and the percentage of IL-17+ CD4+ T cells in the spinal cord cells were reduced upon culturing with GYY4137. Interestingly, peripheral blood mononuclear cells obtained from MS patients had lower expression of the H2S-producing enzyme, 3-mercaptopyruvate-sulfurtransferase (MPST), in comparison to those obtained from healthy donors. A significant inverse correlation between the expression of MPST and several pro-inflammatory factors was also observed. Further studies on the relevance of the observed results for the pathogenesis and therapy of MS are warranted.

The role of CD4+ Treg in immune responses has been well established. More recently a role of CD8+ Treg in the regulation of immune responses in health and autoimmune diseases has been investigated. Furthermore, different investigators have used different markers to define CD8 Treg. Finally, regulatory effects of CD8 Treg have been studied against T cell responses; however, their role in regulating B cell proliferation and immunoglobulin production has not been evaluated. Therefore, in this study we examined the effect of two types of CD8 Treg on B cell proliferation and immunoglobulin production. Methods: Purified CD8+ T cells were activated with anti-CD3/CD28 for 48 hours and then sorted into two different types of CD8 Treg as defined by two different sets of markers, CD8+CD183+CCR7+CD45RA-, and CD8+CD183+CD25highCD278+. Purified B cells were co-cultured with sorted CD8 Treg at 1:1, 1:1/2, 1:1/4 ratios, and activated with anti-CD40 and CpG. B cell proliferation was assessed by CFSE dye dilution assay and immunoglobulin production by ELISA assay. Results: Our data show CD183+CCR7+CD45RA- CD8 T reg significantly inhibited B cell proliferation and inhibited IgM and IgG production but not of IgA production at 1:1 ratio only. However, CD183+CD25highCD278+ CD8 Treg inhibited significantly B cell proliferation at 1:1 and 1:1/2 ratio and IgM, IgG, and IgA production at all ratios. In Conclusion, CD8 Treg regulate B cell responses, and CD183+CD25highCD278+ CD8 Treg are more powerful regulators of B cell proliferation and Immunoglobulin production than CD183+CCR7+CD45RA- CD8 Treg.

Introduction: muscle pain/fibromyalgia (FM) is common among individuals with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). We recently demonstrated that during orthostatic stress testing, adults with ME/CFS reported increased pain. In the current study, we hypothesized that pain pressure thresholds (PPT) would decrease and temporal summation (windup) would increase after head-up tilt testing (HUT), and that the presence of co-morbid FM would be associated with greater change in both measures. Methods and Results: 248 ME/CFS patients (164 with FM and84 without FM), and 22 healthy controls (HC) were analyzed. In HC there were no significant differences in PPT between pre- and post-HUT (finger: from 4.7(1.6) to 4.4(1.5); shoulder: from 2.8(1.0) to 2.9(1.0)). In ME/CFS patients with and without FM, a significant decrease in PPT post-HUT was found compared to HC (both p<0.0001). Patients with FM had a lower PPT pre- and post-HUT (finger: from 2.0(0.9) to 1.5(0.8); shoulder: from 1.2(0.5) to 1.0(0.5) compared to patients without FM (finger: from 5.0(1.6) to 3.3(1.5); shoulder: from 2.2(0.9) to1.9(1.0) (p ranging from 0.001 to <0.0001). In contrast to HC in ME/CFS patients windup was increased compared to HC pre-HUT (both p<0.0001), but did not significantly change post-HUT. Conclusions: Pressure pain threshold decreased in ME/CFS patients with or without fibromyalgia after head-up tilt test (HUT), compared to healthy controls. Windup pre-and post-HUT was significantly higher compared to healthy controls, but did not change from pre- to post-HUT. These results demonstrate that, like exercise, orthostatic stress can negatively influence the physiology of pain perception in ME/CFS.

Primary biliary cholangitis (PBC) is an immune-mediated chronic cholestasis. The disruption of T cell homeostasis plays an important role in PBC pathogenesis. Lysosomal associated membrane protein 2 isoform A (LAMP-2A) has been implicated in the regulation of CD4+ T cell responses, therefore we aim to evaluate the activation state of CD4+ T cells in PBC, and to investigate the role of LAMP-2A in it. The peripheral blood of PBC patients (PBC, n=42) and healthy controls (HC, n=20) were phenotypically analyzed, and LAMP-2A expression in CD4+ T cells was assessed by flow cytometry. Naïve CD4+ T cells of PBC patients were isolated and activated in vitro to estimate their activation responses. Additionally, we assessed the changes induced by silencing LAMP-2A expression. We found that CD4+ T cells of PBC patients exhibited significant hyperactivity, and naïve CD4+ T cells showed high LAMP-2A expression, which could be a novel biomarker for PBC activity. Moreover, by interfering with LAMP-2A expression in vitro, the overreactions of PBC naïve CD4+ T cells were reversed. Our study will help to clarify that increased LAMP-2A expression in the naïve CD4+ T cells of PBC patients may lead to a tendency for increased activation responses, which may be involved in the development and progression of PBC. To reverse the hyperactivity of CD4+ T cells and reduce the resulting biliary injury, LAMP-2A could be a novel therapeutic target for the treatment of PBC.