Guillain–Barre’ syndrome (GBS) is an acute inflammatory and immune-mediated demyelinating disease of peripheral nervous system (PNS). Macrophages playing a central role in its animal model, experimental autoimmune neuritis (EAN) has been well-accepted. Additionally, NF-κB inhibitors has been used to treat cancers and showed beneficial effects. Here we investigated the therapeutic effect of M2 macrophage and NF-κB pathway is correlated with macrophages activation in experimental autoimmune neuritis (EAN) in C57BL/6 mice. We demonstrated that M2 macrophage transfusion can alleviate the clinical symptoms of EAN by reducing the proportion of M1 macrophage in the peak period, inhibiting the phosphorylation of NF-κB p65. The NF-κB inhibitor (BAY-11-7082) could alleviate the clinical symptoms of EAN and shorten the duration of symptoms by reducing the proportion of M1 macrophages and the expression of pro-inflammatory cytokines. Consequently, BAY-11-7082 exhibits strong potential as a therapeutic strategy for ameliorating EAN by influencing the balance of M1/M2 macrophages and inflammatory cytokines.
COVID-19 has been associated with both transient and persistent systemic symptoms that do not appear to be a direct consequence of viral infection. The generation of autoantibodies has been proposed as a mechanism to explain these symptoms. To understand this phenomenon in more detail, we investigated the frequency and specificity of clinically relevant autoantibodies in 84 individuals previously infected with SARS-CoV-2, suffering from COVID-19 of varying severity in both the acute and convalescent setting. These were compared with results from 32 individuals who were on ITU for non COVID reasons. We demonstrate a higher frequency of autoantibodies in the COVID-19 ITU group compared with non-COVID-19 ITU disease control patients and that autoantibodies were also found in the serum 3-5 months post COVID-19 infection. Non-COVID patients displayed a diverse pattern of autoantibodies; in contrast, the COVID-19 groups had a more restricted panel of autoantibodies including skin, skeletal muscle and cardiac antibodies. Our results demonstrate that severe COVID-19 induces a pattern of autoantibodies that may correlate with and contribute to the immune pathology associated with the long-term sequelae of infection.
Since December 2019, Coronavirus disease-19 (COVID-19) has spread rapidly across the world, leading to a global effort to develop vaccines and treatments. Despite extensive progress, there remains a need for treatments to bolster the immune responses in infected immunocompromised individuals, such as cancer patients who recently underwent a haematopoietic stem cell transplantation. Immunological protection against COVID-19 is mediated by both short-lived neutralising antibodies and long-lasting virus-reactive T cells. Therefore, we propose that T cell therapy may augment efficacy of current treatments. For the greatest efficacy with minimal adverse effects, it is important that any cellular therapy is designed to be as specific and directed as possible. Here, we identify T cells from COVID-19 patients with a potentially protective response to two major antigens of the SARS-CoV-2 virus, Spike and Nucleocapsid protein. By generating clones of highly virus-reactive CD4+ T cells, we were able to confirm a set of 9 immunodominant epitopes and characterise T cell responses against these. Accordingly, the sensitivity of T cell clones for their specific epitope, as well as the extent and focus of their cytokine response was examined. Moreover, by using an advanced T cell receptor (TCR) sequencing approach, we determined the paired TCR sequences of clones of interest. While these data on a limited population require further expansion for universal application, the results presented here form a crucial first step towards TCR-transgenic CD4+ T cell therapy of COVID-19.
Signal transducer and activator of transcription 3 (STAT3) gain-of-function (GOF) syndrome is an early-onset monogenic inborn error of immunity characterized by multi-organ autoimmune disorders, growth failure and lymphoproliferation. We describe that STAT3 GOF syndrome may be presented with hypogammaglobulinemia and recurrent severe upper and lower respiratory tract infections. The patient we present here did not have multi-organ autoimmunity and lacked early-onset autoimmune manifestations. Chest CT examinations showed mild bronchiectasis with areas of non-fibrosing alveolar-interstitial disease and maldevelopment of bilateral first ribs. By using Sanger sequencing, we revealed a novel c.508G>C, p.D170H STAT3 variant affecting the coiled coil domain (CCD) of STAT3. Functional studies confirmed that p.D170H was a GOF variant as showed by increased pSTAT3 and STAT3 transcriptional activity. Our observation suggests that STAT3 GOF syndrome can manifest in early childhood with hypogammaglobulinemia and recurrent severe respiratory tract infections and may lack autoimmune manifestations. We suggest that patients with hypogammaglobulinemia and severe, recurrent infections should be screened for STAT3 variants even if autoimmune manifestations are missing.
Summary Myelin oligodendrocyte glycoprotein antibody associated disorders (MOGAD) are rare in both children and adults, and have been recently suggested to be an autoimmune neuroinflammatory group of disorders that are different from aquaporin-4 autoantibody associated neuromyelitis optica spectrum disorder and from classic multiple sclerosis. In vivo imaging of the MOGAD patient central nervous system has shown some distinguishing features when evaluating magnetic resonance imaging of the brain, spinal cord, optic nerves, as well as retinal imaging using optical coherence tomography. In this review, we discuss key clinical and imaging characteristics of paediatric and adult MOGAD. We describe how these imaging techniques may be used to study this group of disorders and discuss how these imaging methods have led to recent insights for consideration in future studies.
Free light chains (FLC), considered a biomarker of B cell activity, are frequently elevated in different systemic inflammatory-autoimmune diseases. As systemic sclerosis (SSc) clinical course may be variable, this study aimed to assess FLCs levels in serum and urine of affected individuals, as biomarkers of disease activity. We assessed FLC levels in serum and urine of 72 SSc patients and 30 healthy controls (HC). Results were analyzed in comparison with overall clinical and laboratory findings, disease activity index (DAI) and disease severity scale (DSS). SSc patients displayed increased levels of k and λ FLC in serum, significantly higher than HC (p=0.0001) alongside with the mean levels of free k/λ ratio and of the k+λ sum (p=0.0001). In addition, SSc patients had significant higher levels in the urine of free k and of k/λ ratio than HC (p=0.0001). SSc patients with increased k+λ sum in serum showed a statistically higher levels of erythro-sedimentation rate (p=0.034), C-reactive protein (p=0.003), higher DAI (p=0.024) and DSS (p=0.015) than SSc patients with normal levels of FLC. A positive linear correlation was found between serum levels of free k and DAI (r=0.29, p=0.014). SSc patients with increased free k in urine had statistically higher DAI (p=0.048) than SSc patients with normal level of free k. The significant increased levels of FLC correlated with disease activity in SSc patients. Our results strengthen the role of FLC as useful biomarkers in clinical practice to early diagnosis and monitor disease activity with an improvement of SSc patients’ management.
Background: Typical murine models of allergic inflammation are induced by the combination of ovalbumin and aluminum hydroxide. However, accumulating evidence indicates that, in models of asthma and atopic dermatitis, allergic inflammation can be generated in the absence of aluminum hydroxide. Moreover, co-administration of S. aureus enterotoxin B with ovalbumin can enhance inflammation. Objective: The objective of this study was to establish a rapid and mast cell-dependent murine model of allergic inflammation by inducing allergic peritonitis using ovalbumin and S. aureus enterotoxin B. Methods: Allergic peritonitis was induced in C57BL/6 mice by subcutaneous sensitization and intraperitoneal challenge with ovalbumin and S. aureus enterotoxin B. Disease characteristics were assessed by flow cytometry, ELISA, Trypan Blue exclusion and colorimetric assays. Results: Time course of the allergic peritonitis revealed a peak of peritoneal inflammation 48h after challenge, as assessed by total cells and eosinophil counts. Decrease of cell numbers started 96h post challenge with complete clearance within 168h. Moreover, significantly higher levels of tryptase and increased vascular permeability were found 30 min following challenge. Allergic inflammation induction by ovalbumin and S. aureus enterotoxin B was impaired in mast cells deficient mice and partially restored by mice reconstitution with bone marrow derived mast cells, indicating the mast cell role in this model. Conclusion: We present a novel model of allergic peritonitis that is mast cell-dependent, simple and robust. Moreover, the use of S. aureus enterotoxin B better resembles human allergic inflammation, which is known to be characterized by the colonization of Staphylococcus aureus.
Arthritis is a common clinical feature of systemic lupus erythematosus (SLE) and is usually non-erosive as opposed to rheumatoid arthritis (RA). While RA synovial pathology has been extensively studied, little is known about the pathophysiology of lupus arthritis. Here, we aimed to explore the cytokine and cellular compartments in synovial fluids of SLE patients with arthritic manifestations. Acellular synovial fluid and paired serum samples from SLE patients (n=17) were analyzed with cytokine bead array for T helper associated cytokines. From two SLE patients, synovial fluid mononuclear cells (SFMC) were analyzed by multiparameter flow cytometry to dissect T cell, B cell, monocyte and dendritic cell phenotypes. SLE-derived SFMC were further stimulated in vitro to measure their capacity for producing IFN and IL-17A. All patients fulfilled the ACR 1982 classification criteria for SLE. Clinical records were reviewed to exclude the presence of comorbidities such as osteoarthritis or overlap with RA. IL-17A and IL-6 levels were high in SLE synovial fluid. A clear subset of the synovial CD4+ T cells expressed CCR6+, a marker associated with Th17 cells. IL-17-production was validated amongst CD4+CCR6+ T cells following in vitro stimulation. Furthermore, a strong IFN production was observed in both CD4+ and CD8+ cells. Our study shows high IL-17A and IL-6 levels in synovial fluids of patients with lupus arthritis. The Th17 pathway have been implicated in several aspects of SLE disease pathogenesis and our data points to Th17 involvement also for lupus arthritis.
Adoptive immunotherapy using Epstein-Barr Virus (EBV)-specific T cells is a potentially curative treatment for patients with EBV-related malignancies where other clinical options have proved ineffective. We describe improved GMP-compliant culture and analysis processes for conventional lymphoblastoid cell line (LCL)-driven EBV-specific T cell manufacture, and describe an improved phenotyping approach for analyzing T cell products. We optimized the current LCL-mediated clinical manufacture of EBV-specific T cells to establish an improved process using xenoprotein-free GMP-compliant reagents throughout, and compared resulting products with our previous banked T cell clinical therapy. We assessed effects of changes to LCL: T cell ratio in T cell expansion, and developed a robust flow cytometric marker panel covering T cell memory, activation, differentiation and intracellular cytokine release to characterize T cells more effectively. These data were analyzed using t-Stochastic Neighbour Embedding (t-SNE) algorithm. The optimized GMP-compliant process resulted in reduced cell processing time and improved retention and expansion of central memory T cells. Multi-parameter flow cytometry determined the optimal protocol for LCL stimulation and expansion of T cells and demonstrated that cytokine profiling using IL-2, TNF-α and IFN-γ was able to determine the differentiation status of T cells throughout culture and in the final product. We show that fully GMP-compliant closed-process culture of LCL-mediated EBV-specific T cells is feasible and profiling of T cells through cytokine expression gives improved characterization of start material, in-process culture conditions and final product. Visualization of the complex multi-parameter flow cytometric data can be simplified using t-SNE analysis.
Peptides that bind to and are presented on the cell surface by Human Leukocyte Antigens (HLA) molecules play a critical role in adaptive immunity. For a long time, it was believed all of the HLA bound peptides were generated through simple proteolysis of linear sequences of cellular proteins, and therefore, are templated in the genome and proteome. However, evidence for untemplated peptide ligands of HLA molecules has accumulated over the last two decades, with a recent global analysis of HLA-bound peptides suggesting that a considerable proportion of HLA bound peptides are potentially generated through splicing/fusion of discontinuous peptide segments from one or two distinct proteins. In this review, we will review recent discoveries and debates on the contribution of spliced peptides to the HLA class I immunopeptidome, consider biochemical rules for splicing, and the potential role of these spliced peptides in immune recognition.
The impact of treatment on the risk of lymphoma in patients with rheumatoid arthritis (RA) is unclear. Here, we aimed to assess if the risk of lymphoma differs according to the type of Tumor Necrosis factor inhibitor (TNFi), comparing monoclonal anti-TNF antibodies (Ab) to the soluble TNF receptor. We used BAFF-transgenic (Tg) mice as a model of autoimmunity-associated lymphoma. Six-month aged BAFF-Tg mice were treated with TNFi for 12 months. Histological examination of the spleen, assessment of the cellular composition of the spleen by flow cytometry and assessment of B cell clonality were performed at sacrifice. Crude mortality and incidence of lymphoma were significantly higher in mice treated with monoclonal anti-TNF Ab compared to both controls and mice treated with the soluble TNF receptor, even at high dose. Flow cytometry analysis revealed decreased splenic macrophage infiltration in mice treated with monoclonal anti-TNF Ab. Overall, this study demonstrates, for the first time, that a very prolonged treatment with monoclonal anti-TNF Ab increase the risk of lymphoma in B cell-driven autoimmunity. This data suggests a closer monitoring for lymphoma development in patients suffering from B cell-driven autoimmune disease with long-term exposure to monoclonal anti-TNF Ab.
Introduction The mechanisms that drives SLE remission.The aim of the present study was to measure CD4+ and CD8+ T cell exhaustion in SLE patients in prolonged remission (PR-SLE) and compared them with patients with active SLE (Act-SLE) and healthy subjects Methods We included 15 PR-SLE patients, 15 Act-SLE and 29 healthy subjects. T-cell exhaustion was determined by flow cytometry according to the expression of PD-1, Tim-3, 2B4, EOMES and T-bet in CD4+ and CD8+ T cells. Dimensionality reduction using the t-Distributed Stochastic Neighbor Embedding algorithm and Clustering Analysis was used for the identification of relevant populations. Results Percentages of CD3+, CD4+ and CD8+ T cells were similar among groups. We identified five subpopulations of CD8+ and seven of CD4+ cells. The CD4+Tbet+CD45RO+ cells identified in the unsupervised analysis were significantly increased in PR-SLE vs Act-SLE (median: 10.20, IQR: 1.74-30.50 vs. 1.68, IQR: 0.4-2.83; p<0.01). CD4+EOMES+ cells were also increased in PR-SLE vs Act-SLE (5.24, IQR: 3.38-14.70 vs. 1.39, IQR: 0.48-2.87; p<0.001). CD8+ EOMES+ cells were increased in PR-SLE vs Act-SLE (37.6, IQR: 24.9-53.2 vs 8.13, IQR: 2.33-20.5; p<0.001). Exhausted and activated T cells presented an increased frequency of PD-1, CD57 and EOMES in SLE patients vs healthy subjects. Conclusions Some subpopulations of T cells expressing markers associated with exhaustion are increased in patients in remission, supporting T-cell exhaustion as a tolerance mechanism in SLE. Exhaustion of specific populations of T cells might represent a potential therapeutic tool that will contribute to the goal of achieving sustained remission in these patients.
The factors responsible for the spectrum of COVID-19 disease severity and the genesis and nature of protective immunity against COVID-19 remain elusive. Multiple studies have investigated the immune responses to COVID 19 in various populations, including those without evidence of COVID 19 infection. Information regarding innate and adaptive immune responses to the novel SARS-CoV-2 has evolved rapidly. Here, data are accumulating defining disease phenotypes that aid in rational and informed development of new therapeutic approaches for the treatment of patients infected with SARS-CoV-2 and the development of novel vaccines. In this article, we summarize data on important innate immune responses including cytokines, specifically IL-6 and complement, and explore potential treatments. We also examine adaptive immune responses and derivative therapeutics such as monoclonal antibodies directed at spike proteins. Finally, we explore data on real-time assessments of adaptive immune responses which include CD4+/CD8+ T-cells, NKT-cells, memory B-cells, and T-follicular cells with specificities for COVID-19 peptides in infected individuals and normals. Data of two novel vaccines have been released, both showing >95% efficacy in preventing SARS-CoV-2 infection. Analysis of humoral and cellular responses to the vaccines will determine the robustness and durability of protection. In addition, long-term assessment of SARS-CoV-2 memory B and T-cell mediated immune responses in patients recovering from an infection or those with cross-reactive immunologic memory will help to define risk for future SARS-CoV infections. Finally, patients recovering from SARS-CoV-2 infection may experience prolonged immune activation likely due to T-cell exhaustion. This will be an important new frontier for study.
When Thetis dipped her son Achilles into the River Styx to make him immortal, she held him by the Heel, which was not submerged, and thus created a weak spot that proved deadly for Achilles. Millennia later, Achilles Heel is part of today’s lexicon meaning an area of weakness or a vulnerable spot that causes failure. Also implied is that an Achilles Heel is often missed, forgotten or underappreciated, until it is under attack, and then failure is fatal. Paris killed Achilles with an arrow ‘guided by the Gods’. At the International Congress of the Immunology of Diabetes Society, 2018, five leading experts were asked to present the case for a particular cell/element that could represent the Achilles Heel of T1D. Their arguments are summarized here, to make this case.
Being the leading cause of mortality by a single infectious agent, tuberculosis (TB) continues as one of the most relevant issues of public health. Another pandemic disease is type 2 diabetes mellitus (T2D) is usually associated with immunodeficiency. Thus, an increased prevalence of TB-T2D comorbidity represents one of the most significant challenges for health providers. During the chronic phase of both diseases, several immunoendocrine abnormalities are occurring, but extra-adrenal production of active glucocorticoids (GCs) is a possible deleterious factor in both entities. Active GCs have been related to insulin resistance and suppression of Th1 responses, contributing to T2D and TB pathogenesis. 11-β-hydroxysteroid dehydrogenase type 1 (11-βHSD1) catalyzes the conversion of inactive GGs in their active form (cortisol or corticosterone in rodents) in the lungs and liver and could be responsible for this immunoendocrine disfunction. Dehydroepiandrosterone (DHEA) is an anabolic adrenal hormone with antagonist effects against GCs on immune cells and glucose metabolism. A synthetic analog of DHEA, the 16a-bromoepindrosterone (BEA), lacks an anabolic effect while keeping his immune and metabolic effect. The therapeutic efficiency of BEA was studied in a murine model of T2D-TB comorbidity. TB-T2D mice underwent more severe lung disease than in TB-infected but non-diabetic animals. BEA decreased the active form of GCs and 11-βHSD1 expression, while increasing 11-βHSD2 expression, which reduced hyperglycemia and liver steatosis, lung bacillary loads, and pneumonia. Thus, it seems that BEA is an efficient therapy to control metabolic and immune abnormalities caused by high active GCs production.
Autoimmune neutropenia (AIN) in childhood is characterized by chronic neutropenia and positivity for antineutrophil antibodies, resulting in the excessive destruction of neutrophils. In this study, we investigated the involvement of regulatory T cells (Tregs) in the pathogenesis of AIN in childhood. Tregs have been classified into three subpopulations based on the expressions of CD45RA and FOXP3: resting Tregs, activated Tregs, and non-suppressive Tregs. The frequency of activated Tregs (CD4+CD25+FOXP3highCD45RA− T cells) as well as that of total Tregs (CD4+CD25+FOXP3+ T cells) in peripheral blood was significantly decreased in patients with AIN. Analysis of the T cell receptor (TCR)-Vβ repertoire of CD4+ T cells revealed skewed usages in patients with AIN compared with that observed in age-matched control subjects. Regarding T cell subsets, the use of four of 24 TCR-Vβ families in Tregs and one in conventional T cells were increased in patients with AIN. The number of patients with AIN who showed skewed usages of TCR-Vβ family in conventional and Tregs was significantly higher than that reported in control subjects. When the preference between Tregs and conventional T cells in each TCR-Vβ family was individually compared, different use was prominently observed in the TCR-Vβ 9 family in patients with AIN. These results suggest that the quantitative abnormalities of Tregs and the skew of the TCR-Vβ repertoire in CD4+ T cells, including Tregs and conventional T cells, may be related to autoantibody production through a human neutrophil antigen-reactive T cell clone.
Tuberculosis kills more people than any other single infectious disease globally. Despite decades of research, there is no vaccine to prevent TB transmission. Bacille Calmette-Guerin (BCG) vaccine developed a century ago has little effect on pulmonary TB and does not control transmission. Lack of an effective vaccine emanates from lack of knowledge on correlates of protective immunity on which to base vaccine design and development. However, some household contacts who are extensively exposed to Mtb infection remain persistently negative to tuberculin skin test and interferon-gamma assay. These individuals called “resisters” clear Mtb infection early before the development of acquired immunity. The immunological basis of early Mtb clearance is yet to be established, however, innate lymphocytes such as monocytes/macrophages, dendritic cells, neutrophils and natural killer cells, and innate like T cells such as mucosal associated invariant T cells, invariant natural killer T cells and gamma-delta (γδ) T cells have been implicated in this early protection. One of the cells that has attracted increasing attention in recent years, in protection against Mtb is the natural killer cell. Emerging data from animal and epidemiological studies indicate that NK cells may play a significant role in the fight against Mtb. NK cells express various surface markers to recognize and kill both Mtb and Mtb-infected cells. In this review, recent advances in our understanding of NK cells in the fight against Mtb early during infection, with emphasis on cohort studies, will be presented.
Tissue damage associated with trauma might release a sufficient autoantigen substrate to break immune tolerance. In a previous study, we showed that the leukopenia observed following severe inflammation is related to adenosine A1-receptor (A1R) desensitization and A2AR upregulation. We hypothesized that, under destructive pathological conditions this mechanism is beneficial in reducing prevalence of autoimmunity. In this study, we aim to evaluate the protective role of A1R and A2AR in prevention of autoimmune diseases. We used two murine models of autoimmune diseases: type 1 diabetes (T1D) induced by low-dose streptozotocin and pristane-induced lupus (PIL) and on neutrophils we studied NETosis regulation by adenosine. In both the T1D and PIL models, A1R-KO mice were predisposed to the development of autoimmunity. In the PIL model, in WT mice, parallel to the decline of A1R mRNA levels, lymphocytes number dropped (-85%) 6h after pristane injection. WT mice remained without any sign of disease at 36 weeks. In contrast, following pristane 43% of A1R-KO mice suffered from lupus-like disease. Compared to A1R-KO, in WT mice at 10 days A2AR mRNA levels were significantly higher. Similar to PIL, in T1D model the presence of A1R and A2AR was protective. In addition, we found that A1R increases and A2AR suppresses NETosis. We suggest that adenosine-dependent immune suppression and reduction in neutrophil extracellular traps (NETs) limits the reactive T-cells and development of anti-double strand DNA (dsDNA) antibodies that promote autoimmunity.