IL-6: regulator of Treg/Th17 balance

Extracellular vesicles from virulent P. brasiliensis induce TLR4 and dectin-1 expression in innate cells and promote enhanced Th1/Th17 response

Extracellular vesicles (EVs) are membrane-enclosed nanoparticles that transport several biomolecules and are involved in important mechanisms and functions related to the pathophysiology of fungal diseases. EVs from Paracoccidioides brasiliensis, the main causative agent of Paracoccidioidomycosis (PCM), modulate the immune response of macrophages. In this study, we assessed the EVs proteome from a virulent P. brasiliensis isolated from granulomatous lesions and compared their immunomodulatory ability with EVs isolated from the fungus before the animal passage (control EVs) when challenging macrophages and dendritic cells (DCs). Proteome showed that virulent EVs have a higher abundance of virulence factors such as GP43, protein 14-3-3, GAPDH, as well as virulence factors never described in PCM, such as aspartyl aminopeptidase and a SidJ analogue compared with control EVs. Virulent extracellular vesicles induced higher expression of TLR4 and Dectin-1 than control EVs in macrophages and dendritic cells (DCs). In opposition, a lower TLR2 expression was induced by virulent EVs. Additionally, virulent EVs induced lower expression of CD80, CD86 and TNF-α, but promoted a higher expression of IL-6 and IL-10, suggesting that EVs isolated from virulent P. brasiliensis-yeast promote a milder DCs and macrophage maturation. Herein, we showed that EVs from virulent fungi stimulated a higher frequency of Th1/Tc1, Th17, and Treg cells, which gives new insights into fungal extracellular vesicles. Taken together, our results suggest that P. brasiliensis utilizes its EVs as virulence bags that manipulate the immune system in its favour, creating a milder immune response and helping with fungal evasion from the immune system.

Regulatory T cell-based therapy in type 1 diabetes: Latest breakthroughs and evidence

Autoimmune diseases (ADs) are among the most significant health complications, with their incidence rising in recent years. Type 1 diabetes (T1D), an AD, targets the insulin-producing β cells in the pancreas, leading to chronic insulin deficiency in genetically susceptible individuals. Regulatory immune cells, particularly T-cells (Tregs), have been shown to play a crucial role in the pathogenesis of diabetes by modulating immune responses. In diabetic patients, Tregs often exhibit diminished effectiveness due to various factors, such as instability in forkhead box P3 (Foxp3) expression or abnormal production of the proinflammatory cytokine interferon-gamma (IFN-γ) by autoreactive T-cells. Consequently, Tregs represent a potential therapeutic target for diabetes treatment. Building on the successful clinical outcomes of chimeric antigen receptor (CAR) T-cell therapy in cancer treatment, particularly in leukemias, the concept of designing and utilizing CAR Tregs for ADs has emerged. This review summarizes the findings on Treg targeting in T1D and discusses the benefits and limitations of this treatment approach for patients suffering from T1D.

Immunosenescence, immunotolerance and rejection: clinical aspects in solid organ transplantation

As a consequence of increased lifespan and rising number of elderly individuals developing end-stage organ disease, the higher demand for organs along with a growing availability for organs from older donors pose new challenges for transplantation. During aging, dynamic adaptations in the functionality and structure of the biological systems occur. Consistently, immunosenescence (IS) accounts for polydysfunctions within the lymphocyte subsets, and the onset of a basal but persistent systemic inflammation characterized by elevated levels of pro-inflammatory mediators. There is an emerging consensus about a causative link between such hallmarks and increased susceptibility to morbidities and mortality, however the role of IS in solid organ transplantation (SOT) remains loosely addressed. Dissecting the immune-architecture of immunologically-privileged sites may prompt novel insights to extend allograft survival. A deeper comprehension of IS in SOT might unveil key standpoints for the clinical management of transplanted patients.

Intragastric administration of transamidated gliadin interferes with the systemic and intestinal immune responses to wheat gliadin in DQ8 transgenic mice

We have previously shown the ability of transamidated gluten (spf) to modulate both innate and adaptive intestinal immunity elicited by wheat gliadin in HLA-DQ8 transgenic mice (DQ8 mice), a model of gluten sensitivity. Herein, we evaluated the influence of spf when administered intragastrically on the immune response to native gliadin in DQ8 mice. To address the issue, we analysed three regimens of antigen administration: before immunisation (pre-treatment), during immunisation (co-treatment) and through breast milk during the lactating phase (suckling treatment). Mice were immunised mucosally by intranasal delivery of digested wheat gliadin along with cholera toxin in multiple doses. After sacrifice, isolated spleen and mesenteric lymph node (MLN) cells were challenged in vitro and the cytokine profile of culture supernatants assessed by ELISA and multiparametric assay. We found that only pre-treatment with spf was effective in down-regulating the gliadin-specific IFN-γ response and only in spleen cells. Interestingly, spf pre-treatment also induced systemic IL-6, IL-17A and TNF-α. By contrast, we found that spf pre-treatment upregulated INF-γ in MLN but also significantly decreased IL-2. In conclusion, our data provide evidence that the preventive intragastric administration of transamidated gluten is able to interfere with the classical cytokine profile induced by gliadin via mucosal immunisation in a transgenic model expressing one of the HLA molecules associated with coeliac disease.

Regulatory T Cells in Pathological Cardiac Hypertrophy: Mechanisms and Therapeutic Potential

BACKGROUND

Pathological cardiac hypertrophy is linked to immune-inflammatory injury, and regulatory T cells (Tregs) play a crucial role in suppressing immune-inflammatory responses. However, the precise role of Tregs in pathological cardiac hypertrophy remains unclear.

OBJECTIVE

To summarize the current knowledge on the role and mechanisms of Tregs in pathological cardiac hypertrophy and explore their perspectives and challenges as a new therapeutic approach.

RESULTS

Treg cells may play an important protective role in pressure overload (hypertension, aortic stenosis), myocardial infarction, metabolic disorders (diabetes, obesity), acute myocarditis, cardiomyopathy (hypertrophic cardiomyopathy, storage diseases), and chronic obstructive pulmonary disease-related pathological cardiac hypertrophy. Although some challenges remain, the safety and efficacy of Treg-based therapies have been confirmed in some clinical trials, and engineered antigen-specific Treg cells may have better clinical application prospects due to stronger immunosuppressive function and stability.

CONCLUSION

Targeting the immune-inflammatory response via Treg-based therapies might provide a promising and novel future approach to the prevention and treatment of pathological cardiac hypertrophy.

Deciphering the mechanisms of the IL-6/CXCL1 and NOD-like receptor signaling pathways in otitis media with effusion in rodents

BACKGROUND

Otitis media with effusion (OME) often leads to pediatric hearing loss and is influenced by innate and adaptive immune responses. Innate immunity serves as the non-specific first line of defense against OME.

METHODS

We induced OME in rats using ovalbumin. We administered IL-6 monoclonal antibodies intranasally to inhibit IL-6, and we injected an NF-κB inhibitor intraperitoneally to explore the role of IL-6 in innate immunity and its interaction with the NOD-like receptor signaling pathway. We analyzed RNA-sequencing data with Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways to assess signaling pathways involved in OME. We also utilized Western blot, quantitative real-time PCR, and immunohistochemistry on middle ear samples and used microscopy to identify immune cells in ear wash fluids.

RESULTS

Our study suggests a pivotal role for IL-6 in the immune pathways of rats with OME via the regulation of CXCL1-mediated pathways. Increased levels of IL-6 and CXCL1 were observed in the middle ear tissues, and activation of the NLRP3 inflammasome in OME rats led to an immune response via NF-κB, thus promoting IL-6 and CXCL1 production, which was reduced by IL-6 antibody treatment.

CONCLUSIONS

Our findings confirm that IL-6 and CXCL1 play significant roles in the innate immune response in OME in rodents, predominantly via the NOD-like receptor signaling pathway and NLRP3 inflammasome activation. This research sheds light on OME pathogenesis and its immune-related mechanisms.

Bronchoalveolar lavage fluid analysis in patients with checkpoint inhibitor pneumonitis

BACKGROUND

Checkpoint inhibitor pneumonitis (CIP) is a relatively uncommon but potentially life-threatening immune-related adverse event (irAE). Lung biopsies have not been commonly performed for CIP patients. Bronchoalveolar lavage fluid (BALF) analysis is a useful diagnostic approach for interstitial lung disease. However, BALF features were inconsistent across different studies.

METHODS

We retrospectively reviewed the medical records of 154 patients with pathologically confirmed malignancies and suffering from CIPs between July 2018 and December 2022. Patients who had bronchoalveolar lavage (BAL) data available were enrolled in our study. Patient clinical, laboratory, radiological and follow-up data were reviewed and analyzed.

RESULTS

The BALF differential cell count and lymphocyte subset analysis were performed for 42 CIP patients. There were 32 males (76.2%). The mean age at diagnosis of CIP was 62.0 ± 10.4 (range: 31-78) years. The median time to onset of CIP was 98.5 days after the start of immunotherapy. There were 18 patients (42.9%) with low-grade CIPs and 24 patients (57.1%) with high-grade CIPs. The mean lymphocyte percentage was 36.7 ± 22.5%. There were 34 (81%) CIP patients with a lymphocytic cellular pattern. The median ratio of CD3+CD4+/CD3+CD8+ lymphocytes was 0.5 (0.3, 1.0). The ratio was less than 1.0 for 31 CIP patients (73.8%). However, there was no significant difference in the BALF features between patients with low-grade CIPs and those with high-grade CIPs.

CONCLUSIONS

The CD3+CD8+ lymphocytosis pattern was the main inflammatory profile in the BALF of CIP patients in this cohort. Targeting CD3+CD8+ lymphocytes might be a treatment option for CIPs.

Genetic evidence for efficacy of targeting IL-2, IL-6 and TYK2 signalling in the prevention of type 1 diabetes: a Mendelian randomisation study

AIMS/HYPOTHESIS

We aimed to investigate the genetic evidence that supports the repurposing of drugs already licensed or in clinical phases of development for prevention of type 1 diabetes.

METHODS

We obtained genome-wide association study summary statistics for the risk of type 1 diabetes, whole-blood gene expression and serum protein levels and investigated genetic polymorphisms near seven potential drug target genes. We used co-localisation to examine whether the same genetic variants that are associated with type 1 diabetes risk were also associated with the relevant drug target genetic proxies and used Mendelian randomisation to evaluate the direction and magnitude of the associations. Furthermore, we performed Mendelian randomisation analysis restricted to functional variants within the drug target genes.

RESULTS

Co-localisation revealed that the blood expression levels of IL2RA (encoding IL-2 receptor subunit α [IL2RA]), IL6R (encoding IL-6 receptor [IL6R]) and IL6ST (encoding IL-6 cytokine family signal transducer [IL6ST]) shared the same causal variant with type 1 diabetes liability near the corresponding genes (posterior probabilities 100%, 96.5% and 97.0%, respectively). The OR (95% CI) of type 1 diabetes per 1-SD increase in the genetically proxied gene expression of IL2RA, IL6R and IL6ST were 0.22 (0.17, 0.27), 1.98 (1.48, 2.65) and 1.90 (1.45, 2.48), respectively. Using missense variants, genetically proxied TYK2 (encoding tyrosine kinase 2) expression levels were associated with type 1 diabetes risk (OR 0.61 [95% CI 0.54, 0.69]).

CONCLUSIONS/INTERPRETATION

Our findings support the targeting of IL-2, IL-6 and TYK2 signalling in prevention of type 1 diabetes.

DATA AVAILABILITY

The analysis code is available at https://github.com/jkoskenniemi/T1DSCREEN , which also includes instructions on how to download the original GWAS summary statistics.

ANCA-associated vasculitis and lung cancer: an immunological perspective

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a severe autoimmune disease that often involves the upper and lower respiratory tracts. In recent years, numerous studies have found a significant increase in the incidence of cancer among AAV patients, but the association between lung cancer and AAV remains inconclusive, with relatively low clinical attention. This review summarizes the current literature on the risk of lung cancer in patients with ANCA-associated vasculitis (AAV), detailing the potential mechanisms by which AAV may contribute to lung cancer, and further elucidates the inherent carcinogenic risks of immunosuppressants.There is a correlation between AAV and lung cancer, which is related to T cell senescence and damage, as well as the abnormal expression of cytokines such as IL-6 and IL-10. In AAV patients, the use of cyclophosphamide and azathioprine (AZA) alone has a clear carcinogenic risk, with frequent use of CYC potentially posing a high risk for lung cancer. Although TNF inhibitors (TNFi) combined with CYC have carcinogenic risks, there is insufficient evidence to link them directly to an increased risk of lung cancer. For patients at high risk for lung cancer, the judicious use of immunosuppressants, timely computed tomography (CT), and lung cancer screening can reduce the risk of lung cancer in AAV patients.

Microbiota-immune-brain interactions: A new vision in the understanding of periodontal health and disease

This review highlights the significance of interactions between the microbiota, immune system, nervous and hormonal systems, and the brain on periodontal health and disease. Microorganisms in the microbiota, immune cells, and neurons communicate via homeostatic nervous and hormonal systems, regulating vital body functions. By modulating pro-inflammatory and anti-inflammatory adaptive immune responses, these systems control the composition and number of microorganisms in the microbiota. The strength of these brain-controlled responses is genetically determined but is sensitive to early childhood stressors, which can permanently alter their responsiveness via epigenetic mechanisms, and to adult stressors, causing temporary changes. Clinical evidence and research with humans and animal models indicate that factors linked to severe periodontitis enhance the responsiveness of these homeostatic systems, leading to persistent hyperactivation. This weakens the immune defense against invasive symbiotic microorganisms (pathobionts) while strengthening the defense against non-invasive symbionts at the gingival margin. The result is an increased gingival tissue load of pathobionts, including Gram-negative bacteria, followed by an excessive innate immune response, which prevents infection but simultaneously destroys gingival and periodontal tissues. Thus, the balance between pro-inflammatory and anti-inflammatory adaptive immunity is crucial in controlling the microbiota, and the responsiveness of brain-controlled homeostatic systems determines periodontal health.

TIM-4 increases the proportion of CD4+CD25+FOXP3+ regulatory T cells in the pancreatic ductal adenocarcinoma microenvironment by inhibiting IL-6 secretion

BACKGROUND

Currently, creating more effector T cells and augmenting their functions is a focal point in pancreatic ductal adenocarcinoma (PDAC) treatment research. T cell immunoglobulin domain and mucin domain molecule 4 (TIM-4), known for promoting cancer progression in various malignancies, is implicated in the suppressive immune microenvironment of tumors. Analyzing of the role of TIM-4 in the immune regulation of PDAC can offer novel insights for immune therapy.

METHODS

We analyzed the TIM-4 expression in tumor specimens from PDAC patients. Meanwhile, multiple fluorescent immunohistochemical staining was used to study the distribution characteristics of TIM-4, and through tissue microarrays, we explored its correlation with patient prognosis. The influence of TIM-4 overexpression on cell function was analyzed using RNA-seq. Flow cytometry and ELISA were used for verification. Finally, the relationship between TIM-4 and T lymphocytes was analyzed by tissue microarray, and the impacts of TIM-4 on T cell subsets were observed by cell coculture technology and a mouse pancreatic cancer in situ model.

RESULTS

In PDAC, TIM-4 is mainly expressed in tumor cells and negatively correlated with patient prognosis. TIM-4 influences the differentiation of Treg by inhibiting IL-6 secretion in pancreatic cancer cells and facilitates the proliferation of pancreatic cancer in mice. Additionally, the mechanism may be through the CD8+ effector T cells (CD8+Tc).

CONCLUSION

TIM-4 has the potential to be an immunotherapeutic target or to improve the efficacy of chemotherapy for PDAC.

Circular RNAs in human diseases

Circular RNAs (circRNAs) are a unique class of RNA molecules formed through back-splicing rather than linear splicing. As an emerging field in molecular biology, circRNAs have garnered significant attention due to their distinct structure and potential functional implications. A comprehensive understanding of circRNAs' functions and potential clinical applications remains elusive despite accumulating evidence of their involvement in disease pathogenesis. Recent research highlights their significant roles in various human diseases, but comprehensive reviews on their functions and applications remain scarce. This review provides an in-depth examination of circRNAs, focusing first on their involvement in non-neoplastic diseases such as respiratory, endocrine, metabolic, musculoskeletal, cardiovascular, and renal disorders. We then explore their roles in tumors, with particular emphasis on exosomal circular RNAs, which are crucial for cancer initiation, progression, and resistance to treatment. By detailing their biogenesis, functions, and impact on disease mechanisms, this review underscores the potential of circRNAs as diagnostic biomarkers and therapeutic targets. The review not only enhances our understanding of circRNAs' roles in specific diseases and tumor types but also highlights their potential as novel diagnostic and therapeutic tools, thereby paving the way for future clinical investigations and potential therapeutic interventions.

IL23R mutations associated with decreased risk of psoriasis lead to the differential expression of genes implicated in the disease

Psoriasis is an incurable immune-mediated skin disease, affecting around 1%-3% of the population. Various lines of evidence implicate IL23 as being pivotal in disease. Genetic variants within the IL23 receptor (IL23R) increase the risk of developing psoriasis, and biologic therapies specifically targeting IL23 demonstrated high efficacy in treating disease. IL23 acts via the IL23R, signalling through the STAT3 pathway, mediating the cascade of events that ultimately results in the clinical presentation of psoriasis. Given the essential role of IL23R in disease, it is important to understand the impact of genetic variants on receptor function with respect to downstream gene regulation. Here we developed model systems in CD4+ (Jurkat) and CD8+ (MyLa) T cells to express either the wild type risk or mutant (R381Q) protective form of IL23R. After confirmation that the model system expressed the genes/proteins and had a differential effect on the phosphorylation of STAT3, we used RNAseq to explore differential gene regulation, in particular for genes implicated with risk to psoriasis, at a single time point for both cell types, and in a time course experiment for Jurkat CD4+ T cells. These experiments discovered differentially regulated genes in the cells expressing wild type and mutant IL23R, including HLA-B, SOCS1, RUNX3, CCR5, CXCR3, CCR9, KLF3, CD28, IRF, SOCS6, TNFAIP and ICAM5, that have been implicated in both the IL23 pathway and psoriasis. These genes have the potential to define a IL23/psoriasis pathway in disease, advancing our understanding of the biology behind the disease.

Efficacy of tocilizumab in highly relapsing MOGAD with an inadequate response to intravenous immunoglobulin therapy: A case series

BACKGROUND

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is an inflammatory disease affecting the central nervous system that may require long-term immunotherapy in relapsing cases. While immunotherapies utilized in neuromyelitis optica spectrum disorder have shown varying efficacy in MOGAD, intravenous immunoglobulin G (IVIG) recently emerged as a promising treatment. Tocilizumab, a monoclonal antibody that targets the interleukin-6 (IL-6) receptor, has been reported to be effective in refractory MOGAD in several case studies, where tocilizumab was introduced primarily due to rituximab failure.

METHODS

This retrospective study was conducted in a single center and focused on MOGAD patients receiving tocilizumab therapy, who have shown limited response to various immunotherapies, including intravenous immunoglobulin G (IVIG) maintenance.

RESULTS

This study included four patients, three adults, and one child. They experienced a median of 9 attacks (range 6-9) throughout their disease course despite at least two immunotherapies. All patients transitioned to tocilizumab after experiencing a median of two relapses (range 1-3) while on IVIG maintenance for a median of 21.9 months (range 21.3-49.6 months). Following the monthly tocilizumab administration at a dose of 8g/kg, all patients remained relapse-free with a median follow-up duration of 25.0 months (range 9.8-51.3 months) without reported adverse events.

CONCLUSION

Targeting the IL-6 pathway appears to offer therapeutic benefits in highly relapsing MOGAD patients who poorly respond to IVIG maintenance therapy.

Adaptive and innate immune response of Leishmania infantum infection in Cirneco dell'Etna dog breed

Leishmania spp. are an intracellular protozoa present in many countries around the world. In Europe, both the parasite and the disease it causes, leishmaniasis, are endemic in the Mediterranean basin. Clinical signs and severity of disease are highly variable depending on the host in both humans and dogs, traditionally considered the main reservoir of the parasite. The reason for these differences is not known, but it has been speculated that some hosts present immune response, related to activation of Th1 and Th17, capable of controlling the spread of the parasite, and that these immune responses are related to the genetic background of the host. The Ibizan hound, an autochthonous canine breed of the Mediterranean basin, has been postulated as a breed resistant to infection, but other canine breeds evolutionarily close to it and native to this region have not been studied. One of them is the Cirneco dell'Etna, native to the island of Sicily in southern Italy. In this study, the immune response against L. infantum infection in this canine breed was analysed. The results showed that infected dogs of this breed present high levels of several cytokines related to Th1 and Th17 immune response, and significant correlation between serum levels of cytokines related to disease resistance. Further studies are necessary in this canine breed to determine the mechanisms of immune response and genetic background related to L. infantum infection control.

The improvement of inflammatory infiltration and pregnancy outcome in mice with recurrent spontaneous abortion by human amniotic mesenchymal stem cells

Recurrent spontaneous abortion is thought to be mostly triggered by immune-related causes. Mesenchymal stem cells, which exhibit the traits of multi-directional differentiation capacity and low immunogenicity, have recently been recommended as a viable treatment for spontaneous abortion-prone mice to increase the success of pregnancy. Amniotic membrane tissue is a byproduct of pregnancy and delivery that has a wide range of potential uses due to its easy access to raw materials and little ethical constraints. To construct an abortion-prone mouse model for this investigation, CBA/J female mice were coupled with male DBA/2 mice, while CBA/J female mice were paired with male BALB/c mice as a control. The identical volume of human amniotic mesenchymal stem cells or phosphate buffer was injected intraperitoneally on the 4.5th day of pregnancy. CBA/J female mice were sacrificed by cervical dislocation on the 13.5th day of pregnancy, the embryo absorption rate was calculated, and the uterus, decidua tissues and placenta were gathered for examination. Through detection, it was discovered that human amniotic mesenchymal stem cells significantly increased the expression of interleukin 10 and transforming growth factor beta, while they significantly decreased the expression of interleukin 1 beta and interleukin 6, improved vascular formation and angiogenesis, and minimized the embryo absorption rate and inflammatory cell infiltration in the recurrent spontaneous abortion + human amniotic mesenchymal stem cells group. In any case, human amniotic mesenchymal stem cells regulate inflammatory factors and cell balance at the maternal-fetal interface, which result in a reduction in the rate of embryo absorption and inflammatory infiltration and provide an innovative perspective to the clinical therapy of recurrent spontaneous abortion.

Innovation and optimization in autoimmune encephalitis trials: the design and rationale for the Phase 3, randomized study of satralizumab in patients with NMDAR-IgG-antibody-positive or LGI1-IgG-antibody-positive autoimmune encephalitis (CIELO)

Background

Autoimmune encephalitis (AIE) encompasses a spectrum of rare autoimmune-mediated neurological disorders, which are characterized by brain inflammation and dysfunction. Autoantibodies targeting the N-methyl-d-aspartic acid receptor (NMDAR) and leucine-rich glioma-inactivated 1 (LGI1) are the most common subtypes of antibody-positive AIE. Currently, there are no approved therapies for AIE. Interleukin-6 (IL-6) signaling plays a role in the pathophysiology of AIE. Satralizumab, a humanized, monoclonal recycling antibody that specifically targets the IL-6 receptor and inhibits IL-6 signaling, has demonstrated efficacy and safety in another autoantibody-mediated neuroinflammatory disease, aquaporin-4 immunoglobulin G antibody-positive neuromyelitis optica spectrum disorder, and has the potential to be an evidence-based disease modifying treatment in AIE.

Objectives

CIELO will evaluate the efficacy, safety, pharmacodynamics, and pharmacokinetics of satralizumab compared with placebo in patients with NMDAR-immunoglobulin G antibody-positive (IgG+) or LGI1-IgG+ AIE.

Study design

CIELO (NCT05503264) is a prospective, Phase 3, randomized, double-blind, multicenter, basket study that will enroll approximately 152 participants with NMDAR-IgG+ or LGI1-IgG+ AIE. Prior to enrollment, participants will have received acute first-line therapy. Part 1 of the study will consist of a 52-week primary treatment period, where participants will receive subcutaneous placebo or satralizumab at Weeks 0, 2, 4, and every 4 weeks thereafter. Participants may continue to receive background immunosuppressive therapy, symptomatic treatment, and rescue therapy throughout the study. Following Part 1, participants can enter an optional extension period (Part 2) to continue the randomized, double-blind study drug, start open-label satralizumab, or stop study treatment and continue with follow-up assessments.

Endpoints

The primary efficacy endpoint is the proportion of participants with a ≥1-point improvement in the modified Rankin Scale (mRS) score from study baseline and no use of rescue therapy at Week 24. Secondary efficacy assessments include mRS, Clinical Assessment Scale of Autoimmune Encephalitis (CASE), time to rescue therapy, sustained seizure cessation and no rescue therapy, Montreal Cognitive Assessment, and Rey Auditory Verbal Learning Test (RAVLT) measures. Safety, pharmacokinetics, pharmacodynamics, exploratory efficacy, and biomarker endpoints will be captured.

Conclusion

The innovative basket study design of CIELO offers the opportunity to yield prospective, robust evidence, which may contribute to the development of evidence-based treatment recommendations for satralizumab in AIE.

Use of Neutrophil-to-Lymphocyte Ratio to Predict In-Hospital Mortality in Patients Admitted with Acute Decompensation of Atrial Fibrillation

Background/Objectives: The prevalence of atrial fibrillation (AF) has been on the rise over the last 20 years. It is considered to be the most common cardiac arrhythmia and is associated with significant morbidity and mortality. The need for in-hospital management of patients having AF is increasing. Acute decompensation of cardiac rhythm is an indication for hospital admission. In the existing literature, several studies on different pathologies have observed that the risk of death was greater for patients with an increased neutrophil-to-lymphocyte ratio (NLR) and suggested that the NLR can be a useful biomarker to predict in-hospital mortality. This study aims to evaluate the link between the neutrophil-to-lymphocyte ratio at admission and death among the patients admitted to the medical ward for the acute manifestation of AF, and to gain a better understanding of how we can predict in-hospital all-cause death based on the NLR for these patients. Methods: A single-center retrospective study in an academic medical clinic was conducted. We analyzed if the NLR at in-hospital admission can be related to in-hospital mortality among the patients admitted for AF at the Medical Ward of Municipal Emergency University Hospital Timisoara between 2015 and 2016. After identifying a total of 1111 patients, we divided them into two groups: in-hospital death patients and surviving patients. We analyzed the NLR in both groups to determine if it is related to in-hospital mortality or not. One patient was excluded because of missing data. Results: Our analysis showed that patients who died during in-hospital admission had a significantly higher NLR compared to those who survived (p < 0.0001, 95% CI (1.54 to 3.48)). The NLR was found to be an independent predictor of in-hospital death among patients with AF, even for the patients with no raised level of blood leukocytes (p < 0.0001, 95% CI (0.6174 to 3.0440)). Additionally, there was a significant correlation between the NLR and the risk of in-hospital death for patients admitted with decompensated AF (p < 0.0001), with an area under the ROC curve of 0.745. Other factors can increase the risk of death for these patients (such as the personal history of stroke, HAS-BLED score, and age). Conclusions: The NLR is a useful biomarker to predict in-hospital mortality in patients with AF and can predict the risk of death with a sensitivity of 72.8% and a specificity of 70.4%. Further studies are needed to determine the clinical utility of the NLR in risk stratification and management of patients with AF.

Pathophysiological Mechanisms of Peritoneal Fibrosis and Peritoneal Membrane Dysfunction in Peritoneal Dialysis

The characteristic feature of chronic peritoneal damage in peritoneal dialysis (PD) is a decline in ultrafiltration capacity associated with pathological fibrosis and angiogenesis. The pathogenesis of peritoneal fibrosis is attributed to bioincompatible factors of PD fluid and peritonitis. Uremia is associated with peritoneal membrane inflammation that affects fibrosis, neoangiogenesis, and baseline peritoneal membrane function. Net ultrafiltration volume is affected by capillary surface area, vasculopathy, peritoneal fibrosis, and lymphangiogenesis. Many inflammatory cytokines induce fibrogenic growth factors, with crosstalk between macrophages and fibroblasts. Transforming growth factor (TGF)-β and vascular endothelial growth factor (VEGF)-A are the key mediators of fibrosis and angiogenesis, respectively. Bioincompatible factors of PD fluid upregulate TGF-β expression by mesothelial cells that contributes to the development of fibrosis. Angiogenesis and lymphangiogenesis can progress during fibrosis via TGF-β-VEGF-A/C pathways. Complement activation occurs in fungal peritonitis and progresses insidiously during PD. Analyses of the human peritoneal membrane have clarified the mechanisms by which encapsulating peritoneal sclerosis develops. Different effects of dialysates on the peritoneal membrane were also recognized, particularly in terms of vascular damage. Understanding the pathophysiologies of the peritoneal membrane will lead to preservation of peritoneal membrane function and improvements in technical survival, mortality, and quality of life for PD patients.

Epigenetic regulation of human FOXP3+ Tregs: from homeostasis maintenance to pathogen defense

Regulatory T cells (Tregs), characterized by the expression of Forkhead Box P3 (FOXP3), constitute a distinct subset of T cells crucial for immune regulation. Tregs can exert direct and indirect control over immune homeostasis by releasing inhibitory factors or differentiating into Th-like Treg (Th-Treg), thereby actively contributing to the prevention and treatment of autoimmune diseases. The epigenetic regulation of FOXP3, encompassing DNA methylation, histone modifications, and post-translational modifications, governs the development and optimal suppressive function of Tregs. In addition, Tregs can also possess the ability to maintain homeostasis in diverse microenvironments through non-suppressive mechanisms. In this review, we primarily focus on elucidating the epigenetic regulation of Tregs as well as their multifaceted roles within diverse physiological contexts while looking forward to potential strategies involving augmentation or suppression of Tregs activity for disease management, particularly in light of the ongoing global COVID-19 pandemic.

Anti-inflammatory effect of the combined treatment of LMT-28 and kaempferol in a collagen-induced arthritis mouse model

Rheumatoid arthritis (RA) is an autoimmune disease characterized by joint inflammation and swelling. Several studies have demonstrated that RA fibroblast-like synovial cells (RA-FLS) play an important role in RA pathogenesis. Activated RA-FLS contribute to synovial inflammation by secreting inflammatory cytokines including interleukin (IL)-1β, IL-6 and tumor necrosis factor-α. LMT-28 is derivative of oxazolidone and exerts anti-inflammatory effects on RA via IL-6 signaling pathway regulation. LMT-28 also regulates T cell differentiation in RA condition. However, the effect of LMT-28 on the migration and invasion of RA-FLS remains unknown. Kaempferol has been reported to have pharmacological effects on various diseases, such as inflammatory diseases, autoimmune diseases, and cancer. Additionally, kaempferol has been reported to inhibit RA-FLS migration and invasion, but it is not known about the therapeutic mechanism including molecular mechanism such as receptor. The present study aimed to investigate the synergistic effects of the combined treatment of LMT-28 and kaempferol on RA-FLS activation and RA pathogenesis in mouse model. LMT-28 and kaempferol co-administration inhibited RA disease severity and histological collapse in the joint tissues of CIA mice, as well as downregulated the levels of pro-inflammatory cytokines in mouse serum. Additionally, the combined treatment inhibited excessive differentiation of T helper 17 cells and osteoclasts. Furthermore, compared with single treatments, combined treatment showed enhanced inhibitory effects on the hyperactivation of IL-6-induced signaling pathway in RA-FLS. Combined treatment also inhibited RA-FLS cell proliferation, migration, and invasion and suppressed the expression of matrix metalloproteinase in RA-FLS. Furthermore, we confirmed that the combined treatment inhibited chondrocyte proliferation, migration, and invasion. In conclusion, our results suggest that the combined treatment of LMT-28 and kaempferol exerts a synergistic effect on the RA development via the regulation of IL-6-induced hyperactivation of RA-FLS. Furthermore, this study suggests that combination therapies can be an effective therapeutic option for arthritis.

An overview of multi-omics technologies in rheumatoid arthritis: applications in biomarker and pathway discovery

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease with a complex pathological mechanism involving autoimmune response, local inflammation and bone destruction. Metabolic pathways play an important role in immune-related diseases and their immune responses. The pathogenesis of rheumatoid arthritis may be related to its metabolic dysregulation. Moreover, histological techniques, including genomics, transcriptomics, proteomics and metabolomics, provide powerful tools for comprehensive analysis of molecular changes in biological systems. The present study explores the molecular and metabolic mechanisms of RA, emphasizing the central role of metabolic dysregulation in the RA disease process and highlighting the complexity of metabolic pathways, particularly metabolic remodeling in synovial tissues and its association with cytokine-mediated inflammation. This paper reveals the potential of histological techniques in identifying metabolically relevant therapeutic targets in RA; specifically, we summarize the genetic basis of RA and the dysregulated metabolic pathways, and explore their functional significance in the context of immune cell activation and differentiation. This study demonstrates the critical role of histological techniques in decoding the complex metabolic network of RA and discusses the integration of histological data with other types of biological data.

[Value of calprotectin S100 A8/A9 in predicting the severity of Mycoplasma pneumoniae pneumonia in children]

OBJECTIVES

To investigate the role of calprotectin S100 A8/A9 complex in evaluating the condition of children with severe Mycoplasma pneumoniae pneumonia (SMPP).

METHODS

A prospective study was conducted among 136 children with Mycoplasma pneumoniae pneumonia (MPP) and 30 healthy controls. According to the severity of the condition, the children with MPP were divided into mild subgroup (40 children) and SMPP subgroup (96 children). The levels of S100 A8/A9 complex and related inflammatory factors were compared between the MPP group and the healthy control group, as well as between the two subgroups of MPP. The role of S100 A8/A9 in assessing the severity of MPP was explored.

RESULTS

The MPP group had a significantly higher level of S100 A8/A9 than the healthy control group, with a significantly greater increase in the SMPP subgroup (P<0.05). The multivariate logistic regression analysis showed that the increases in serum C reactive protein (CRP) and S100A8/A9 were closely associated with SMPP (P<0.05). The receiver operating characteristic (ROC) curve analysis showed that the combined measurement of serum S100 A8/A9 and CRP had an area under the ROC curve of 0.904 in predicting SMPP, which was significantly higher than the AUC of S100 A8/A9 or CRP alone (P<0.05), with a specificity of 0.718 and a sensitivity of 0.952.

CONCLUSIONS

S100 A8/A9 is closely associated with the severity of MPP, and the combination of S100 A8/A9 with CRP is more advantageous for assessing the severity of MPP in children.

Toosendanin inhibits T-cell proliferation through the P38 MAPK signalling pathway

In recent years, immunosuppressants have shown significant success in the treatment of autoimmune diseases. Therefore, there is an urgent need to develop additional immunosuppressants that offer more options for patients. Toosendanin has been shown to have immunosuppressive activity in vitro as well as effects on autoimmune hepatitis (AIH) in vivo. Toosendanin did not induce apoptosis in activated T-cells and affect the survival rate of naive T-cells. Toosendanin did not affect the expression of CD25 or secretion of IL-2 by activated T-cells, and not affect the expression of IL-4 and INF-γ. Toosendanin did not affect the phosphorylation of STAT5, ERK, AKT, P70S6K. However, toosendanin inhibited proliferation of anti-CD3/anti-CD28 mAbs-activated T-cells with IC50 of (10 ± 2.02) nM. Toosendanin arrested the cell cycle in the G0/G1 phase, significantly inhibited IL-6 and IL-17A secretion, promoted IL-10 expression, and inhibited the P38 MAPK pathway. Finally, toosendanin significantly alleviated ConA-induced AIH in mice. In Summary, toosendanin exhibited immunosuppressive activity in vivo and in vitro. Toosendanin inhibits the proliferation of activated T-cells through the P38 MAPK signalling pathway, significantly suppresses the expression of inflammatory factors, enhances the expression of anti-inflammatory factors, and effectively alleviates ConA-induced AIH in mice, suggesting that toosendanin may be a lead compound for the development of novel immunomodulatory agents with improved efficacy and reduced toxicity.

Benefits of maternal pectin supplementation in gestation diet on vaginal microbiota of sows and intestinal health of newborn piglets

Pectin is a proven prebiotic and widely used in human health products. This study aims to assess the impact of dietary pectin supplementation during gestation on sow vaginal microbiota and the offspring's intestinal composition. Thirty sows were randomly allocated to two groups and fed a standard diet (CON) or a standard diet supplemented with 3 g/kg pectin (PEC). Blood, feces, and vaginal swab samples from the sows and blood, intestines issue, and colonic content samples from the offspring were collected and analyzed. The results indicate that the relative abundance of vaginal Lactobacillus was notably enhanced in the PEC group and fecal β-glucuronidase (β-G) activity and plasma 17β-estradiol (E2) concentration were also significantly increased in the PEC group. Newborn piglets were found to host different microbial communities as well. At the phylum level, Proteobacteria dominated in the CON group, and Firmicutes was predominant in the PEC group. Newborn piglets in the PEC group had a lower interleukin-6 (IL-6) concentration in their plasma. The expression of intestinal cytokines of offspring was improved as well. Villus height and villus height/crypt depth (V/C) in the PEC group were extremely higher than those in the CON group. In conclusion, dietary pectin supplementation can be of benefit to both sows and newborn piglets.

IL-6 inhibition prevents costimulation blockade-resistant allograft rejection in T cell-depleted recipients by promoting intragraft immune regulation in mice

The efficacy of costimulation blockade with CTLA4-Ig (belatacept) in transplantation is limited due to T cell-mediated rejection, which also persists after induction with anti-thymocyte globulin (ATG). Here, we investigate why ATG fails to prevent costimulation blockade-resistant rejection and how this barrier can be overcome. ATG did not prevent graft rejection in a murine heart transplant model of CTLA4-Ig therapy and induced a pro-inflammatory cytokine environment. While ATG improved the balance between regulatory T cells (Treg) and effector T cells in the spleen, it had no such effect within cardiac allografts. Neutralizing IL-6 alleviated graft inflammation, increased intragraft Treg frequencies, and enhanced intragraft IL-10 and Th2-cytokine expression. IL-6 blockade together with ATG allowed CTLA4-Ig therapy to achieve long-term, rejection-free heart allograft survival. This beneficial effect was abolished upon Treg depletion. Combining ATG with IL-6 blockade prevents costimulation blockade-resistant rejection, thereby eliminating a major impediment to clinical use of costimulation blockers in transplantation.

Effect of continuous positive airway pressure treatment on Th17/Treg imbalance in patients with obstructive sleep apnea and a preliminary study on its mechanism

BACKGROUND

Obstructive sleep apnea (OSA) can be considered a chronic inflammatory disease that impacts all bodily systems, including the immune system. This study aims to assess the Th17/Treg pattern in patients with OSA and the effect of continuous positive airway pressure (CPAP) treatment.

METHODS

OSA patients and healthy controls were recruited. OSA patients recommended for CPAP treatment were followed up for three months. Flow cytometry was employed to determine the proportion of Th17 and Treg cells. Real-time quantitative polymerase chain reaction (PCR) and western blotting were utilized to detect the mRNA and protein levels of receptor-related orphan receptor γt (RORγt) and forkhead/winged helix transcription factor (Foxp3), respectively, in peripheral blood mononuclear cells (PBMCs). Enzyme-linked immunosorbent assay (ELISA) was performed to measure the serum levels of interleukin-17 (IL-17), IL-6, transforming growth factor-β1 (TGF-β1), and hypoxia-induced factor-1α (HIF-1α).

RESULTS

A total of 56 OSA patients and 40 healthy controls were recruited. The proportion of Th17 cells, Th17/Treg ratio, mRNA and protein levels of RORγt, and serum IL-17, IL-6, and HIF-1α levels were higher in OSA patients. Conversely, the proportion of Treg cells, mRNA and protein levels of Foxp3, and serum TGF-β1 levels were decreased in OSA patients. The proportion of Th17 and Treg cells in OSA can be predicted by the apnea hypopnea index (AHI), IL-6, TGF-β1 and, HIF-1α. 30 moderate-to-severe OSA patients were adherent to three-month CPAP treatment, with improved Th17/Treg imbalance, IL-17, IL-6, TGF-β1, and HIF-1α levels compared to pre-treatment values.

CONCLUSION

There was a Th17/Treg imbalance in OSA patients. The prediction of Th17 and Treg cell proportions in OSA can be facilitated by AHI, as well as serum IL-6, TGF-β1, and HIF-1α levels. Furthermore, CPAP treatment can potentially improve the Th17/Treg imbalance and reduce proinflammatory cytokines in OSA patients.

Potential biomarkers for immune monitoring after renal transplantation

Renal transplantation represents the foremost efficacious approach for ameliorating end-stage renal disease. Despite the current state of advanced renal transplantation techniques and the established postoperative immunosuppression strategy, a subset of patients continues to experience immune rejection during both the early and late postoperative phases, ultimately leading to graft loss. Consequently, the identification of immunobiomarkers capable of predicting the onset of immune rejection becomes imperative in order to facilitate early intervention strategies and enhance long-term prognoses. Upon reviewing the pertinent literature, we identified several indicators that could potentially serve as immune biomarkers to varying extents. These include the T1/T2 ratio, Treg/Th17 ratio, IL-10/TNF-α ratio, IL-33, IL-34, IL-6, IL-4, other cytokines, and NOX2/4.

Interleukin-6 classic and trans-signaling utilize glucose metabolism reprogramming to achieve anti- or pro-inflammatory effects

Interleukin (IL)-6 has anti- and pro-inflammatory functions, controlled by IL-6 classic and trans-signaling, respectively. Differences in the downstream signaling mechanism between IL-6 classic and trans-signaling have not been identified. Here, we report that IL-6 activates glycolysis to regulate the inflammatory response. IL-6 regulates glucose metabolism by forming a complex containing signal-transducing activators of transcription 3 (STAT3), hexokinase 2 (HK2), and voltage-dependent anion channel 1 (VDAC1). The IL-6 classic signaling directs glucose flux to oxidative phosphorylation (OxPhos), while IL-6 trans-signaling directs glucose flux to anaerobic glycolysis. Classic IL-6 signaling promotes STAT3 translocation into mitochondria to interact with pyruvate dehydrogenase kinase-1 (PDK1), leading to pyruvate dehydrogenase α (PDHA) dissociation from PDK1. As a result, PDHA is dephosphorylated, and STAT3 is phosphorylated at Ser727. By contrast, IL-6 trans-signaling promotes the interaction of sirtuin 2 (SIRT2) and lactate dehydrogenase A (LDHA), leading to the dissociation of STAT3 from SIRT2. As a result, LDHA is deacetylated, and STAT3 is acetylated and phosphorylated at Tyr705. IL-6 classic signaling promotes the differentiation of regulatory T cells via the PDK1/STAT3/PDHA axis, whereas IL-6 trans-signaling promotes the differentiation of Th17 cells via the SIRT2/STAT3/LDHA axis. Conclusion: IL-6 classic signaling generates anti-inflammatory functions by shifting energy metabolism to OxPhos, while IL-6 trans-signaling generates pro-inflammatory functions by shifting energy metabolism to anaerobic glycolysis.

Preventing Preterm Birth: Exploring Innovative Solutions

This review examines the complexities of preterm birth (PTB), emphasizes the pivotal role of inflammation in the pathogenesis of preterm labor, and assesses current available interventions. Antibiotics, progesterone analogs, mechanical approaches, nonsteroidal anti-inflammatory drugs, and nutritional supplementation demonstrate a limited efficacy. Tocolytic agents, targeting uterine activity and contractility, inadequately prevent PTB by neglecting to act on uteroplacental inflammation. Emerging therapies targeting toll-like receptors, chemokines, and interleukin receptors exhibit promise in mitigating inflammation and preventing PTB.

Akkermansia muciniphila extracellular vesicles have a protective effect against hypertension

Akkermansia muciniphila (Am) shows a beneficial role as a probiotic in the treatment of metabolic syndrome. However, the mechanism remains to be elucidated. We tested the hypothesis that Am extracellular vesicles (AmEVs) have a protective effect against hypertension. Extracellular vesicles purified from anaerobically cultured Am were characterized by nanoparticle tracking analysis, transmission electron microscopy, and silver stain after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). AmEVs (1.0 × 1010 log particles/L) or vehicles were added into organ baths to induce vasorelaxation. In addition, AmEVs (1.0 × 108 or 1.0 × 109 particles/kg) or vehicles were injected into the tail veins of Wistar-Kyoto rats (WKYs) and spontaneously hypertensive rats (SHRs) weekly for 4 weeks. Peripheral blood mononuclear cells (PBMCs) and splenocytes isolated from both rat strains were analyzed by flow cytometry, RT-qPCR, and western blot. AmEVs affected neither vascular contraction nor endothelial relaxation in thoracic aortas. Moreover, AmEVs protected against the development of hypertension in SHRs without a serious adverse reaction. Additionally, AmEVs increased the population of T regulatory (Treg) cells and tended to reduce proinflammatory cytokines. These results indicate that AmEVs have a protective effect against hypertension without a serious adverse reaction. Therefore, it is foreseen that AmEVs may be utilized as a novel therapeutic for the treatment of hypertension.

Pharmacometabolomics applied to low-dose interleukin-2 treatment in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating motor neuron disease. The immunosuppressive functions of regulatory T lymphocytes (Tregs) are impaired in ALS, and correlate to disease progression. The phase 2a IMODALS trial reported an increase in Treg number in ALS patients following the administration of low-dose (ld) interleukin-2 (IL-2). We propose a pharmacometabolomics approach to decipher metabolic modifications occurring in patients treated with ld-IL-2 and its relationship with Treg response. Blood metabolomic profiles were determined on days D1, D64, and D85 from patients receiving 2 MIU of IL-2 (n = 12) and patients receiving a placebo (n = 12). We discriminated the three time points for the treatment group (average error rate of 42%). Among the important metabolites, kynurenine increased between D1 and D64, followed by a reduction at D85. The percentage increase of Treg number from D1 to D64, as predicted by the metabolome at D1, was highly correlated with the observed value. This study provided a proof of concept for metabolic characterization of the effect of ld-IL-2 in ALS. These data could present advances toward a personalized medicine approach and present pharmacometabolomics as a key tool to complement genomic and transcriptional data for drug characterization, leading to systems pharmacology.

Efficacy and safety of tocilizumab in patients with refractory generalized myasthenia gravis

BACKGROUND

We aimed to compare the efficacy of tocilizumab with conventional immunotherapy in refractory patients with acetylcholine receptor antibody-positive (AChR-Ab+) generalized myasthenia gravis (gMG).

METHODS

This single-center prospective cohort study was based on patients from an MG registry study in China and conducted from February 10, 2021 to March 31, 2022. Adult refractory patients with AChR-Ab+ gMG were assigned to tocilizumab or conventional immunotherapy groups. The primary efficacy outcome was the mean difference of MG activities of daily living (MG-ADL) change at weeks 4, 8, 12, 16, 20, 24 corresponding to that at the baseline between the two groups. A generalized estimating equation model was used for the primary outcome analysis. Safety was assessed based on adverse events.

RESULTS

Of 34 eligible patients, 20 (mean [standard deviation] age, 53.8 [21.9] years; 12 [60.0%] female) received tocilizumab and 14 received conventional immunotherapy (45.8 [18.0] years; 8 [57.1%] female). The tocilizumab group had greater reduction in MG-ADL score at week 4 (adjusted mean difference, -3.4; 95% CI, -4.7 to -2.0; p < 0.001) than the conventional immunotherapy group, with significant differences sustained through week 24 (adjusted mean difference, -4.5; 95% CI, -6.4 to -2.6; p < 0.001). At week 24, the proportion of patients achieving higher levels of MG-ADL (up to 7-point reduction) and QMG (up to 11-point reduction) scores improvement was significantly greater with tocilizumab. Tocilizumab had acceptable safety profiles without severe or unexpected safety issues.

CONCLUSION

Tocilizumab is safe and effective in improving the MG-ADL score and reducing prednisone dose in refractory AChR-Ab+ gMG, suggesting tocilizumab has the potential to be a valuable therapeutic option for such patients.

Anti-Inflammatory and Immunomodulatory Effects of 0.1 Sub-Terahertz Irradiation in Collagen-Induced Arthritis Mice

The primary emphasis of photoimmunology is the impact of nonionizing radiation on the immune system. With the development of terahertz (THz) and sub-terahertz (sub-THz) technology, the biological effects of this emerging nonionizing radiation, particularly its influence on immune function, remain insufficiently explored but are progressively attracting attention. Here, we demonstrated that 0.1 sub-THz radiation can modulate the immune system and alleviate symptoms of arthritis in collagen-induced arthritis (CIA) mice through a nonthermal manner. The application of 0.1 sub-THz irradiation led to a decrease in proinflammatory factors within the joints and serum, reducing the levels of blood immune cells and the quantity of splenic CD4+ T cells. Notably, 0.1 sub-THz irradiation restored depleted Treg cells in CIA mice and re-established the Th17/Treg equilibrium. These findings suggested that sub-THz irradiation plays a crucial role in systemic immunoregulation. Further exploration of its immune modulation mechanisms revealed the anti-inflammatory properties of 0.1 sub-THz on LPS-stimulated skin keratinocytes. Through the reduction in NF-κB signaling and NLRP3 inflammasome activation, 0.1 sub-THz irradiation effectively decreased the production of inflammatory factors and immune-active substances, including IL-1β and PGE2, in HaCaT cells. Consequently, 0.1 sub-THz irradiation mitigated the inflammatory response and contributed to the maintenance of immune tolerance in CIA mice. This research provided significant new evidence supporting the systemic impacts of 0.1 sub-THz radiation, particularly on the immune system. It also enhanced the field of photoimmunology and offered valuable insights into the potential biomedical applications of 0.1 sub-THz radiation for treating autoimmune diseases.

Nitazoxanide protects against experimental ulcerative colitis through improving intestinal barrier and inhibiting inflammation

Ulcerative colitis is a chronic disease with colonic mucosa injury. Nitazoxanide is an antiprotozoal drug in clinic. Nitazoxanide and its metabolite tizoxanide have been demonstrated to activate AMPK and inhibit inflammation, therefore, the aim of the present study is to investigate the effect of nitazoxanide on dextran sulfate sodium (DSS)-induced colitis and the underlying mechanism. Oral administration of nitazoxanide ameliorated the symptoms of mice with DSS-induced colitis, as evidenced by improving the increased disease activity index (DAI), the decreased body weight, and the shortened colon length. Oral administration of nitazoxanide ameliorated DSS-induced intestinal barrier dysfunction and reduced IL-6 and IL-17 expression in colon tissues. Mechanistically, nitazoxanide and its metabolite tizoxanide treatment activated AMPK and inhibited JAK2/STAT3 signals. Nitazoxanide and tizoxanide treatment increased caudal type homeobox 2 (CDX2) expression, increased alkaline phosphatase (ALP) activity and promoted tight junctions in Caco-2 cells. Nitazoxanide and tizoxanide treatment restored the decreased zonula occludens-1(ZO-1) and occludin protein levels induced by LPS or IL-6 in Caco-2 cells. On the other hand, nitazoxanide and tizoxanide regulated macrophage bias toward M2 polarization, as evidenced by the increased arginase-1expression in bone marrow-derived macrophages (BMDM). Nitazoxanide and tizoxanide reduced the increased IL-6, iNOS and CCL2 pro-inflammatory gene expressions and inhibited JAK2/STAT3 activation in BMDM induced by LPS. In conclusion, nitazoxanide protects against DSS-induced ulcerative colitis in mice through improving intestinal barrier and inhibiting inflammation and the underlying mechanism involves AMPK activation and JAK2/STAT3 inhibition.

Exposure to gestational diabetes mellitus increases subclinical inflammation mediated in part by obesity

Gestational diabetes mellitus (GDM) is a frequent and serious complication of pregnancy, often associated with obesity. Metabolic dysfunction and metainflammation are evident in both obesity and GDM. In this cross-sectional study, we aimed at defining the direct contribution of the immune system in GDM, across the main metabolic tissues, specifically focussing on elucidating the roles of obesity and GDM to the clinical outcome. Using immunoassays and multicolour flow cytometry, cytokine profiles and immune cell frequencies were measured in maternal circulation and central metabolic tissues [placenta and visceral adipose tissue (VAT)] in GDM-diagnosed (n = 28) and normal glucose tolerant (n = 32) women undergoing caesarean section. Participants were sub-grouped as non-obese [body mass index (BMI) < 30 kg/m2] or obese (BMI ≥ 30 kg/m2). Unsupervised data analysis was performed on the flow cytometry data set to identify functional alterations. GDM obese participants had significantly elevated circulating IL-6 and IL-17A levels. GDM non-obese participants had elevated circulating IL-12p70, elevated placental IL-17A, and VAT IFN-γ production. Unsupervised clustering of immune populations across the three biological sites simultaneously, identified different NK- and T-cell phenotypes that were altered in NGT obese and GDM non-obese participants, while a classical tissue monocyte cluster was increased in GDM obese participants. In this study, there was significant evidence of subclinical inflammation, and significant alterations in clusters of NK cells, T cells, and tissue monocyte populations in GDM. While increased adiposity assimilates with increased inflammation in the non-pregnant state, this overt relationship may not be as evident during pregnancy and warrants further examination in future longitudinal studies.

Regulation of Treg cells by cytokine signaling and co-stimulatory molecules

CD4+CD25+Foxp3+ regulatory T cells (Tregs), a vital component of the immune system, are responsible for maintaining immune homeostasis and preventing excessive immune responses. This review explores the signaling pathways of the cytokines that regulate Treg cells, including transforming growth factor beta (TGF-β), interleukin (IL)-2, IL-10, and IL-35, which foster the differentiation and enhance the immunosuppressive capabilities of Tregs. It also examines how, conversely, signals mediated by IL-6 and tumor necrosis factor -alpha (TNF-α) can undermine Treg suppressive functions or even drive their reprogramming into effector T cells. The B7 family comprises indispensable co-stimulators for T cell activation. Among its members, this review focuses on the capacity of CTLA-4 and PD-1 to regulate the differentiation, function, and survival of Tregs. As Tregs play an essential role in maintaining immune homeostasis, their dysfunction contributes to the pathogenesis of autoimmune diseases. This review delves into the potential of employing Treg-based immunotherapy for the treatment of autoimmune diseases, transplant rejection, and cancer. By shedding light on these topics, this article aims to enhance our understanding of the regulation of Tregs by cytokines and their therapeutic potential for various pathological conditions.

CIRP increases Foxp3+ regulatory T cells and inhibits development of Th17 cells by enhancing TLR4-IL-2 signaling in the late phase of sepsis

BACKGROUND

T helper (Th) cell imbalances have been associated with the pathophysiology of sepsis, including the Th1/Th2 and Th17/T regulatory cells (Treg) paradigms. Cold-inducible RNA-binding protein (CIRP), a novel damage-associated molecular pattern (DAMP) was reported that could induce T cell activation, and skew CD4+ T cells towards a Th1 profile. However, the effect and underlying mechanisms of CIRP on Th17/Treg differentiation in sepsis still remains unknown.

METHODS

A prospective exploratory study including patients with sepsis was conducted. Blood samples were collected from patients on days 0, 3 and 7 on admission. The serum CIRP and peripheral blood Treg/Th17 percentage was determined by ELISA and flow cytometry. CD4+ T cells from the spleen and lymph nodes of mice with experimental sepsis were collected after treatment with normal saline (NS), recombinant murine CIRP (rmCIRP) and C23 (an antagonist for CIRP-TLR4) at late stage of sepsis. RNA-seq was conducted to reveal the pivotal molecular mechanism of CIRP on Treg/Th17 differentiation. Naïve CD4+ T cell was isolated from the Tlr4 null and wildtype mice in the presence or absence rmCIRP and C23 to confirmed above findings.

RESULTS

A total of 19 patients with sepsis finally completed the study. Serum CIRP levels remained high in the majority of patients up to 1 week after admittance was closely associated with high Treg/Th17 ratio of peripheral blood and poor outcome. A univariate logistic analysis demonstrated that higher CIRP concentration at Day 7 is an independent risk factor for Treg/Th17 ratio increasing. CIRP promotes Treg development and suppresses Th17 differentiation was found both in vivo and in vitro. Pretreated with C23 not only alleviated the majority of negative effect of CIRP on Th17 differentiation, but also inhibited Treg differentiation, to some extent. Tlr4 deficiency could abolish almost all downstream effects of rmCIRP. Furthermore, IL-2 is proved a key downstream molecules of the effect CIRP, which also could amplify the activated CD4+ T lymphocytes.

CONCLUSIONS

Persistent high circulating CIRP level may lead to Treg/Th17 ratio elevated through TLR4 and subsequent active IL-2 signaling which contribute to immunosuppression during late phases of sepsis.

The immunopathogenesis of sarcoidosis

Sarcoidosis is a granulomatous multiorgan disease, thought to result from exposure to yet unidentified antigens in genetically susceptible individuals. The exaggerated inflammatory response that leads to granuloma formation is highly complex and involves the innate and adaptive immune system. Consecutive immunological studies using advanced technology have increased our understanding of aberrantly activated immune cells, mediators and pathways that influence the formation, maintenance and resolution of granulomas. Over the years, it has become increasingly clear that disease immunopathogenesis can only be understood if the clinical heterogeneity of sarcoidosis is taken into consideration, along with the distribution of immune cells in peripheral blood and involved organs. Most studies offer an immunological snapshot during disease course, while the cellular composition of both the circulation and tissue microenvironment may change over time. Despite these challenges, novel insights on the role of the immune system are continuously published, thus bringing the field forward. This review highlights current knowledge on the innate and adaptive immune responses involved in sarcoidosis pathogenesis, as well as the pathways involved in non-resolving disease and fibrosis development. Additionally, we describe proposed immunological mechanisms responsible for drug-induced sarcoid like reactions. Although many aspects of disease immunopathogenesis remain to be unraveled, the identification of crucial immune reactions in sarcoidosis may help identify new treatment targets. We therefore also discuss potential therapies and future strategies based on the latest immunological findings.

Pollutants, microbiota and immune system: frenemies within the gut

Pollution is a critical concern of modern society for its heterogeneous effects on human health, despite a widespread lack of awareness. Environmental pollutants promote several pathologies through different molecular mechanisms. Pollutants can affect the immune system and related pathways, perturbing its regulation and triggering pro-inflammatory responses. The exposure to several pollutants also leads to alterations in gut microbiota with a decreasing abundance of beneficial microbes, such as short-chain fatty acid-producing bacteria, and an overgrowth of pro-inflammatory species. The subsequent intestinal barrier dysfunction, together with oxidative stress and increased inflammatory responses, plays a role in the pathogenesis of gastrointestinal inflammatory diseases. Moreover, pollutants encourage the inflammation-dysplasia-carcinoma sequence through various mechanisms, such as oxidative stress, dysregulation of cellular signalling pathways, cell cycle impairment and genomic instability. In this narrative review, we will describe the interplay between pollutants, gut microbiota, and the immune system, focusing on their relationship with inflammatory bowel diseases and colorectal cancer. Understanding the biological mechanisms underlying the health-to-disease transition may allow the design of public health policies aimed at reducing the burden of disease related to pollutants.

A double-blind, placebo-controlled, randomized withdrawal trial of sarilumab for the treatment of glucocorticoid-dependent sarcoidosis

OBJECTIVES

Effective steroid-sparing therapies for the treatment of sarcoidosis are lacking; IL-6 antagonists may reduce sarcoidosis disease activity. This study assessed the safety and efficacy of the IL-6 receptor antagonist, sarilumab, in subjects with glucocorticoid-dependent sarcoidosis.

METHODS

This phase II, double-blind, placebo-controlled, randomized withdrawal trial enrolled 15 subjects with biopsy-proven sarcoidosis at Stanford University from November 2019 to September 2022. In period 1, subjects were treated with open-label s.c. sarilumab 200 mg every 2 weeks for 16 weeks, with predefined tapering of prednisone. Subjects who completed period 1 without a sarcoidosis flare entered period 2 and were randomized to continue sarilumab or to receive matching placebo for 12 weeks. The end points included flare-free survival, as well as changes in pulmonary function tests, chest imaging, patient-reported outcomes, and laboratory values.

RESULTS

Fifteen subjects were enrolled in the study (median age 57 years, 80% male, 73.3% White), and 10 subjects successfully completed period 1. During period 1, 4 of the 15 subjects (26.7%) discontinued due to worsening of their sarcoidosis, and CT chest imaging worsened in 5 of the 15 subjects (35.7%). During period 2, 0 of 2 subjects in the sarilumab group and 1 of 8 subjects (12.5%) in the placebo group had a flare. Treatment with sarilumab 200 mg was generally well tolerated in subjects with sarcoidosis.

CONCLUSION

In this double-blind, placebo-controlled, randomized withdrawal trial, a meaningful signal of improvement in subjects with sarcoidosis treated with sarilumab was not observed. Given the small numbers in this study, no definitive conclusions can be drawn.

TRIAL REGISTRATION

ClinicalTrials.gov, http://clinicaltrials.gov, NCT04008069.

Interleukin-6-Positive Immune Cells as a Possible New Immunologic Marker Associated With the Colorectal Cancer Prognosis

Chronic inflammation creates tumor microenvironment (TME) that facilitates colorectal cancer (CRC) cell proliferation, migration, metastasis, and tumor progression. Interleukin-6 (IL-6) is a proinflammatory cytokine with a pleiotropic effect on CRC development. We aimed to evaluate IL-6 expression in tumor cells and in immune cells in TME, to assess the serum level and IL6 -174 G/C genotype distribution and to correlate the results with selected morphologic and clinical parameters that may add useful information in understanding the mechanisms of human CRC progression. A total of 153 patients with CRC were recruited in the current study. We assessed the IL-6 serum concentration through the ELISA method, the expression of IL-6 in tumor and in immune cells by immunohistochemical and double immunofluorescence staining, the MSI status by immunоhistochemistry for 4 mismatch repair (MMR) proteins, and the genotype distributions for IL6 -174G/C (rs1800795) single-nucleotide polymorphism through PCR-RFLP method. Our results showed that serum IL-6 level were increased in CRC patients as compared with healthy controls (P<0.0001), and in patients with cancers with advanced histologic type (type IV). However, the higher concentration (above the median of 55.71 pg/mL) was with borderline association with longer survival of the patients after surgical therapy (P=0.055, Log rank test). We also found that IL-6+ immune cells prevailed in the invasive front (IF) of tumors compared with the tumor stroma (TS) (P<0.0001). More IL-6+ cells were recruited in the tumors with less advanced histologic type (I+II), with stronger inflammatory infiltrate in the IF, in early pTNM stages (I+II), without lymph node and distant metastases and the higher levels of IL-6+ cells, especially in the IF, were associated with longer survival (P=0.012). The results of our study suggest that although the serum levels of IL-6 are higher in CRC, the increased IL-6+ cells in tumor microenvironment, both in the invasive front and in tumor stroma, as well as the higher serum levels are associated with good prognostic variables and longer survival of the patients mainly in the early stages of CRC.

IL-6 receptor antibody treatment improves muscle weakness in experimental autoimmune myasthenia gravis mouse model

Myasthenia gravis (MG) is a chronic autoimmune disease characterized by muscle weakness and fatigue. It is caused by pathological autoantibodies against components expressed at neuromuscular junctions, such as acetylcholine receptor (AChR). Interleukin-6 (IL-6) has been suggested to play a role in the pathogenesis of MG, and IL-6 receptor (IL-6R) antibody treatment may provide a novel therapeutic option. In this study, we investigated the effects of IL-6R antibody treatment in an experimental autoimmune MG (EAMG) mouse model. We demonstrated that IL-6R antibody treatment improved muscle weakness, reduced IgG deposition at neuromuscular junctions, and the levels of AChR autoantibodies in serum. In addition, follicular helper T cells and Th17, plasma cells in lymph nodes were lower in IL-6R antibody treated mice. Our findings suggest that IL-6R blockade may be a novel and effective therapeutic strategy for the treatment of MG.

Exploring the therapeutic potential of regulatory T cell in rheumatoid arthritis: Insights into subsets, markers, and signaling pathways

Rheumatoid arthritis (RA) is a complex autoimmune inflammatory rheumatic disease characterized by an imbalance between immunological reactivity and immune tolerance. Regulatory T cells (Tregs), which play a crucial role in controlling ongoing autoimmunity and maintaining peripheral tolerance, have shown great potential for the treatment of autoimmune inflammatory rheumatic diseases such as RA. This review aims to provide an updated summary of the latest insights into Treg-targeting techniques in RA. We focus on current therapeutic strategies for targeting Tregs based on discussing their subsets, surface markers, suppressive function, and signaling pathways in RA.

Suppressor T helper type 17 cell responses in intestinal transplant recipients with allograft rejection

BACKGROUND

Intestinal transplant (ITx) rejection is associated with memory T helper type 17 cell (Th17) infiltration of grafted tissues. Modulation of Th17 effector cell response is facilitated by T regulatory (Treg) cells, but a phenotypic characterization of this process is lacking in the context of allograft rejection.

METHODS

Flow cytometry was performed to examine the expression of surface receptors, cytokines, and transcription factors in Th17 and Treg cells in ITx control (n = 34) and rejection patients (n = 23). To elucidate key pathways guiding the rejection biology, we utilized RNA sequencing (RNAseq) and assessed epigenetic stability through pyrosequencing of the Treg-specific demethylated region (TSDR).

RESULTS

We found that intestinal allograft rejection is characterized by Treg cellular infiltrates, which are polarized toward Th17-type chemokine receptor, ROR-γt transcription factor expression, and cytokine production. These Treg cell subsets have maintained epigenetic stability, as defined by FoxP3-TSDR methylation status, but displayed upregulation of functional Treg and purinergic signaling genes by RNAseq analysis such as CD39, in keeping with suppressor Th17 properties.

CONCLUSION

We show that ITx rejection is associated with increased polarized cells that express a Th17-like phenotype concurrent with regulatory purinergic markers.

Beyond Immune Balance: The Pivotal Role of Decidual Regulatory T Cells in Unexplained Recurrent Spontaneous Abortion

Recurrent spontaneous abortion (RSA) is defined as two or more consecutive pregnancy failures, which brings tremendous stress to women of childbearing age and seriously affects family well-being. However, the reason in about 50% of cases remains unknown and is defined as unexplained recurrent spontaneous abortion (URSA). The immunological perspective in URSA has attracted widespread attention in recent years. The embryo is regarded as a semi-allogeneic graft to the mother. A successful pregnancy requires transition to an immune environment conducive to embryo survival at the maternal-fetal interface. As an important member of regulatory immunity, regulatory T (Treg) cells play a key role in regulating immune tolerance at the maternal-fetal interface. This review will focus on the phenotypic plasticity and lineage stability of Treg cells to illustrate its relationship with URSA.

Dietary inflammatory pattern and risk of hip fracture in the Nurses' Health Study

Our immune system activity is impacted by what we eat and can influence fracture risk under certain conditions. In this article, we show that postmenopausal women with a pro-inflammatory dietary pattern have an increased risk of hip fracture.

PURPOSE

The immune system influences bone homeostasis and can increase the risk of fracture under certain pro-inflammatory conditions. Immune system activity is impacted by dietary patterns. Using the empirical dietary inflammatory pattern (EDIP), we investigated whether postmenopausal women with a pro-inflammatory dietary pattern had an increased risk of hip fracture.

METHODS

The study population consisted of postmenopausal women participating in the Nurses' Health Study from 1980 to 2014, who reported information on lifestyle and health, including hip fractures, on biennial questionnaires, while semiquantitative food frequency questionnaires (FFQs) were completed every fourth year. Hazard ratios (HR) for hip fracture were computed using Cox proportional hazards models, adjusting for potential confounders.

RESULTS

EDIP was calculated using intake information from the FFQ for 87,955 postmenopausal participants, of whom 2348 sustained a non-traumatic hip fracture during follow-up. After adjustment for confounders, there was a 7% increase in the risk of hip fracture per 1 SD increase in EDIP (HR 1.07, 95% CI 1.02-1.12), and the uppermost quintile had a 22% greater risk compared to the lowest (HR 1.22, 95% CI 1.06-1.40). For the separate components of the EDIP, we found that higher intakes of low-energy beverages (diet sodas) were independently associated with an increased risk of hip fracture, while higher intakes of green leafy vegetables were associated with a reduced risk.

CONCLUSION

A pro-inflammatory dietary pattern was associated with an increased risk of hip fracture among postmenopausal women.

1-L Transcription of SARS-CoV-2 Spike Protein S1 Subunit

The COVID-19 pandemic prompted rapid research on SARS-CoV-2 pathogenicity. Consequently, new data can be used to advance the molecular understanding of SARS-CoV-2 infection. The present bioinformatics study discusses the "spikeopathy" at the molecular level and focuses on the possible post-transcriptional regulation of the SARS-CoV-2 spike protein S1 subunit in the host cell/tissue. A theoretical protein-RNA recognition code was used to check the compatibility of the SARS-CoV-2 spike protein S1 subunit with mRNAs in the human transcriptome (1-L transcription). The principle for this method is elucidated on the defined RNA binding protein GEMIN5 (gem nuclear organelle-associated protein 5) and RNU2-1 (U2 spliceosomal RNA). Using the method described here, it was shown that 45% of the genes/proteins identified by 1-L transcription of the SARS-CoV-2 spike protein S1 subunit are directly linked to COVID-19, 39% are indirectly linked to COVID-19, and 16% cannot currently be associated with COVID-19. The identified genes/proteins are associated with stroke, diabetes, and cardiac injury.

Cerebral malaria pathogenesis: Dissecting the role of CD4+ and CD8+ T-cells as major effectors in disease pathology

Cerebral malaria (CM) is a severe complication of Plasmodium falciparum (P. falciparum) infection, with complex pathogenesis involving multiple factors, including the host's immunological response. T lymphocytes, specifically CD4+ T helper cells and CD8+ cytotoxic T cells, are crucial in controlling parasite growth and activating cells for parasite clearance via cytokine secretion. Contrary to this, reports also suggest the pathogenic nature of T lymphocytes as they are often involved in disease progression and severity. CD8+ cytotoxic T cells migrate to the host's brain vasculature, disrupting the blood-brain barrier and causing neurological manifestations. CD4+ T helper cells on the other hand play a variety of functions as they differentiate into different subtypes which may function as pro-inflammatory or anti-inflammatory. The excessive pro-inflammatory response in CM can lead to multi-organ failure, necessitating a check mechanism to maintain immune homeostasis. This is achieved by regulatory T cells and their characteristic cytokines, which counterbalance the pro-inflammatory immune response. Maintaining a critical balance between pro and anti-inflammatory responses is crucial for determining disease outcomes in CM. A slight change in this balance may contribute to a disease severity owing to an extreme inflammatory response or unrestricted parasite growth, a potential target for designing immunotherapeutic treatment approaches. The review briefly discusses the pathogenesis of CM and various mechanisms responsible for the disruption of the blood-brain barrier. It also highlights the role of different T cell subsets during infection and emphasizes the importance of balance between pro and anti-inflammatory T cells that ultimately decides the outcome of the disease.

Characterizing the polygenic overlap and shared loci between rheumatoid arthritis and cardiovascular diseases

BACKGROUND

Despite substantial research revealing that patients with rheumatoid arthritis (RA) have excessive morbidity and mortality of cardiovascular disease (CVD), the mechanism underlying this association has not been fully known. This study aims to systematically investigate the phenotypic and genetic correlation between RA and CVD.

METHODS

Based on UK Biobank, we conducted two cohort studies to evaluate the phenotypic relationships between RA and CVD, including atrial fibrillation (AF), coronary artery disease (CAD), heart failure (HF), and stroke. Next, we used linkage disequilibrium score regression, Local Analysis of [co]Variant Association, and bivariate causal mixture model (MiXeR) methods to examine the genetic correlation and polygenic overlap between RA and CVD, using genome-wide association summary statistics. Furthermore, we explored specific shared genetic loci by conjunctional false discovery rate analysis and association analysis based on subsets.

RESULTS

Compared with the general population, RA patients showed a higher incidence of CVD (hazard ratio [HR] = 1.21, 95% confidence interval [CI]: 1.15-1.28). We observed positive genetic correlations of RA with AF and stroke, and a mixture of negative and positive local genetic correlations underlying the global genetic correlation for CAD and HF, with 13 ~ 33% of shared genetic variants for these trait pairs. We further identified 23 pleiotropic loci associated with RA and at least one CVD, including one novel locus (rs7098414, TSPAN14, 10q23.1). Genes mapped to these shared loci were enriched in immune and inflammatory-related pathways, and modifiable risk factors, such as high diastolic blood pressure.

CONCLUSIONS

This study revealed the shared genetic architecture of RA and CVD, which may facilitate drug target identification and improved clinical management.