IL-6 Revisited: From Rheumatoid Arthritis to CAR T Cell Therapy and COVID-19

Associations of Rheumatoid Factor, Rheumatoid Arthritis, and Interleukin-6 Inhibitor with the Prognosis of Ischemic Stroke: a Prospective Multicenter Cohort Study and Mendelian Randomization Analysis

Rheumatoid factor (RF), an established diagnostic biomarker for rheumatoid arthritis (RA), is associated with cardiovascular diseases, but its impact on clinical outcomes of ischemic stroke remains unclear. We aimed to investigate the observational associations between serum RF and prognosis of ischemic stroke, and further examined the genetic associations of RA and its therapeutic strategy, interleukin-6 (IL-6) inhibitor, with prognosis of ischemic stroke. We measured serum RF levels in 3474 Chinese ischemic stroke patients from the China Antihypertensive Trial in Acute Ischemic Stroke. The primary outcome was the composite outcome of death or major disability (modified Rankin Scale score ≥3) at 3 months after stroke onset. Mendelian randomization (MR) analyses were performed to examine the associations of genetically predicted RA and IL-6 inhibition with prognosis of ischemic stroke. During 3 months of follow-up, 866 patients (25.43%) experienced death or major disability. After multivariate adjustment, RF-positive was significantly associated with a high risk of primary outcome (OR, 1.47; 95% CI, 1.08-2.00; P =0.016) compared with RF-negative. The two-sample MR analyses suggested that genetically predicted RA was associated with an increased risk of primary outcome (OR, 1.09; 95% CI, 1.01-1.18; P=0.021), while genetically predicted IL-6 inhibition was associated with a decreased risk of primary outcome (OR, 0.88; 95% CI, 0.77-0.99; P=0.041). We found that positive RF was associated with increased risks of adverse outcomes after atherosclerotic ischemic stroke, and genetically predicted RA and IL-6 inhibition increased and decreased the risks of adverse outcomes after ischemic stroke, respectively.

Targeting cytokine and chemokine signaling pathways for cancer therapy

Cytokines are critical in regulating immune responses and cellular behavior, playing dual roles in both normal physiology and the pathology of diseases such as cancer. These molecules, including interleukins, interferons, tumor necrosis factors, chemokines, and growth factors like TGF-β, VEGF, and EGF, can promote or inhibit tumor growth, influence the tumor microenvironment, and impact the efficacy of cancer treatments. Recent advances in targeting these pathways have shown promising therapeutic potential, offering new strategies to modulate the immune system, inhibit tumor progression, and overcome resistance to conventional therapies. In this review, we summarized the current understanding and therapeutic implications of targeting cytokine and chemokine signaling pathways in cancer. By exploring the roles of these molecules in tumor biology and the immune response, we highlighted the development of novel therapeutic agents aimed at modulating these pathways to combat cancer. The review elaborated on the dual nature of cytokines as both promoters and suppressors of tumorigenesis, depending on the context, and discussed the challenges and opportunities this presents for therapeutic intervention. We also examined the latest advancements in targeted therapies, including monoclonal antibodies, bispecific antibodies, receptor inhibitors, fusion proteins, engineered cytokine variants, and their impact on tumor growth, metastasis, and the tumor microenvironment. Additionally, we evaluated the potential of combining these targeted therapies with other treatment modalities to overcome resistance and improve patient outcomes. Besides, we also focused on the ongoing research and clinical trials that are pivotal in advancing our understanding and application of cytokine- and chemokine-targeted therapies for cancer patients.

Association between premature vascular smooth muscle cells senescence and vascular inflammation in Takayasu's arteritis

OBJECTIVES

Arterial wall inflammation and remodelling are the characteristic features of Takayasu's arteritis (TAK). It has been proposed that vascular smooth muscle cells (VSMCs) are the main targeted cells of inflammatory damage and participate in arterial remodelling in TAK. Whether VSMCs are actively involved in arterial wall inflammation has not been elucidated. Studies have shown that cellular senescence in tissue is closely related to local inflammation persistence. We aimed to investigate whether VSMCs senescence contributes to vascular inflammation and the prosenescent factors in TAK.

METHODS

VSMCs senescence and senescence-associated secretory phenotype were detected by histological examination, bulk RNA-Seq and single-cell RNA-seq conducted on vascular surgery samples of TAK patients. The key prosenescent factors and the downstream signalling pathway were investigated in a series of in vitro and ex vivo experiments.

RESULTS

Histological findings, primary cell culture and transcriptomic analyses demonstrated that VSMCs of TAK patients had the features of premature senescence and contributed substantially to vascular inflammation by upregulating the expression of senescence-associated inflammatory cytokines. IL-6 was found to be the critical cytokine that drove VSMCs senescence and senescence-associated mitochondrial dysfunction in TAK. Mechanistically, IL-6-induced non-canonical mitochondrial localisation of phosphorylated STAT3 (Tyr705) prevented mitofusin 2 (MFN2) from proteasomal degradation, and subsequently promoted senescence-associated mitochondrial dysfunction and VSMCs senescence. Mitochondrial STAT3 or MFN2 inhibition ameliorated VSMCs senescence in ex vivo cultured arteries of TAK patients.

CONCLUSIONS

VSMCs present features of cellular senescence and are actively involved in vascular inflammation in TAK. Vascular IL-6-mitochondrial STAT3-MFN2 signalling is an important driver of VSMCs senescence.

Serum GM-CSF level is a predictor of treatment response to tocilizumab in rheumatoid arthritis patients: a prospective observational cohort study

BACKGROUND

The aim of this prospective observational cohort study was to unveil the predictors of treatment response to tocilizumab (TCZ) therapy in rheumatoid arthritis (RA) patients, in terms of clinical characteristics and serum proinflammatory cytokines, especially to explore the predictive value of granulocyte macrophage-colony stimulating factor (GM-CSF).

METHODS

Active adult RA patients with inadequate response to MTX intending to receive TCZ therapy were recruited prospectively in the study. A total of 174 severe RA patients were included for the identification of the associations between treatment response and the following characteristic features: demographics, medications, disease activity, serum proinflammatory cytokines and so on.

RESULTS

Disease duration (OR = 0.996), tender joint count (TJC)/68 (OR = 0.943), neutrophil ratio (W4/baseline) (OR = 0.224), the high level of GM-CSF > 5 ng/ml (OR = 0.414) at baseline were the independent adverse predictors of good response assessed by clinical disease activity index (CDAI) at week 24 (W24) for TCZ therapy in RA patients. Moreover, DAS28-ESR (OR = 2.951, P = 0.002) and the high level of GM-CSF > 10 ng/ml at baseline (OR = 5.419, P = 0.002) were independent predictors of poor response, but not the high level of GM-CSF > 5 ng/ml (OR = 2.713, P = 0.054). The patients in the high GM-CSF group had significantly higher DAS28-ESR and serum levels of cytokines (IL-17A, IL-1β, IL-6, TNF-α) at baseline, as well as significantly higher rate of non-good response (62.8% vs. 39.4%, P = 0.010) and poor response (27.9% vs. 9.1%, P = 0.004) than the low GM-CSF group at W24. In addition, poor responders had significantly higher levels of GM-CSF with concomitant increase in the serum levels of IL-17A and IL-1β at baseline than those in moderate and good response groups, while serum levels of IL-6 and TNF-α at baseline were not significantly different in three response groups.

CONCLUSION

The high levels of GM-CSF (> 5 ng/ml and > 10 ng/ml) at baseline were the independent predictors of non-good response and poor response to TCZ at W24 respectively. The high level of GM-CSF at baseline is a marker of high disease activity and a predictor of poor response to TCZ in severe RA patients, which may facilitate the development of individualized treatment strategies for refractory RA.

The double-edged effects of IL-6 in liver regeneration, aging, inflammation, and diseases

Interleukin-6 (IL-6) is a pleiotropic cytokine and exerts its complex biological functions mainly through three different signal modes, called cis-, trans-, and cluster signaling. When IL-6 binds to its membrane or soluble receptors, the co-receptor gp130 is activated to initiate downstream signaling and induce the expression of target genes. In the liver, IL-6 can perform its anti-inflammatory activities to promote hepatocyte reprogramming and liver regeneration. On the contrary, IL-6 also exerts the pro-inflammatory functions to induce liver aging, fibrosis, steatosis, and carcinogenesis. However, understanding the roles and underlying mechanisms of IL-6 in liver physiological and pathological processes is still an ongoing process. So far, therapeutic agents against IL‑6, IL‑6 receptor (IL‑6R), IL-6-sIL-6R complex, or IL-6 downstream signal transducers have been developed, and determined to be effective in the intervention of inflammatory diseases and cancers. In this review, we summarized and highlighted the understanding of the double-edged effects of IL-6 in liver homeostasis, aging, inflammation, and chronic diseases, for better shifting the "negative" functions of IL-6 to the "beneficial" actions, and further discussed the potential therapeutic effects of targeting IL-6 signaling in the clinics.

Analysis of potential diagnostic markers and therapeutic targets for rheumatoid arthritis with comorbid depression immunologic indicators

OBJECTIVE

Depression can impact the severity of rheumatoid arthritis (RA). This study aimed to investigate the relationship between Th1, Th2, Th17, Treg cell subsets, and their associated cytokines (e.g., IL-2, IL-4, IL-6, IL-10, IL-17, IFN-γ, and TNF-α), and the occurrence of RA both with and without comorbid depression. The objective is to identify potential biological markers, therapeutic targets, and the therapeutic effects of RA with comorbid depression.

RESULTS

53 RA patients,46 RA with comorbid depression patients and 51 healthy subjects were included in the RA,RD and HC group from August 2021 and October 2022. Among RA patients, 46.46 % were comorbid with depression. IL-6 concentrations were significantly higher in RD group than in RA group.Comparison between the HC and RA and RD groups revealed that Th1 %, Th17 %, Th1, Th17, Th1/Th2, Th17/Treg and Th1/Treg were significantly higher in the RA and RD groups, and conversely, Th2 %, Treg%, Th2 and Treg were significantly lower than in the HC group.The RA group compared to the RD group found that Th17 %, Th17 and Th17/Treg were significantly higher in the RD group than in the RA group, however, Th1 %, Treg and Th2/Treg were significantly lower than in the RA group. The total HAMD score had a medium strength positive correlation with IL-6.

CONCLUSION

These findings suggest that elevated the autoimmunity status was overactivated in RA with or without depression activates patients, IL-6 may be a predictor of the severity of RA with comorbid depression, IL-6 concentrations and an imbalance in the Th17/Treg may underlie the comorbidity of RA and depression, offering potential targets for therapeutic intervention, prompting further evaluation of the role of indirect inflammatory markers in RA with comorbid depression, highlighting the need for additional research to clarify the complex relationship between inflammation and psychological health.

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.

A single infusion of engineered long-lived and multifunctional T cells confers durable remission of asthma in mice

Asthma, the most prevalent respiratory disease, affects more than 300 million people and causes more than 250,000 deaths annually. Type 2-high asthma is characterized by interleukin (IL)-5-driven eosinophilia, along with airway inflammation and remodeling caused by IL-4 and IL-13. Here we utilize IL-5 as the targeting domain and deplete BCOR and ZC3H12A to engineer long-lived chimeric antigen receptor (CAR) T cells that can eradicate eosinophils. We call these cells immortal-like and functional IL-5 CAR T cells (5TIF) cells. 5TIF cells were further modified to secrete an IL-4 mutein that blocks IL-4 and IL-13 signaling, designated as 5TIF4 cells. In asthma models, a single infusion of 5TIF4 cells in fully immunocompetent mice, without any conditioning regimen, led to sustained repression of lung inflammation and alleviation of asthmatic symptoms. These data show that asthma, a common chronic disease, can be pushed into long-term remission with a single dose of long-lived CAR T cells.

Associations of inflammatory cytokines with palmoplantar pustulosis: a bidirectional Mendelian randomization study

Background

Variations in circulatory cytokine levels have been observed during the onset and course of palmoplantar pustulosis (PPP); however, whether these changes are due to etiological or secondary factors is unclear. To clarify the causal relationship, we conducted a summarized-level bidirectional Mendelian randomization (MR) analysis in this study.

Methods

A FinnGen biobank genome-wide association study (GWAS) of 212,766 individuals (524 PPP patients and 212,242 controls) provided summary data for PPP, whereas genetic instrumental variables (IVs) linked to circulation cytokine levels were gathered from a GWAS of 14,824 European individuals. The inverse-variance weighted (IVW), weighted median (WME), simple mode, and MR-Egger methods were used to ascertain the changes in PPP pathogenic cytokine taxa. Sensitivity analysis, which included horizontal pleiotropy analysis, was then conducted. The reliability of the results was assessed using the leave-one-out approach and the MR Steiger test, which evaluated the strength of a causal relationship. To evaluate the reverse causality between PPP and circulating cytokine levels, a reverse MR analysis was carried out.

Results

Our study demonstrated positive associations between C-X-C motif chemokine 6 (CXCL6) and PPP (odds ratio, OR 1.257, 95%CI: 1.001-1.570, p = 0.043). C-C motif chemokine 19 (CCL19) and interleukin-6 (IL-6) were suggested to be protectively associated with the development of PPP (OR: 0.698,95% CI: 0.516-0.944, p = 0.020; OR: 0.656, 95%CI:0.437-0.985, p = 0.042). The results were steady after sensitivity and heterogeneity analyses.

Conclusion

At the genetic prediction level, we identified causally connected inflammation-related variables that contributed to the onset and development of PPP. The therapeutic options for some refractory PPP have expanded due to tailored cytokine therapy, generating fresh concepts for PPP diagnostics and mechanism investigation.

LC-MS-based rheumatoid arthritis serum metabolomics reveals the role of deoxyinosine in attenuating collagen-induced arthritis in mice

Rheumatoid arthritis (RA) is a persistent autoimmune condition with no identified cure currently. Recently, scientists have applied metabolomics to investigate altered metabolic profiles and unique diseases-associated metabolic signatures. Herein, we applied metabolomics approach to analyze serum samples of 41 RA patients and 42 healthy controls (HC) with the aim to characterize RA patients' metabolic profile, investigate related underlying pathological processes, and identify target metabolites. By utilizing ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry, we found 168 proposed metabolites and 45 vital metabolic pathways. Our analysis revealed that deoxyinosine (DI), a metabolite of the purine metabolic pathway, was the most significant reduced metabolite in RA patients. Furthermore, through targeted detection, we confirmed lower concentration of DI in RA patients' peripheral blood. Moreover, DI inhibited lipopolysaccharide-induced inflammation both in vitro and in vivo. We further assessed DI's therapeutic potential in a collagen-induced arthritis (CIA) murine model. The results revealed that DI attenuated CIA, as evidenced by significantly lowered clinical scores of arthritis, alleviated joint swelling, and mitigated bone destruction. Moreover, we elucidated the underlying mechanism by which DI increased the population of myeloid-derived suppressor cells (MDSCs) and suppressed the proliferation of induced T cells. Collectively, these findings suggested that DI potentially ameliorated RA by inducing immunosuppressive MDSCs. The study provides key observations on RA pathogenesis and may contribute to developing novel therapeutic strategies for this debilitating condition.

Drugs targeting CMPK2 inhibit pyroptosis to alleviate severe pneumonia caused by multiple respiratory viruses

Severe pneumonia caused by respiratory viruses has become a major threat to humans, especially with the SARS-CoV-2 outbreak and epidemic. The aim of this study was to investigate the universal molecular mechanism of severe pneumonia induced by multiple respiratory viruses and to search for therapeutic strategies targeting this universal molecular mechanism. The common differential genes of four respiratory viruses, including respiratory syncytial virus (RSV), rhinovirus, influenza, and SARS-CoV-2, were screened by GEO database, and the hub gene was obtained by Sytohubba in Cytoscape. Then, the effect of hub genes on inflammasome and pyrodeath was investigated in the model of RSV infection in vitro and in vivo. Finally, through virtual screening, drugs targeting the hub gene were obtained, which could alleviate severe viral pneumonia in vitro and in vivo. The results showed that CMPK2 is one of the hub genes after infection by four respiratory viruses. CMPK2 activates the inflammasome by activating NLRP3, and promotes the releases of inflammatory factors interleukin (IL)-1β and IL-18 to induce severe viral pneumonia. Z25 and Z08 can reduce the expression level of CMPK2 mRNA and protein, thereby inhibiting NLRP3 and alleviating the development of severe viral pneumonia. In conclusion, the inflammatory response mediated by CMPK2 is the common molecular mechanism of severe pneumonia induced by viral infection, and Z25 and Z08 can effectively alleviate viral infection and severe pneumonia through this mechanism.

The new era of immunological treatment, last updated and future consideration of CAR T cell-based drugs

Cancer treatment is one of the fundamental challenges in clinical setting, especially in relapsed/refractory malignancies. The novel immunotherapy-based treatments bring new hope in cancer therapy and achieve various treatment successes. One of the distinguished ways of cancer immunotherapy is adoptive cell therapy, which utilizes genetically modified immune cells against cancer cells. Between different methods in ACT, the chimeric antigen receptor T cells have more investigation and introduced a promising way to treat cancer patients. This technology progressed until it introduced six US Food and Drug Administration-approved CAR T cell-based drugs. These drugs act against hematological malignancies appropriately and achieve exciting results, so they have been utilized widely in cell therapy clinics. In this review, we introduce all CAR T cells-approved drugs based on their last data and investigate them from all aspects of pharmacology, side effects, and compressional. Also, the efficacy of drugs, pre- and post-treatment steps, and expected side effects are introduced, and the challenges and new solutions in CAR T cell therapy are in the last speech.

Laboratory features of effects of peloidotherapy and aromatherapy in patients with rheumatoid arthritis

Peloidotherapy and aromatherapy have been used for years in the treatment of numerous inflammatory conditions, including rheumatoid arthritis (RA). The exact mechanism of their action in RA is unclear. The goal of our research is to determine the effect of peloidotherapy and aromatherapy on inflammation parameters in RA patients. Our study included 20 patients of both sexes, with confirmed diagnosis of RA, older than 18 years. Patients were treated during 28 days with combination of peloidotherapy and aromatherapy. Serum samples for detection of levels of inflammation parameters were taken at two intervals: before the start of therapy and at the end of treatment. The results of our study show that there were no significant changes in the parameters of the complete blood count. Nevertheless, a statistically significant decrease in the serum concentration of two markers of inflammation-interleukin-6 (IL-6) and nitrogen-oxide (NO)-was detected. Correlation analyses results say that there is a synchronized drop in the serum concentrations of CRP and the sedimentation rate, and the serum concentrations of fibrinogen and IL-6 are in the same relationship as well as serum levels of IL-6 and NO. Bearing in mind the importance of IL-6 and NO in the pathogenesis of inflammation in RA, we conclude that the application of our therapeutic protocol can be a significant add-on treatment to classic immunomodulators. Due to the small number of study participants, the lack of a control group, and the short follow-up time of patients, additional research is needed.

Development and validation of machine learning-based models for predicting healthcare-associated bacterial/fungal infections among COVID-19 inpatients: a retrospective cohort study

BACKGROUND

COVID-19 and bacterial/fungal coinfections have posed significant challenges to human health. However, there is a lack of good tools for predicting coinfection risk to aid clinical work.

OBJECTIVE

We aimed to investigate the risk factors for bacterial/fungal coinfection among COVID-19 patients and to develop machine learning models to estimate the risk of coinfection.

METHODS

In this retrospective cohort study, we enrolled adult inpatients confirmed with COVID-19 in a tertiary hospital between January 1 and July 31, 2023, in China and collected baseline information at admission. All the data were randomly divided into a training set and a testing set at a ratio of 7:3. We developed the generalized linear and random forest models for coinfections in the training set and assessed the performance of the models in the testing set. Decision curve analysis was performed to evaluate the clinical applicability.

RESULTS

A total of 1244 patients were included in the training cohort with 62 healthcare-associated bacterial/fungal infections, while 534 were included in the testing cohort with 22 infections. We found that patients with comorbidities (diabetes, neurological disease) were at greater risk for coinfections than were those without comorbidities (OR = 2.78, 95%CI = 1.61-4.86; OR = 1.93, 95%CI = 1.11-3.35). An indwelling central venous catheter or urinary catheter was also associated with an increased risk (OR = 2.53, 95%CI = 1.39-4.64; OR = 2.28, 95%CI = 1.24-4.27) of coinfections. Patients with PCT > 0.5 ng/ml were 2.03 times (95%CI = 1.41-3.82) more likely to be infected. Interestingly, the risk of coinfection was also greater in patients with an IL-6 concentration < 10 pg/ml (OR = 1.69, 95%CI = 0.97-2.94). Patients with low baseline creatinine levels had a decreased risk of bacterial/fungal coinfections(OR = 0.40, 95%CI = 0.22-0.71). The generalized linear and random forest models demonstrated favorable receiver operating characteristic curves (ROC = 0.87, 95%CI = 0.80-0.94; ROC = 0.88, 95%CI = 0.82-0.93) with high accuracy, sensitivity and specificity of 0.86vs0.75, 0.82vs0.86, 0.87vs0.74, respectively. The corresponding calibration evaluation P statistics were 0.883 and 0.769.

CONCLUSIONS

Our machine learning models achieved strong predictive ability and may be effective clinical decision-support tools for identifying COVID-19 patients at risk for bacterial/fungal coinfection and guiding antibiotic administration. The levels of cytokines, such as IL-6, may affect the status of bacterial/fungal coinfection.

Factors Associated with Mortality Among Severe Omicron Patients for COVID-19

Purpose

The purpose of the study was to explore the potential risk factors of mortality in patients with severe pneumonia during the omicron pandemic in South China in 2022.

Methods

Clinical data was collected from patients hospitalized with omicron COVID-19. Then, patients were categorized into the non-survival and survival groups. A comprehensive analysis was conducted to analyze the factors associated with negative outcome in individuals suffering from severe omicron COVID-19.

Results

In this study, 155 severe COVID-19 patients were included, comprising 55 non-survivors and 100 survivors. Non-survivors, in comparison to survivors, exhibited elevated levels of various biomarkers including neutrophil count, hypersensitive troponin T, urea, creatinine, C-reactive protein, procalcitonin, interleukin-6, plasma D-dimer, and derived neutrophil-to-lymphocyte ratio (dNLR) (P < 0.05). They also displayed reduced lymphocyte count, platelet count, and albumin levels (P < 0.05) and were more prone to developing comorbidities, including shock, acute cardiac and renal injury, acute respiratory distress syndrome, coagulation disorders, and secondary infections. Platelet count (PLT) <100 × 10^/L, interleukin-6 (IL-6) >100 pg/mL, and dNLR >5.0 independently contributed to the risk of death in patients suffering from severe COVID-19.

Conclusion

PLT, IL-6, and dNRL independently contributed to the risk of mortality in patients with severe pneumonia during the 2022 omicron pandemic in South China.

Improving the safety of CAR-T-cell therapy: The risk and prevention of viral infection for patients with relapsed or refractory B-cell lymphoma undergoing CAR-T-cell therapy

Chimeric antigen receptor (CAR) T-cell therapy, an innovative immunotherapeutic against relapsed/refractory B-cell lymphoma, faces challenges due to frequent viral infections. Despite this, a comprehensive review addressing risk assessment, surveillance, and treatment management is notably absent. This review elucidates immune response compromises during viral infections in CAR-T recipients, collates susceptibility risk factors, and deliberates on preventive strategies. In the post-pandemic era, marked by the Omicron variant, new and severe threats to CAR-T therapy emerge, necessitating exploration of preventive and treatment measures for COVID-19. Overall, the review provides recommendations for viral infection prophylaxis and management, enhancing CAR-T product safety and recipient survival.

Navigating IL-6: From molecular mechanisms to therapeutic breakthroughs

This concise review navigates the intricate realm of Interleukin-6 (IL-6), an important member of the cytokine family. Beginning with an introduction to cytokines, this narrative review unfolds with the historical journey of IL-6, illuminating its evolving significance. A crucial section unravels the three distinct signaling modes employed by IL-6, providing a foundational understanding of its versatile interactions within cellular landscapes. Moving deeper, the review meticulously dissects IL-6's signaling mechanisms, unraveling the complexities of its pleiotropic effects in both physiological responses and pathological conditions. A significant focus is dedicated to the essential role IL-6 plays in inflammatory diseases, offering insights into its associations and implications for various health conditions. The review also takes a therapeutic turn by exploring the emergence of anti-IL-6 monoclonal inhibitors, marking a profound stride in treatment modalities. Diving into the molecular realm, the review explores small molecules as agents for IL-6 inhibition, providing a nuanced perspective on diverse intervention strategies. As the review embarks on the final chapters, it contemplates future aspects, offering glimpses into potential research trajectories and the evolving landscape of IL-6-related studies.

Structural insights into IL-6 signaling inhibition by therapeutic antibodies

Antibody inhibitors of the interleukin-6 (IL-6) signaling pathway, such as tocilizumab and sarilumab, have been used to treat rheumatoid arthritis, chimeric antigen receptor T cell-induced cytokine storm, and severe COVID-19 pneumonia. Here, we solve the cryogenic electron microscopy structures of sarilumab and tocilizumab in complex with IL-6R to resolutions of 3.2 and 3.3 Å, respectively. These structures reveal that both tocilizumab and sarilumab bind to the D3 domain of IL-6R. The binding surfaces of the two antibodies largely overlap, but the detailed interactions are different. Functional studies of various mutants show results consistent with our structural analysis of the antibodies and IL-6R interactions. Structural comparisons with the IL-6/IL-6R/gp130 complex indicate that sarilumab and tocilizumab probably inhibit IL-6/IL-6R signaling by competing for the IL-6 binding site. In summary, this work reveals the antibody-blocking mechanism of the IL-6 signaling pathway and paves the way for future antibody discovery.

An Evaluation of Type 1 Interferon Related Genes in Male and Female-Matched, SARS-CoV-2 Infected Individuals Early in the COVID-19 Pandemic

SARS-CoV-2 infection has claimed just over 1.1 million lives in the US since 2020. Globally, the SARS-CoV-2 respiratory infection spread to 771 million people and caused mortality in 6.9 million individuals to date. Much of the early literature showed that SARS-CoV-2 immunity was defective in the early stages of the pandemic, leading to heightened and, sometimes, chronic inflammatory responses in the lungs. This lung-associated 'cytokine storm' or 'cytokine release syndrome' led to the need for oxygen supplementation, respiratory distress syndrome, and mechanical ventilation in a relatively high number of people. In this study, we evaluated circulating PBMC from non-hospitalized, male and female, COVID-19+ individuals over the course of infection, from the day of diagnosis (day 0) to one-week post diagnosis (day 7), and finally 4 weeks after diagnosis (day 28). In our early studies, we included hospitalized and critically care patient PBMC; however, most of these individuals were lymphopenic, which limited our assessments of their immune integrity. We chose a panel of 30 interferon-stimulated genes (ISG) to evaluate by PCR and completed flow analysis for immune populations present in those PBMC. Lastly, we assessed immune activation by stimulating PBMC with common TLR ligands. We identified changes in innate cells, primarily the innate lymphoid cells (ILC, NK cells) and adaptive immune cells (CD4+ and CD8+ T cells) over this time course of infection. We found that the TLR-7 agonist, Resiquimod, and the TLR-4 ligand, LPS, induced significantly better IFNα and IFNγ responses in the later phase (day 28) of SARS-CoV-2 infection in those non-hospitalized COVID-19+ individuals as compared to early infection (day 0 and day 7). We concluded that TLR-7 and TLR-4 agonists may be effective adjuvants in COVID-19 vaccines for mounting immunity that is long-lasting against SARS-CoV-2 infection.

Amelioration of inflammation through reduction of oxidative stress in rheumatoid arthritis by treating fibroblast-like synoviocytes (FLS) with DMF-loaded PLGA nanoparticles

BACKGROUND

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory condition, and Dimethyl fumarate (DMF) is known for inducing antioxidant enzymes and reducing reactive oxygen species (ROS). Fibroblast-like synoviocytes (FLS) contribute to joint damage by releasing interleukins (IL-1β, IL-6, and IL-8) in response to ROS. Given ROS's impact on FLS acquiring an invasive phenotype, our study explored the effects of poly lactic-co-glycolic acid (PLGA) nanoparticles containing DMF on the expression of the HO-1 enzyme and the inflammatory cytokines IL-1β, IL-6, and IL-8 in FLS cells.

METHODS

In this study, we evaluated and compared the impact of Free-DMF and PLGA-DMF, on the gene expression of the HO-1 and inflammatory cytokines (IL-1β, IL-6, and IL-8) in FLS cells derived from 13 patients with rheumatoid arthritis. qRT-PCR method was used to quantify the gene expression levels.

RESULTS

PLGA-DMF nanoparticles demonstrated a significant increase in HO-1 expression and a significant decrease in IL-1β gene expression. Also, a significant decrease in IL-6 gene expression was seen under the effect of Free-DMF. These results indicate the potential effectiveness of PLGA-DMF nanoparticles in reducing inflammation and improving rheumatoid arthritis symptoms.

DISCUSSION

According to the findings, PLGA-DMF nanoparticles are expected to be effective in reducing inflammation and improving the symptoms of rheumatoid arthritis. Also, further studies on other factors affected by oxidative stress such as cell invasion factors and survival factors after the effect of PLGA-DMF nanoparticle are recommended.

Construction and validation of a diagnostic model for rheumatoid arthritis based on mitochondrial autophagy-related genes

Rheumatoid arthritis (RA) is an autoimmune disease associated with an increased risk of disability. Due to its slow progression, timely diagnosis and treatment during the early stages can effectively decelerate disease advancement. Consequently, there is a pressing need to investigate additional biomarkers and therapeutic targets relevant to RA diagnosis. Mitochondrial autophagy, a biological process that regulates the quantity of mitochondria, is intricately linked to the development of tumor diseases. However, the role of autophagy in RA remains unclear. To address this, transcriptome data from the GEO database were collected for RA and its controls and subjected to differential expression analysis. The differentially expressed genes obtained were then intersected with mitochondrial autophagy-related genes. Subsequently, the overlapping genes were further intersected with genes from critical modules obtained through the weighted co-expression network algorithm. Diagnostic genes were identified, and diagnostic models were constructed for the resulting genes using the random forest and LASSO algorithms. The model achieved an AUC of 0.916 in the GSE93272 dataset and 0.951 in the GSE17755 dataset. Additionally, qPCR experiments were conducted on the diagnostic genes. Finally, we explored the correlation between the abundance of immune cell infiltration and diagnostic genes, constructing a drug-gene interaction network. The diagnostic genes identified in this study can serve as a reference for early diagnosis and the discovery of therapeutic targets in RA.

When idiopathic multicentric Castleman disease meets COVID-19: a multicenter retrospective study from China

Idiopathic multicentric Castleman disease (iMCD) is a rare and cytokine storm-driven inflammatory disorder. The exact cause of iMCD is still unknown, although several hypotheses have been proposed. However, regardless of the underlying cause, the ultimate result is the activation of the inflammatory pathway, which can lead to damage in multiple organs. Currently, there have been several reports highlighting the intricate link between coronavirus disease 2019 (COVID-19) and iMCD. To better understand the impact of COVID-19-induced immune storm on iMCD, we conducted a multicenter retrospective study in three hospitals in China. A total of 28 patients with iMCD were included, among whom 25 had confirmed COVID-19 infection, and we presented 4 cases that showed different disease progression after the infection of COVID-19, including 2 who did not receive any treatment for Castleman disease before. Our findings underscore the necessity of carefully monitoring iMCD patients with COVID-19 and promptly intervening to address any changes in their condition. Besides, this study also summarized the shared cytokines between COVID-19 and iMCD. Recent studies have shown promising results in treating severe COVID-19 and iMCD using tocilizumab, an interleukin-6 receptor antagonist. Therefore, it suggests that other potential cytokine storm therapy targets that have been effective in COVID-19 may also be explored for the treatment of iMCD.

Anti-Acidification and Immune Regulation by Nano-Ceria-Loaded Mg-Al Layered Double Hydroxide for Rheumatoid Arthritis Therapy

Rheumatoid arthritis (RA) is a chronic autoimmune disease featuring an abnormal immune microenvironment and resultant accumulation of hydrogen ions (H+ ) produced by activated osteoclasts (OCs). Currently, clinic RA therapy can hardly achieve sustained or efficient therapeutic outcomes due to the failures in generating sufficient immune modulation and manipulating the accumulation of H+ that deteriorates bone damage. Herein, a highly effective immune modulatory nanocatalytic platform, nanoceria-loaded magnesium aluminum layered double hydroxide (LDH-CeO2 ), is proposed for enhanced immune modulation based on acid neutralization and metal ion inherent bioactivity. Specifically, the mild alkaline LDH initiates significant M2 repolarization of macrophages triggered by the elevated antioxidation effect of CeO2 via neutralizing excessive H+ in RA microenvironment, thus resulting in the efficient recruitment of regulatory T cell (Treg) and suppressions on T helper 17 cell (Th 17) and plasma cells. Moreover, the osteogenic activity is stimulated by the Mg ion released from LDH, thereby promoting the damaged bone healing. The encouraging therapeutic outcomes in adjuvant-induced RA model mice demonstrate the high feasibility of such a therapeutic concept, which provides a novel and efficient RA therapeutic modality by the immune modulatory and bone-repairing effects of inorganic nanocatalytic material.

Immunotherapy Strategy for Systemic Autoimmune Diseases: Betting on CAR-T Cells and Antibodies

Systemic autoimmune diseases (SAIDs), such as systemic lupus erythematosus (SLE), systemic sclerosis (SSc) and rheumatoid arthritis (RA), are fully related to the unregulated innate and adaptive immune systems involved in their pathogenesis. They have similar pathogenic characteristics, including the interferon signature, loss of tolerance to self-nuclear antigens, and enhanced tissue damage like necrosis and fibrosis. Glucocorticoids and immunosuppressants, which have limited specificity and are prone to tolerance, are used as the first-line therapy. A plethora of novel immunotherapies have been developed, including monoclonal and bispecific antibodies, and other biological agents to target cellular and soluble factors involved in disease pathogenesis, such as B cells, co-stimulatory molecules, cytokines or their receptors, and signaling molecules. Many of these have shown encouraging results in clinical trials. CAR-T cell therapy is considered the most promising technique for curing autoimmune diseases, with recent successes in the treatment of SLE and SSc. Here, we overview novel therapeutic approaches based on CAR-T cells and antibodies for targeting systemic autoimmune diseases.

JAK/STAT Signaling Predominates in Human and Murine Fungal Post-infectious Inflammatory Response Syndrome

Post-infection inflammatory syndromes have been increasingly recognized as a cause of host damage in a variety of infectious diseases including tuberculosis, bacterial meningitis, and COVID-19. Recently, a post-infectious inflammatory response syndrome (PIIRS) was described in non-HIV-infected cryptococcal fungal meningoencephalitis (CM) as a major cause of mortality. Inflammatory syndromes are particularly severe in neurological infections due to the skull's rigid structure which limits unchecked tissue expansion from inflammatory-induced edema. In the present studies, neurologic transcriptional pathway analysis utilizing a murine PIIRS model demonstrated a predominance of Janus kinase/signal transducer and activator of transcription (JAK/STAT) activation. JAK/STAT inhibitor treatment resulted in improvements in CNS damage markers, reductions in intrathecal CD44hiCD62lo CD4+ effector CD4+ T-cells and MHC II+ inflammatory myeloid cells, and weight gains in mice, the latter after treatment with antifungals. Based on these data, pathway-driven steroid-sparing human treatment for steroid-refractory PIIRS was initiated using short courses of the JAK/STAT inhibitor ruxolitinib. These were well tolerated and reduced activated HLA-DR+ CD4+ and CD8+ cells and inflammatory monocytes as well as improved brain imaging. Together, these findings support the role of JAK/STAT in PIIRS as well as further study of JAK/STAT inhibitors as potential adjunctive therapy for PIRS and other neural inflammatory syndromes.

Exploring the mechanism of Celastrol in the treatment of rheumatoid arthritis based on systems pharmacology and multi-omics

To explore the molecular network mechanism of Celastrol in the treatment of rheumatoid arthritis (RA) based on a novel strategy (integrated systems pharmacology, proteomics, transcriptomics and single-cell transcriptomics). Firstly, the potential targets of Celastrol and RA genes were predicted through the database, and the Celastrol-RA targets were obtained by taking the intersection. Then, transcriptomic data and proteomic data of Celastrol treatment of RA were collected. Subsequently, Celastrol-RA targets, differentially expressed genes, and differentially expressed proteins were imported into Metascape for enrichment analysis, and related networks were constructed. Finally, the core targets of Celastrol-RA targets, differentially expressed genes, and differentially expressed proteins were mapped to synoviocytes of RA mice to find potential cell populations for Celastrol therapy. A total of 195 Celastrol-RA targets, 2068 differential genes, 294 differential proteins were obtained. The results of enrichment analysis showed that these targets, genes and proteins were mainly related to extracellular matrix organization, TGF-β signaling pathway, etc. The results of single cell sequencing showed that the main clusters of these targets, genes, and proteins could be mapped to RA synovial cells. For example, Mmp9 was mainly distributed in Hematopoietic cells, especially in Ptprn+fibroblast. The results of molecular docking also suggested that Celastrol could stably combine with molecules predicted by network pharmacology. In conclusion, this study used systems pharmacology, transcriptomics, proteomics, single-cell transcriptomics to reveal that Celastrol may regulate the PI3K/AKT signaling pathway by regulating key targets such as TNF and IL6, and then play an immune regulatory role.

Gp130-HIF1α axis-induced vascular damage is prevented by the short-term inhibition of IL-6 receptor signaling

Protection against endothelial damage is recognized as a frontline approach to preventing the progression of cytokine release syndrome (CRS). Accumulating evidence has demonstrated that interleukin-6 (IL-6) promotes vascular endothelial damage during CRS, although the molecular mechanisms remain to be fully elucidated. Targeting IL-6 receptor signaling delays CRS progression; however, current options are limited by persistent inhibition of the immune system. Here, we show that endothelial IL-6 trans-signaling promoted vascular damage and inflammatory responses via hypoxia-inducible factor-1α (HIF1α)-induced glycolysis. Using pharmacological inhibitors targeting HIF1α activity or mice with the genetic ablation of gp130 in the endothelium, we found that inhibition of IL-6R (IL-6 receptor)-HIF1α signaling in endothelial cells protected against vascular injury caused by septic damage and provided survival benefit in a mouse model of sepsis. In addition, we developed a short half-life anti-IL-6R antibody (silent anti-IL-6R antibody) and found that it was highly effective at augmenting survival for sepsis and severe burn by strengthening the endothelial glycocalyx and reducing cytokine storm, and vascular leakage. Together, our data advance the role of endothelial IL-6 trans-signaling in the progression of CRS and indicate a potential therapeutic approach for burns and sepsis.

The latest advances in the use of biological DMARDs to treat Still's disease

INTRODUCTION

Currently, the therapeutic management of Still's disease, a multisystemic inflammatory rare disorder, is directed to target the inflammatory symptoms and signs of patients. The treatment varies from glucocorticoids to disease-modifying antirheumatic drugs (DMARDs), both conventional synthetic and biological (bDMARDs). Usually, in refractory patients, bDMARDs are administered.

AREAS COVERED

Among bDMARDs, IL-1 and IL-6 inhibitors are frequently used, as data reported from both clinical trials and 'real-life' experiences. Recently, innovative therapeutic strategies have suggested an early administration of bDMARDs to increase the rate of clinical response and drug-free remission. Some new targets have been also proposed targeting IL-18, IFN-γ, and JAK/STAT pathway, which could be applied to Still's disease and its life-threatening evolution.

EXPERT OPINION

Many lines of evidence improved the knowledge about the therapeutic management of Still's disease with bDMARDs. However, many unmet needs may be still highlighted which could provide the basis to arrange further specific research in increasing the rate of clinical response. In fact, Still's disease remains a highly heterogeneous disease suggesting possible diverse underlying pathogenic mechanisms, at least partially, and consequent different therapeutic strategies. A better patient stratification may help in arranging specific studies to improve the long-term outcome of Still's disease.

Anemia in elderly rheumatoid arthritis patients: a cohort study

Introduction

Anemia is common in elderly patients with rheumatoid arthritis (RA). This study aimed to evaluate the current status and influencing factors of anemia in RA patients, to provide insights for clinical RA treatment and care.

Material and methods

This study included elderly patients with high RA activity treated in our hospital from June 1, 2021 to December 31, 2022 for analysis. The characteristics of RA patients were analyzed. Pearson correlation and logistic regression analysis were conducted to analyze the influencing factors of anemia in elderly patients with RA.

Results

A total of 285 RA patients were included. The incidence of anemia in high RA activity patients was 62.46%. There were significant differences in the course of RA, hemoglobin (Hb), low-density lipoprotein cholesterol (LDL-C), platelet/lymphocyte rate (PLR) and albumin (Alb) between RA patients with anemia and without anemia (all p < 0.05). Pearson correlation analysis indicated that course of RA (r = 0.522), Hb (r = 0.797), LDL-C (r = 0.558), PLR (r = 0.615) and Alb (r = 0.604) were correlated with anemia in patients with high RA activity (all p < 0.05). Logistic regression analysis indicated that course of RA ≥ 8 years (OR = 2.584, 95% CI: 1.822-3.647), LDL-C ≤ 2.8 mmol/l (OR = 3.202, 95% CI: 2.804-3.431), PLR ≥ 8 (OR = 2.183, 95% CI: 1.744-2.457), Alb ≤ 35 g/l (OR = 1.716, 95% CI: 1.401-2.006) were the risk factors of anemia in elderly patients with high RA activity (all p < 0.05).

Conclusions

Anemia in elderly patients with high RA activity is closely related to the course of RA, LDL-C, PLR and Alb. Close attention should be paid to the monitoring of those indicators to take early intervention measures to improve the prognosis of RA patients.

Targeting IL-6 trans-signalling: past, present and future prospects

Interleukin-6 (IL-6) is a key immunomodulatory cytokine that affects the pathogenesis of diverse diseases, including autoimmune diseases, chronic inflammatory conditions and cancer. Classical IL-6 signalling involves the binding of IL-6 to the membrane-bound IL-6 receptor α-subunit (hereafter termed 'mIL-6R') and glycoprotein 130 (gp130) signal-transducing subunit. By contrast, in IL-6 trans-signalling, complexes of IL-6 and the soluble form of IL-6 receptor (sIL-6R) signal via membrane-bound gp130. A third mode of IL-6 signalling - known as cluster signalling - involves preformed complexes of membrane-bound IL-6-mIL-6R on one cell activating gp130 subunits on target cells. Antibodies and small molecules have been developed that block all three forms of IL-6 signalling, but in the past decade, IL-6 trans-signalling has emerged as the predominant pathway by which IL-6 promotes disease pathogenesis. The first selective inhibitor of IL-6 trans-signalling, sgp130, has shown therapeutic potential in various preclinical models of disease and olamkicept, a sgp130Fc variant, had promising results in phase II clinical studies for inflammatory bowel disease. Technological developments have already led to next-generation sgp130 variants with increased affinity and selectivity towards IL-6 trans-signalling, along with indirect strategies to block IL-6 trans-signalling. Here, we summarize our current understanding of the biological outcomes of IL-6-mediated signalling and the potential for targeting this pathway in the clinic.

The NQR Complex Regulates the Immunomodulatory Function of Bacteroides thetaiotaomicron

The gut microbiome and intestinal immune system are engaged in a dynamic interplay that provides myriad benefits to host health. However, the microbiome can also elicit damaging inflammatory responses, and thus establishing harmonious immune-microbiome interactions is essential to maintain homeostasis. Gut microbes actively coordinate the induction of anti-inflammatory responses that establish these mutualistic interactions. Despite this, the microbial pathways that govern this dialogue remain poorly understood. We investigated the mechanisms through which the gut symbiont Bacteroides thetaiotaomicron exerts its immunomodulatory functions on murine- and human-derived cells. Our data reveal that B. thetaiotaomicron stimulates production of the cytokine IL-10 via secreted factors that are packaged into outer membrane vesicles, in a TLR2- and MyD88-dependent manner. Using a transposon mutagenesis-based screen, we identified a key role for the B. thetaiotaomicron-encoded NADH:ubiquinone oxidoreductase (NQR) complex, which regenerates NAD+ during respiration, in this process. Finally, we found that disruption of NQR reduces the capacity of B. thetaiotaomicron to induce IL-10 by impairing biogenesis of outer membrane vesicles. These data identify a microbial pathway with a previously unappreciated role in gut microbe-mediated immunomodulation that may be targeted to manipulate the capacity of the microbiome to shape host immunity.

CAR-T cells targeting CD38 and LMP1 exhibit robust antitumour activity against NK/T cell lymphoma

BACKGROUND

Natural killer/T cell lymphoma (NKTCL) is an aggressive lymphoma with a poor prognosis. Chimeric antigen receptor-transduced T (CAR-T) cell therapy has become a promising immunotherapeutic strategy against haematologic malignancies.

METHODS

In this study, four CAR-T cell lines (CD38-CAR, LMP1-CAR, CD38-LMP1 tandem CAR 1 and CD38-LMP1 tandem CAR 2) were generated. The effect of CAR-T cells against NKTCL cells was evaluated both in vitro and in vivo. Expression of T cell activation markers and cytokines produced by CAR-T cells were detected by flow cytometry.

RESULTS

The four CAR-T cell lines could effectively eliminate malignant NKTCL cells. They could be activated and produce inflammatory cytokines in a target-dependent manner. In vivo tests showed that the CAR-T cells exhibited significant antitumour effects in a xenotransplanted NKTCL mouse model.

CONCLUSIONS

In summary, four CAR-T cell lines exhibited significant cytotoxicity against NKTCL cells both in vitro and in vivo. These results indicated the effective therapeutic promise of CD38 and LMP1 CAR-T cells in NKTCL.

Carnosol Alleviates Collagen-Induced Arthritis by Inhibiting Th17-Mediated Immunity and Favoring Suppressive Activity of Regulatory T Cells

Current approaches are incurable for rheumatoid arthritis (RA). Regulatory T (Treg) cells and T helper cells (Th1 and Th17) are crucial in controlling the process of RA, which is characterized by inflammatory cell infiltration and bone destruction. Carnosol is an orthodiphenolic diterpene that has been extensively applied in traditional medicine for the treatment of multiple autoimmune and inflammatory diseases. Herein, we indicate that administration of carnosol dramatically alleviated the severity of collagen-induced arthritis (CIA) model with a decreased clinical score and inflammation reduction. Cellular mechanistically, carnosol inhibits the Th17 cell differentiation and maintains Treg cell suppressive function in vitro and in vivo. Meanwhile, it also restrains Treg cells from transdifferentiation into Th17 cells under inflammatory milieu. Furthermore, carnosol modulates the function of Th17 and Treg cells possibly via limiting IL-6R (CD126) expression. Collectively, our results suggest that carnosol can alleviate the severity of CIA via hiding Th17 cell differentiation and maintain the stability of Treg cells. Administration of carnosol can be applied as a potential therapy for patients with RA.

Effect of fluvoxamine on plasma interleukin-6 in patients with major depressive disorder: a prospective follow-up study

Introduction

Major depressive disorder (MDD) is associated with low-grade inflammation, and anti-inflammatory treatment can help improve depressive symptoms. A recent study found that fluvoxamine (FLV) can reduce Interleukin-6 (IL-6) production via sigma-1 receptor in inflammation models. However, the anti- IL-6 effect of FLV in treating patients with MDD and whether it can contribute to antidepressant effects remain unclear.

Methods

A total of 65 patients with MDD and 34 healthy controls were recruited at baseline, and 50 patients completed the FLV treatment for 2 months. We assessed depression and anhedonia and collected plasma IL-6 levels at baseline, 1 month, and 2 months after baseline. This study evaluated the changes in clinical measures and IL-6 during treatment and analyzed their association. Further subgroup analyses were conducted in patients with MDD with high, medium, or low IL-6.

Results

Depression and anhedonia were significantly improved in patients with MDD, while the IL-6 did not significantly change after the FLV treatment. However, IL-6 significantly declined after the FLV treatment among patients with MDD with higher baseline IL-6. No significant associations were found between the changes in depressive symptoms and IL-6.

Conclusion

Our study provided preliminary evidence suggesting that the anti-IL-6 effect of FLV might not play a vital role in its antidepressant treatment, at least in patients with MDD with low inflammation. However, for patients with MDD with higher IL-6, FLV can help reduce IL-6 significantly in the antidepressant treatment, which may help guide the individual treatment of MDD with higher IL-6 levels.

Clinical trial registration

https://clinicaltrials.gov/ct2/show/NCT04160377, identifier NCT04160377.

Roles of inflammasomes in viral myocarditis

Viral myocarditis (VMC), characterized by viral infection-induced inflammation, is a life-threatening disease associated with dilated cardiomyopathy or heart failure. Innate immunity plays a crucial role in the progression of inflammation, in which inflammasomes provide a platform for the secretion of cytokines and mediate pyroptosis. Inflammasomes are rising stars gaining increasing attention. The nucleotide oligomerization domain-, leucine-rich repeat-, and pyrin domain-containing protein 3 (NLRP3) inflammasome, the caspase recruitment domain-containing protein 8 (CARD8) inflammasome, and the caspase-11 inflammasome are three inflammasomes that were reported to affect the process and prognosis of VMC. These inflammasomes can be activated by a wide range of cellular events. Accumulating evidence has suggested that inflammasomes are involved in different stages of VMC, including the trigger and progression of myocardial injury and remodeling after infection. In this review, we summarized the pathways involving inflammasomes in VMC and discussed the potential therapies targeting inflammasomes and related pathways.

Human retinal endothelial cells express functional interleukin-6 receptor

BACKGROUND

Interleukin (IL)-6 is an inflammatory cytokine present in the eye during non-infectious uveitis, where it contributes to the progression of inflammation. There are two major IL-6 signaling pathways: classic signaling and trans-signaling. Classic signaling requires cellular expression of the IL-6 receptor (IL-6R), which exists in membrane-bound (mIL-6R) and soluble (sIL-6R) forms. Prevailing dogma is that vascular endothelial cells do not produce IL-6R, relying on trans-signaling during inflammation. However, the literature is inconsistent, including with respect to human retinal endothelial cells.

FINDINGS

We examined IL-6R transcript and protein expression in multiple primary human retinal endothelial cell isolates, and assessed the effect of IL-6 on the transcellular electrical resistance of monolayers. Using reverse transcription-polymerase chain reaction, IL-6R, mIL-6R and sIL-6R transcripts were amplified in 6  primary human retinal endothelial isolates. Flow cytometry on 5 primary human retinal endothelial cell isolates under non-permeabilizing conditions and following permeabilization demonstrated intracellular stores of IL-6R and the presence of mIL-6R. When measured in real-time, transcellular electrical resistance of an expanded human retinal endothelial cell isolate, also shown to express IL-6R, decreased significantly on treatment with recombinant IL-6 in comparison to non-treated cells across 5 independent experiments.

CONCLUSIONS

Our findings indicate that human retinal endothelial cells produce IL-6R transcript and functional IL-6R protein. The potential for classic signaling in human retinal endothelial cells has implications for the development of therapeutics targeted against IL-6-mediated pathology in non-infectious uveitis.

Associations of habitual glucosamine use with SARS-CoV-2 infection and hospital admission and death with COVID-19: Evidence from a large population based cohort study

The coronavirus disease 2019 (COVID-19) pandemic has led to a fundamental number of morbidity and mortality worldwide. Glucosamine was indicated to help prevent and control RNA virus infection preclinically, while its potential therapeutic effects on COVID-19-related outcomes are largely unknown. To assess the association of habitual glucosamine use with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, hospital admission, and mortality with COVID-19 in a large population based cohort. Participants from UK Biobank were reinvited between June and September 2021 to have SARS-CoV-2 antibody testing. The associations between glucosamine use and the risk of SARS-CoV-2 infection were estimated by logistic regression. Hazard ratios (HRs) and 95% confidence intervals (CIs) for COVID-19-related outcomes were calculated using COX proportional hazards model. Furthermore, we carried out propensity-score matching (PSM) and stratified analyses. At baseline, 42 673 (20.7%) of the 205 704 participants reported as habitual glucosamine users. During median follow-up of 1.67 years, there were 15 299 cases of SARS-CoV-2 infection, 4214 cases of COVID-19 hospital admission, and 1141 cases of COVID-19 mortality. The fully adjusted odds ratio of SARS-CoV-2 infection with glucosamine use was 0.96 (95% CI: 0.92-1.01). The fully adjusted HR were 0.80 (95% CI: 0.74-0.87) for hospital admission, and 0.81 (95% CI: 0.69-0.95) for mortality. The logistic regression and Cox proportional hazard analyses after PSM yielded consistent results. Our study demonstrated that habitual glucosamine use is associated with reduced risks of hospital admission and death with COVID-19, but not the incidence of SARS-CoV-2 infection.

Long COVID and hypertension-related disorders: a report from the Japanese Society of Hypertension Project Team on COVID-19

The coronavirus disease 2019 (COVID-19) affects infected patients even after the acute phase and impairs their health and quality of life by causing a wide variety of symptoms, referred to as long COVID. Although the evidence is still insufficient, hypertension is suspected to be a potential risk factor for long COVID, and the occurrence of cardiovascular diseases seems to be a key facet of multiple conditions observed in long COVID. Nonetheless, there are few reports that comprehensively review the impacts of long COVID on hypertension and related disorders. As a sequel to our previous report in 2020 which reviewed the association of COVID-19 and hypertension, we summarize the possible influences of long COVID on hypertension-related organs, including the cardiovascular system, kidney, and endocrine system, as well as the pathophysiological mechanisms associated with the disorders in this review. Given that the clinical course of COVID-19 is highly affected by age and sex, we also review the impacts of these factors on long COVID. Lastly, we discuss areas of uncertainty and future directions, which may lead to better understanding and improved prognosis of clinical problems associated with COVID-19.

Determination of Heterogeneous Proteomic and Metabolomic Response in anti-TNF and anti-IL-6 Treatment of Patients with Rheumatoid Arthritis

Reduction in tumor necrosis factor (αTNF) and interleukin-6 (IL-6) activities is a widely utilized strategy for the treatment of rheumatoid arthritis (RA) with a high success rate. Despite both schemes targeting the deprivation of inflammatory reactions caused by the excessive activity of cytokines, their mechanisms of action and the final output are still unequal. This was a comparative longitudinal study that lasted for 24 weeks and aimed to find the answer to why the two schemes of therapy can pass out of proportion in attitude of their efficiency. What are the differences in metabolic and proteomic responses among patients who were being treated by either the anti-TNF or anti-IL-6 strategy? We found increased levels of immunoglobulins A and G (more than 2-fold in anti-IL-6 and more than 4-5-fold in anti-TNF groups) at the final stage (24 weeks) of monitoring but the most profound increase was determined for µ-chains of immunoglobulins in both groups of study. Metabolomic changes displayed main alterations with regard to arginine metabolism and collagen maintenance, where arginine increased 8.86-fold (p < 0.001) in anti-TNF and 5.71-fold (p < 0.05) in anti-IL-6 groups but patients treated by the anti-TNF scheme suffered a higher depletion of arginine before the start of therapy. Some indicators of matrix and bone tissue degradation also increased 4-hydroxyproline (4-HP) more than 6-fold (p < 0.001) in anti-TNF and more than 2-fold (p < 0.05) in the anti-IL-6 group, but the growth dynamics in the anti-IL6 group was delayed (gradually raised at week 24) compared to the anti-TNF group (raised at week 12) following a smooth reduction. The ELISA analysis of IL-6 and TNFα concentration in the study population supported proteomic and metabolomic data. A positive correlation between ΔCDAI and ΔDAS28 indicators and ESR and CRP was established for the majority of patients after 24 weeks of treatment where ESR and CRP reduced by 20% and 40% finally, respectively. A regression model using the Forest Plot was estimated to elucidate the impact of the most significant clinical, biochemical, and anthropometric indicators for the evaluation of differences between considered anti-TNF and anti-IL-6 schemes of therapy.

The advent of immune stimulating CAFs in cancer

The theory that cancer-associated fibroblasts (CAFs) are immunosuppressive cells has prevailed throughout the past decade. However, recent high-throughput, high-resolution mesenchyme-directed single-cell studies have harnessed computational advances to functionally characterize cell states, highlighting the existence of immunostimulatory CAFs. Our group and others have uncovered and experimentally substantiated key functions of cancer antigen-presenting CAFs in T cell immunity, both in vitro and in vivo, refuting the conventional assumption that CAFs impede adaptive immune rejection of tumours. In this Perspective, I unify the follicular and non-follicular, non-endothelial stroma of tumours under the 'peripheral adaptive immune mesenchyme' framework and position subsets of CAFs as direct positive regulators of the adaptive immune system. Building on the understanding of cancer antigen presentation by CAFs and the second touch hypothesis, which postulates that full T cell polarization requires interaction with antigen-presenting cells in the non-lymphoid tissue where the antigen resides, I re-design the 'cancer-immunity cycle' to incorporate intratumoural activation of cancer-specific CD4⁺ T cells. Lastly, a road map to therapeutic harnessing of immunostimulatory CAF states is proposed.

Baseline erythrocyte sedimentation rate level predicts long-term inhibition of radiographic progression by tocilizumab: the KURAMA cohort

The short-term effect of tocilizumab (TCZ) on the radiographic progression of rheumatoid arthritis has been reported; however, reports on its long-term effects are scarce. In this study, we aimed to evaluate its long-term effects on joint destruction in patients who had been treated with TCZ for at least two years and for whom X-rays were available. Radiographic progression was evaluated with modified Total Sharp Score (mTSS), and structural remission was defined as the mean annual change in mTSS ≤0.5. Of the 59 patients included in this study (median age, 62 years; female, 81.4%), 34 patients (57.6%) achieved structural remission. Patients who achieved structural remission were relatively younger (59 years vs. 64 years, p = .06), had relatively higher proportion of anti-citrullinated protein antibody positivity (91.2% vs. 72.0%, p = .08), relatively lower C-reactive protein level (0.6 mg/dL vs. 2.2 mg/dL, p = .05), and significantly lower erythrocyte sedimentation rate (ESR) level (28.0 mm/h vs 65.5 mm/h, p = .003) than those who did not. Multivariate logistic regression analysis demonstrated that the baseline ESR level was significantly associated with structural remission (odds ratio, 0.98; 95% confidence interval: 0.96-0.99, p = .049). The baseline ESR level is a critical determinant of the long-term effect of TCZ on joint destruction.

The prospects of interleukin-6 inhibition in rheumatoid arthritis: Olokizumab (novel monoclonal antibodies to IL-6)

Rheumatoid arthritis (RA) is a chronic immune-mediated rheumatic diseases (IMRDs) manifested with progressive destruction of joints, systemic inflammation of visceral organs and a wide range of co-morbidities associated with chronic inflammation. Among the cytokines involved in the pathogenesis of RA and certain other IMRDs, the role of interleukin (IL) 6 is of special interest. The introduction of mAbs tocilizumab (TCZ) and later sarilumab (SAR), both blocking the receptor of this cytokine, into clinical practice was an important achievement in the treatment of IIRDs at the beginning of the 21st century. As a novel approach in the treatment of RA, the humanized mAb against IL-6 olokizumab (OKZ) is in development by the Russian company R-PHARM under the license agreement with UCB Pharma. The review examines new data on efficacy and safety of OKZ in RA and the prospects of its use in rheumatology

Orchestration of mesenchymal plasticity and immune evasiveness via rewiring of the metabolic program in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is the most fatal cancer in humans, due to its difficulty of early detection and its high metastatic ability. The occurrence of epithelial to mesenchymal transition in preinvasive pancreatic lesions has been implicated in the early dissemination, drug resistance, and cancer stemness of PDAC. PDAC cells also have a reprogrammed metabolism, regulated by driver mutation-mediated pathways, a desmoplastic tumor microenvironment (TME), and interactions with stromal cells, including pancreatic stellate cells, fibroblasts, endothelial cells, and immune cells. Such metabolic reprogramming and its functional metabolites lead to enhanced mesenchymal plasticity, and creates an acidic and immunosuppressive TME, resulting in the augmentation of protumor immunity via cancer-associated inflammation. In this review, we summarize our recent understanding of how PDAC cells acquire and augment mesenchymal features via metabolic and immunological changes during tumor progression, and how mesenchymal malignancies induce metabolic network rewiring and facilitate an immune evasive TME. In addition, we also present our recent findings on the interesting relevance of the small G protein ADP-ribosylation factor 6-based signaling pathway driven by KRAS/TP53 mutations, inflammatory amplification signals mediated by the proinflammatory cytokine interleukin 6 and RNA-binding protein ARID5A on PDAC metabolic reprogramming and immune evasion, and finally discuss potential therapeutic strategies for the quasi-mesenchymal subtype of PDAC.

Roles of RNA-binding proteins in immune diseases and cancer

Genetic information that is transcribed from DNA to mRNA, and then translated from mRNA to protein, is regulated by complex and sophisticated post-transcriptional mechanisms. Recently, it has become clear that mRNA degradation not only acts to remove unnecessary mRNA, but is also closely associated with the regulation of translation initiation, and is essential for maintaining cellular homeostasis. Various RNA-binding proteins (RBPs) have been reported to play central roles in the mechanisms of mRNA stability and translation initiation through various signal transduction pathways, and to modulate gene expression faster than the transcription process via post-transcriptional modifications in response to intracellular and extracellular stimuli, without de novo protein synthesis. On the other hand, inflammation is necessary for the elimination of pathogens associated with infection, and is tightly controlled to avoid the overexpression of inflammatory cytokines, such as interleukin 6 (IL-6) and tumor necrosis factor (TNF). It is increasingly becoming clear that RBPs play important roles in the post-transcriptional regulation of these immune responses. Furthermore, it has been shown that the aberrant regulation of RBPs leads to chronic inflammation and autoimmune diseases. Although it has been recognized since the time of Rudolf Virchow in the 19th century that cancer-associated inflammation contributes to tumor onset and progression, involvement of the disruption of the balance between anti-tumor immunity via the immune surveillance system and pro-tumor immunity by cancer-associated inflammation in the malignant transformation of cancer remains elusive. Recently, the dysregulated expression and activation of representative RBPs involved in regulation of the production of pro-inflammatory cytokines have been shown to be involved in tumor progression. In this review, we summarize the recent progress in our understanding of the functional roles of these RBPs in several types of immune responses, and the involvement of RBP dysregulation in the pathogenesis of immune diseases and cancer, and discuss possible therapeutic strategies against cancer by targeting RBPs, coupled with immunotherapy.

COVID-19 hospitalization with later long COVID in a person with Down syndrome

Viruses that induce pulmonary difficulties and auto-inflammation are more common in people with Down syndrome. They also have a higher number of comorbidities associated with a worse prognosis than the overall population. Adult patients with acute COVID-19 are increasingly being diagnosed with Long COVID. However, patients with Down syndrome with later long COVID-19 are the first example documented in Bangladesh.

Roles of Interleukin-6-mediated immunometabolic reprogramming in COVID-19 and other viral infection-associated diseases

Interleukin-6 (IL-6) is a highly pleiotropic glycoprotein factor that can modulate innate and adaptive immunity as well as various aspects of metabolism, including glycolysis, fatty acid oxidation and oxidative phosphorylation. Recently, the expression and release of IL-6 is shown to be significantly increased in numerous diseases related to virus infection, and this increase is positively correlated with the disease severity. Immunity and metabolism are two highly integrated and interdependent systems, the balance between them plays a pivotal role in maintaining body homeostasis. IL-6-elicited inflammatory response is found to be closely associated with metabolic disorder in patients with viral infection. This brief review summarizes the regulatory role of IL-6 in immunometabolic reprogramming among seven viral infection-associated diseases.

Idiopathic multicentric Castleman disease and associated autoimmune and autoinflammatory conditions: practical guidance for diagnosis

Idiopathic multicentric Castleman disease (iMCD) is an infrequent and life-threatening disorder characterised by systemic inflammatory symptoms, generalised lymphadenopathy, polyclonal lymphocyte proliferation, and organ dysfunction caused by a hyperinflammatory state. It accounts for one third to one half of all multicentric Castleman disease (MCD) cases. iMCD is often associated with autoimmune manifestations that may precede the iMCD diagnosis, be identified at the same time or follow it. In addition, iMCD may also coincide with a number of autoimmune diseases (such as psoriasis or myasthenia gravis) or autoinflammatory diseases (such as familial Mediterranean fever). Moreover, diverse inflammatory disorders, such as rheumatoid arthritis, systemic lupus erythematosus, adult-onset Still disease, systemic juvenile idiopathic arthritis, immunoglobulin (IgG4) related disease, or the recently described VEXAS syndrome, can present clinical features or lymphadenopathy with histopathological "Castleman-like" findings compatible with those of iMCD. Given the iMCD clinical heterogeneity and the overlap with other autoimmune or autoinflammatory disorders, iMCD diagnosis can be challenging. In this review, we explore the overlap between iMCD and inflammatory diseases and provide practical guidance on iMCD diagnosis in order to avoid misdiagnosis and confusion with other autoimmune or autoinflammatory conditions.

Central Roles of STAT3-Mediated Signals in Onset and Development of Cancers: Tumorigenesis and Immunosurveillance

Since the time of Rudolf Virchow in the 19th century, it has been well-known that cancer-associated inflammation contributes to tumor initiation and progression. However, it remains unclear whether a collapse of the balance between the antitumor immune response via the immunological surveillance system and protumor immunity due to cancer-related inflammation is responsible for cancer malignancy. The majority of inflammatory signals affect tumorigenesis by activating signal transducer and activation of transcription 3 (STAT3) and nuclear factor-κB. Persistent STAT3 activation in malignant cancer cells mediates extremely widespread functions, including cell growth, survival, angiogenesis, and invasion and contributes to an increase in inflammation-associated tumorigenesis. In addition, intracellular STAT3 activation in immune cells causes suppressive effects on antitumor immunity and leads to the differentiation and mobilization of immature myeloid-derived cells and tumor-associated macrophages. In many cancer types, STAT3 does not directly rely on its activation by oncogenic mutations but has important oncogenic and malignant transformation-associated functions in both cancer and stromal cells in the tumor microenvironment (TME). We have reported a series of studies aiming towards understanding the molecular mechanisms underlying the proliferation of various types of tumors involving signal-transducing adaptor protein-2 as an adaptor molecule that modulates STAT3 activity, and we recently found that AT-rich interactive domain-containing protein 5a functions as an mRNA stabilizer that orchestrates an immunosuppressive TME in malignant mesenchymal tumors. In this review, we summarize recent advances in our understanding of the functional role of STAT3 in tumor progression and introduce novel molecular mechanisms of cancer development and malignant transformation involving STAT3 activation that we have identified to date. Finally, we discuss potential therapeutic strategies for cancer that target the signaling pathway to augment STAT3 activity.

Interleukin-6 cytokine: An overview of the immune regulation, immune dysregulation, and therapeutic approach

Several studies have shown that interleukin 6 (IL-6) is a multifunctional cytokine with both pro-inflammatory and anti-inflammatory activity, depending on the immune response context. Macrophages are among several cells that secrete IL-6, which they express upon activation by antigens, subsequently inducing fever and production of acute-phase proteins from the liver. Moreover, IL-6 induces the final maturation of B cells into memory B cells and plasma cells as well as an adaptive role for short-term energy allocation. Activation of IL-6 receptors results in the intracellular activation of the JAK/STAT pathway with resultant production of inflammatory cytokines. Several mechanisms-controlled IL-6 expression, but aberrant production was shown to be crucial in the pathogenesis of many diseases, which include autoimmune and chronic inflammatory diseases. IL-6 in combination with transforming growth factor β (TGF-β) induced differentiation of naïve T cells to Th17 cells, which is the cornerstone in autoimmune diseases. Recently, IL-6 secretion was shown to form the backbone of hypercytokinemia seen in the Coronavirus disease 2019 (COVID-19)-associated hyperinflammation and multiorgan failure. There are two classes of approved IL-6 inhibitors: anti-IL-6 receptor monoclonal antibodies (e.g., tocilizumab) and anti-IL-6 monoclonal antibodies (i.e., siltuximab). These drugs have been evaluated in patients with rheumatoid arthritis, juvenile idiopathic arthritis, cytokine release syndrome, and COVID-19 who have systemic inflammation. JAK/STAT pathway blockers were also successfully used in dampening IL-6 signal transduction. A better understanding of different mechanisms that modulate IL-6 expression will provide the much-needed solution with excellent safety and efficacy profiles for the treatment of autoimmune and inflammatory diseases in which IL-6 derives their pathogenesis.