The decreased serum levels of interleukin-38 in patients with gout and its clinical significance.

Background: Interleukin (IL)-38 is a newly discovered anti-inflammatory cytokine. However, its concentration and clinical significance in patients with gout remain unclear. This study aimed to investigate the levels of IL-38 in patients with gout and evaluate their clinical significance. Methods: Thirty-two patients with active gout, 27 patients with inactive gout, and 20 negative controls (NCs) were included in the study. Clinical parameters, including white blood cell count, C-reactive protein, serum amyloid A, erythrocyte sedimentation rate, uric acid, urea, creatinine, alanine aminotransferase, aspartate aminotransferase, glutamyl transpeptidase, and glycoserated serum protein, were obtained from laboratory tests of blood samples. The serum concentration of IL-38 was determined using enzyme-linked immunosorbent assay. Spearman's correlation analysis and receiver operating characteristic curve assessments were used to investigate the role and diagnostic value of IL-38 in gout. Results: Patients with active and inactive gout exhibited significantly lower serum IL-38 levels than NCs. No significant differences were observed between the two gout groups. A negative correlation was observed between IL-38 and white blood cell counts, whereas a positive correlation was found between IL-38 and creatinine levels. Furthermore, IL-38, either alone or in combination with uric acid, demonstrated substantial diagnostic potential. Conclusion: The findings suggest that the decreased serum levels of IL-38 in patients with gout compared to that in NCs indicates that IL-38 may have immunomodulatory effects on gout inflammation and possesses clinical application value.

Interleukin-26 expression in tuberculosis disease and its regulatory effect in macrophage polarization and intracellular elimination of Mycobacterium tuberculosis.

Tuberculosis(TB), an infectious disease caused by Mycobacterium tuberculosis (Mtb) infections, remains the leading cause of mortality from a single infectious agent globally. The progression of tuberculosis disease is contingent upon the complex interplay between the host's immune system and the pathogen Mtb. Interleukin-26 (IL-26), the most recently identified cytokine belonging to the IL-10 family, exhibits both extracellular antimicrobial properties and pro-inflammatory functions. However, the precise role of IL-26 in the host immune defense against Mtb infections and intracellular killing remains largely unexplored. In this study, we observed significantly elevated IL-26 mRNA expression in peripheral blood mononuclear cells of active-TB patients compared to healthy individuals. Conversely, circulating IL-26 levels in the plasma of adult TB patients were markedly lower than those of healthy cohorts. We purified recombinant IL-26 from an E. coli expression system using the Ni-NTA resin. Upon stimulations with the recombinant IL-26, human THP1 cells exhibited rapid morphological changes characterized by increased irregular spindle shape and formation of granular structures. Treating THP1 cells with IL-26 can also lead to heightened expressions of CD80, TNF-α, and iNOS but not CD206 and Arg1 in these cells, indicating an M1 macrophage differentiation phenotype. Furthermore, our investigations revealed a dose-dependent escalation of reactive oxygen species production, decreased mitochondrial membrane potential, and enhanced autophagy flux activity in THP1 macrophages following IL-26 treatment. Moreover, our results demonstrated that IL-26 contributed to the elimination of intracellular Mycobacterium tuberculosis via orchestrated ROS production. In conclusion, our findings elucidated the role of IL-26 in the development of tuberculosis and its contributions to intracellular bacilli killing by macrophages through the induction of M1-polarization and ROS production. These insights may have significant implications for understanding the pathogenesis of tuberculosis and developing novel therapeutic strategies.

Nicotine promotes pathogenic bacterial growth and biofilm formation in peri-implant.

Introduction. Peri-implantitis is a plaque-associated disease that leads to implant loss and arises from bacterial biofilms on the surface of the implant. Smoking is a risk factor for peri-implantitis and impedes treatment effectiveness. Additionally, aryl hydrocarbon receptor (AHR), IL-6, and IL-22 levels are related to peri-implantitis.Aim. We aimed to investigate the effects of nicotine on inflammatory response, bacterial growth and biofilm formation.Hypothesis/Gap Statement. We hypothesized that nicotine promoted pathogenic bacterial growth and biofilm formation, thereby aggravating inflammation.Methodology. The expression of AHR, IL-6 and IL-22 was measured in peri-implant sulci fluid using quantitative PCR and Western blot analyses. The cementum was incubated with bacterial suspension including Porphyromonas gingivalis, Streptococcus sanguinis and Fusobacterium nucleatum and treated with 100, 200, 250 and 300 µg ml-1 nicotine, and then, the absorbance and number of colony-forming units were detected. Biofilm formation was evaluated using the tissue culture plate method and safranin O staining. Carbohydrates and proteins were measured by the phenol-sulfuric acid method and the bicinchoninic acid method, respectively.Results. The results indicated that smoking increased the levels of AHR, IL-6 and IL-22. Functionally, nicotine promoted the growth of P. gingivalis, S. sanguinis and F. nucleatum. Additionally, it promoted the biofilm formation of these bacteria and increased the contents of carbohydrates and proteins.Conclusion. Nicotine promoted bacterial growth and biofilm build-up, suggesting that smoking may aggravate the progression of peri-implantitis.

Interleukin signaling in the regulation of natural killer cells biology in breast cancer.

In the field of breast cancer treatment, the immunotherapy involving natural killer (NK) cells is increasingly highlighting its distinct potential and significance. Members of the interleukin (IL) family play pivotal regulatory roles in the growth, differentiation, survival, and apoptosis of NK cells, and are central to their anti-tumor activity. These cytokines enhance the ability of NK cells to recognize and eliminate tumor cells by binding to specific receptors and activating downstream signaling pathways. Furthermore, interleukins do not function in isolation; the synergistic or antagonistic interactions between different interleukins can drive NK cells toward various functional pathways, ultimately leading to diverse outcomes for breast cancer patients. This paper reviews the intricate relationship between NK cells and interleukins, particularly within the breast cancer tumor microenvironment. Additionally, we summarize the latest clinical studies and advancements in NK cell therapy for breast cancer, along with the potential applications of interleukin signaling in these therapies. In conclusion, this article underscores the critical role of NK cells and interleukin signaling in breast cancer treatment, providing valuable insights and a significant reference for future research and clinical practice.

Interferon regulatory factor 7 alleviates the experimental colitis through enhancing IL-28A-mediated intestinal epithelial integrity.

BACKGROUND: The incidence of inflammatory bowel disease (IBD) is on the rise in developing countries, and investigating the underlying mechanisms of IBD is essential for the development of targeted therapeutic interventions. Interferon regulatory factor 7 (IRF7) is known to exert pro-inflammatory effects in various autoimmune diseases, yet its precise role in the development of colitis remains unclear. METHODS: We analyzed the clinical significance of IRF7 in ulcerative colitis (UC) by searching RNA-Seq databases and collecting tissue samples from clinical UC patients. And, we performed dextran sodium sulfate (DSS)-induced colitis modeling using WT and Irf7-/- mice to explore the mechanism of IRF7 action on colitis. RESULTS: In this study, we found that IRF7 expression is significantly reduced in patients with UC, and also demonstrated that Irf7-/- mice display heightened susceptibility to DSS-induced colitis, accompanied by elevated levels of colonic and serum pro-inflammatory cytokines, suggesting that IRF7 is able to inhibit colitis. This increased susceptibility is linked to compromised intestinal barrier integrity and impaired expression of key molecules, including Muc2, E-cadherin, ß-catenin, Occludin, and Interleukin-28A (IL-28A), a member of type III interferon (IFN-III), but independent of the deficiency of classic type I interferon (IFN-I) and type II interferon (IFN-II). The stimulation of intestinal epithelial cells by recombinant IL-28A augments the expression of Muc2, E-cadherin, ß-catenin, and Occludin. The recombinant IL-28A protein in mice counteracts the heightened susceptibility of Irf7-/- mice to colitis induced by DSS, while also elevating the expression of Muc2, E-cadherin, ß-catenin, and Occludin, thereby promoting the integrity of the intestinal barrier. CONCLUSION: These findings underscore the pivotal role of IRF7 in preserving intestinal homeostasis and forestalling the onset of colitis.

The Association of IFNL4 Gene Polymorphisms with Hepatitis B Virus (HBV) Infection in the Northern Region of Pará, Brazil.

It is heavily suggested that one IFNL4 gene polymorphism, rs12979860 (T/C), exerts influence on the outcome of HBV infection, with the rs12979860-T allele being classified as a risk predictor, and the rs12979860-C allele being classified as a protective one. This study investigated whether the rs12979860 IFNL4 gene polymorphism presented any association with the clinical severity for HBV carriers in an admixed population in Northern Brazil. A total of 69 samples were investigated from infected people from the city of Belém-Pará. The rs12979860-T allele was positively associated with HBV infection, suggesting a higher risk of chronicity. This research's importance is that the polymorphism influence was investigated in a population of HBV carriers with a heterogeneous genetic profile, formed through the extensive admixture of different ethnic groups, including Europeans, Africans, and Natives with indigenous heritage. This analysis is particularly important since highly mixed populations do not always follow the same association patterns previously established by studies using populations classified as more genetically homogeneous, due to a different formation process.

Host cytokine genetic polymorphisms in a selected population of persons living with hepatitis B virus infection in the central region of Ghana.

BACKGROUND: Hepatitis B virus (HBV) infection is a public health concern in resource limited settings like Ghana. Over the past decades, it is noted that the natural course of HBV in persons infected are taking a worse turn leading to liver cirrhosis and cancer. The outcome of HBV infection is influenced by viral and host factors including genetics. Cytokine variations affect virus survival and progression and may even influence associated complications. Cytokines such as tumor necrosis factor alpha (TNF-α), interleukins (IL-4, IL-6, IL-8, IL-10, IL-18), interferon gamma (IFN)-γ, and tumor growth factor-beta (TGF-ß) have key roles in HBV infection and modulation. In this study, polymorphisms occurring in five cytokines were analysed to understand how they can influence prognosis of HBV infection. METHODS: The study is a single centre cross-sectional study involving 227 participants made up of HBV infected participants and HBV-negative controls. Recruitment was from March 2021 to April 2022. Blood samples were taken for full blood count, HBV antigen profile, liver function tests, HBV DNA quantification and cytokine genotyping. FIB score was calculated using available tools. Statistical analysis was undertaken with p < 0.05 set as statistically significant. RESULTS: The 20-39-year-old group formed majority of the HBV infected participants with 60% of all participants being classified as healthy HBsAg carriers. IL2 rs1479920 GG carriers ((1258.93; 0.00-5011.87) IU/mL had reduced HBV DNA in comparison to IL2 rs1479920 AA ((5011.87; 2113.49-5956.62) /AG (3548.13; 0.00-6309.57) IU/mL carriers. TNF-α rs1800629 AA carriers (1258.93; 0.00-3981.07) IU/mL had a reduction in HBV DNA levels in comparison to TNF-α rs1800629 GG carriers (1584.89; 0.00-5011.87) IU/mL. The results of univariate (OR = 0.08, 0.00-0.93; p = 0.043) and multivariate (OR = 0.02, 0.00-0.67; p = 0.029) analysis, showed that carrying TNF-α rs1800629 AA genotype reduce susceptibility to high FIB score compared with GG genotypes. In univariate analysis, subjects aged 20-39 years (OR = 5.00, 1.13-6.10; p = 0.034) and 40-59 years (OR = 41.99, 3.74-47.21; p = 0.0002) were more susceptible to high FIB score compared to subjects aged 1-19 years. Being female (OR = 2.42, 1.03-5.71; p = 0.043) in the univariate models showed higher odds of having high levels of HBV DNA in the multivariate model. There was a reduced likelihood of herbal medicine usage influencing HBV DNA levels significantly (OR = 0.29, 0.10-0.86; p = 0.025). CONCLUSION: In conclusion, variations in IL2 rs1479920 GG and IL2 rs1479921 AA could offer protective effects by reducing HBV DNA. TNF-α rs179924CT may also cause elevation in HBV DNA levels whiles TNF-α -308A/G, showed a potential protective effect on liver scarring in HBV infected participants. It is therefore important to take a further look at such variations for understanding of HBV modulation in the Ghanaian population.

Regional variations in serum IL-35 levels and association with systemic lupus erythematosus: a systematic review and meta-analysis.

Interleukin (IL)-35 is an anti-inflammatory cytokine that regulates autoimmune diseases, including systemic lupus erythematosus (SLE). However, the association between the cytokine and disease may vary by geographical region. This study performed a meta-analysis to quantitatively assess the correlation between the serum IL-35 levels in SLE patients and sub-group analyses were conducted. Four main electronic databases-Scopus, Embase, Science Direct, PubMed-were searched for relevant studies. After a database search, Endnote software was used to find and remove duplicate studies. Random-effects models were used to estimate standard mean differences in serum/plasma IL-35 levels by Hedges' g with 95% confidence intervals (CIs). Publication bias was assessed with funnel plots, and risk of bias was assessed according to the Newcastle-Ottawa Scale (NOS). Sixteen studies met the eligibility criteria and were included in a qualitative review; data from 15 studies were included in the meta-analysis. Total IL-35 levels (pg/mL) did not differ among patients with active SLE and healthy controls (Hedges's g: 0.22, 95% CI - 0.51, 0.95, p = 0.55). Sub-group analysis revealed that IL-35 levels in patients with active SLE were lower than in healthy controls in Chinese studies (Hedges's g: - 3.11, 95% CI - 5.72, - 0.51), but not in non-Chinese studies (Hedges's g: 1.63, 95% CI - 0.31, 3.57). This regional difference was statistically significant (p < 0.01). The analysis comparing patients with inactive SLE and healthy controls showed a similar trend. This study suggests that serum IL-35 levels are lower in patients with SLE in studies from China, but not other regions. However, standardized protocols with large sample sizes are needed to confirm these findings.

Inflammasome activation links enteric Salmonella Typhimurium infection to a rapid, cytokine-dependent increase in intestinal mucin release.

The host restricts Salmonella enterica serovar Typhimurium infection of the gut via inflammasome-dependent sloughing of infected epithelial cells. Here we determined that concurrent caspase 1/11-dependent release of the goblet cell-derived mucin, Muc2, into the intestinal lumen also controls Salmonella burdens in infected mice. The increased release of mucins from goblet cells in the cecum and nearby proximal colon, and the subsequent thickening of the protective mucus barrier layer in the distal colon, were all dependent on the cytokines interleukin (IL)-18 and IL-22, as deficiencies in either cytokine resulted in reduced mucin secretion. Supplementation of IL-18 into IL-22 deficient mice restored mucin secretion, indicating that IL-22 acted upstream of IL-18 secretion during infection. In contrast, IL-18 and IL-22 independent signaling through Nlrp6 underlies only a modest, infection-induced increase in mucin secretion from goblet cells in the distal colon. These findings reveal that inflammasome signaling orchestrates multiple levels of protection centered on the intestinal epithelium, including pyroptosis and expulsion of infected enterocytes, as well as the release of mucins by goblet cells in the cecum and along the length of the colon. Our studies underscore the pivotal, multi-faceted role of inflammasome signaling in promoting host defense at the intestinal mucosal surface.

Interleukin-27 Regulates Adaptative Immune Responses Associated With Control of Parasite Replication in Canine Leishmaniasis.

Interleukin 27 (IL-27) is a cytokine that regulates susceptibility to Leishmania infantum infection in humans and experimental models. This cytokine has not yet been described in canine leishmaniasis (CanL). Therefore, we investigated whether IL-27 has a regulatory role in CanL. The EBI3 and p28 subunits of IL-27 were measured in splenic leukocytes culture supernatant from dogs with CanL and compared to control dogs. We also correlated EBI3 and p28 levels with IL-21, anti-L. infantum antibodies and parasite loads. We performed functional assays followed by IL-27 blockade and measured parasite loads, production of cytokines in splenic leukocytes culture supernatant, and the expression of PD-1, CTLA-4, phospho-Stat-1/3, T-bet, GATA3 and nitric oxide production (NO). Both IL-27 subunits increased in the supernatant of dogs with CanL compared to control dogs. EBI3 and p28 levels showed a moderate positive correlation with IL-21 (r = 0.67, p < 0.0001 and r = 0.45, p < 0.012, respectively), and the EBI3 subunit was positively associated with anti-L. infantum IgG antibodies (r = 0.38, p < 0.040) and parasite load (r = 0.47, p < 0.009). IL-27 and IL-21 participate of immune responses in CanL. IL-27 may be associated with the failure of immunity to control parasite replication via upregulation of the expression of PD-1, CTLA-4, T-bet and NO in splenic leukocytes from dogs with CanL. These findings suggest that the pathways regulated by IL-27 are involved in CanL pathogenesis in the host, and may be targets for new therapies.

CD27 is not an ideal marker for human memory B cells and can be modulated by IL-21 upon stimulated by Anti-CD40.

B cells play a key role in humoral immune responses by producing antibodies. Although there are numerous research on memory B cells definition markers and cytokines on B cell development, different studies have yielded contradictory conclusions due to species studied, the different cells and stimulating agents used. In the current study, we conducted a detailed characterization of B cells in human CBMCs, PBMCs and tonsil, including expression of Igs, activation and memory markers. Furthermore, we found that considerable amounts of IgA and IgG were expressed by CD27- B cells. These "Atypical" memory B cells corresponded to approximately 50% of IgG+ and IgA+B cells in blood, this proportion even reached 90% in tonsil. In addition, we investigated the effect of IL-21 and TGF-ß1 on the membrane-bound form and secreted form of Igs using PBMCs and purified blood B cells. There were actual differences between the effect of cytokines on Igs secretion and surface expression. Our study will be helpful to advance the knowledge and understanding of humoral memory.

Expression of Macrophage Colony-Stimulating Factor CSF-1 in Spinal Cord Neurons in Mice with Experimental Autoimmune Encephalomyelitis.

In mice with acute and chronic models of experimental autoimmune encephalomyelitis (EAE), a quantitative study of the dynamics of CSF-1 and IL-34 protein levels in the spinal cord and blood plasma was conducted by ELISA and the specificity of CSF-1 expression in spinal cord cells was examined by immunohistological methods. A significant increase in the level of CSF-1 in the spinal cord was detected and populations of motoneurons with intense CSF-1 immunoreactivity were identified in mice with acute and chronic EAE. The obtained results suggest a possible role of CSF-1 in the pathogenesis and progression of EAE/multiple sclerosis.

Human IL-22 receptor-targeted small protein antagonist suppress murine DSS-induced colitis.

BACKGROUND: Human interleukin-22 (IL-22) is known as a "dual function" cytokine that acts as a master regulator to maintain homeostasis, structural integrity of the intestinal epithelial barrier, and shielding against bacterial pathogens. On the other hand, the overexpression of IL-22 is associated with hyper-proliferation and recruitment of pathologic effector cells, leading to tissue damage and chronic inflammation in specific diseases including inflammatory bowel disease (IBD). To study a role of IL-22-mediated signaling axis during intestinal inflammation, we generated a set of small protein blockers of IL-22R1 and verified their inhibitory potential on murine model of colitis. METHODS: We used directed evolution of proteins to identify binders of human IL-22 receptor alpha (IL-22R1), designated as ABR ligands. This approach combines the assembly of a highly complex combinatorial protein library derived from small albumin-binding domain scaffold and selection of promising protein variants using ribosome display followed by large-scale ELISA screening. The binding affinity and specificity of ABR variants were analyzed on transfected HEK293T cells by flow cytometry and LigandTracer. Inhibitory function was further verified by competition ELISA, HEK-Blue IL-22 reporter cells, and murine dextran sulfate sodium (DSS)-induced colitis. RESULTS: We demonstrate that ABR specifically recognizes transgenic IL-22R1 expressed on HEK293T cells and IL-22R1 on TNFα/IFNγ-activated HaCaT cells. Moreover, some ABR binders compete with the IL-22 cytokine and function as IL-22R1 antagonists in HEK-Blue IL22 reporter cells. In a murine model of DSS-induced acute intestinal inflammation, daily intraperitoneal administration of the best IL-22R1 antagonist, ABR167, suppressed the development of clinical and histological markers of colitis including prevention of mucosal inflammation and architecture deterioration. In addition, ABR167 reduces the DSS-induced increase in mRNA transcript levels of inflammatory cytokines such as IL-1ß, IL-6, IL-10, and IL-17A. CONCLUSIONS: We developed small anti-human IL-22R1 blockers with antagonistic properties that ascertain a substantial role of IL-22-mediated signaling in the development of intestinal inflammation. The developed ABR blockers can be useful as a molecular clue for further IBD drug development.

The diagnostic value and validation of IL-22 combimed with sCD40L in tuberculosis pleural effusion.

BACKGROUND: There is substantial evidence indicating that cytokines play a role in the immune defense against tuberculosis. This study aims to evaluate the levels of various cytokines in pleural effusion to ditinguish between tuberculosis pleurisy and malignant pleurisy. METHODS: A total of 82 participants with pleural effusion were included in the training cohort, and 76 participants were included in the validation cohort. The individuals were divided into tuberculosis and malignant pleurisy groups. The concentrations of interleukin-1ß (IL-1ß), IL-4, IL-6, IL-10, IL-17 A, IL-17 F, IL-21, IL-22, IL-25, IL-31, IL-33, interferon-γ (IFN-γ), soluble CD40 ligand (sCD40L) and tumor necrosis factor-α (TNF-α) in pleural effusion were measured using a multiplex cytokine assay. The threshold values were calculated according to the receiver operating characteristic (ROC) curve analysis to aid in diagnosing tuberculosis pleurisy. Furthermore, the combined measure was validated in the validation cohort. RESULTS: The levels of all 14 cytokines in pleural effusion were significantly higher in participants with tuberculosis compared to those with malignant pleurisy (all P < 0.05). The area under the curve (AUC) was ≥ 0.920 for the IL-22, sCD40L, IFN-γ, TNF-α and IL-31, which were significantly increased in tuberculous pleural effusion (TPE) compared to MPE in the training cohort. Threshold values of 95.80 pg/mL for IFN-γ, 41.80 pg/mL for IL-31, and 18.87 pg/mL for IL-22 provided ≥ 90% sensitivity and specificity in distinguishing between tuberculosis pleurisy and malignant pleurisy in the training cohort. Among these, IL-22 combined with sCD40L showed the best sensitivity and specificity (94.0% and 96.9%) for diagnosing tuberculosis pleurisy, and this finding was validated in the validation cohort. CONCLUSION: We demonstrated that the levels of IL-1ß, IL-4, IL-6, IL-10, IL-17 A, IL-17 F, IL-21, IL-22, IL-25, IL-31, IL-33, IFN-γ, sCD40L and TNF-α in pleural effusion had significant difference between tuberculosis pleurisy and malignant pleurisy. Specifically, IL-22 ≥ 18.87 pg/mL and sCD40L ≥ 53.08 pg/mL can be clinically utilized as an efficient diagnostic strategy for distinguishing tuberculosis pleurisy from malignant pleurisy.

Immunological and cytokine profile (IL-25 and IL-35) in patients with Entamoeba histolytica infection in Southern Iraq.

Amoebiasis is an intestinal disease caused by a unicellular parasite called Entamoeba histolytica. Interleukin-35 (IL-35) is the youngest specific member of the IL-12 family that plays a major role in the inhibitory function of regulatory T cells (Tregs) to curb inflammatory responses. IL-25 of the IL-17 family, which is widely released by Th2 cells and epithelial cells, is a warning signal produced upon cell or tissue injury to activate immune cells. The present study aimed to determine the cytokine profile (IL-25 and IL-35) in patients with E. histolytica infection in southern Iraq. This hospital-based study was conducted from August 2022 to May 2023. The study participants were patients with E. histolytica infection admitted to the infection department of general hospitals in Thi-qar province, southern Iraq. Initially, E. histolytica amebiasis was detected in the patients by nested multiplex PCR. All collected sera were tested with the Human Interleukin 35 (Biotech, China, Cat.RD-IL35-Hu) and IL25 (Biotech, China, Cat.RD-IL25-Hu) ELISA kits according to the instructions of the manufacturer. A total of 80 patients, including 50 patients with E. histolytica infection and 30 subjects in the control group without E. histolytica infection, were enrolled in the present study. The results showed a significant difference (p<0.001) in the serum level of IL-25 in patients with E. histolytica infection (4275.19 pg/mL) compared to individuals in the control group without E. histolytica infection (2186 pg/mL). Statistical analysis showed that there was no significant difference in the serum levels of IL-35 patients with E. histolytica infection compared with individuals in the control group without E. histolytica infection. The results of the present study show that the level of IL-25 is high in patients with E. histolytica infection. This indicates the important role of IL-25 in the activation of the immune system during intestinal inflammation. Therefore, this cytokine can be used as a diagnostic marker for E. histolytica infection.

CXCL13 promotes broad immune responses induced by circular RNA vaccines.

Antibody responses induced by current vaccines for influenza and SARS-CoV-2 often lack robust cross-reactivity. As hubs where diverse immune cells converge and interact, the alterations in the immune microenvironment within lymph nodes (LNs) are intricately linked to immune responses. Herein, we designed a lipid nanoparticle (LNP) loaded with circular RNA (circRNA) and targeted to LNs, in which CXCL13 was directly integrated into antigen-encoding circRNA strands. We demonstrated that CXCL13 alters the transcriptomic profiles of LNs, especially the upregulation of IL-21 and IL-4. Meanwhile, CXCL13 promotes the formation of germinal center and elicits robust antigen-specific T cell responses. With the codelivery of CXCL13 and the antigen, CXCL13 enhances cross-reactive antibodies against influenza virus and SARS-CoV-2, achieving protection against both homologous and heterologous influenza virus challenges in a mouse model. Notably, the targeted modification of LNP surfaces with antibodies helps address some of the challenges associated with lyophilized LNP vaccines, which is crucial for the long-term storage of LNP-circRNA vaccines. Overall, the circRNA-based antigen-CXCL13 coexpression system developed herein provides a simple and robust platform that enhances the magnitude and breadth of antibody responses against multiple viral glycoproteins, highlighting the potential utility of CXCL13 in inducing broad immune responses.

Systemic increase in IL-26 is associated with severe COVID-19 and comorbid obstructive lung disease.

Background: IL-26 is a key mediator of pulmonary host defense given its abundant expression in human airways and its established antibacterial properties. Moreover, recent studies indicate that IL-26 can also inhibit viral replication. Along these lines, we have previously reported an increase in the plasma concentration of IL-26 among patients with acute COVID-19 that is linked to harmful hyperinflammation. Nevertheless, it is still unclear whether this systemic increase in IL-26 relates to disease severity, sex, comorbidities, viral load, or the innate immune response in acute COVID-19. Methods: IL-26 was quantified using ELISA in plasma samples from a large cohort of well-characterized patients with acute COVID-19 (n=178) and healthy controls (n=30). The plasma concentrations of SARS-CoV-2 nucleocapsid and spike protein, as well as those of IFN-α2a, IFN-ß, and IFN-γ, were determined using electrochemiluminescence immunoassay. The concentration of double-stranded DNA was determined using fluorometry. Results: The plasma concentration of IL-26 was increased in patients with severe/critical COVID-19, particularly among males and patients with comorbid obstructive lung disease. Moreover, the concentration of IL-26 displayed positive correlations with length of hospital stay, as well as with systemic markers of viral load, antiviral immunity, and extracellular DNA. Conclusions: Systemic IL-26 is involved in severe COVID-19, especially in males and patients with comorbid obstructive lung disease. These findings argue that systemic IL-26 has pathogenic and antiviral relevance, as well as biomarker potential.

Emerging Roles of IL-27 in Trophoblast Cells and Pregnancy Complications.

PROBLEM: Pregnancy complications such as spontaneous abortion, preeclampsia, and preterm birth persist, despite current interventions aimed at their prevention and treatment largely proving unsuccessful. Interleukin-27 (IL-27), composed of p28 and EBI3 subunits, binds to IL-27R, which consists of gp130 and IL-27Rα (also known as WSX-1 or TCCR), and plays a pivotal role in tumor development and inflammation regulation. At the maternal-fetal interface, IL-27 expression has been detected in trophoblasts, endometrial stromal cells, and decidual cells. Abnormal levels of IL-27/IL-27R have been linked to adverse pregnancy outcomes, including spontaneous miscarriage, preeclampsia, and preterm birth. This review aims to explore the expression of IL-27 at the maternal-fetal interface and its signaling pathway, uncovering the complex role of IL-27 in pregnancy complications. METHOD OF STUDY: A comprehensive literature review was conducted using PubMed/Medline, Scopus, and Embase databases, analyzing studies on IL-27 expression and its signaling pathways at the maternal-fetal interface. The review focused on identifying the presence of IL-27 in various cell types and linking abnormal IL-27/IL-27R expression to pregnancy complications such as spontaneous miscarriage, preeclampsia, and preterm birth. DISCUSSION AND CONCLUSION: IL-27 plays a complex role at the maternal-fetal interface, with abnormal expression linked to several pregnancy complications. These findings highlight the need for further research to elucidate IL-27's mechanisms and develop targeted interventions. Future studies should aim to develop targeted interventions and improve therapeutic strategies for managing pregnancy complications.

[The role and its regulatory significance of interleukin-25 in ovalbumin induced atopic dermatitis of mice].

OBJECTIVE: To investigate the effect of interleukin-25 (IL-25) on ovalbumin (OVA) induced atopic dermatitis of mice, and the significance of regulating IL-25. METHODS: In this study, 90 healthy male 6-week-old specific pathogen free (SPF) BALB/c mice were divided into 6 groups (15 in each group): ① subcutaneous injection of phosphate buffered saline (PBS) group (normal control group); ② subcutaneous injection of mouse IL-25 group (IL-25 group); ③ subcutaneous injection of anti-mouse IL-25 monoclonal antibody (anti-IL-25 group), each group received subcutaneous injection once a day for 1 week, 2 weeks apart, repeated daily subcutaneous injections for 1 week, 2 weeks apart, and repeated daily subcutaneous injections for 1 week, for a total of 7 weeks; ④ OVA treated group (model group); ⑤ OVA treated and IL-25 subcutaneous injection group (IL-25 treated dermatitis group); ⑥ OVA treated and anti-mouse IL-25 monoclonal antibody injection group (anti-IL-25 treated dermatitis group). The ⑤ and ⑥ groups in the process of treatment with OVA, IL-25 or anti-IL-25 antibody were given in the same way as the ② and ③ groups. Scratching behavior and skin performance of the mice were recorded during the seven-week-treatment. Twenty four hours after the final treatment, blood was taken from the mouse heart, and the serum was separated to detect the total IgE, IL-4, IL-5, IL-13, etc. The skin samples of the treatment sites were used for hematoxylin-eosin (HE) staining, immunohistochemistry, real-time PCR and Western blot detections. A single factor (ANOVA) analysis of variance was used to compare the differences in various indicators between the groups. RESULTS: The frequency of scratches in the IL-25 treated dermatitis group was higher than that in the model group, and the scratching behavior of the anti-IL-25 treated dermatitis group was significantly lower than that in the model group. The appearance of atopic dermatitis, thickening of the epidermis and the degree of dermal inflammation in the IL-25 treated dermatitis group were more serious than those in the model group and the anti-IL-25 treated dermatitis group. The levels of serum IgE, IL-4, IL-5, and IL-13 in the IL-25 treated dermatitis group were significantly higher than that in the model group and the anti-IL-25 treated dermatitis group. There were significantly more CD4+ T cells in the dermis of IL-25 treated dermatitis group than that in the anti-IL-25 treated dermatitis group. The expression levels of filaggrin and defensin ß2 proteins in the IL-25 treated dermatitis group were significantly lower than those in the model group and the anti-IL-25 treated dermatitis group. CONCLUSION: In the OVA induced atopic dermatitis mice model, IL-25 can significantly promote the damage of the epidermal barrier function and aggravate the OVA-induced dermatitis. Antagonizing IL-25 can alleviate OVA induced dermatitis to a certain extent.

Clostridium sporogenes-derived metabolites protect mice against colonic inflammation.

Gut microbiota-derived metabolites play a pivotal role in the maintenance of intestinal immune homeostasis. Here, we demonstrate that the human commensal Clostridium sporogenes possesses a specific metabolic fingerprint, consisting predominantly of the tryptophan catabolite indole-3-propionic acid (IPA), the branched-chain acids (BCFAs) isobutyrate and isovalerate and the short-chain fatty acids (SCFAs) acetate and propionate. Mono-colonization of germ-free mice with C. sporogenes (CS mice) affected colonic mucosal immune cell phenotypes, including up-regulation of Il22 gene expression, and increased abundance of transcriptionally active colonic tuft cells and Foxp3+ regulatory T cells (Tregs). In DSS-induced colitis, conventional mice suffered severe inflammation accompanied by loss of colonic crypts. These symptoms were absent in CS mice. In conventional, but not CS mice, bulk RNAseq analysis of the colon revealed an increase in inflammatory and Th17-related gene signatures. C. sporogenes-derived IPA reduced IL-17A protein expression by suppressing mTOR activity and by altering ribosome-related pathways in Th17 cells. Additionally, BCFAs and SCFAs generated by C. sporogenes enhanced the activity of Tregs and increased the production of IL-22, which led to protection from colitis. Collectively, we identified C. sporogenes as a therapeutically relevant probiotic bacterium that might be employed in patients with inflammatory bowel disease (IBD).