Interleukin-35 regulates peripheral T cell activity in patients with Kawasaki disease

Association of interleukin-35 polymorphisms with Kawasaki disease in Chinese children

Kawasaki disease is a leading cause of acquired heart disease in children in the developed world, characterised by acute systemic vasculitis, with a complex aetiology that remains poorly understood. Recent studies have highlighted the potential anti-inflammatory effects of Interleukin-35 in various proinflammatory and cardiovascular conditions. However, the relationship between Interleukin-35 gene polymorphisms and Kawasaki disease susceptibility, particularly in Chinese children, has not been well-explored.In this study, we investigated the association between five Interleukin-35 single-nucleotide polymorphisms-rs2243115, rs2243123, rs583911, rs353698, and rs2302164-and Kawasaki disease in a cohort of Chinese children. A total of ninety-four Kawasaki disease patients and one hundred healthy controls were enrolled, with the Kawasaki disease patients further divided into subgroups based on the presence or absence of coronary artery lesions and incomplete or complete Kawasaki disease. Genotyping of Interleukin-35 polymorphisms was performed using the MassARRAY system.The results showed the GT + GG genotypes and G allele of rs2243115 (T > G) were significantly more prevalent in Kawasaki disease patients with coronary artery lesions than in those without coronary artery lesions, suggesting a possible association with the development of coronary artery lesions. Additionally, the G allele of rs353698 (A > G) was more frequently observed in the incomplete Kawasaki disease group compared to the complete Kawasaki disease group, suggesting a possible association with the risk of incomplete Kawasaki disease.

Increased Peripheral Interleukin-35 Suppresses CD4+ T and CD8+ T-Cell Activity in Patients Living with Chronic Human Immunodeficiency Virus-1 Infection

Interleukin-35 (IL-35) has an immunosuppressive function through the regulation of immune cells during infectious diseases, autoimmune disorders, and cancers. The modulatory role of IL-35 in T lymphocytes, which are involved in host immune responses during human immunodeficiency virus-1 (HIV-1) infection, has not been elucidated. The aim of the current study was to investigate the role of regulatory function of IL-35 to T-cell activity in patients living with chronic HIV-1 infection. Sixty-seven patients living with chronic HIV-1 infection and 17 controls were enrolled in the study. IL-35 levels were measured via an enzyme-linked immunosorbent assay. Purified CD4+ and CD8+ T cells were stimulated with recombinant human IL-35. The secretion of cytokines and cytotoxic molecules, the mRNA levels of IL-35 receptor subunits and transcription factors, the expression of immune checkpoint molecules, and cell proliferation were assessed to evaluate the effect of IL-35 on T lymphocyte function in vitro. Compared with controls, patients living with chronic HIV-1 infection presented increased plasma IL-35 levels. IL-35 stimulation did not affect either the expression of IL-35 receptor subunits or the proliferation of CD4+ and CD8+ T cells from either patients living with chronic HIV-1 infection or controls. IL-35 stimulation downregulated transcription factor mRNA expression and cytokine secretion by CD4+ T cells as well as cytotoxic molecule production by CD8+ T cells from both patients living with chronic HIV-1 infection and controls. This process was accompanied by increased expression of immune checkpoint molecules on CD4+ and CD8+ T cells. The addition of IL-35 also reduced perforin and granzyme B secretion by HIV-1-specific CD8+ T cells from patients living with chronic HIV-1 infection. Increased plasma IL-35 in patients living with chronic HIV-1 infection might dampen the activation of CD4+ and CD8+ T cells, leading to T-cell exhaustion.

Interleukin-36 receptor antagonist stimulation in vitro inhibits peripheral and lung-resident T cell response isolated from patients with ventilator-associated pneumonia

Interleukin-36 (IL-36) cytokine family members play an immunomodulatory function to immune cells through IL-36 receptor signaling pathway. However, the regulatory role of IL-36 exerted on T cells is not completely elucidated in patients with ventilator-associated pneumonia (VAP). For this purpose, this study enrolled 51 VAP patients and 27 controls. IL-36 levels were measured by ELISA. The mRNA levels of IL-36 receptor subunits were determined by real-time PCR. CD4+ and CD8+ T cells were enriched, and stimulated with recombinant IL-36 receptor antagonist (IL-36RA). The influence of IL-36RA on transcription factors and cytokine secretions by CD4+ T cells was investigated. The modulatory function of IL-36RA on CD8+ T cells was assessed by measuring target cell death and cytokine secretions. There were no significant differences in serum IL-36 levels between VAP patients and controls. Only IL-36RA, but not IL-36α, IL-36β, or IL-36γ, in bronchoalveolar lavage fluid was elevated in infection site of VAP patients. IL-36 receptor subunits in CD4+ and CD8+ T cells were comparable between VAP patients and controls. 10 ng/mL of IL-36RA stimulation dampened peripheral effector CD4+ T cell response isolated from both VAP patients and controls. Target cell death mediated by CD8+ T cells isolated from BAFL of VAP patients was suppressed by 100 ng/mL of IL-36RA stimulation in vitro. The down-regulations of perforin, granzyme B, interferon-γ, tumor necrosis factor-α, and Fas ligand following IL-36RA stimulation in vitro were responsible for reduced CD8+ T cell-mediated cytotoxicity. IL-36RA revealed an immunosuppressive property for T cell response in vitro, and may be involved in the protective mechanism in VAP patients.

Integration of scRNA-Seq and bulk RNA-Seq uncover perturbed immune cell types and pathways of Kawasaki disease

Introduction

Kawasaki disease (KD) is an acute febrile illness primarily affecting children and characterized by systemic inflammation and vasculitis that can lead to coronary artery complications. The aim of this study was to gain a comprehensive understanding of immune dysregulation in KD.

Methods

To this end, we employed integration of single-cell RNA sequencing (scRNA-Seq) and bulk RNA sequencing (bulk RNA-Seq) data. Furthermore, we conducted flow cytometry analysis for a cohort of 82 KD patients.

Results

Our analysis revealed significant heterogeneity within immune cell populations in KD patients, with distinct clusters of T cells, B cells, and natural killer (NK) cells. Importantly, CD4+ naïve T cells in KD patients were found to predominantly differentiate into Treg cells and Th2 cells, potentially playing a role in the excessive inflammation and vascular damage characteristic of the disease. Dysregulated signaling pathways were also identified, including the mTOR signaling pathway, cardiomyopathy pathway, COVID-19 signaling pathway, and pathways involved in bacterial or viral infection.

Discussion

These findings provide insights into the immunopathogenesis of KD, emphasizing the importance of immune cell dysregulation and dysregulated signaling pathways. Integration of scRNA-Seq and bulk RNA-Seq data offers a comprehensive view of the molecular and cellular alterations in KD and highlights potential therapeutic targets for further investigation. Validation and functional studies are warranted to elucidate the roles of the identified immune cell types and pathways in KD pathogenesis and to develop targeted interventions to improve patient outcomes.

Interleukin-35 Enhances Regulatory T Cell Function by Potentially Suppressing Their Transdifferentiation into a T Helper 17-Like Phenotype in Kawasaki Disease

Interleukin-35 (IL-35) modulates immune cell activity in inflammation and autoimmune disorders. However, its specific effects on regulatory T cells (Tregs) in Kawasaki disease remain ambiguous. We enrolled 37 patients with Kawasaki disease and 20 healthy controls in this study. The percentages of CD4⁺CD25⁺CD127^dim/- Tregs and CD4⁺IL-17A⁺ T helper 17 (Th17) cells were determined via flow cytometry. Tregs were enriched and stimulated by recombinant IL-35. Immunosuppressive activity of Tregs was via co-culture with autologous CD4⁺CD25^- T cells. Purified Tregs were cultured for Th17 polarization, and the influence of IL-35 on Tregs transdifferentiation into a Th17-like phenotype was determined. The percentage of Tregs was elevated in patients with Kawasaki disease and positively correlated with C-reactive protein levels. There was no significant difference in the percentage of Th17 cells between the two groups. IL-35 stimulation increased the percentage of Tregs in both groups, but decreased the percentage of Tregs Th17 cells in affected patients. IL-35 enhanced the immunosuppressive activity of Tregs in both groups, resulting in decreased cellular proliferation and increased IL-35 subunit mRNA relative levels in co-culture system. IL-35 did not affect the immune checkpoint molecule expression in Tregs, but inhibited the transdifferentiation of Tregs into a Th17-like phenotype in affected patients, indicating by the down-regulations of C-C motif chemokine receptor-4/6 expression, retinoid-related orphan nuclear receptor γt mRNA levels, and IL-17 secretion. IL-35 contributes to the immunosuppressive function of Tregs by inhibiting the cellular proliferation and transdifferentiation of Tregs into a Th17-like phenotype, which may be a protective mechanism against Kawasaki disease.

Advances in understanding Kawasaki disease-related immuno-inflammatory response and vascular endothelial dysfunction

Kawasaki disease (KD) is a systemic vasculitis of unknown etiology, which tends to involve coronary arteries and can lead to acquired heart disease in children. The immuno-inflammatory response and vascular endothelial dysfunction are important causes of coronary artery disease in patients with KD. Multisystem inflammatory syndrome in children (MIS-C) is a rare inflammatory disease in children identified in recent years, which is caused by severe acute respiratory syndrome coronavirus 2 infection; this disease overlaps with KD. This review examines research progress concerning the immuno-inflammatory response and vascular endothelial dysfunction associated with KD, as well as differences between KD and MIS-C.

Interleukin-35 has a Protective Role in Infectious Mononucleosis-Induced Liver Inflammation Probably by Inhibiting CD8+ T Cell Function

Interleukin (IL)-35 plays an immunosuppressive role in infectious diseases, autoimmune disorders, and cancers. However, IL-35 expression and its regulation of CD8⁺ T cells in infectious mononucleosis (IM) are not fully understood. In this study, three groups of participants were compared, including twenty-three patients of IM without liver inflammation, twenty-eight patients of IM with liver inflammation, and twenty-one controls. Plasma and peripheral blood mononuclear cells (PBMCs) were isolated. CD8⁺ T cells were purified. Plasma IL-35 was measured by ELISA. PBMCs and CD8⁺ T cells were stimulated with recombinant human IL-35 in vitro. Perforin and granzyme B secretion was assessed by ELISPOT. Immune checkpoint molecule expression was investigated by flow cytometry. CD8⁺ T cells were co-cultured with HepG2 cells in direct contact and indirect contact manner. The cytotoxicity of CD8⁺ T cells was calculated by measuring lactate dehydrogenase release and proinflammatory cytokine expression. There was no significant difference in plasma IL-35 levels between patients with IM without liver inflammation and the controls, but the IL-35 level was notably increased in patients with IM who presented with liver inflammation and negatively correlated with aminotransferase. CD8⁺ T cells in patients with IM with liver inflammation showed stronger cytotoxicity. IL-35 stimulation inhibited CD8⁺ T cell-induced target cell death in patients with IM, mainly through suppression of IFN-γ/TNF-α secretion and elevation of immune checkpoint molecule expression, but did not affect perforin or granzyme B secretion. The current data indicated that IL-35 dampened the cytotoxicity of CD8⁺ T cells in patients with IM probably via repression of cytokine secretion. Elevated IL-35 may protect against CD8⁺ T cell-induced liver inflammation in patients with IM.