Interleukin-23 facilitates Th1 and Th2 cell differentiation in vitro following respiratory syncytial virus infection

Insulin resistance in nonobese type 2 diabetic Goto Kakizaki rats is associated with a proinflammatory T lymphocyte profile

Goto-Kakizaki (GK) rats develop a well-defined insulin resistance (IR) and type 2 diabetes mellitus (T2DM) without presenting obesity. The lymphocyte profile in nonobese diabetic conditions is not yet characterized. Therefore, GK rats were chosen to explore T lymphocyte (TL) dynamics at various stages (21, 60, and 120 days) compared to Wistar rats. GK rats exhibit progressive disruption of glucose regulation, with early glucose intolerance at 21 days and reduced insulin sensitivity at 60 days, confirming IR. Glucose transporter 1 (GLUT1) expression was consistently elevated in GK rats, suggesting heightened TL activation. T-regulatory lymphocyte markers diminished at 21 days. However, GK rats showed increased Th1 markers and reduced Gata-3 expression (crucial for Th2 cell differentiation) at 120 days. These findings underscore an early breakdown of anti-inflammatory mechanisms in GK rats, indicating a proinflammatory TL profile that may worsen chronic inflammation in T2DM.

Interleukin-23 receptor defines T helper 1-like regulatory T cells in oral squamous cell carcinoma

BACKGROUND

The immune responses play significant roles in the onset, progression, and outcome of oral squamous cell carcinoma (OSCC). CD4+ regulatory T cells (Tregs) significantly impact tumor immunity. However, their role in OSCC development remains elusive.

METHODS

In a carcinogen-induced mouse OSCC model, interleukin-23 receptor (IL-23R) expression on Tregs and Treg function were determined by flow cytometry. IL-23R overexpression in Tregs was achieved by lentiviral infection, followed by evaluation of the expression of Forkhead box P3 (Foxp3), T-bet, retineic-acid-receptor-related orphan nuclear receptor gamma t, and cytokines by flow cytometry. Adoptive transfer assays were applied to analyze the function of IL-23R- overexpressing Tregs in vivo. The cellular sources of IL-23 were also determined by flow cytometry.

RESULTS

IL-23R- Tregs and IL-23R+ Tregs were found in the tongues but not spleens of OSCC-bearing mice. IL-23R+ Tregs expressed lower Foxp3 but higher T-bet than IL-23R- Tregs. IL-23R- Tregs produced abundant IL-10 and transforming growth factor (TGF)-β, while IL-23R+ Tregs produced lower IL-10 and TGF-β but remarkably higher interferon (IFN)-γ. Furthermore, IL-23R+ Tregs possessed more phosphorylated signal transducer and activator of transcription (STAT3) and STAT4 than IL-23R- Tregs. IL-23R+ Tregs were less immunosuppressive than IL-23R- Tregs, as evidenced by weaker inhibition of activated conventional T cells. IL-23R overexpression in splenic Tregs remarkably reduced the expression of IL-10 and TGF-β but increased IFN-γ expression when Tregs were adoptively transferred into OSCC-bearing mice. In the OSCC microenvironment, macrophages, dendritic cells, and malignant OSCC cells produced IL-23 which might modulate the function of IL-23R+ Tregs.

CONCLUSIONS

This study unveils Treg heterogeneity, thus deepening the understanding of Treg biology and tumor immunity in OSCC.

Th17/IL-17 Axis Regulated by Airway Microbes Get Involved in the Development of Asthma

PURPOSE OF REVIEW

Bronchial asthma is a common respiratory disease induced by immune imbalance, characterized by chronic non-specific airway inflammation and airway hyperresponsiveness (AHR). Many factors induce asthma, among which respiratory infection is the important cause. In this review, we discuss how respiratory microbes participate in the occurrence and progression of asthma via Th17/IL-17 axis.

RECENT FINDINGS

Pathogenesis of asthma has been considered as closely related to the imbalance in number and function of Th1/Th2 in the CD4⁺ T lymphocyte subsets. Recent studies have shown that Th17 cell and its secretory IL-17 also play an important role in AHR. Respiratory virus, bacteria, fungi, and other respiratory microbial infections can directly or indirectly induce the differentiation of Th17 cell and the production of related cytokines to induce AHR. Respiratory microbial infection can affect the TH17/IL-17A axis through a variety of mechanisms, thereby promoting the occurrence and development of asthma, and these specific mechanisms may provide new effective therapeutic ideas for asthma.

Immunoregulatory Functions of the IL-12 Family of Cytokines in Antiviral Systems

Members of the interleukin 12 (IL-12) family have been known to be inflammatory factors since their discovery. The IL-12 family consists of IL-12, IL-23, IL-27, IL-35, and a new member, IL-39, which has recently been identified and has not yet been studied extensively. Current literature has described the mechanisms of immunity of these cytokines and potential uses for therapy and medical cures. IL-12 was found first and is effective in combatting a wide range of naturally occurring viral infections through the upregulation of various cytokines to clear the infected cells. IL-23 has an essential function in immune networks, can induce IL-17 production, and can antagonize inhibition from IL-12 in the presence of T helper (Th) 17 cells, resulting in type II IFN (IFN-γ) regulation. IL-27 has a competitive relationship to IL-35 because they both include the same subunit, the Epstein–Barr virus-induced gene3 (EBi3). This review provides a simple introduction to the IL-12 family and focuses on their functions relevant to their actions to counteract viral infections.

IL-23 and dendritic cells: What are the roles of their mutual attachment in immune response and immunotherapy?

Interleukin-23 (IL-23) is a cytokine that is composed of the subunits p19 and p40, while its receptor (IL-23R) consists of two subunits, that is, IL-23Rα and IL-12Rβ1. The interaction between IL-23 and IL-23R is necessary for exerting cardinal biological effects upon certain cell types, including promotion of memory T cell proliferation and Th17 cell-mediated IL-17 secretion. Accordingly, dendritic cells (DCs) are one of the main sources for IL-23 secretion. Interestingly, IL-23R is also present on the DC plasma membrane, suggesting that IL-23 potentially acts on DCs via an autocrine manner. In this review, we have summarized a variety of IL-23-mediated effects on the intracellular signaling pathways such as Janus kinase 2, tyrosine kinase 2, signal transducer and activator of transcription (STAT), mitogen-activated protein kinase signaling, and so forth, which may underlie numerous processes such as DC maturation, antigen presentation, T cell proliferation/activation, and cytokine secretion, which may be implicated in many immune-related diseases through IL-23/DC interactions. Accordingly, these signaling pathways are extensively involved in the pathogenesis and progression of numerous diseases, including autoimmune disease (e.g., atopic dermatitis, asthma, and multiple sclerosis) and infection (e.g., bacterial, fungal, and viral infections). Taken together, they are potentially applicable to novel but promising strategies for treating numerous diseases associated with the mutual attachment of IL-23 and DCs.

The role of Th17 and Treg responses in the pathogenesis of RSV infection

The respiratory syncytial virus (RSV) represents the leading cause of viral bronchiolitis and pneumonia in children worldwide and is associated with high morbidity, hospitalization rate, and significant mortality rates. The immune response elicited by RSV is one of the main factors contributing to the pathogenesis of the disease. Two subsets of the cellular immune response, the T helper 17 cell (Th17) and the regulatory T-cell (Treg), and more particularly the balance between these two subsets, might play a significant role in the pathogenesis of the RSV infection. The developmental pathways of Th17 and Treg cells are closely and reciprocally interconnected and plasticity has been demonstrated from Treg toward Th17. During an RSV infection, the functions of both subsets are opposed to one another regarding viral clearance and clinical severity. Th17 and Treg cells offer a promising new view on the pathogenesis of an RSV infection and deserve further exploration.

Inflammatory damage on respiratory and nervous systems due to hRSV infection

The exacerbated inflammatory response elicited by human Respiratory Syncytial Virus (hRSV) in the lungs of infected patients causes a major health burden in the pediatric and elderly population. Since the discovery of hRSV, the exacerbated host immune-inflammatory response triggered by this virus has been extensively studied. In this article, we review the effects on the airways caused by immune cells and cytokines/chemokines secreted during hRSV infection. While molecules such as interferons contribute at controlling viral infection, IL-17 and others produce damage to the hRSV-infected lung. In addition to affecting the airways, hRSV infection can cause significant neurologic abnormalities in the host, such as seizures and encephalopathy. Although the origin of these symptoms remains unclear, studies from patients suffering neurological alteration suggest an involvement of the inflammatory response against hRSV.