Crucial role of OX40/OX40L signaling in a murine model of asthma

OX40-Fc Fusion Protein Alleviates PD-1-Fc-Aggravated Rheumatoid Arthritis by Inhibiting Inflammatory Response

BACKGROUND

Researches have confirmed that the abnormal signals of OX40 and PD-1 lead to the changes of T cell biological behavior, thus participating the immunopathological process of RA. However, the pathogenesis of RA immunopathological process has not been clarified yet.

METHODS

30 DBA/1 mice were randomly divided into 5 groups (6 mice per group): control group, collagen-induced arthritis (CIA) group, PD-1-Fc/CIA group, OX40-Fc/CIA group, and PD-1-Fc + OX40-Fc/CIA group. The pathological changes in mice joints were observed by H&E staining. The proportion of CD4+ T, CD8+ T, CD28+, and CD19+ cells in peripheral blood mononuclear cells (PBMCs) was detected by flow cytometry. Serum inflammatory factors (CRP, IL-2, IL-4, IL-1β, INF-γ) and bone metabolism-related genes (CTX-I, TRACP-5b, BALP) were detected by ELISA assay. Western blotting was applied to measure the NF-κB signaling pathway-related protein (p-IKKβ, p-IκBα, p50) expression in synovial tissue of mice joint.

RESULTS

Compared with the control group, CIA mice showed significant increases in arthritis score and pathological score. In the CIA group, a marked decrease was identified in the proportion of CD8+ T, CD19+, and CD68+ cells. Additionally, the CIA group was associated with upregulation of secretion of inflammatory factors in serum and expression of bone metabolism-related genes and NF-κB pathway-related proteins. Compared with the CIA group, the same indexes above showed a further aggravation in the PD-1-Fc group while all indexes improved in the OX40-Fc group. Besides, OX40-Fc fusion protein slowed down significantly the further deterioration of CIA mouse pathological process caused by PD-1-Fc fusion protein.

CONCLUSION

OX40-Fc fusion protein alleviates PD-1-Fc-aggravated RA by inhibiting inflammatory response. This research provides biological markers with clinical significance for diagnosis and prognosis of RA, as well as offers theoretical and experimental foundation to the new targets for immune intervention.

Enhancement of the Soluble Form of OX40 and OX40L Costimulatory Molecules but Reduction of the Membrane Form in Type 1 Diabetes (T1D)

This study analyzed the expression of membrane OX40 and OX40L (mOX40 and mOX40L) and levels of soluble OX40 and OX40L (sOX40 and sOX40L) in T1D patients to determine their clinical significance. Peripheral blood (PB) was collected from patients with T1D and healthy control participants. Expression of mOX40 and mOX40L on immune cells was detected by flow cytometry. Levels of sOX40 and sOX40L in sera were measured by ELISA. We demonstrated for the first time enhanced sOX40 and sOX40L expression and reduced mOX40 and mOX40L levels in T1D patients which correlated with the clinical characteristics and inflammatory factors. These results suggest that OX40/OX40L signal may be promising biomarkers and associated with the pathogenesis of T1D.

Elevated serum OX40L is a biomarker for identifying corticosteroid resistance in pediatric asthmatic patients

BACKGROUND

Corticosteroids are widely used to control asthma symptoms, but steroid resistance (SR) is a common adverse reaction. Therefore, it is important to accurately predict the corticosteroid response of asthmatic patients. This study aims to evaluate the serum OX40 ligand (OX40L) in pediatric asthmatic patients, and to investigated its correlations with clinical characteristics and corticosteroid response.

METHODS

A total of 192 pediatric asthmatic patients with inhaled corticosteroid (ICS) therapy and 130 healthy controls were selected. Clinical data were collected, and the serum levels of immunoglobulin (IgE), interleukin-6 (IL-6), thymic stromal lymphopoietin (TSLP), and OX40L were measured by enzyme-linked immunosorbent assay (ELISA). The level of serum OX40L was compared between the steroid-sensitive asthma (SSA) and steroid-resistant asthma (SRA) groups.

RESULTS

The serum OX40L level in asthmatic patients (713.5 ± 165.7 pg/mL) was significantly higher than that of the healthy controls (238.6 ± 27.8 pg/mL) (P < 0.001), and significantly higher in SRA group (791.2 ± 167.9 pg/mL) than in SSA group (655.6 ± 138.8 pg/mL) (P < 0.001). The serum OX40L level showed a significant positive correlation with serum IgE, blood percentages of eosinophils and neutrophils, serum IL-6 and TSLP, and showed a negative correlation with asthma control test (ACT) score and forced expiratory volume in first second (FEV1%). Receiver operating characteristics (ROC) curve was performed to obtain a cutoff value of serum OX40L as 780 pg/mL (sensitivity = 58.5%; specificity = 86.4%), which can identify SRA in asthmatic patients. Multivariate logistic regression analysis showed that elevated serum OX40L (≥780 pg/mL), as well as lymphocytes (%), ACT score, serum IL-6 and TSLP, were independent predictors of SRA (OX40L ≥ 780 pg/mL: odds ratio = 4.188; 95% CI = 1.800-9.746; P = 0.001). The serum OX40L level was decreased after ICS treatment in asthmatic patients, and the reduction in serum OX40L was significant higher in SSA group compared with SRA group.

CONCLUSION

High serum OX40L can be used as a biomarker to identify asthmatic patients with corticosteroid resistance, and the change in OX40L level also reflects the response to ICS treatment. These results suggest an association of OX40L with the pathophysiology, inflammation, and clinical outcomes of asthma. New agents targeting OX40L can provide more precise and personalized therapy for asthma.

The In Vitro Impact of Glycyrrhizic Acid on CD4+ T Lymphocytes through OX40 Receptor in the Patients with Allergic Rhinitis

Glycyrrhizic acid (GA), the major bioactive component of glycyrrhiza, possesses anti-inflammatory, anti-allergic, and immunomodulatory activities. This study aimed to investigate the in vitro anti-allergic effect of GA through the OX40 receptor in patients with allergic rhinitis. Purified naive CD4+ T cells of patients with allergic rhinitis (n = 12) were activated with anti-CD3/anti-CD28 with and without anti-OX40 agonist mAbs and then treated with 50, 100, and 200 μM GA and 0.1 μM dexamethasone. Cells were incubated (72 h) to measure cell proliferation. Expression of OX40 in anti-OX40 mAb stimulated CD4+ T cells was evaluated by flow cytometry. mRNA expression of the OX40 receptor and T-bet, GATA-3, and forkhead box P3 (FoxP3) transcriptional factors were measured by a quantitative polymerase chain reaction. The levels of interleukin (IL)-4, IL-10, and interferon-γ (IFN-γ) were also measured. GA inhibited significantly the augmented T cell proliferation induced with anti-OX40 mAb. Protein and gene expression of OX40 was also decreased significantly. Dexamethasone and GA inhibited T-bet and GATA-3 genes expression, but this inhibition was only significant for GATA-3. In contrast, enhanced gene expression of FoxP3 was seen using 200 μM GA and dexamethasone. The levels of IL-4, IL-10, and IFN-γ decreased after treatment with both dexamethasone and GA, but the ratio of IFN-γ/IL-4 (Th1/Th2 balance) increased significantly due to 200 μM GA treatment. This study suggests that GA may have a therapeutic effect on allergic rhinitis, partly by modulation of the Th1/Th2 balance through suppression of OX40 and increasing the activity of regulatory T cells.