Clinical Significance of OX40 and OX40 Ligand in the Peripheral Blood of Patients with Myasthenia Gravis.

Background: A previous study on thymomas in myasthenia gravis (MG) patients indicated that OX40 expression may be upregulated in thymic tissues adjacent to germinal centers (GCs) and thymomas, and OX40 may interact with OX40L in GCs to enhance anti-acetylcholine receptor antibody production. However, little is known about the clinical significance of the expression of OX40 and OX40L in the peripheral blood of patients with MG. We aimed to characterize the expression of membrane-bound and soluble OX40 and OX40L in the peripheral blood of patients with MG and to identify their clinical significance. Methods: For membrane molecules, we collected peripheral blood (PB) from 39 MG patients at baseline, 22 patients in relapse, and 42 patients in remission, as well as from 36 healthy participants as controls. For soluble molecules, plasma from 37 MG patients at baseline, 34 patients in relapse, and 30 patients in remission, as well as plasma from 36 healthy controls (HC), was retrospectively collected from the sample bank of the First Hospital of Soochow University. The expression of membrane-bound OX40 and OX40L (mOX40 and mOX40L) by immune cells was measured using flow cytometry. Plasma levels of soluble OX40 and OX40L (sOX40 and sOX40L) were measured by ELISA. Results: (1) The expression of OX40 on CD4+ T cells and that of OX40L on B cells and monocytes were significantly increased, and the levels of sOX40 were significantly decreased in MG patients at baseline compared with HC, while the expression of sOX40L was not significantly different between the two groups. (2) Dynamic observation of the molecules showed significantly higher expression of OX40 on CD4+ T cells and higher levels of sOX40 in MG patients in relapse than in MG patients at baseline and MG patients in remission. Furthermore, the expression levels of sOX40 were significantly elevated in MG patients in remission compared with MG patients at baseline, and the expression of sOX40L was significantly lower in MG patients in remission than in MG patients at baseline and MG patients in relapse. (3) Plasma levels of sOX40 and sOX40L were significantly decreased in 13 patients with relapsed MG after immunosuppressive treatment compared with those before treatment. (4) Correlation analysis showed that the expression of OX40 on CD4+ T cells in patients with relapsed MG was positively correlated with the concentration of acetylcholine receptor antibodies (AchR-Ab), whereas the expression of OX40L on CD19+ B cells and CD14+ monocytes was negatively correlated with disease duration. (5) Binary regression analysis showed that patients with high CD4+ OX40 expression and high sOX40L levels had an increased risk of relapse. Conclusions: OX40 and OX40L are abnormally expressed in the peripheral blood of patients with MG and may be closely associated with disease status and treatment. The OX40/OX40L pathway may be involved in the immunopathological process of MG and may play a role mainly in the later stage of MG.

Immune Checkpoint Expression on Immune Cells of HNSCC Patients and Modulation by Chemo- and Immunotherapy.

Endogenous control mechanisms, including immune checkpoints and immunosuppressive cells, are exploited in the process of tumorigenesis to weaken the anti-tumor immune response. Cancer treatment by chemotherapy or immune checkpoint inhibition can lead to changes of checkpoint expression, which influences therapy success. Peripheral blood lymphocytes (PBL) and tumor-infiltrating lymphocytes (TIL) were isolated from head and neck squamous cell carcinoma (HNSCC) patients (n = 23) and compared to healthy donors (n = 23). Immune checkpoint expression (programmed cell death ligand 1 (PD-1), tumor necrosis factor receptor (TNFR)-related (GITR), CD137, tumor necrosis factor receptor superfamily member 4 (TNFRSF4) (OX40), t-cell immunoglobulin and mucin-domain containing-3 (TIM3), B- and T-lymphocyte attenuator (BTLA), lymphocyte-activation gene 3 (LAG3)) was determined on immune cells by flow cytometry. PD-L1 expression was detected on tumor tissue by immunohistochemistry. Immune cells were treated with immuno- and chemotherapeutics to investigate treatment-specific change in immune checkpoint expression, in vitro. Specific changes of immune checkpoint expression were identified on PBL and TIL of HNSCC patients compared to healthy donors. Various chemotherapeutics acted differently on the expression of immune checkpoints. Changes of checkpoint expression were significantly less pronounced on regulatory T cells compared to other lymphocyte populations. Nivolumab treatment significantly reduced the receptor PD-1 on all analyzed T cell populations, in vitro. The specific immune checkpoint expression patterns in HNSCC patients and the investigated effects of immunomodulatory agents may improve the development and efficacy of targeted immunotherapy.

High serum OX40 ligand correlates with severity and mortality in patients with massive cerebral infarction.

OX40 ligand (OX40L) is a member of tumor necrosis factors (TNF)/TNFR superfamily and is mainly expressed in activated T cells and participates in various inflammatory reactions. However, it remains unclear about the role of serum OX40L as a biomarker of cerebral infarction (CI). This study aimed to explore the possibility of serum OX40L as a meaningful predictor in mortality of CI. Severe CI patients were included to collect clinicopathological and laboratory data and measure serum OX40L level. Patients were followed up after discharge and 60-day survival rate was used as the study endpoint. The results showed that of all 294 patients, 123 (41.8%) died within 60 days after admission. Serum OX40L levels were significantly higher in patients with severe CI compared to healthy controls, and were significantly higher in nonsurvivors compared to survivors (P < .05). The levels of OX40L were correlated with Glasgow Coma Scale score, serum creatinine and high-sensitive C-reactive protein. Multivariate logistic regression analysis showed that serum OX40L level was an independent prognostic factor for 60-day mortality, after control of pulmonary infection, glasgow coma scale score and high-sensitive C-reactive protein (odds ratio = 1.089; 95% confidence interval = 1.053-1.126; P < .001). The receiver operating characteristic (ROC) curve was used to predict the best cut-off of serum OX40L for 60-day survival as 35.5 ng/mL. Patients with high serum OX40L levels (>35.5 ng/mL) had a significantly higher mortality within 60 days (hazard ratio = 2.885; 95% confidence interval = 1.901-4.378). In conclusion, OX40L is a serum biomarker of patients with CI and associated with severity and mortality of this disease.

The OX40 Axis is Associated with Both Systemic and Local Involvement in Atopic Dermatitis.

Atopic dermatitis (AD) is a chronic, or chronically relapsing, inflammatory skin disease associated with asthma and allergic rhinitis, and is dominated by Th2 cells. The co-stimulatory T-cell receptor OX40 and its ligand, OX40L, play a central role in the pathogenesis of AD, as their interactions are crucial for the generation of TH2 memory cells. Using enzyme-linked immunoassay (ELISA) and flow cytometry on blood samples from patients with AD and healthy volunteers, this study shows that the serum level of soluble (s) OX40 is decreased in patients with AD, and the expression of OX40 by activated skin-homing CD4+ T cells is increased. This study further shows, using immunofluorescence on skin biopsies, that OX40+ and OX40L+ cells are co-located within the dermis, indicating local activity of OX40/OX40L. Serum levels of sOX40 were associated with atopic diseases and, together, these results support that the OX40 system is important for chronic inflammation in AD skin.

High Serum OX40 and OX40 Ligand (OX40L) Levels Correlate with Reduced Survival in Patients with Advanced Lung Adenocarcinoma.

INTRODUCTION: Interaction of OX40 and OX40 ligand (OX40L) is associated with immune activation. OX40-OX40L axis is also suggested to play a role in immunity against several solid malignancies. OBJECTIVE: In this study, serum OX40 and OX40L levels in patients with advanced lung adenocarcinoma were assessed and their correlation with survival and clinicopathologic parameters was determined. METHODS: Serum samples were collected from patients with advanced lung adenocarcinoma, then OX40 and OX40L were quantified via enzyme-linked immunosorbent assay. Immunohistochemical (IHC) analysis of OX40 and OX40L in resected primary lesions was also performed. The association between OX40 and OX40L levels and clinicopathologic status and patient survival was retrospectively analyzed. RESULTS: A total of 56 patients were analyzed. Median serum OX40 and OX40L levels were 156.2 pg/mL and 186.6 pg/mL, respectively. IHC analysis in 5 patients indicated high positivity of OX40 in tumor-infiltrating lymphocytes and of OX40L in tumor cells in mucinous adenocarcinoma. Patients with a high OX40 level (≥152.2 pg/mL) had poorer prognosis than those with a low serum OX40 level (median survival, 7.36 vs. 21.19 months, respectively, p = 0.04). Patients with a high OX40L level (≥207.3 pg/mL) had poorer prognosis than those with a low serum OX40L level (median survival, 7.36 vs. 14.26 months, respectively, p = 0.04). In the subset of patients treated with immune checkpoint inhibitors (ICIs) (n = 12), those with a high OX40L level were found to have longer survival from ICI initiation than those with a low OX40L level (p = 0.023). CONCLUSIONS: High OX40 and OX40L levels are associated with poor prognosis and may reflect the immune-exhausted status against lung adenocarcinoma.

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.

Increased Expressions of OX40 and OX40 Ligand in Patients with Primary Immune Thrombocytopenia.

BACKGROUND: OX40, which is also known as tumor necrosis factor receptor superfamily member 4 (TNFRSF4), and its ligand (OX40L) play a critical role in the pathogenesis of autoimmune diseases. Immune thrombocytopenia (ITP), a hemorrhagic autoimmune disorder, is characterized by low platelet counts that are predominantly caused by antiplatelet autoantibodies. In this study, we firstly investigated the clinical significance of OX40 and OX40L expression in the pathogenesis of ITP in patients. METHODS: Fifty-four newly diagnosed ITP patients and 24 healthy controls (HCs) were enrolled in this study. The percentage of OX40+CD4+T cells among CD4+T cells was analyzed by flow cytometry, and the expression levels of OX40 and OX40L mRNA were analyzed by quantitative real-time PCR. Plasma soluble OX40L (sOX40L) levels were analyzed by ELISA, and plasma levels of antiplatelet autoantibodies were analyzed by a solid-phase technique. RESULTS: Compared with HCs, the frequencies of OX40+CD4+T cells were significantly increased in ITP patients, particularly in patients with positive antiplatelet autoantibodies compared to those with negative antiplatelet autoantibodies. The elevated frequencies of OX40+CD4+T cells were negatively correlated with low platelet counts in patients with positive antiplatelet autoantibodies. Plasma sOX40L levels in ITP patients were significantly greater than those in HCs and increased in patients with positive antiplatelet autoantibodies compared to those with negative antiplatelet autoantibodies. Plasma sOX40L levels were negatively correlated with low platelet counts in patients with positive antiplatelet autoantibodies. Additionally, the mRNA expression levels of OX40 and OX40L in PBMCs from ITP patients were also notably greater than those from HCs, and the expression levels of OX40 and OX40L were significantly different in ITP patients with positive and negative antiplatelet autoantibodies. CONCLUSION: These data indicated that increased expression levels of OX40 and OX40L were involved in the pathogenesis of ITP, and OX40 and OX40L may be valuable therapeutic targets for ITP.

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.

Relative Expression of OX40, OX40L mRNA, and OX40L Serum Levels in Women with Recurrent Spontaneous Abortion.

This study determined the roles of OX40 and OX40L in women with recurrent spontaneous abortion (RSA). We compared the expression of OX40 and OX40L genes in peripheral blood mRNA levels and serum levels of OX40L in women with a history of RSA to the control group. In this case-control study, 40 women with a history of RSA (case group), and 40 others with no history of abortion (control group) were investigated. The expressions of OX40 mRNA and OX40L mRNA were determined in the two groups using the quantitative polymerase chain reaction. Also, the enzyme-linked immunosorbent assay was used to determine the levels of serum OX40L in the two groups. There were no significant differences in the maternal age of women in the two groups (30.1 ± 4.28 years in the case vs. 30.03 ± 4.23 years in the control group). There was no difference in terms of the levels of OX40 and OX40L mRNA between the groups (p = 0.08 and p = 0.56, respectively). In addition, there was no significant correlation between the expression of OX40 and OX40L mRNA levels with age or the number of abortions. The correlation between OX40 and OX40L mRNA levels was not significant. RSA history group turned to show a higher level of serum OX40L than the control group (p = 0.03). In conclusion, our findings demonstrated that the expression of OX40 mRNA and OX40L mRNA was similar between women with a history of RSA and the control group. The elevation of serum OX40L level may be considered as a risk factor for RSA.

Kawasaki disease OX40-OX40L axis acts as an upstream regulator of NFAT signaling pathway.

BACKGROUND: We investigated a costimulatory molecule OX40-OX40L acting as an upstream regulator to regulate the nuclear factor of activated T cell (NFAT) in the acute phase of Kawasaki disease (KD). METHODS: One hundred and one samples were collected and divided into six groups: coronary artery lesion (KD-CAL) before intravenous immunoglobulin (IVIG), KD-CAL after IVIG, KD without CAL (KD-nCAL) before IVIG, KD-nCAL after IVIG, fever of unknown (Fou), and Healthy. In vitro OX40-stimulating and OX40L-inhibiting tests were conducted in Healthy and KD groups, respectively. Both the messenger RNA (mRNA) and protein expression levels of OX40, OX40L, NFAT1, and NFAT2 were investigated using quantitative reverse transcription PCR and immunoblotting assay, respectively. RESULTS: The mRNA and protein expression levels of NFAT1, NFAT2, OX40, and OX40L were significantly increased in KD-CAL and KD-nCAL groups before IVIG compared with Fou and Healthy groups and decreased after IVIG. A positive correlation was found between them in KD. In vitro OX40-stimulating test demonstrated the significantly increased mRNA and protein expression levels of NFAT1 and NFAT2 in the peripheral blood mononuclear cells of the Healthy group. Meanwhile, OX40L-inhibiting test showed significantly decreased expression levels of NFAT1 and NFAT2 in the KD group. CONCLUSION: OX40-OX40L acts as an upstream regulator in the NFAT signaling pathway involved in KD.

Preparation, characterization and application of anti-human OX40 ligand (OX40L) monoclonal antibodies and establishment of a sandwich ELISA for autoimmune diseases detection.

OX40L (CD252, TNFSF4), a type II transmembrane protein which like other tumor necrosis factor ligands, involved in the costimulation and differentiation of T cells, functions as a positive signal in immune response. To investigate the biological function of soluble OX40L (sOX40L), three functional anti-OX40L monoclonal antibodies (mAbs) 3D2, 3F7 and 2H3 were obtained by hybridoma technology. Besides, specificity of the mAbs was further demonstrated by ELISA, Western blot and Immunofluorescence experiments. We also developed a novel enzyme-linked immunosorbent assay (ELISA) based on two anti-human OX40L antibodies 3D2 and 3F7 with different epitopes. Using the ELISA system, we found that sOX40L in the sera of healthy donors increases in an age-dependent manner and that enhanced sOX40L expression in some autoimmune diseases especially in rheumatoid arthritis (RA) patients, suggesting the potential diagnostic significance of sOX40L in the autoimmune diseases. Together, these data demonstrate that the existence of circulating sOX40L in human sera might play an important role in immunoregulation.

Candidate gene biodosimetry markers of exposure to external ionizing radiation in human blood: A systematic review.

PURPOSE: To compile a list of genes that have been reported to be affected by external ionizing radiation (IR) and to assess their performance as candidate biomarkers for individual human radiation dosimetry. METHODS: Eligible studies were identified through extensive searches of the online databases from 1978 to 2017. Original English-language publications of microarray studies assessing radiation-induced changes in gene expression levels in human blood after external IR were included. Genes identified in at least half of the selected studies were retained for bio-statistical analysis in order to evaluate their diagnostic ability. RESULTS: 24 studies met the criteria and were included in this study. Radiation-induced expression of 10,170 unique genes was identified and the 31 genes that have been identified in at least 50% of studies (12/24 studies) were selected for diagnostic power analysis. Twenty-seven genes showed a significant Spearman's correlation with radiation dose. Individually, TNFSF4, FDXR, MYC, ZMAT3 and GADD45A provided the best discrimination of radiation dose < 2 Gy and dose ≥ 2 Gy according to according to their maximized Youden's index (0.67, 0.55, 0.55, 0.55 and 0.53 respectively). Moreover, 12 combinations of three genes display an area under the Receiver Operating Curve (ROC) curve (AUC) = 1 reinforcing the concept of biomarker combinations instead of looking for an ideal and unique biomarker. CONCLUSION: Gene expression is a promising approach for radiation dosimetry assessment. A list of robust candidate biomarkers has been identified from analysis of the studies published to date, confirming for example the potential of well-known genes such as FDXR and TNFSF4 or highlighting other promising gene such as ZMAT3. However, heterogeneity in protocols and analysis methods will require additional studies to confirm these results.

OX40L induces helper T cell differentiation during cell immunity of asthma through PI3K/AKT and P38 MAPK signaling pathway.

BACKGROUND: The aim of this study was to investigate the mechanisms of OX40L in regulating helper T (Th) cells differentiation through phosphoinositide 3-kinase (PI3K)/AKT and p38 mitogen-activated protein kinase signaling pathway in vitro and in vivo experiments. METHODS: Serum samples of patients with asthma and healthy controls were used to explore the association between OX40L and Th cells. Enzyme-linked immunosorbent assay (ELISA) was used to measure the serum concentrations of OX40L, IL-4, IFN-γ, IL-17 and TGF-ß. Flow cytometry method was used to analyze Th1, Th2, Th17 and Treg cells. 3H-thymidine was used to determine the proliferation of T cells. Western Blot was used to detect protein expression and phosphorylation. Immunohistochemistry was used to detect the expression of OX40L in lung tissues. RESULTS: OX40L, IL-4, IL-17 increased in patient serum compared to healthy control and in the ovalbumin (OVA)-primed mononuclear cells compared to normal cells, while IFN-γ and TGF-ß were decreased. Besides, the OVA-primed CD4+ T cells treated with OX40L-Ig fusion protein promoted the proliferation of T cells and Th2 and Th17 cells differentiation as well as PI3K/AKT and p38 MAPK signaling pathway, but suppressed Th1 and Treg cells differentiation. Moreover, helper T cells differentiation in OVA-primed CD4+ T cells could be markedly reversed by the addition of PI3K/AKT inhibition, p38 MAPK inhibition and anti-OX40L monoclonal antibody. CONCLUSIONS: In this study, we revealed that OX40L could regulate differentiation of helper T cells via PI3K/AKT and p38 MAPK signaling pathway in asthma. Besides, blockade of OX40/OX40L could inhibit the proliferation of CD4+ T cells and regulate polarization of helper T cells.

OX40L blockade protects against inflammation-driven fibrosis.

Treatment for fibrosis represents a critical unmet need, because fibrosis is the leading cause of death in industrialized countries, and there is no effective therapy to counteract the fibrotic process. The development of fibrosis relates to the interplay between vessel injury, immune cell activation, and fibroblast stimulation, which can occur in various tissues. Immunotherapies have provided a breakthrough in the treatment of immune diseases. The glycoprotein OX40-OX40 ligand (OX40L) axis offers the advantage of a targeted approach to costimulatory signals with limited impact on the whole immune response. Using systemic sclerosis (SSc) as a prototypic disease, we report compelling evidence that blockade of OX40L is a promising strategy for the treatment of inflammation-driven fibrosis. OX40L is overexpressed in the fibrotic skin and serum of patients with SSc, particularly in patients with diffuse cutaneous forms. Soluble OX40L was identified as a promising serum biomarker to predict the worsening of lung and skin fibrosis, highlighting the role of this pathway in fibrosis. In vivo, OX40L blockade prevents inflammation-driven skin, lung, and vessel fibrosis and induces the regression of established dermal fibrosis in different complementary mouse models. OX40L exerts potent profibrotic effects by promoting the infiltration of inflammatory cells into lesional tissues and therefore the release of proinflammatory mediators, thereafter leading to fibroblast activation.

OX40, OX40L and Autoimmunity: a Comprehensive Review.

The tumour necrosis factor receptor OX40 (CD134) is activated by its cognate ligand OX40L (CD134L, CD252) and functions as a T cell co-stimulatory molecule. OX40-OX40L interactions have been proposed as a potential therapeutic target for treating autoimmunity. OX40 is expressed on activated T cells, and in the mouse at rest on regulatory T cells (Treg). OX40L is found on antigen-presenting cells, activated T cells and others including lymphoid tissue inducer cells, some endothelia and mast cells. Expression of both molecules is increased after antigen presentation occurs and also in response to multiple other pro-inflammatory factors including CD28 ligation, CD40L ligation and interferon-gamma signaling. Their interactions promote T cell survival, promote an effector T cell phenotype, promote T cell memory, tend to reduce regulatory function, increase effector cytokine production and enhance cell mobility. In some circumstances, OX40 agonism may be associated with increased tolerance, although timing with respect to antigenic stimulus is important. Further, recent work has suggested that OX40L blockade may be more effective than OX40 blockade in reducing autoimmunity. This article reviews the expression of OX40 and OX40L in health, the effects of their interactions and insights from their under- or over-expression. We then review OX40 and OX40L expression in human autoimmune disease, identified associations of variations in their genes (TNFRSF4 and TNFSF4, respectively) with autoimmunity, and data from animal models of human diseases. A rationale for blocking OX40-OX40L interaction in human autoimmunity is then presented along with commentary on the one trial of OX40L blockade in human disease conducted to date. Finally, we discuss potential problems with clinical use of OX40-OX40L directed pharmacotherapy.

Soluble OX40L is associated with presence of autoantibodies in early rheumatoid arthritis.

INTRODUCTION: OX40 and its ligand OX40L are key components in the generation of adaptive memory response and provide necessary co-stimulatory signals for activated effector T cells. Here we investigate the dual roles of the membrane and soluble (s) forms of OX40 and OX40L in plasma and synovial fluid and their association with autoantibodies and disease activity in rheumatoid arthritis (RA). METHODS: Soluble OX40 and sOX40L plasma levels were measured in treatment-naïve early RA patients (eRA) at baseline and after 3, 6, and 12 months of treatment with methotrexate and adalimumab (n = 39) and with methotrexate alone (n = 37). Adalimumab was discontinued after the first year, and patients were followed for additional 12 months. For comparison, sOX40 and sOX40L were measured in patients with chronic RA (cRA, n = 15) and healthy volunteers (HV, n = 34). Membrane-bound OX40 and OX40L expression on T cells, B cells and monocytes were quantified. RESULTS: Soluble OX40 plasma levels of eRA patients were not different at the time of treatment initiation, but were significantly higher after 12 months of treatment, compared with HV or cRA patients. Soluble OX40L was significantly elevated throughout the first 12 months of treatment compared with HVs and patients with cRA. Adalimumab treatment did not influence sOX40 or sOX40L plasma levels. At baseline, sOX40L levels were strongly associated with the presence of anti-citrullinated protein antibodies (ACPA) (P <0.001) and IgM-RF (P <0.0001). The sOX40/sOX40L ratio was decreased in eRA, and a low ratio at the time of adalimumab discontinuation was associated with increased DAS28CRP and risk of flare the following year. T cells in the synovial fluid had the highest expression of OX40, while monocytes and B cells were the main expressers of OX40L in the joint. CONCLUSIONS: Plasma levels of sOX40 and sOX40L were increased in eRA and sOX40L was correlated with ACPA and IgM-RF. Further, expression of membrane-bound OX40 and OX40L was increased in eRA and cRA. Combined, these findings could reflect that increased activity in the OX40 systems facilitate to drive disease activity and autoantibody production in RA. TRIAL REGISTRATION: Clincaltrials.gov NCT00660647, 10 April 2008.

X-ray-induced expression changes of TNFSF4 gene in human peripheral blood.

This study examined ionizing radiation-induced tumor necrosis factor (ligand) superfamily, member 4 (TNFSF4) mRNA expression changes in human peripheral blood cells and their distribution in a normal population. The results showed that expression level of TNFSF4 mRNA exhibited a dose-dependent response after different irradiation doses, but that was independent of incubation time post-irradiation. Moreover, it was not affected by age and gender in 51 healthy donors. Our studies indicate that TNFSF4 can be considered as a candidate gene to develop a new biodosimeter.

[Expressions and clinical significance of OX40 and OX40L in peripheral blood of patients with primary Sjogren's syndrome].

OBJECTIVE: To investigate the expressions of costimulatory molecules OX40 and OX40L on peripheral blood mononuclear cells (PBMC) and their relationship with clinical characteristics of patients with primary Sjogren's syndrome (pSS). METHODS: Peripheral blood samples were collected from 51 pSS patients and 36 healthy subjects (HC). The expressions of OX40 and OX40L on PBMC were detected by immunofluorescence and flow cytometry. In addition, we observed the changes in the levels of OX40 and OX40L after treatment in 11 patients with primary pSS and searched for the relationship between their expression levels and patients' clinical manifestations. RESULTS: The expression of OX40 on CD4(+);T cells in pSS patients was significantly higher than that in the HC group (8.65%±3.51% vs 5.68%±1.68%, P<0.01). However, there was no significant difference in OX40 expression on CD8(+);T cells between patient group and HC group. In comparison with HC group, the expression of OX40L on CD14(+); monocytes (6.76%±3.60% vs 3.15%±1.89%, P<0.01) and CD19(+);B cells (4.69%±2.40% vs 2.76%±1.33%, P<0.01) significantly increased in pSS patients. Moreover, OX40 expression on CD4(+);T cells and OX40L expression on monocytes and B cells rose significantly in active pSS patients compared with those in inactive patients. The expression levels of OX40 and OX40L were higher in pSS patients with multiple system damage than in patients with simple exocrine gland injury. In addition, immunosuppressive therapy significantly reduced the expressions of OX40 and OX40L. CONCLUSION: The expressions of OX40 and OX40L on peripheral lymphocytes was upregulated in pSS patients. The high levels of OX40 and OX40L expression were significantly correlated with clinical outcome and therapeutic response, suggesting that OX40/OX40L pathway may play a critical role in pSS pathogenesis.

SOX40L: an important inflammatory mediator in adult bronchial asthma.

INTRODUCTION: The role of soluble OX40 ligand (sOX40L) in adult bronchial asthma is unclear. This study aims to determine the serum concentrations of sOX40L in adult patients with bronchial asthma, and discussed its relationship with pulmonary function. MATERIALS AND METHODS: We measured the pulmonary function using the spirometer and detected the serum concentrations of sOX40L by enzyme linked immunosorbent assay (ELISA) in 19 healthy persons in the control group, 58 acute asthmatic adult patients who were grouped according to their disease severity: 18 mild grade, 24 moderate grade, 16 severe grade, and 24 persons in a stable asthmatic group. RESULTS: The serum concentrations of sOX40L in asthmatic adult patients (6.80 ± 4.95 ng/L) were distinctly higher than those in the control group (3.98 ± 2.83 ng/L, P <0.05), and they were negatively correlated with pulmonary function indexes (FEV1%, FVC%, FEV1/FVC) (r = -0.754, P <0.01, r = -0.557, P <0.01, r = -0.457, P <0.01, respectively). Moreover, the serum concentrations of sOX40L showed obvious differences among control, mild, moderate, and severe groups (3.98 ± 2.83, 4.87 ± 1.89, 6.97 ± 5.91, 8.71 ± 5.18 ng/L, respectively; P <0.01). The concentrations of sOX40L decreased to the same extent as the control group after therapeutic treatments were provided to the asthmatic adult patients. CONCLUSION: The concentrations of sOX40L were found to be high in adult asthmatic patients and were associated with the severity of the disease. Therefore, sOX40L could be a potential inflammatory mediator in the pathogenesis of asthma.