HVEM: An unusual TNF receptor family member important for mucosal innate immune responses to microbes

Genetically predicted N-methylhydroxyproline levels mediate the association between naive CD8+ T cells and allergic rhinitis: a mediation Mendelian randomization study

Background

Allergic rhinitis (AR), a prevalent chronic inflammatory condition triggered by immunoglobulin E (IgE), involves pivotal roles of immune and metabolic factors in its onset and progression. However, the intricacies and uncertainties in clinical research render current investigations into their interplay somewhat inadequate.

Objective

To elucidate the causal relationships between immune cells, metabolites, and AR, we conducted a mediation Mendelian randomization (MR) analysis.

Methods

Leveraging comprehensive publicly accessible summary-level data from genome-wide association studies (GWAS), this study employed the two-sample MR research method to investigate causal relationships among 731 immune cell phenotypes, 1400 metabolite levels, and AR. Additionally, employing the mediation MR approach, the study analyzed potential mediated effect of metabolites in the relationships between immune cells and AR. Various sensitivity analysis methods were systematically employed to ensure the robustness of the results.

Results

Following false discovery rate (FDR) correction, we identified three immune cell phenotypes as protective factors for AR: Naive CD8br %CD8br (odds ratio (OR): 0.978, 95% CI = 0.966-0.990, P = 4.5×10-4), CD3 on CD39+ activated Treg (OR: 0.947, 95% CI = 0.923-0.972, P = 3×10-5), HVEM on CD45RA- CD4+ (OR: 0.967, 95% CI = 0.948-0.986, P = 4×10-5). Additionally, three metabolite levels were identified as risk factors for AR: N-methylhydroxyproline levels (OR: 1.219, 95% CI = 1.104-1.346, P = 9×10-5), N-acetylneuraminate levels (OR: 1.133, 95% CI = 1.061-1.211, P = 1.7×10-4), 1-stearoyl-2-arachidonoyl-gpc (18:0/20:4) levels (OR: 1.058, 95% CI = 1.029-1.087, P = 5×10-5). Mediation MR analysis indicated a causal relationship between Naive CD8br %CD8br and N-methylhydroxyproline levels, acting as a protective factor (OR: 0.971, 95% CI = 0.950-0.992, P = 8.31×10-3). The mediated effect was -0.00574, accounting for 26.1% of the total effect, with a direct effect of -0.01626. Naive CD8+ T cells exert a protective effect on AR by reducing N-methylhydroxyproline levels.

Conclusion

Our study, delving into genetic information, has substantiated the intricate connection between immune cell phenotypes and metabolite levels with AR. This reveals a potential pathway to prevent the onset of AR, providing guiding directions for future clinical investigations.

Development of a novel, high-efficacy oncolytic herpes simplex virus type 1 platform equipped with two distinct retargeting modalities

To retarget oncolytic herpes simplex virus (oHSV) to cancer-specific antigens, we designed a novel, double-retargeted oHSV platform that uses single-chain antibodies (scFvs) incorporated into both glycoprotein H and a bispecific adapter expressed from the viral genome to mediate infection predominantly via tumor-associated antigens. Successful retargeting was achieved using a nectin-1-detargeted HSV that remains capable of interacting with herpesvirus entry mediator (HVEM), the second canonical HSV entry receptor, and is, therefore, recognized by the adapter consisting of the virus-binding N-terminal 82 residues of HVEM fused to the target-specific scFv. We tested both an epithelial cell adhesion molecule (EpCAM)- and a human epidermal growth factor receptor 2-specific scFv separately and together to target cells expressing one, the other, or both receptors. Our results show not only dose-dependent, target receptor-specific infection in vitro, but also enhanced virus spread compared with single-retargeted virus. In addition, we observed effective infection and spreading of the EpCAM double-retargeted virus in vivo. Remarkably, a single intravenous dose of the EpCAM-specific virus eliminated all detectable tumors in a subcutaneous xenograft model, and the same intravenous dose seemed to be harmless in immunocompetent FVB/N mice. Our findings suggest that our double-retargeted oHSV platform can provide a potent, versatile, and systemically deliverable class of anti-cancer therapeutics that specifically target cancer cells while ensuring safety.

Blood transcriptome analysis revealing aging gene expression profiles in red panda

The red panda is an endangered forest species distributed on the edge of the Qinghai Tibet Plateau. The species has been conserved in ex-situ in many countries and its survival is threatened by many diseases. Its immune system is vulnerable to age-associated alterations, which accumulate and result in a progressive deterioration that leads to an increased incidence of diseases. We identified 2,219 differentially expressed genes (DEGs) between geriatric (11-16 years) and adult individuals (4-8 years), and 1690 DEGs between adults and juveniles (1 year). The gene expression and functional annotation results showed that the innate immunity of red pandas increases significantly in geriatric individuals, whereas its change remains unclear when comparing adults and juveniles. We found that the adaptive immunity of red pandas first increased and then decreased with age. We identified CXCR3, BLNK, and CCR4 as the hub genes in the age-related protein-protein interaction network, which showed their central role in age-related immune changes. Many DNA repair genes were down-regulated in geriatric red pandas, suggesting that the DNA repair ability of the blood tissue in geriatric red pandas is significantly reduced. The significantly up-regulated TLR5 in geriatric individuals also suggests the possibility of enhancing the vaccination immune response by incorporating flagellin, which could be used to address decreased vaccine responses caused by age-related declines in immune system function. This work provides an insight into gene expression changes associated with aging and paves the way for effective disease prevention and treatment strategies for red pandas in the future.

Type 3 Innate Lymphoid Cells as Regulators of the Host-Pathogen Interaction

Type 3 Innate lymphoid cells (ILC3s) have been described as tissue-resident cells and characterized throughout the body, especially in mucosal sites and classical first barrier organs such as skin, gut and lungs, among others. A significant part of the research has focused on their role in combating pathogens, mainly extracellular pathogens, with the gut as the principal organ. However, some recent discoveries in the field have unveiled their activity in other organs, combating intracellular pathogens and as part of the response to viruses. In this review we have compiled the latest studies on the role of ILC3s and the molecular mechanisms involved in defending against different microbes at the mucosal surface, most of these studies have made use of conditional transgenic mice. The present review therefore attempts to provide an overview of the function of ILC3s in infections throughout the body, focusing on their specific activity in different organs.

Plasma TNFSF13B and TNFSF14 Function as Inflammatory Indicators of Severe Adenovirus Pneumonia in Pediatric Patients

Background

Human adenoviruses (HAdV) infection caused pneumonia remains a major threat to global children health. Currently, diagnosis of severe HAdV pneumonia in children is hampered by the lack of specific biomarkers. Also, the severity of adenovirus pneumonia in pediatric patients is generally based on clinical features and existing biomarkers do not reliably correlate to clinical severity. Here, we asked whether local and systemic inflammatory mediators could act as biomarkers predicting severe HAdV pneumonia in children.

Methods

Totally 37 common inflammatory protein levels were determined by Luminex assay in plasma and bronchoalveolar lavage (BAL) from pediatric patients who were diagnosed with HAdV pneumonia, and their correlation with the disease severity and lung lesion were assessed using statistical and bioinformatic analysis.

Results

Among 37 inflammatory cytokines, the protein levels of 4 TNF superfamily (TNFSF) members and their receptors (TNF receptor superfamily, TNFRSF) [TNFSF13B, TNFSF14, sTNF-R1 and sTNF-R2] in the plasma and 7 TNFSF/TNFRSF members [TNFSF12, TNFSF13, TNFSF13B, TNFSF14, TNFRSF8, sTNF-R1, and sTNF-R2] in the BAL were enhanced in patients with HAdV pneumonia compared with control subjects with airway foreign body. Moreover, the protein levels of all the tested TNFSF/TNFRSF members (except TNFSF12) were elevated in the BAL of severe group compared with non-severe HAdV pneumonia patients, while only TNFSF13B and TNFSF14 were dramatically increased in the plasma of severe cases, and positively related to the plasma CRP levels. In addition, ROC analysis indicated that TNFSF13B and TNFSF14 displayed a great potential to predict severe HAdV pneumonia.

Conclusion

In pediatric HAdV pneumonia, TNFSF/TNFRSF members function as key molecules in local and systemic inflammatory network, and the plasma TNFSF13B and TNFSF14 may be the potential local and systemic inflammatory indicators of severe HAdV pneumonia in pediatric patients.

HVEM signaling promotes protective antibody-dependent cellular cytotoxicity (ADCC) vaccine responses to herpes simplex viruses

Herpes simplex virus (HSV) glycoprotein D (gD) not only is required for virus entry and cell-to-cell spread but also binds the host immunomodulatory molecule, HVEM, blocking interactions with its ligands. Natural infection primarily elicits neutralizing antibodies targeting gD, but subunit protein vaccines designed to induce this response have failed clinically. In contrast, preclinical studies demonstrate that an HSV-2 single-cycle strain deleted in gD, ΔgD-2, induces primarily non-neutralizing antibodies that activate Fcγ receptors (FcγRs) to mediate antibody-dependent cellular cytotoxicity (ADCC). These studies were designed to test the hypothesis that gD interferes with ADCC through engagement of HVEM. Immunization of Hvem-/- mice with ΔgD-2 resulted in significant reduction in HSV-specific IgG2 antibodies, the subclass associated with FcγR activation and ADCC, compared with wild-type controls. This translated into a parallel reduction in active and passive vaccine protection. A similar decrease in ADCC titers was observed in Hvem-/- mice vaccinated with an alternative HSV vaccine candidate (dl5-29) or an unrelated vesicular stomatitis virus-vectored vaccine. Unexpectedly, not only did passive transfer of immune serum from ΔgD-2-vaccinated Hvem-/- mice fail to protect wild-type mice but transfer of immune serum from ΔgD-2-vaccinated wild-type mice failed to protect Hvem-/- mice. Immune cells isolated from Hvem-/- mice were impaired in FcγR activation, and, conversely, addition of gD protein or anti-HVEM antibodies to in vitro murine or human FcγR activation assays inhibited the response. These findings uncover a previously unrecognized role for HVEM signaling in generating and mediating ADCC and an additional HSV immune evasion strategy.

Restoring Herpesvirus Entry Mediator (HVEM) Immune Function in HVEM-/- Mice Rescues Herpes Simplex Virus 1 Latency and Reactivation Independently of Binding to Glycoprotein D

The immune modulatory protein herpes virus entry mediator (HVEM) is one of several cellular receptors used by herpes simplex virus 1 (HSV-1) for cell entry. HVEM binds to HSV-1 glycoprotein D (gD) but is not necessary for HSV-1 replication in vitro or in vivo Previously, we showed that although HSV-1 replication was similar in wild-type (WT) control and HVEM-/- mice, HSV-1 does not establish latency or reactivate effectively in mice lacking HVEM, suggesting that HVEM is important for these functions. It is not known whether HVEM immunomodulatory functions contribute to latency and reactivation or whether its binding to gD is necessary. We used HVEM-/- mice to establish three transgenic mouse lines that express either human WT HVEM or human or mouse HVEM with a point mutation that ablates its ability to bind to gD. Here, we show that HVEM immune function, not its ability to bind gD, is required for WT levels of latency and reactivation. We further show that HVEM binding to gD does not affect expression of the HVEM ligands BTLA, CD160, or LIGHT. Interestingly, our results suggest that binding of HVEM to gD may contribute to efficient upregulation of CD8α but not PD1, TIM-3, CTLA4, or interleukin 2 (IL-2). Together, our results establish that HVEM immune function, not binding to gD, mediates establishment of latency and reactivation.IMPORTANCE HSV-1 is a common cause of ocular infections worldwide and a significant cause of preventable blindness. Corneal scarring and blindness are consequences of the immune response induced by repeated reactivation events. Therefore, HSV-1 therapeutic approaches should focus on preventing latency and reactivation. Our data suggest that the immune function of HVEM plays an important role in the HSV-1 latency and reactivation cycle that is independent of HVEM binding to gD.

Herpes Virus Entry Mediator (HVEM) Expression Promotes Inflammation/ Organ Injury in Response to Experimental Indirect-Acute Lung Injury

Therapeutic interventions to treat acute lung injury (ALI) remain largely limited to lung-protective strategies, as a real molecular pathophysiologically driven therapeutic intervention has yet to become available. While we have previously documented the expression of herpes virus entry mediator (HVEM) on leukocytes of septic mice and critically ill patients, its functional role in shock/sepsis-induced ALI has not yet been studied. Inasmuch, a murine model of indirect ALI (iALI) was induced by hemorrhagic shock (HEM) followed by cecal ligation and puncture (CLP), septic challenge and HVEM-siRNA or phosphate buffered saline was administrated by intratracheal instillation 2 h after hemorrhage to determine the role of HVEM in the development of experimental iALI. Indices of lung injury were measured. HVEM expression was significantly elevated in iALI mice. Compared with phosphate buffered saline treated iALI mice, HVEM knock-down by siRNA caused a reduction of cytokine/chemokine levels, myeloperoxidase activity, broncho-alveolar lavage fluid (BALF) cell count and protein concentration. HVEM-siRNA treatment reduced inflammation and attenuated pulmonary architecture destruction as well as provided an early (60 h post HEM-CLP) survival benefit in iALI mice. This ability of anti-HVEM treatment to prevent the development of iALI and provide a transient survival benefit implies that mitigating signaling through HVEM may be a novel target worth further investigation.

Expression of herpesvirus entry mediator gene as a potential biomarker for disease severity in patients with persistent asthma

Objectives: Herpes virus entry mediator (HVEM) is a costimulatory molecule, and has been proved to play an important role in airway inflammatory and remodeling processes of asthma. We aimed to investigate the expression of HVEM gene in patients with asthma as a means of assessing disease severity.Methods: This study was carried out on 59 subjects, 16 patients with mild persistent asthma, 11 patients with moderate persistent asthma, 13 patients with severe persistent asthma, and 19 age and gender matched healthy controls. The HVEM mRNA expressions of all subjects were determined by real time PCR. Correlations between HVEM mRNA expression and fractional exhaled nitric oxide (FeNO), pulmonary function test values, total blood white cell count and differential, total immunoglobulin E (IgE) level, and Asthma Control Test (ACT) score were analyzed, respectively. The discrimination abilities of HVEM mRNA between different groups were tested using receiver operating characteristics (ROC) curve analyses.Results: This study showed the expressions of HVEM mRNA were significantly higher in the patients with severe and moderate persistent asthma than in patients with mild persistent asthma and healthy subjects (2.97 ± 1.23 vs. 1.17 ± 0.42 vs. 0.62 ± 0.38 vs. 0.46 ± 0.18/NAPDH, p < 0.001), but there was no significant difference between patients with mild persistent asthma and health controls (0.62 ± 0.38 vs. 0.46 ± 0.18/NAPDH, p = 0.557). HVEM mRNA expression at cut off point [1.01/NAPDH, area under the ROC curve (AUC) = 0.99] is sufficient to discriminate severe patients from mild-to-moderate patients, and at cut off point (0.93/NAPDH, AUC = 0.91) for discrimination of moderate-to-severe patients from mild ones, while at cut off point (0.76/NAPDH, AUC = 0.75) for discrimination of asthmatic patients from controls. Furthermore, HVEM mRNA expression was positively correlated with FeNO level (r = 0.524, p = 0.015), and total lymphocyte count (r = 0.426, p = 0.017) in patients with persistent asthma.Conclusions: HVEM gene expressions can be used as a potential biomarker for evaluating the severity of patients with persistent asthma.

HVEM LIGHTs the Way for ILC3s

The early response to bacterial infection requires cytokine responses by immune cells. In this issue of Cell Host & Microbe, Seo et al. (2018) demonstrate that TNF-TNFR superfamily molecules LIGHT and HVEM stimulate early IFN-γ production by type 3 innate lymphoid cells, which are critical for defense against Yersinia enterocolitica.

Expression, purification, and efficient refolding of the extracellular domain of Escherichia coli-expressed signaling receptor herpesvirus entry mediator

Herpesvirus entry mediator (HVEM), a member of the TNF-receptor superfamily, plays an important role in the regulation of the immune system. It forms a complex with ligands and can either activate or inhibit the response of the immune system. Furthermore, HVEM can exhibit pro-inflammatory or anti-inflammatory effects in many human diseases. Therefore, understanding the mechanism underlying the interaction of HVEM with other receptors is extremely important to design small therapeutic molecules that can stimulate the response of the immune system. In this study, we attempted to develop the most efficient method for the expression and purification of the extracellular domain of HVEM using Escherichia coli. The soluble fraction constituted only a small portion of the E. coli-expressed protein, whereas majority of the protein was found to be accumulated in the insoluble fraction. Three different protein refolding methods were analyzed: dialysis, dilution, and using chromatographic column. The oligomeric state of the protein was determined by characterizing the obtained fractions using analytical size exclusion chromatography. All the obtained fractions were tested for their ability to form a complex with B- and T-lymphocyte attenuator using enzyme-linked immunosorbent assay. The results of this study provide crucial information regarding the production of HVEM protein in a robust, well-established, and convenient heterologous expression system using E. coli as a host. In addition, it allows for the selection of the most effective method for appropriate refolding of HVEM protein, which gets accumulated in the insoluble fraction.

Immune checkpoint molecule herpes virus entry mediator is overexpressed and associated with poor prognosis in human glioblastoma

Background

Dysregulation of immune checkpoint molecules leads to immune evasion in human tumours but has become a viable target for tumour therapy. Here, we examined expression of Herpes virus entry mediator (HVEM), an immune checkpoint molecule, in human glioblastoma (GBM) to assess its potential as a molecular target for treatment.

Methods

Molecular and clinical data from publicly available genomic databases containing WHO grade II-IV human glioma cases (n = 1866) were analyzed. Immunohistochemistry was applied to assess HVEM protein levels in primary tumour sections. Statistical analysis was performed using Matlab and R language.

Findings

HVEM was found to be elevated in aggressive gliomas, particularly in the mesenchymal and isocitrate dehydrogenase (IDH) wild-type molecular subtypes of GBM. HVEM^high tumours tended to be associated with amplification of EGFR and loss of PTEN, while HVEM^low tumours harbored mutations in IDH1 (93%). HVEM exhibited potential as a prognostic marker based on Cox regression and nomogram models. HVEM displayed intra-tumour heterogeneity and was more highly expressed in peri-necrotic and microvascular regions. Gene ontology and pathway analysis revealed enrichment of HVEM in multiple immune regulatory processes, such as suppression of T cell mediated immunity in GBM. Finally, in cell lineage analysis, HVEM was found to be tightly associated with several infiltrating immune and stromal cell types which localized to the tumour microenvironment.

Interpretation

Our data highlights the importance of HVEM in the development of GBM and as a potential molecular target in combination with current immune checkpoint blockades for treatment of GBM.

Soluble Fc-Disabled Herpes Virus Entry Mediator Augments Activation and Cytotoxicity of NK Cells by Promoting Cross-Talk between NK Cells and Monocytes

CD160 is highly expressed by NK cells and is associated with cytolytic effector activity. Herpes virus entry mediator (HVEM) activates NK cells for cytokine production and cytolytic function via CD160. Fc-fusions are a well-established class of therapeutics, where the Fc domain provides additional biological and pharmacological properties to the fusion protein including enhanced serum t 1/2 and interaction with Fc receptor-expressing immune cells. We evaluated the specific function of HVEM in regulating CD160-mediated NK cell effector function by generating a fusion of the HVEM extracellular domain with human IgG1 Fc bearing CD16-binding mutations (Fc*) resulting in HVEM-(Fc*). HVEM-(Fc*) displayed reduced binding to the Fc receptor CD16 (i.e., Fc-disabled HVEM), which limited Fc receptor-induced responses. HVEM-(Fc*) functional activity was compared with HVEM-Fc containing the wild type human IgG1 Fc. HVEM-(Fc*) treatment of NK cells and PBMCs caused greater IFN-γ production, enhanced cytotoxicity, reduced NK fratricide, and no change in CD16 expression on human NK cells compared with HVEM-Fc. HVEM-(Fc*) treatment of monocytes or PBMCs enhanced the expression level of CD80, CD83, and CD40 expression on monocytes. HVEM-(Fc*)-enhanced NK cell activation and cytotoxicity were promoted via cross-talk between NK cells and monocytes that was driven by cell-cell contact. In this study, we have shown that soluble Fc-disabled HVEM-(Fc*) augments NK cell activation, IFN-γ production, and cytotoxicity of NK cells without inducing NK cell fratricide by promoting cross-talk between NK cells and monocytes without Fc receptor-induced effects. Soluble Fc-disabled HVEM-(Fc*) may be considered as a research and potentially therapeutic reagent for modulating immune responses via sole activation of HVEM receptors.

Transcriptome Sequencing Identifies Novel Immune Response Genes Highly Related to the Severity of Human Adenovirus Type 55 Infection

Human adenovirus type 55 (HAdV-55) is considered a highly virulent pathogen causing severe and even deadly pneumonia in immunocompetent people. The mechanisms of HAdV-55-induced initiation and progression of severe pneumonia remain ambiguous. In the current study, we endeavored to identify novel immune response genes which are substantially involved in the pathogenesis of severe inflammation in HAdV-55-infected patients. HAdV-55-infected patients with upper respiratory tract symptoms (minor patients) and pneumonia (severe patients) were enrolled. Through transcriptome sequencing and quantitative real-time PCR, the peripheral blood mononuclear cells of the patients were analyzed. We found that the expression of eight genes, including Il18, Il36b, Il17rc, Tnfsf10, Tnfsf11, Tnfsf14, Tnfsf15, and Il1a, were closely correlated with the severity of HAdV-55 infection. Most of these genes belong to interleukin-1 family or tumor necrosis factor (TNF) superfamily, respectively. The changes in gene expression were confirmed by Western blot assay. Our data will be crucial for deepening the understanding of the pathogenic mechanisms of severe pneumonia in HAdV-55 infection.

LIGHT-HVEM Signaling in Innate Lymphoid Cell Subsets Protects Against Enteric Bacterial Infection

Innate lymphoid cells (ILCs) are important regulators of early infection at mucosal barriers. ILCs are divided into three groups based on expression profiles, and are activated by cytokines and neuropeptides. Yet, it remains unknown if ILCs integrate other signals in providing protection. We show that signaling through herpes virus entry mediator (HVEM), a member of the tumor necrosis factor (TNF) receptor superfamily, in ILC3 is important for host defense against oral infection with the bacterial pathogen Yersinia enterocolitica. HVEM stimulates protective interferon-γ (IFN-γ) secretion from ILCs, and mice with HVEM-deficient ILC3 exhibit reduced IFN-γ production, higher bacterial burdens and increased mortality. In addition, IFN-γ production is critical as adoptive transfer of wild-type but not IFN-γ-deficient ILC3 can restore protection to mice lacking ILCs. We identify the TNF superfamily member, LIGHT, as the ligand inducing HVEM signals in ILCs. Thus HVEM signaling mediated by LIGHT plays a critical role in regulating ILC3-derived IFN-γ production for protection following infection. VIDEO ABSTRACT.

First Impressions-the Potential of Altering Initial Host-Virus Interactions for Rational Design of Herpesvirus Vaccine Vectors

Purpose

The earliest host-virus interactions occur during virus attachment and entry into cells. These initial steps in the virus lifecycle influence the outcome of infection beyond delivery of the viral genome into the cell. Herpesviruses alter host signaling pathways and processes during attachment and entry to facilitate virus infection and modulate innate immune responses. We suggest in this review that understanding these early signaling events may inform the rational design of therapeutic and prevention strategies for herpesvirus infection, as well as the engineering of viral vectors for immunotherapy purposes.

Recent Findings

Recent reports demonstrate that modulation of Herpes Simplex Virus Type-1 (HSV-1) entry results in unexpected enhancement of antiviral immune responses.

Summary

A variety of evidence suggests that herpesviruses promote specific cellular signaling responses that facilitate viral replication after binding to cell surfaces, as well as during virus entry. Of particular interest is the ability of the virus to alter innate immune responses through these cellular signaling events. Uncovering the underlying immune evasion strategies may lead to the design of live-attenuated vaccines that can generate robust and protective anti-viral immune responses against herpesviruses. These adjuvant properties may be extended to a variety of heterologous antigens expressed by herpesviral vectors.

Herpesvirus Entry Mediator and Ocular Herpesvirus Infection: More than Meets the Eye

As its name suggests, the host receptor herpesvirus entry mediator (HVEM) facilitates herpes simplex virus (HSV) entry through interactions with a viral envelope glycoprotein. HVEM also bridges several signaling networks, binding ligands from both tumor necrosis factor (TNF) and immunoglobulin (Ig) superfamilies with diverse, and often opposing, outcomes. While HVEM was first identified as a viral entry receptor for HSV, it is only recently that HVEM has emerged as an important host factor in immunopathogenesis of ocular HSV type 1 (HSV-1) infection. Surprisingly, HVEM exacerbates disease development in the eye independently of entry. HVEM signaling has been shown to play a variety of roles in modulating immune responses to HSV and other pathogens, and there is increasing evidence that these effects are responsible for HVEM-mediated pathogenesis in the eye. Here, we review the dual branches of HVEM function during HSV infection: entry and immunomodulation. HVEM is broadly expressed; intersects two important immunologic signaling networks; and impacts autoimmunity, infection, and inflammation. We hope that by understanding the complex range of effects mediated by this receptor, we can offer insights applicable to a wide variety of disease states.

Increased BTLA and HVEM in gastric cancer are associated with progression and poor prognosis

Purpose

Deregulation of immune checkpoint molecules by tumor cells is related to immune escape. This study was conducted to investigate the relationship between the appearance of B- and T-lymphocyte attenuator (BTLA) and its ligand herpesvirus entry mediator (HVEM) with the prognosis in gastric cancer patients.

Patients and methods

A total of 136 patients with curative gastrectomy were included. The expression of BTLA and HVEM was detected by immunohistochemistry, and its correlation with the clinical significance of gastric cancer was further analyzed.

Results

The positivity of BTLA and HVEM was detected in 74.3% (101/136) and 89.0% (121/136) of the gastric cancer specimens, respectively. A high expression of BTLA and HVEM was detected, respectively, in 28.7% (39/136) and 44.9% (61/136) of the specimens. Characteristics analysis showed that the high expression of BTLA was significantly associated with lymph node metastasis (P=0.030). Similarly, the high expression of HVEM was also significantly correlated with lymph node metastasis (P=0.007) and depth of invasion (P=0.011). In addition, there was a positive correlation between the expression of BTLA and HVEM in gastric cancer specimens (r=0.245, P=0.004). Univariate analysis revealed that the high expression of BTLA and HVEM was associated with overall survival of patients along with tumor size, Borrmann type, depth of invasion, lymph node metastasis, and histological grade (P<0.05). Multivariate analysis established that the high expression of HVEM (P=0.010), depth of invasion (P=0.001), lymph node metastasis (P<0.001), and histological grade (P=0.027) were independent prognostic factors associated with overall survival in patients with gastric cancer.

Conclusion

The increased BTLA and HVEM levels correlate with the development and poor prognosis of gastric cancer. HVEM is an important prognostic indicator, and BTLA/HVEM pathway is considered to be a promising candidate for immunotherapy of gastric cancer.

Pathogenic Function of Herpesvirus Entry Mediator in Experimental Autoimmune Uveitis by Induction of Th1- and Th17-Type T Cell Responses

Herpesvirus entry mediator (HVEM), a member of the TNFR superfamily, serves as a unique molecular switch to mediate both stimulatory and inhibitory cosignals, depending on its functions as a receptor or ligand interacting with multiple binding partners. In this study, we explored the cosignaling functions of HVEM in experimental autoimmune uveitis (EAU), a mouse model resembling human autoimmune uveitis conditions such as ocular sarcoidosis and Behcet disease. Our studies revealed that EAU severity significantly decreased in HVEM-knockout mice compared with wild-type mice, suggesting that stimulatory cosignals from the HVEM receptor are predominant in EAU. Further studies elucidated that the HVEM cosignal plays an important role in the induction of both Th1- and Th17-type pathogenic T cells in EAU, including differentiation of IL-17-producing αβ(+)γδ(-) conventional CD4(+) T cells. Mice lacking lymphotoxin-like, inducible expression, competes with herpes simplex virus glycoprotein D for HVEM, a receptor expressed by T lymphocytes : LIGHT), B- and T-lymphocyte attenuator (BTLA) or both LIGHT and BTLA are also less susceptible to EAU, indicating that LIGHT-HVEM and BTLA-HVEM interactions, two major molecular pathways mediating HVEM functions, are both important in determining EAU pathogenesis. Finally, blocking HVEM cosignals by antagonistic anti-HVEM Abs ameliorated EAU. Taken together, our studies revealed a novel function of the HVEM cosignaling molecule and its ligands in EAU pathogenesis through the induction of Th1- and Th17-type T cell responses and suggested that HVEM-related molecular pathways can be therapeutic targets in autoimmune uveitis.

HVEM is a TNF Receptor with Multiple Regulatory Roles in the Mucosal Immune System

The herpes virus entry mediator (HVEM) is a member of the tumor necrosis factor receptor superfamily (TNFRSF), and therefore it is also known as TNFRSF14 or CD270 (1,2). In recent years, we have focused on understanding HVEM function in the mucosa of the intestine, particularly on the role of HVEM in colitis pathogenesis, host defense and regulation of the microbiota (2,3,4). HVEM is an unusual TNF receptor because of its high expression levels in the gut epithelium, its capacity to bind ligands that are not members of the TNF super family, including immunoglobulin (Ig) superfamily members BTLA and CD160, and its bi-directional functionality, acting as a signaling receptor or as a ligand for the receptor BTLA. Clinically, Hvem recently was reported as an inflammatory bowel disease (IBD) risk gene as a result of genome wide association studies (5,6). This suggests HVEM could have a regulatory role influencing the regulation of epithelial barrier, host defense and the microbiota. Consistent with this, using mouse models, we have revealed how HVEM is involved in colitis pathogenesis, mucosal host defense and epithelial immunity (3,7). Although further studies are needed, our results provide the fundamental basis for understanding why Hvem is an IBD risk gene, and they confirm that HVEM is a mucosal gatekeeper with multiple regulatory functions in the mucosa.

The Multifaceted Roles of STAT3 Signaling in the Progression of Prostate Cancer

The signal transducer and activator of transcription (STAT)3 governs essential functions of epithelial and hematopoietic cells that are often dysregulated in cancer. While the role for STAT3 in promoting the progression of many solid and hematopoietic malignancies is well established, this review will focus on the importance of STAT3 in prostate cancer progression to the incurable metastatic castration-resistant prostate cancer (mCRPC). Indeed, STAT3 integrates different signaling pathways involved in the reactivation of androgen receptor pathway, stem like cells and the epithelial to mesenchymal transition that drive progression to mCRPC. As equally important, STAT3 regulates interactions between tumor cells and the microenvironment as well as immune cell activation. This makes it a major factor in facilitating prostate cancer escape from detection of the immune response, promoting an immunosuppressive environment that allows growth and metastasis. Based on the multifaceted nature of STAT3 signaling in the progression to mCRPC, the promise of STAT3 as a therapeutic target to prevent prostate cancer progression and the variety of STAT3 inhibitors used in cancer therapies is discussed.

The co-inhibitory pathway and cellular immune imbalance in the progress of HBV infection

OBJECTIVE

Chronic hepatitis B (CHB) affects 400 million people and is the most common cause of liver cirrhosis (LC) and hepatocellular carcinoma (HCC) worldwide. Cellular immune regulation plays an important role in determining the infection outcome. Co-signal molecules and Th17/Treg were studied to explore their association with the progression of HBV infection.

METHODS

Ninety-four HBV-infected patients were categorized into three groups: 31 patients with LC caused by CHB, 30 with HCC caused by CHB and 33 with HCC caused by CHB. Co-signal molecules, Th17/Treg, and Stat3 and Stat5 were analyzed by flow cytometry.

RESULTS

CHB patients who progressed to LC or HCC showed a significantly higher level of co-inhibitory molecules such as BTLA and PD-1, while there was no significant difference in co-stimulatory molecules among LC, HCC and CHB. Stat3 and Stat5 were significantly increased in LC and HCC compared to CHB patients.

CONCLUSION

Co-inhibitory molecules play more important roles than co-stimulatory molecules. Increased PD-1 and BTLA/HVEM inhibited immune cells and the immune process. At the same time activated Stat3 and Stat5 stimulate the key factors in differentiation of Th17 and Treg, thus leading to imbalanced expansion of Th17 and Treg; immune tolerance was induced and HBV persistent. This resulted in hepatic inflammation that progressed to cirrhosis and carcinoma.