Herpes simplex virus type 2 infection of human epithelial cells induces CXCL9 expression and CD4+ T cell migration via activation of p38-CCAAT/enhancer-binding protein-β pathway

Genital Herpes Simplex Virus Infections in Women-A Clinical Update

Genital herpes is a relatively common chronic lower genital tract sexually transmitted infection caused by herpes simplex virus types 1 and 2 (HSV-1 and HSV-2). It is characterized by recurrent, self-limited genital ulcers, and it is the leading cause of genital ulcer disease worldwide (1). The impact of genital herpes on sexual and reproductive health, including the risk of perinatal infection, necessitates a profound understanding of its clinical presentation, diagnosis, treatment, and prevention. This chapter aims to review the critical clinical aspects of HSV in women, emphasizing relevant evidence-based data.

Human Tendon-on-Chip: Unveiling the Effect of Core Compartment-T Cell Spatiotemporal Crosstalk at the Onset of Tendon Inflammation

The lack of representative in vitro models recapitulating human tendon (patho)physiology is among the major factors hindering consistent progress in the knowledge-based development of adequate therapies for tendinopathy.Here, an organotypic 3D tendon-on-chip model is designed that allows studying the spatiotemporal dynamics of its cellular and molecular mechanisms.Combining the synergistic effects of a bioactive hydrogel matrix with the biophysical cues of magnetic microfibers directly aligned on the microfluidic chip, it is possible to recreate the anisotropic architecture, cell patterns, and phenotype of tendon intrinsic (core) compartment. When incorporated with vascular-like vessels emulating the interface between its intrinsic-extrinsic compartments, crosstalk with endothelial cells are found to drive stromal tenocytes toward a reparative profile. This platform is further used to study adaptive immune cell responses at the onset of tissue inflammation, focusing on interactions between tendon compartment tenocytes and circulating T cells.The proinflammatory signature resulting from this intra/inter-cellular communication induces the recruitment of T cells into the inflamed core compartment and confirms the involvement of this cellular crosstalk in positive feedback loops leading to the amplification of tendon inflammation.Overall, the developed 3D tendon-on-chip provides a powerful new tool enabling mechanistic studies on the pathogenesis of tendinopathy as well as for assessing new therapies.

IL-2/GM-CSF enhances CXCR3 expression in CAR-T cells via the PI3K/AKT and ERK1/2 pathways

OBJECTIVE

To investigate the effects of cytokines IL-2 and GM-CSF on CXCR3 expression and chemotaxis of CAR-T cells.

BACKGROUND

High lymphocyte infiltration within the tumor is a basic requirement for good results in tumor immunotherapy; C-X-C motif chemokine receptor 3 (CXCR3) is an important factor for the chemotaxis of lymphocytes to tumor tissues. The tumor microenvironment can exhibit diverse cytokine suppression or promote antitumor immunity. Both interleukin (IL)-2 and granulocyte macrophage colony-stimulating factor (GM-CSF) contribute to the regulation of immunosuppression in the tumor microenvironment. However, the effects of IL-2 and GM-CSF on CXCR3 expression on the T cell surface and its mechanisms are not well understood. Here, we explored the effects of polycytokines on CXCR3 expression in chimeric antigen receptor T cells (CAR-T cells) and on HuH-7 in situ hepatocellular carcinoma.

MATERIALS AND METHODS

Peripheral blood mononuclear cells (PBMCs) were isolated, followed by purifying using CD3 immunomagnetic beads. Cells were divided into three groups. After 24h of activation using CD3/CD28 antibody, T cells were transfected using lentiviral vector, pGC-SV40-EGFP-GPC3-CAR. Three culture methods were used to amplify the transfected T cells. Method 'A' was to incubate T cells with CD3/CD28 antibody; method 'B' was with CD3/CD28 antibody and IL-2 at a final concentration of 1000 U/ml; method 'C' was with method B in addition of GM-CSF at a final concentration of 1000 U/ml. The phosphorylation of MAPK and PI3K/AKT was determined by western blot. The chemotaxis effect of CAR-T cells on Huh-7 HCCIA in situ was assayed by immunofluorescence and immunohistochemistry.

RESULTS

The CD3/CD28/IL-2/GM-CSF combination is the most potent for stimulating activated CAR-T cell proliferation and CXCR3 expression in vitro; CD3/CD28/IL-2 induces CAR-T cell expression of CXCR3 through the activation of the PI3K/APK pathway and GM-CSF induces CXCR3 expression in CAR-T cells through the activation of ERK1/2 rather than the p38 MAPK signaling pathway. CAR-GPC3-T cells with high CXCR3 expression showed increased chemotaxis ability to HuH in situ hepatocellular carcinoma, and considerably inhibited the growth of in situ tumors in nude mouse livers.

CONCLUSION

A multi-factorial amplification protocol can effectively improve CXCR3 expression on the surface of activated CAR-T cells in vitro, as well as enhance the chemotaxis ability of CAR-T cells in vivo, which significantly inhibit the growth of liver cancer.

p38 activation and viral infection

Viruses completely rely on the energy and metabolic systems of host cells for life activities. Viral infections usually lead to cytopathic effects and host diseases. To date, there are still no specific clinical vaccines or drugs against most viral infections. Therefore, understanding the molecular and cellular mechanisms of viral infections is of great significance to prevent and treat viral diseases. A variety of viral infections are related to the p38 MAPK signalling pathway, and p38 is an important host factor in virus-infected cells. Here, we introduce the different signalling pathways of p38 activation and then summarise how different viruses induce p38 phosphorylation. Finally, we provide a general summary of the effect of p38 activation on virus replication. Our review provides integrated data on p38 activation and viral infections and describes the potential application of targeting p38 as an antiviral strategy.

Potential Molecular Mechanisms and Remdesivir Treatment for Acute Respiratory Syndrome Corona Virus 2 Infection/COVID 19 Through RNA Sequencing and Bioinformatics Analysis

Introduction:

Severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) infections (COVID 19) is a progressive viral infection that has been investigated extensively. However, genetic features and molecular pathogenesis underlying remdesivir treatment for SARS-CoV-2 infection remain unclear. Here, we used bioinformatics to investigate the candidate genes associated in the molecular pathogenesis of remdesivir-treated SARS-CoV-2-infected patients.

Methods:

Expression profiling by high-throughput sequencing dataset (GSE149273) was downloaded from the Gene Expression Omnibus, and the differentially expressed genes (DEGs) in remdesivir-treated SARS-CoV-2 infection samples and nontreated SARS-CoV-2 infection samples with an adjusted P value of <.05 and a |log fold change| > 1.3 were first identified by limma in R software package. Next, pathway and gene ontology (GO) enrichment analysis of these DEGs was performed. Then, the hub genes were identified by the NetworkAnalyzer plugin and the other bioinformatics approaches including protein-protein interaction network analysis, module analysis, target gene—miRNA regulatory network, and target gene—TF regulatory network. Finally, a receiver-operating characteristic analysis was performed for diagnostic values associated with hub genes.

Results:

A total of 909 DEGs were identified, including 453 upregulated genes and 457 downregulated genes. As for the pathway and GO enrichment analysis, the upregulated genes were mainly linked with influenza A and defense response, whereas downregulated genes were mainly linked with drug metabolism—cytochrome P450 and reproductive process. In addition, 10 hub genes (VCAM1, IKBKE, STAT1, IL7R, ISG15, E2F1, ZBTB16, TFAP4, ATP6V1B1, and APBB1) were identified. Receiver-operating characteristic analysis showed that hub genes (CIITA, HSPA6, MYD88, SOCS3, TNFRSF10A, ADH1A, CACNA2D2, DUSP9, FMO5, and PDE1A) had good diagnostic values.

Conclusion:

This study provided insights into the molecular mechanism of remdesivir-treated SARS-CoV-2 infection that might be useful in further investigations.

Conserved and breed-specific differences in the cervical transcriptome of sheep with divergent fertility at the follicular phase of a natural oestrus cycle

BACKGROUND

The outcome of cervical artificial insemination (AI) with frozen-thawed semen in sheep is limited by the inability of sperm to traverse the cervix of some ewe breeds. Previous research has demonstrated that cervical sperm transport is dependent on ewe breed, as sperm can traverse the cervix in greater numbers in some higher fertility ewe breeds. However, the molecular mechanisms underlying ewe breed differences in sperm transport through the cervix remain unknown. In this study, we aimed to characterise the cervical transcriptome of four European ewe breeds with known differences in pregnancy rates following cervical AI using frozen-thawed semen at the follicular phase of a natural oestrous cycle. Cervical post mortem tissue samples were collected from two Irish ewe breeds (Belclare and Suffolk; medium and low fertility, respectively) and from two Norwegian ewe breeds (Norwegian White Sheep (NWS) and Fur; high fertility compared to both Irish breeds) at the follicular phase of a natural oestrous cycle (n = 8 to 10 ewes per breed).

RESULTS

High-quality RNA extracted from biopsies of the mid-region of the cervix was analysed by RNA-sequencing and Gene Ontology (GO). After stringent filtering (P <  0.05 and FC > 1.5), a total of 11, 1539 and 748 differentially expressed genes (DEGs) were identified in Belclare, Fur and NWS compared to the low fertility Suffolk breed, respectively. Gene ontology analysis identified significantly enriched biological processes involved in muscle contraction, extracellular matrix (ECM) development and the immune response. Gene co-expression analysis revealed similar patterns in muscle contraction and ECM development modules in both Norwegian ewe breeds, which differed to the Irish ewe breeds.

CONCLUSIONS

These breed-specific biological processes may account for impaired cervical sperm transport through the cervix in sheep during the follicular phase of the reproductive cycle. This novel and comprehensive dataset provides a rich foundation for future targeted initiatives to improve cervical AI in sheep.

Bioinformatics analyses of significant genes, related pathways, and candidate diagnostic biomarkers and molecular targets in SARS-CoV-2/COVID-19

Severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) infection is a leading cause of pneumonia and death. The aim of this investigation is to identify the key genes in SARS-CoV-2 infection and uncover their potential functions. We downloaded the expression profiling by high throughput sequencing of GSE152075 from the Gene Expression Omnibus database. Normalization of the data from primary SARS-CoV-2 infected samples and negative control samples in the database was conducted using R software. Then, joint analysis of the data was performed. Pathway and Gene ontology (GO) enrichment analyses were performed, and the protein-protein interaction (PPI) network, target gene - miRNA regulatory network, target gene - TF regulatory network of the differentially expressed genes (DEGs) were constructed using Cytoscape software. Identification of diagnostic biomarkers was conducted using receiver operating characteristic (ROC) curve analysis. 994 DEGs (496 up regulated and 498 down regulated genes) were identified. Pathway and GO enrichment analysis showed up and down regulated genes mainly enriched in the NOD-like receptor signaling pathway, Ribosome, response to external biotic stimulus and viral transcription in SARS-CoV-2 infection. Down and up regulated genes were selected to establish the PPI network, modules, target gene - miRNA regulatory network, target gene - TF regulatory network revealed that these genes were involved in adaptive immune system, fluid shear stress and atherosclerosis, influenza A and protein processing in endoplasmic reticulum. In total, ten genes (CBL, ISG15, NEDD4, PML, REL, CTNNB1, ERBB2, JUN, RPS8 and STUB1) were identified as good diagnostic biomarkers. In conclusion, the identified DEGs, hub genes and target genes contribute to the understanding of the molecular mechanisms underlying the advancement of SARS-CoV-2 infection and they may be used as diagnostic and molecular targets for the treatment of patients with SARS-CoV-2 infection in the future.

Adenovirus 7 Induces Interlukin-6 Expression in Human Airway Epithelial Cells via p38/NF-κB Signaling Pathway

Human Adenovirus (AdV) infection is very common and usually has a significant impact on children. AdV-induced inflammation is believed to be one of the main causes of severe symptoms. However, an inflammatory response profile in the airway in AdV-infected children is still lacking, and the mechanism underlying AdV-induced inflammation in the airway is also poorly understood. In the current study, we determined the expression of a panel of inflammation cytokines in the airway samples from AdV 7 infected children and further investigated the molecular mechanism underlying AdV 7-induced cytokine expression. Our results showed that eight out of 13 tested inflammatory cytokines were significantly increased in nasal washes of AdV 7-infected children comparing to healthy control, with IL-6 showing the highest enhancement. AdV 7 infection of bronchial epithelial cell line and primary airway epithelial cells confirmed that AdV 7 increased IL-6 mRNA and protein expression in an infection dose-dependent manner. Promoter analysis revealed that AdV 7 infection transactivated IL-6 promoter and a NF-κB binding site in IL-6 promoter was involved in the transactivation. Further analysis showed that upon AdV 7 infection, NF-κB p65 was phosphorylated and translocated into nucleus and bound onto IL-6 promoter. Signaling pathway analysis revealed that p38/NF-κB pathway was involved in AdV 7 infection induced IL-6 elevation. Taken together, our study shows that AdV 7 infection triggers the expression of a range of inflammatory cytokines including IL-6 in the airway of infected children, and AdV 7 enhances IL-6 expression by transactivating IL-6 promoter via p38/NF-κB signaling pathway. Findings of our current study have provided more information toward a better understanding of AdV-induced airway inflammation, which might also benefit the development of intervention strategies.

Equine herpesvirus 1 infection orchestrates the expression of chemokines in equine respiratory epithelial cells

The ancestral equine herpesvirus 1 (EHV1), closely related to human herpes viruses, exploits leukocytes to reach its target organs, accordingly evading the immune surveillance system. Circulating EHV1 strains can be divided into abortigenic/neurovirulent, causing reproductive/neurological disorders. Neurovirulent EHV1 more efficiently recruits monocytic CD172a⁺ cells to the upper respiratory tract (URT), while abortigenic EHV1 tempers monocyte migration. Whether similar results could be expected for T lymphocytes is not known. Therefore, we questioned whether differences in T cell recruitment could be associated with variations in cell tropism between both EHV1 phenotypes, and which viral proteins might be involved. The expression of CXCL9 and CXCL10 was evaluated in abortigenic/neurovirulent EHV1-inoculated primary respiratory epithelial cells (ERECs). The bioactivity of chemokines was tested with a functional migration assay. Replication of neurovirulent EHV1 in the URT resulted in an enhanced expression/bioactivity of CXCL9 and CXCL10, compared to abortigenic EHV1. Interestingly, deletion of glycoprotein 2 resulted in an increased recruitment of both monocytic CD172a⁺ cells and T lymphocytes to the corresponding EREC supernatants. Our data reveal a novel function of EHV1-gp2, tempering leukocyte migration to the URT, further indicating a sophisticated virus-mediated orchestration of leukocyte recruitment to the URT.

Hepatitis B virus upregulates cellular inhibitor of apoptosis protein 2 expression via the PI3K/AKT/NF-κB signaling pathway in liver cancer

Activation of antiapoptotic genes has been indicated as one of the factors that contributes to hepatitis B virus (HBV) infection-induced liver cancer. The cellular inhibitor of apoptosis protein 2 (cIAP2), a member of the IAP family, is upregulated in various types of cancer and serves as a potential treatment target. However, to the best of our knowledge, the importance of cIAP2 in HBV-induced liver cancer has not been investigated. In the present study, cIAP2 expression in liver cells in response to HBV infection and the underlying mechanism involved was investigated. Western blot analysis of clinical liver samples showed that higher cIAP2 expression was detected in HBV-positive non-cancerous tissue compared with that in HBV-negative non-cancerous tissue, and the expression was further increased in HBV-positive liver cancer tissue. Reverse transcription-quantitative PCR and western blot experiments performed on two liver cell lines also confirmed that cIAP2 expression was increased upon HBV infection at both the mRNA and protein levels. Promoter analysis revealed that HBV could activate cIAP2 promoter in an infection dose-dependent manner, and this activation involved a NF-κB-binding site in the cIAP2 promoter. Further analysis demonstrated that HBV enhanced NF-κB phosphorylation and nuclear translocation via the PI3K/AKT signaling pathway, leading to the binding and activation of cIAP2 promoter. The present data demonstrates that HBV-infection induces cIAP2 expression in the liver by activation of the PI3K/AKT/NF-κB signaling pathway through promoting the binding of NF-κB to cIAP2 promoter, which may lead to carcinogenesis. The findings from the present study provide more information for understanding HBV-induced liver cancer and also offer a potential target for treatment or diagnosis of this disease.

HSV-2 Infection of Human Genital Epithelial Cells Upregulates TLR9 Expression Through the SP1/JNK Signaling Pathway

It is known that herpes simplex virus type 2 (HSV-2) triggers the activation of Toll-like receptor (TLR) 9 signaling pathway and the consequent production of antiviral cytokines in dendritic cells. However, the impact of HSV-2 infection on TLR9 expression and signaling in genital epithelial cells, the primary HSV-2 targets, has yet to be determined. In the current study, by using both human genital epithelial cell lines and primary genital epithelial cells as models, we found that HSV-2 infection enhances TLR9 expression at both mRNA and protein levels. Such enhancement is virus replication-dependent and CpG-independent, while the HSV-2-mediated upregulation of TLR9 does not activate TLR9 signaling pathway. Mechanistically, a SP1 binding site on TLR9 promoter appears to be essential for HSV-2-induced TLR9 transactivation. Upon HSV-2 infection, SP1 translocates from the cytoplasm to the nucleus, and consequently binds to TLR9 promoter. By using specific inhibitors, the JNK signaling pathway is shown to be involved in the HSV-2-induced TLR9 transactivation, while HSV-2 infection increases the phosphorylation but not the total level of JNK. In agreement, antagonism of JNK signaling pathway inhibits the HSV-2-induced SP1 nuclear translocation. Taken together, our study demonstrates that HSV-2 infection of human genital epithelial cells promotes TLR9 expression through SP1/JNK signaling pathway. Findings in this study provide insights into HSV-2-host interactions and potential targets for immune intervention.

The combination of CXCL9, CXCL10 and CXCL11 levels during primary HIV infection predicts HIV disease progression

Background

Chemokines are small chemotactic cytokines involved in inflammation, cell migration, and immune regulation in both physiological and pathological contexts. Here, we investigated the profile of chemokines during primary HIV infection (PHI).

Methods

Fifty-four participants with blood samples before and during HIV infection and clinical information available were selected from an HIV-negative man who have sex with men (MSM) prospective cohort. Thirty chemokines and 10 cytokines were measured pre- and post-HIV infection in the same individuals using a Bio-Plex Pro™ Human Chemokine Panel.

Results

Levels of 18 chemokines/cytokines changed significantly during PHI relative to pre-HIV infection levels; 14 were up-regulated and 4 down-regulated. Among them, CXCL9, CXCL10, and CXCL11 were the most prominently raised. Levels of CXCL9 and CXCL10 were much higher in the high-set point group (log viral load (lgVL) ≥ 4.5) than those in the low-set point group (lgVL < 4.5) and levels of CXCL9, CXCL10, and CXCL11 were higher in the low-CD4⁺ T-cell count group (CD4⁺ T-cell count ≥ 500). A formula to predict HIV disease progression using a combination panel comprising CXCL9, CXCL10, and CXCL11 was developed, where risk score = 0.007 × CXCL9 + 0.004 × CXCL10 − 0.033 × CXCL11 − 1.724, with risk score values higher than the cutoff threshold (0.5211) indicating more rapid HIV disease progression.

Conclusions

A panel of plasma CXCL9, CXCL10, and CXCL11 measured during primary HIV-1 infection could predict long-term HIV disease prognosis in an MSM group and has potential as a novel biomarker in the clinic.

Aberrant histone deacetylase 1 expression upregulates vimentin expression via an NF-κB-dependent pathway in hepatocellular carcinoma

Aberrantly elevated expression levels of histone deacetylase 1 (HDAC1) and vimentin are closely associated with disease progression in hepatocellular carcinoma (HCC). It was previously demonstrated that knocking down expression of HDAC1 resulted in a concurrent decrease in the expression levels of vimentin. However, a causal link between these two proteins has not yet been demonstrated, to the best of our knowledge. In the present study, the association between HDAC1 and vimentin was investigated using an HDAC1 overexpression platform. HDAC1 and vimentin were significantly increased in HCC cells, and HDAC1 overexpression enhanced vimentin mRNA and protein expression levels in an HDAC1 dose-dependent manner. Subsequently, truncation and mutation of a vimentin promoter demonstrated that HDAC1-induced vimentin expression was dependent on a nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) binding site in the vimentin promoter sequence. Furthermore, HDAC1 induced vimentin expression by promoting NF-κB translocation between the cytoplasm and the nucleus, as opposed to modulating the total expression level of vimentin directly. The data in the present study demonstrated that HDAC1 is overexpressed in HCC and that HDAC1 may upregulate vimentin expression through the NF-κB signaling pathway, thus demonstrating a causal link between HDAC1 and vimentin in HCC, and may provide valuable information in understanding the pathogenesis of HCC.

Dual monoclonal antibody-based sandwich ELISA for detection of in vitro packaged Ebola virus

Background

Rapid transmission and high mortality of Ebola virus disease (EVD) highlight a urgent need of large scale, convenient and effective measure for Ebola virus screening. Application of monoclonal antibodies (mAbs) are crucial for establishment of an enzyme-linked immunosorbent assay (ELISA) with high sensitivity and specificity.

Methods

The traditional cell fusion technique was used to generate a panel of hybridomas. Two mAbs were characterized by SDS-PAGE, Western blot, Indirect immunofluorescence assay (IFA). A sandwich ELISA was established using the two mAbs. The detection capability of the ELISA was evaluated.

Results

In the current study, we produced two murine-derived mAbs (designated as 6E3 and 3F21) towards Zaire Ebola virus glycoprotein (GP), the major viral transmembrane spike protein associated with viral attachment. It was shown that 6E3 and 3F21 recognized GP1 and GP2 subunits of the GP respectively. Furthermore, 6E3 and 3F21 bound to corresponding epitopes on GP without reciprocal topographical interpretation. Subsequently, a sandwich ELISA based on the two mAbs were established and evaluated. The detection limit was 3.6 ng/ml, with a linear range of 3.6–100 ng/ml. More importantly, Ebola virus like particles (eVLPs) were able to be detected by this established virus detection measure.

Conclusions

We produced and characterized two murine-derived mAbs (designated as 6E3 and 3F21) towards Zaire Ebola virus glycoprotein (GP), and established a sandwich ELISA based on the mAbs. It was suggested that the sandwich ELISA provided an alternative method for specific and sensitive detection of Ebola virus in the field setting.

Herpes Simplex Virus Type 2 Infection-Induced Expression of CXCR3 Ligands Promotes CD4+ T Cell Migration and Is Regulated by the Viral Immediate-Early Protein ICP4

HSV-2 infection-induced CXCR3 ligands are important for the recruitment of virus-specific CD8⁺ T cells, but their impact on CD4⁺ T cell trafficking remains to be further determined. Given that recruitment of CD4⁺ T cells to infection areas may be one of the mechanisms that account for HSV-2 infection-mediated enhancement of HIV-1 sexual transmission, here we investigated the functionality of HSV-2 infection-induced CXCR3 ligands CXCL9, CXCL10, and CXCL11 in vivo and in vitro, and determined the viral components responsive for such induction and the underlying mechanisms. We first found that the expression of CXCR3 ligands CXCL9, CXCL10, and CXCL11 was increased in mice following vaginal challenge with HSV-2, while CXCL9 played a predominant role in the recruitment of CD4⁺ T cells to the vaginal foci of infected mice. HSV-2 infection also induced the production of CXCL9, CXCL10, and CXCL11 in human cervical epithelial cells. Of note, although HSV-2 induced the expression of all the three CXCR3 ligands, the induced CXCL9 appeared to play a predominant role in promoting CD4⁺ T cell migration, reflecting that the concentrations of CXCL10 and CXCL11 required for CD4⁺ T cell migration are higher than that of CXCL9. We further revealed that, ICP4, an immediate-early protein of HSV-2, is crucial in promoting CXCR3 ligand expression through the activation of p38 MAPK pathway. Mechanistically, ICP4 binds to corresponding promoters of CXCR3 ligands via interacting with the TATA binding protein (TBP), resulting in the transcriptional activation of the corresponding promoters. Taken together, our study highlights HSV-2 ICP4 as a vital viral protein in promoting CXCR3 ligand expression and CXCL9 as the key induced chemokine in mediating CD4⁺ T cell migration. Findings in this study have shed light on HSV-2 induced leukocyte recruitment which may be important for understanding HSV-2 infection-enhanced HIV-1 sexual transmission and the development of intervention strategies.

Interleukin-1β induces CXCR3-mediated chemotaxis to promote umbilical cord mesenchymal stem cell transendothelial migration

BACKGROUND

Mesenchymal stem cells (MSCs) are known to home to injured and inflamed regions via the bloodstream to assist in tissue regeneration in response to signals of cellular damage. However, the factors and mechanisms that affect their transendothelial migration are still unclear. In this study, the mechanisms involved in interleukin-1β (IL-1β) enhancing the transendothelial migration of MSCs were investigated.

METHODS

Immunofluorescence staining and Western blotting were used to observe IL-1β-induced CXC chemokine receptor 3 (CXCR3) expression on MSCs. Quantitative real-time PCR and ELISA were used to demonstrate IL-1β upregulated both chemokine (C-X-C motif) ligand 9 (CXCL9) mRNA and CXCL9 ligand secretion in human umbilical vein endothelial cells (HUVECs). Monolayer co-cultivation, agarose drop chemotaxis, and transwell assay were conducted to investigate the chemotaxis invasion and transendothelial migration ability of IL-1β-induced MSCs in response to CXCL9.

RESULTS

In this study, our immunofluorescence staining showed that IL-1β induces CXCR3 expression on MSCs. This result was confirmed by Western blotting. Following pretreatment with protein synthesis inhibitor cycloheximide, we found that IL-1β induced CXCR3 on the surface of MSCs via protein synthesis pathway. Quantitative real-time PCR and ELISA validated that IL-1β upregulated both CXCL9 mRNA and CXCL9 ligand secretion in HUVECs. In response to CXCL9, chemotaxis invasion and transendothelial migration ability were increased in IL-1β-stimulated MSCs. In addition, we pretreated MSCs with CXCR3 antagonist AMG-487 and p38 MAPK inhibitor SB203580 to confirm CXCR3-CXCL9 interaction and the role of CXCR3 in IL-1β-induced chemotaxis invasion and transendothelial migration.

CONCLUSION

We found that IL-1β induces the expression of CXCR3 through p38 MAPK signaling and that IL-1β also enhances CXCL9 ligand secretion in HUVECs. These results indicated that IL-1β promotes the transendothelial migration of MSCs through CXCR3-CXCL9 axis. The implication of the finding could enhance the efficacy of MSCs homing to target sites.

Infectivity and growth kinetics of Herpes Simplex Virus type-2 in MOLT4 CCR5+ and CEM CCR5+ T cell lines

Herpes simplex virus type-2 (HSV-2) is an important sexually transmitted pathogen that infects the genital mucosal epithelial cells causing ulcerative lesions at the site of entry, facilitating HIV infection. The infection of epithelial cells and skin resident dendritic cells with HSV-2 causes a release of chemokine and retinoic acid which attracts CD4⁺ T-cells to the genital mucosa. In this study, we investigated whether HSV-2 (ATCC VR734) could infect and replicate in two T-cell lines (CEM CCR5+ and MOLT4 CCR5+). The growth of HSV-2 was assessed by plaque assay while the intracellular HSV-2 was identified using infectious center and indirect immunofluorescence assays. The replication of HSV-2 in T-cell lines was compared to a cell line (Vero) which is routinely used for growing HSV-2. Analysis indicated that a low level of infection was detected in the two T-cells lines and was dependent on the infectious dose as well as the time of adsorption. Indirect immunofluorescence showed presence of HSV-2 antigens in the CEM CCR5+ and Vero cell lines but not in MOLT4 CCR5+. The data suggests that T-cells can support growth of HSV-2 which might contribute to changes in gene expression of T-cells. This is an important aspect that needs to be further investigated in relation of HIV-1/HSV-2 viral synergy.

Speckle-Type POZ Protein Down-Regulates Matrix Metalloproteinase 2 Expression via Sp1/PI3K/Akt Signaling Pathway in Colorectal Cancer

BACKGROUND

Elevated expression of matrix metalloproteinases (MMPs) is correlated with invasion and metastasis of colorectal cancer (CRC). Recently, a previous study has suggested that speckle-type POZ protein (SPOP) could inhibit cancer cell proliferation and migration through down-regulation of MMP2 and MMP7, with a mechanism remaining unknown.

AIM

In this study, we, by using both CRC cells and normal colorectal cells, aimed to investigate the causal relationship between SPOP and MMP2, as well as the potential signaling pathways.

METHODS

The causal relationship between SPOP and MMP2 was determined by both RT-PCR and Western blot in cells with SPOP expression or siRNA interference. The signaling pathway involved in MMP2 down-regulation by SPOP was subsequently identified by determination on the expression and phosphorylation of key signaling pathway proteins. Transcription factor involving in this MMP2 regulation was identified by determination on expression, phosphorylation, and nuclear translocation of key transcription factors.

RESULTS

SPOP overexpression could significantly decrease MMP2 expression, while the knockdown of SPOP, in contrast, resulted in enhanced MMP2 level. Measurement of expression and phosphorylation of key signaling pathway proteins revealed that SPOP could inhibit PI3K and p-Akt level. Further tests on transcription factors showed that SPOP could inhibit SP1 phosphorylation and nuclear translocation.

CONCLUSIONS

SPOP could down-regulate MMP2 expression in CRC, and this regulation is mediated by inhibiting SP1 phosphorylation and nuclear translocation through PI3K/Akt signaling pathway. Our findings in this study provide understanding of MMP2 regulation in CRC and may also shed lights on the development of anti-CRC treatments.

Serum Cytokine Profiles in Patients with Dengue Fever at the Acute Infection Phase

Background

Dengue virus (DENV) is transmitted by mosquito and has been circulating in Guangdong, China, for over 30 years. Dengue infection causes mild to severe disease symptoms in human. Cytokine profiles were suggested to be crucial especially during the acute stage in the dengue infection.

Aim

To determine the cytokine profiles at the acute stage in patients with primary or secondary dengue infection in Guangzhou city in the 2014 outbreak.

Methods

We investigated 23 inflammatory cytokines in serum collected from dengue-infected patients and analyzed their correlations with their clinical indexes.

Results

The concentrations of CXCL9, IP-10, CXCL11, IL-8, IL-10, and CCL2 in serum were significantly higher in the groups of DENV-infected patients during the first two weeks than those of control group while CCL17 and CXCL5 showed lower expression level in the patients. Among these cytokines, CXCL9, CCL17, and CXCL5 showed statistical difference between the groups of primary and secondary infections. The platelet count and lactate dehydrogenase were correlated with the level of CCL17 and MIP-1α/CXCL5, respectively, in the group of secondary infection.

Conclusions

We determined the cytokine profiles in serum of the patients during the 2014 dengue outbreak. The expression of specific cytokines was associated with the secondary infection.

Virtual Sorting Has a Distinctive Advantage in Identification of Anticorrelated Genes and Further Negative Regulators of Immune Cell Subpopulations

Immune cells are highly plastic in both gene expression and cell phenotype. We have established a method of gene expressional plasticity and virtual sorting to evaluate immune cell subpopulations and their characteristic genes in human CD4⁺ T cells. In this study, we continued to investigate the informatics mechanism on the effectiveness of virtual sorting. We found that virtual sorting had an overall positive correlation to the Pearson correlation in the identification of positively correlated genes. However, owing to nonlinear biological anticorrelation, virtual sorting showed a distinctive advantage for anticorrelated genes, suggesting an important role in the identification of negative regulators. In addition, based on virtual sorting results, we identified two basic gene sets among highly plastic genes, i.e., highly plastic cell cycle-associated molecules and highly plastic immune and defense response-associated molecules. Genes within each set tended to be positively connected, but genes between two sets were often anticorrelated. Further analysis revealed preferential transcription factor binding motifs existed between highly plastic cell cycle-associated molecules and highly plastic immune and defense response-associated molecules. Our results strongly suggested predetermined regulation, which was called an immune cell internal phenotype, should exist and could be mined by virtual sorting analysis. This provided efficient functional clues to study immune cell phenotypes and their regulation. Moreover, the current substantial virtual sorting results in both CD4⁺ T cells and B cells provide a useful resource for big-data-driven experimental studies and knowledge discoveries.

Ex vivo 2D and 3D HSV-2 infection model using human normal vaginal epithelial cells

Herpes simplex virus type 2 (HSV-2) infects human genital mucosa and establishes life-long latent infection. It is unmet need to establish a human cell-based microphysiological system for virus biology and anti-viral drug discovery. One of barriers is lacking of culture system of normal epithelial cells in vitro over decades. In this study, we established human normal vaginal epithelial cell (HNVEC) culture using co-culture system. HNVEC cells were then propagated rapidly and stably in a defined culture condition. HNVEC cells exhibited a normal diploid karyotype and formed the well-defined and polarized spheres in matrigel three-dimension (3D) culture, while malignant cells (HeLa) formed disorganized and nonpolar solid spheres. HNVEC cells had a normal cellular response to DNA damage and had no transforming property using soft agar assays. HNVEC expressed epithelial marker cytokeratin 14 (CK14) and p63, but not cytokeratin 18 (CK18). Next, we reconstructed HNVEC-derived 3D vaginal epithelium using air-liquid interface (ALI) culture. This 3D vaginal epithelium has the basal and apical layers with expression of epithelial markers as its originated human vaginal tissue. Finally, we established an HSV-2 infection model based on the reconstructed 3D vaginal epithelium. After inoculation of HSV-2 (G strain) at apical layer of the reconstructed 3D vaginal epithelium, we observed obvious pathological effects gradually spreading from the apical layer to basal layer with expression of a viral protein. Thus, we established an ex vivo 2D and 3D HSV-2 infection model that can be used for HSV-2 virology and anti-viral drug discovery.

Interaction between herpesvirus entry mediator and HSV-2 glycoproteins mediates HIV-1 entry of HSV-2-infected epithelial cells

Herpes simplex virus type 2 (HSV-2) increases human immunodeficiency virus type 1 (HIV-1) acquisition and transmission via unclear mechanisms. Herpesvirus entry mediator (HVEM), an HSV-2 entry receptor, is highly expressed on HIV-1 target cells (CD4+ T cells) and may be incorporated into HIV-1 virions, while HSV-2 glycoproteins can be present on the infected cell surface. Since HVEM-gD interaction together with gB/gH/gL is essential for HSV-2 entry, HVEM-bearing HIV-1 (HIV-1/HVEM) may enter HSV-2-infected cells through such interactions. To test this hypothesis, we first confirmed the presence of HVEM on HIV-1 virions and glycoproteins on the HSV-2-infected cell surface. Additional studies showed that HIV-1/HVEM bound to the HSV-2-infected cell surface in an HSV-2 infection-time-dependent manner via HVEM-gD interaction. HIV-1/HVEM entry of HSV-2-infected cells was dependent on HVEM-gD interaction and the presence of gB/gH/gL, and was inhibited by azidothymidine. Furthermore, peripheral blood mononuclear cell-derived HIV-1 infected HSV-2-infected primary foreskin epithelial cells and the infection was inhibited by anti-HVEM/gD antibodies. Together, our results indicate that HIV-1 produced from CD4+ T cells bears HSV-2 receptor HVEM and can bind to and enter HSV-2-infected epithelial cells depending on HVEM-gD interaction and the presence of gB/gH/gL. Our findings provide a potential new mechanism underlying HSV-2 infection-enhanced HIV-1 mucosal transmission and may shed light on HIV-1 prevention.

Degradable bioadhesive nanoparticles for prolonged intravaginal delivery and retention of elvitegravir

New methods for long-lasting protection against sexually transmitted disease, such as the human immunodeficiency virus (HIV), are needed to help reduce the severity of STD epidemics, especially in developing countries. Intravaginal delivery of therapeutics has emerged as a promising strategy to provide women with local protection, but residence times of such agents are greatly reduced by the protective mucus layer, fluctuating hormone cycle, and complex anatomical structure of the reproductive tract. Polymeric nanoparticles (NPs) capable of encapsulating the desired cargo, penetrating through the mucosal surfaces, and delivering agents to the site of action have been explored. However, prolonged retention of polymer carriers and their enclosed materials may also be needed to ease adherence and confer longer-lasting protection against STDs. Here, we examined the fate of two poly (lactic acid)-hyperbranched polyglycerols (PLA-HPG) NP formulations - 1) nonadhesive PLA-HPG NPs (NNPs) and 2) surface-modified bioadhesive NPs (BNPs) - loaded with the antiretroviral elvitegravir (EVG) after intravaginal administration. BNP distribution was widespread throughout the reproductive tract, and retention was nearly 5 times higher than NNPs after 24 h. Moreover, BNPs were found to be highly associated with submucosal leukocytes and epithelial cell populations for up to 48 h after topical application, and EVG was retained significantly better in the vaginal lumen when delivered with BNPs as opposed to NNPs over a 24 h period. Our results suggest that bioadhesive PLA-HPG NPs can greatly improve and prolong intravaginal delivery of agents, which may hold potential in providing sustained protection over longer durations.

Progesterone augments cell susceptibility to HIV-1 and HIV-1/HSV-2 co-infections

In human immunodeficiency virus type 1 (HIV-1)-infected women, oral or injectable progesterone containing contraceptive pills may enhance HIV-1 acquisition in vivo, and the mechanism by which this occurs is not fully understood. In developing countries, Herpes simplex virus type-2 (HSV-2) co-infection has been shown to be a risk for increase of HIV-1 acquisition and, if co-infected women use progesterone pills, infections may increase several fold. In this study, we used an in vitro cell culture system to study the effects of progesterone on HIV-1 replication and to explore the molecular mechanism of progesterone effects on infected cells. In our in vitro model, CEMss cells (lymphoblastoid cell line) were infected with either HIV-1 alone or co-infected with HSV-2. HIV-1 viral load was measured with and without sex hormone treatment. Progesterone-treated cells showed an increase in HIV-1 viral load (1411.2 pg/mL) compared with cells without progesterone treatment (993.1 pg/mL). Increased cell death was noted with HSV-2 co-infection and in progesterone-treated cells. Similar observations were noted in peripheral blood mononuclear cells (PBMC) cells derived from three female donors. Progesterone-treated cells also showed reduced antiviral efficacy. Inflammatory cytokines and associations with biomarkers of disease progression were explored. Progesterone upregulated inflammatory cytokines and chemokines conversely and downregulated anti-apoptotic Bcl-2 expression. Nuclear protein analysis by electrophoretic mobility shift assay showed the association of progesterone with progesterone response element (PRE), which may lead to downregulation of Bcl-2. These data indicate that progesterone treatment enhances HIV-1 replication in infected cells and co-infection with HSV-2 may further fuel this process.

Interventions for men and women with their first episode of genital herpes

BACKGROUND

Genital herpes is incurable, and is caused by the herpes simplex virus (HSV). First-episode genital herpes is the first clinical presentation of herpes that a person experiences. Current treatment is based around viral suppression in order to decrease the length and severity of the episode.

OBJECTIVES

To determine the effectiveness and safety of the different existing treatments for first-episode genital herpes on the duration of symptoms and time to recurrence.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (from inception to April 2016), MEDLINE (from inception to April 2016), the Specialised Register of the Cochrane Sexually Transmitted Infections Review Group (from inception to April 2016), EMBASE (from inception to April 2016), PsycINFO (from inception to April 2016), CINAHL (from inception to April 2016), LILACS (from inception to April 2016), AMED (from inception to April 2016), and the Alternative Medicines Specialised Register (from inception to April 2016). We handsearched a number of relevant journals, searched reference lists of all included studies, databases of ongoing trials, and other Internet databases.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) on participants with first-episode genital herpes. We excluded vaccination trials, and trials in which the primary objective assessed a complication of HSV infection.

DATA COLLECTION AND ANALYSIS

All studies written in English were independently assessed by at least two review authors for inclusion, risk of bias for each trial, and to extract data. Studies requiring translation were assessed for inclusion, trial quality, and data extraction by external translators.

MAIN RESULTS

We included 26 trials with 2084 participants analysed. Most of the studies were conducted in the United Kingdom (UK) and United States (US), and involved men and women experiencing their first episode of genital herpes, with the exception of three studies which included only women. We rated the majority of these studies as having an unclear risk of bias; largely due to lack of information supplied in the publications, and due to the age of the trials. This review found low quality evidence from two studies of oral acyclovir, when compared to placebo, reduced the duration of symptoms in individuals undergoing their first episode of genital herpes (mean difference (MD) -3.22, 95% confidence interval (CI) -5.91 to -0.54; I(2) = 52%). In two studies (112 participants), intravenous acyclovir decreased the median number of days that patients with first-episode herpes suffered symptoms. Oral valaciclovir (converted to acyclovir) also showed a similar length of symptom duration when compared to acyclovir in two studies.There is currently no evidence that topical acyclovir reduces symptoms (MD -0.61 days, 95% CI -2.16 to 0.95; 3 RCTs, 195 participants, I(2) statistic = 56%). There is also no current evidence that the topical treatments of cicloxolone cream, carbenoxolone sodium cream, adenosine arabinoside, idoxuridine in dimethyl sulfoxide, when compared to placebo reduced the duration of symptoms in people undergoing their first episode of herpes.Two studies reported no evidence of a reduction in the number of median days to recurrence following treatment with oral acyclovir versus placebo. Adverse events were generally poorly reported by all of the included studies and we were unable to quantitatively analyse this outcome. For those taking acyclovir, there were no serious adverse events; the most common adverse events reported for oral acyclovir were coryza, dizziness, tiredness, diarrhoea and renal colic. For intravenous acyclovir these were phlebitis, nausea and abnormal liver function tests and for topical acyclovir there was pain with the topical application.Those undergoing interferon treatment had significantly more adverse events compared to those taking placebo.

AUTHORS' CONCLUSIONS

There is low quality evidence from this review that oral acyclovir reduced the duration of symptoms for genital herpes. However, there is low quality evidence which did not show that topical antivirals reduced symptom duration for patients undergoing their first episode of genital herpes. This review was limited by the inclusion of skewed data, resulting in few trials that we were able to meta-analyse.

Blocking CXCL9 Decreases HIV-1 Replication and Enhances the Activity of Prophylactic Antiretrovirals in Human Cervical Tissues

OBJECTIVES

The interferon-gamma-induced chemokine CXCL9 is expressed in a wide range of inflammatory conditions including those affecting the female genital tract. CXCL9 promotes immune cell recruitment, activation, and proliferation. The role of CXCL9 in modulating HIV-1 infection of cervicovaginal tissues, a main portal of viral entry, however, has not been established. We report a link between CXCL9 and HIV-1 replication in human cervical tissues and propose CXCL9 as a potential target to enhance the anti-HIV-1 activity of prophylactic antiretrovirals.

DESIGN

Using ex vivo infection of human cervical tissues as a model of mucosal HIV-1 acquisition, we described the effect of CXCL9 neutralization on HIV-1 gene expression and mucosal CD4 T-cell activation. The anti-HIV-1 activity of tenofovir, the leading mucosal pre-exposure prophylactic microbicide, alone or in combination with CXCL9 neutralization was also studied.

METHODS

HIV-1 replication was evaluated by p24 ELISA. HIV-1 DNA and RNA, and CD4, CCR5, and CD38 transcription were evaluated by quantitative real-time polymerase chain reaction. Frequency of activated cervical CD4 T cells was quantified using fluorescence-activated cell sorting.

RESULTS

Antibody blocking of CXCL9 reduced HIV-1 replication by decreasing mucosal CD4 T-cell activation. CXCL9 neutralization in combination with suboptimal concentrations of tenofovir, possibly present in the cervicovaginal tissues of women using the drug inconsistently, demonstrated an earlier and greater decrease in HIV-1 replication compared with tissues treated with tenofovir alone.

CONCLUSIONS

CXCL9 neutralization reduces HIV-1 replication and may be an effective target to enhance the efficacy of prophylactic antiretrovirals.

Piracy on the molecular level: human herpesviruses manipulate cellular chemotaxis

Cellular chemotaxis is important to tissue homeostasis and proper development. Human herpesvirus species influence cellular chemotaxis by regulating cellular chemokines and chemokine receptors. Herpesviruses also express various viral chemokines and chemokine receptors during infection. These changes to chemokine concentrations and receptor availability assist in the pathogenesis of herpesviruses and contribute to a variety of diseases and malignancies. By interfering with the positioning of host cells during herpesvirus infection, viral spread is assisted, latency can be established and the immune system is prevented from eradicating viral infection.

Pedilanthus tithymaloides Inhibits HSV Infection by Modulating NF-κB Signaling

Pedilanthus tithymaloides (PT), a widely used ethnomedicinal plant, has been employed to treat a number of skin conditions. To extend its utility and to fully exploit its medicinal potential, we have evaluated the in vitro antiviral activity of a methanolic extract of PT leaves and its isolated compounds against Herpes Simplex Virus type 2 (HSV-2). Bioactivity-guided studies revealed that the extract and one of its constituents, luteolin, had potent antiviral activity against wild-type and clinical isolates of HSV-2 (EC₅₀ 48.5–52.6 and 22.4–27.5 μg/ml, respectively), with nearly complete inhibition at 86.5–101.8 and 40.2–49.6 μg/ml, respectively. The inhibitory effect was significant (p<0.001) when the drug was added 2 h prior to infection, and was effective up to 4 h post-infection. As viral replication requires NF-κB activation, we examined whether the observed extract-induced inhibition of HSV-2 was related to NF-κB inhibition. Interestingly, we observed that treatment of HSV-2-infected cells with extract or luteolin suppressed NF-κB activation. Although NF-κB, JNK and MAPK activation was compromised during HSV replication, neither the extract nor luteolin affected HSV-2-induced JNK1/2 and MAPK activation. Moreover, the PT leaf extract and luteolin potently down-regulated the expression of tumor necrosis factor (TNF)-α, Interleukin (IL)-1β, IL-6, NO and iNOS and the production of gamma interferon (IFN-γ), which are directly involved in controlling the NF-κB signaling pathway. Thus, our results indicate that both PT leaf extract and luteolin modulate the NF-κB signaling pathway, resulting in the inhibition of HSV-2 replication.

Herpes Simplex Virus: The Interplay Between HSV, Host, and HIV-1

Herpes simplex virus proteins interact with host (human) proteins and create an environment conducive for its replication. Genital ulceration due to herpes simplex virus type 2 (HSV-2) infections is an important clinical manifestation reported to increase the risk of human immunodeficiency virus type 1 (HIV-1) acquisition and replication in HIV-1/HSV-2 coinfection. Dampening the innate and adaptive immune responses of the skin-resident dendritic cells, HSV-2 not only helps itself, but creates a "yellow brick road" for one of the most dreaded viruses HIV, which is transmitted mainly through the sexual route. Although, data from clinical trials show that HSV-2 suppression reduces HIV-1 viral load, there are hardly any reports presenting conclusive evidence on the impact of HSV-2 coinfection on HIV-1 disease progression. Be that as it may, understanding the interplay between these three characters (HSV, host, and HIV-1) is imperative. This review endeavors to collate studies on the influence of HSV-derived proteins on the host response and HIV-1 replication. Studying such complex interactions may help in designing and developing common strategies for the two viruses to keep these "partners in crime" at bay.

Contribution of N-linked glycans on HSV-2 gB to cell-cell fusion and viral entry

HSV-2 is the major cause of genital herpes and its infection increases the risk of HIV-1 acquisition and transmission. HSV-2 glycoprotein B together with glycoproteins D, H and L are indispensable for viral entry, of which gB, as a class III fusogen, plays an essential role. HSV-2 gB has seven potential N-linked glycosylation (N-CHO) sites, but their significance has yet to be determined. For the first time, we systematically analyzed the contributions of N-linked glycans on gB to cell-cell fusion and viral entry. Our results demonstrated that, of the seven potential N-CHO sites on gB, mutation at N390, N483 or N668 decreased cell-cell fusion and viral entry, while mutation at N133 mainly affected protein expression and the production of infectious virus particles by blocking the transport of gB from the endoplasmic reticulum to Golgi. Our findings highlight the significance of N-linked glycans on HSV-2 gB expression and function.

Evasion of early antiviral responses by herpes simplex viruses

Besides overcoming physical constraints, such as extreme temperatures, reduced humidity, elevated pressure, and natural predators, human pathogens further need to overcome an arsenal of antimicrobial components evolved by the host to limit infection, replication and optimally, reinfection. Herpes simplex virus-1 (HSV-1) and herpes simplex virus-2 (HSV-2) infect humans at a high frequency and persist within the host for life by establishing latency in neurons. To gain access to these cells, herpes simplex viruses (HSVs) must replicate and block immediate host antiviral responses elicited by epithelial cells and innate immune components early after infection. During these processes, infected and noninfected neighboring cells, as well as tissue-resident and patrolling immune cells, will sense viral components and cell-associated danger signals and secrete soluble mediators. While type-I interferons aim at limiting virus spread, cytokines and chemokines will modulate resident and incoming immune cells. In this paper, we discuss recent findings relative to the early steps taking place during HSV infection and replication. Further, we discuss how HSVs evade detection by host cells and the molecular mechanisms evolved by these viruses to circumvent early antiviral mechanisms, ultimately leading to neuron infection and the establishment of latency.

HSV-2 immediate-early protein US1 inhibits IFN-β production by suppressing association of IRF-3 with IFN-β promoter

HSV-2 is the major cause of genital herpes, and its infection increases the risk of HIV-1 acquisition and transmission. After initial infection, HSV-2 can establish latency within the nervous system and thus maintains lifelong infection in humans. It has been suggested that HSV-2 can inhibit type I IFN signaling, but the underlying mechanism has yet to be determined. In this study, we demonstrate that productive HSV-2 infection suppresses Sendai virus (SeV) or polyinosinic-polycytidylic acid-induced IFN-β production. We further reveal that US1, an immediate-early protein of HSV-2, contributes to such suppression, showing that US1 inhibits IFN-β promoter activity and IFN-β production at both mRNA and protein levels, whereas US1 knockout significantly impairs such capability in the context of HSV-2 infection. US1 directly interacts with DNA binding domain of IRF-3, and such interaction suppresses the association of nuclear IRF-3 with the IRF-3 responsive domain of IFN-β promoter, resulting in the suppression of IFN-β promoter activation. Additional studies demonstrate that the 217-414 aa domain of US1 is critical for the suppression of IFN-β production. Our results indicate that HSV-2 US1 downmodulates IFN-β production by suppressing the association of IRF-3 with the IRF-3 responsive domain of IFN-β promoter. Our findings highlight the significance of HSV-2 US1 in inhibiting IFN-β production and provide insights into the molecular mechanism by which HSV-2 evades the host innate immunity, representing an unconventional strategy exploited by a dsDNA virus to interrupt type I IFN signaling pathway.

Herpes simplex virus enhances chemokine function through modulation of receptor trafficking and oligomerization

Glycoprotein G (gG) from herpes simplex virus 1 and 2 (HSV-1 and HSV-2, important human neurotropic pathogens) is the first viral chemokine-binding protein found to potentiate chemokine function. Here we show that gG attaches to cell surface glycosaminoglycans and induces lipid raft clustering, increasing the incorporation of CXCR4 receptors into these microdomains. gG induces conformational rearrangements in CXCR4 homodimers and changes their intracellular partners, leading to sustained, functional chemokine/receptor complexes at the surface. This results in increased chemotaxis dependent on the cholesterol content of the plasma membrane and receptor association to Src-kinases and phosphatidylinositol-3-kinase signalling pathways, but independent of clathrin-mediated endocytosis. Furthermore, using electron microscopy, we show that such enhanced functionality is associated with the accumulation of low-order CXCR4 nanoclusters. Our results provide insights into basic mechanisms of chemokine receptor function and into a viral strategy of immune modulation.

Hedgehog pathway inhibitors promote adaptive immune responses in basal cell carcinoma

PURPOSE

Basal cell carcinomas (BCCs) are tumors ignored by immune surveillance. Activated Hedgehog (Hh) signaling within primary cilia is a key driver in the pathogenesis of BCCs. We examined immune alterations during treatment with systemic Hh inhibitors.

EXPERIMENTAL DESIGN

We investigated biopsies from patients with BCC before (23 patients) and after 4 weeks of treatment (5 patients) with Hh signaling inhibitor. Ber-Ep4, BCL-2, Ki-67, CD4, CD8, MHC class I, HLA-DR-class II, and SOX9 were analyzed by immunohistochemistry. Primary cilia were analyzed by double immunofluorescence of acetylated tubulin and SOX9. Differential gene expression for 84 cytokines and chemokines was analyzed in 3 patients.

RESULTS

After 4 weeks of treatment, we found reduction of Ki-67, SOX9, Ber-EP4, and BCL-2 expression in tumors associated with morphologic signs of squamous differentiation. In addition, the number of cilia-positive BCC cells was significantly decreased. An upregulation of MHC I expression on the cell membranes of residual tumor cells and an influx of CD4(+), HLA-DR-class II(+), and CD8(+) cells with invasion into the tumor cell nests were found. Finally, qPCR arrays showed the differential expression of genes involved in modulating immune responses.

CONCLUSIONS

We show that Hh pathway inhibitor-induced tumor regression is accompanied by a dynamic change of the microenvironment with a disruption of immune privilege involving an influx of cytotoxic T cells, activation of the adaptive immune functions, and a profound alteration of the local chemokine/cytokine network.

Tetherin restricts HSV-2 release and is counteracted by multiple viral glycoproteins

Tetherin has been defined as a restriction factor of HIV-1 and several other enveloped viruses. However, the significance of tetherin in viral infection remains to be further addressed. Here, we investigated whether tetherin plays a role in HSV-2 infection. Our study revealed that overexpression of tetherin restricted the release of HSV-2 into the extracellular medium, while knockdown of tetherin by siRNA enhanced its release. We further demonstrated that HSV-2 infection and viral glycoproteins gB, gD, gH and gL but not gM significantly downregulated the endogenous expression of tetherin. Additional study indicated that tetherin likely physically interacted with gB, gD, gH and gL. This is the first time that tetherin has been shown to be counteracted by multiple viral components of a virus. Our findings inform the complexity of HSV-2-host interactions, providing basis for understanding the role of tetherin as a viral restriction factor and the mechanisms underlying viral countermeasures.

Herpes simplex virus type-2 stimulates HIV-1 replication in cervical tissues: implications for HIV-1 transmission and efficacy of anti-HIV-1 microbicides

Herpes Simplex virus Type-2 (HSV-2) increases the risk of HIV-1 acquisition, yet the mechanism for this viral pathogen to regulate the susceptibility of the cervicovaginal mucosa to HIV-1 is virtually unknown. Using ex vivo human ectocervical tissue models, we report greater levels of HIV-1 reverse transcription, DNA integration, RNA expression, and virions release in HIV-1/HSV-2 co-infected tissues compared with HIV-1 only infected tissues (P<0.05). Enhanced HIV-1 replication was associated with increased CD4, CCR5, and CD38 transcription (P<0.05) and increased number of CD4(+)/CCR5(+)/CD38(+) T cells in HIV-1/HSV-2 co-infected tissues compared with tissues infected with HIV-1 alone. Tenofovir (TFV) 1% gel, the leading microbicide candidate, demonstrated only partial protection against HIV-1, when applied vaginally before and after sexual intercourse. It is possible that mucosal inflammation, in particular that induced by HSV-2 infection, may have decreased TFV efficacy. HSV-2 upregulated the number of HIV-1-infected cells and elevated the concentration of TFV needed to decrease HIV-1 infection. Similarly, only high concentrations of TFV inhibited HSV-2 replication in HIV-1/HSV-2-infected tissues. Thus, HSV-2 co-infection and mucosal immune cell activation should be taken into consideration when designing preventative strategies for sexual transmission of HIV-1.

Mucosal resident memory CD4 T cells in protection and immunopathology

Tissue-resident memory T cells (TRM) comprise a newly defined subset, which comprises a major component of lymphocyte populations in diverse peripheral tissue sites, including mucosal tissues, barrier surfaces, and in other non-lymphoid and lymphoid sites in humans and mice. Many studies have focused on the role of CD8 TRM in protection; however, there is now accumulating evidence that CD4 TRM predominate in tissue sites, and are integral for in situ protective immunity, particularly in mucosal sites. New evidence suggests that mucosal CD4 TRM populations differentiate at tissue sites following the recruitment of effector T cells by local inflammation or infection. The resulting TRM populations are enriched in T-cell specificities associated with the inducing pathogen/antigen. This compartmentalization of memory T cells at specific tissue sites may provide an optimal design for future vaccination strategies. In addition, emerging evidence suggests that CD4 TRM may also play a role in immunoregulation and immunopathology, and therefore, targeting TRM may be a viable therapeutic approach to treat inflammatory diseases in mucosal sites. This review will summarize our current understanding of CD4 TRM in diverse tissues, with an emphasis on their role in protective immunity and the mechanisms by which these populations are established and maintained in diverse mucosal sites.

A dihydro-pyrido-indole potently inhibits HSV-1 infection by interfering the viral immediate early transcriptional events

In our continued quest for identifying novel molecules from ethnomedicinal source we have isolated an alkaloid 7-methoxy-1-methyl-4,9-dihydro-3H-pyrido[3,4-b]indole, also known as Harmaline (HM), from an ethnomedicinal herb Ophiorrhiza nicobarica. The compound exhibited a potent anti-HSV-1 activity against both wild type and clinical isolates of HSV-1. Further we demonstrated that HM did not interfere in viral entry but the recruitment of lysine-specific demethylase-1 (LSD1) and the binding of immediate-early (IE) complex on ICP0 promoter. This leads to the suppression of viral IE gene synthesis and thereby the reduced expression of ICP4 and ICP27. Moreover, HM at its virucidal concentration is nontoxic and reduced virus yields in cutaneously infected Balb/C mice. Thus, the interference in the binding of IE complex, a decisive factor for HSV lytic cycle or latency by HM reveals an interesting target for developing non-nucleotide antiherpetic agent with different mode of action than Acyclovir.

Activator Protein 1 transcription factor Fos-related antigen 1 (Fra-1) is dispensable for murine liver fibrosis, but modulates xenobiotic metabolism

The Activator Protein 1 (AP-1) transcription factor subunit Fos-related antigen 1 (Fra-1) has been implicated in liver fibrosis. Here we used loss-of-function as well as switchable, cell type-specific, gain-of-function alleles for Fra-1 to investigate the relevance of Fra-1 expression in cholestatic liver injury and fibrosis. Our results indicate that Fra-1 is dispensable in three well-established, complementary models of liver fibrosis. However, broad Fra-1 expression in adult mice results in liver fibrosis, which is reversible, when ectopic Fra-1 is switched off. Interestingly, hepatocyte-specific Fra-1 expression is not sufficient to trigger the disease, although Fra-1 expression leads to dysregulation of fibrosis-associated genes. Both opn and cxcl9 are controlled by Fra-1 in gain-of-function and loss-of-function experiments. Importantly, Fra-1 attenuates liver damage in the 3,5-diethoxycarbonyl-1,4-dihydrocollidine-feeding cholestatic liver injury model. Strikingly, manipulating Fra-1 expression affects genes involved in hepatic transport and detoxification, in particular glutathione S-transferases. Molecular analyses indicate that Fra-1 binds to the promoters of cxcl9 and gstp1 in vivo. Furthermore, loss of Fra-1 sensitizes, while hepatic Fra-1 expression protects from acetaminophen-induced liver damage, a paradigm for glutathione-mediated acute liver failure.

CONCLUSION

These data define a novel function of Fra-1/AP-1 in modulating the expression of detoxification genes and the adaptive response of the liver to bile acids/xenobiotic overload.

Proinflammatory cytokines and chemokines - but not interferon-β - produced in response to HSV-2 in primary human genital epithelial cells are associated with viral replication and the presence of the virion host shutoff protein

PROBLEM

It is unknown whether viral replication or viral components that subvert innate responses in other cells, specifically the virion host shutoff (VHS) protein, play a role in determining primary genital epithelial cell (GEC) innate antiviral responses.

METHOD OF STUDY

Cultures of primary female GECs were exposed to wildtype (WT), VHS-deleted (vhsB), or UV-inactivated HSV-2. Antiviral pathway induction was evaluated by measuring nuclear factor-κB (NFκB) translocation by immunofluorescent microscopy. Proinflammatory cytokines, chemokines, and interferon (IFN) were measured by Luminex or ELISA. Biological activity of IFN-β was evaluated via VSV-GFP bioassay, by blocking secreted IFN-β with neutralizing antibodies and by measuring interferon-stimulated genes by RT-PCR.

RESULTS

Proinflammatory cytokines and chemokines were upregulated in primary GECs in response to replication-competent HSV-2, but suppressed in the presence of the VHS protein. In contrast, upregulation of IFN-β depended on viral replication, but was not affected by VHS. However, the IFN-β produced was biologically active and reduced the viral burden.

CONCLUSION

Viral factors such as replication and the presence of the VHS protein play important roles in regulating innate antiviral responses against HSV-2 from primary GECs.

Peripheral prepositioning and local CXCL9 chemokine-mediated guidance orchestrate rapid memory CD8+ T cell responses in the lymph node

After an infection, the immune system generates long-lived memory lymphocytes whose increased frequency and altered state of differentiation enhance host defense against reinfection. Recently, the spatial distribution of memory cells was found to contribute to their protective function. Effector memory CD8+ T cells reside in peripheral tissue sites of initial pathogen encounter, in apparent anticipation of reinfection. Here we show that within lymph nodes (LNs), memory CD8+ T cells were concentrated near peripheral entry portals of lymph-borne pathogens, promoting rapid engagement of infected sentinel macrophages. A feed-forward CXCL9-dependent circuit provided additional chemotactic cues that further increase local memory cell density. Memory CD8+ T cells also produced effector responses to local cytokine triggers, but their dynamic behavior differed from that seen after antigen recognition. These data reveal the distinct localization and dynamic behavior of naive versus memory T cells within LNs and how these differences contribute to host defense.

IFN-α and lipopolysaccharide upregulate APOBEC3 mRNA through different signaling pathways

APOBEC3 (A3) proteins are virus-restriction factors that provide intrinsic immunity against infections by viruses like HIV-1 and mouse mammary tumor virus. A3 proteins are inducible by inflammatory stimuli, such as LPS and IFN-α, via mechanisms that are not fully defined. Using genetic and pharmacological studies on C57BL/6 mice and cells, we show that IFN-α and LPS induce A3 via different pathways, independently of each other. IFN-α positively regulates mouse APOBEC3 (mA3) mRNA expression through IFN-αR/PKC/STAT1 and negatively regulates mA3 mRNA expression via IFN-αR/MAPKs-signaling pathways. Interestingly, LPS shows some variation in its regulatory behavior. Although LPS-mediated positive regulation of mA3 mRNA occurs through TLR4/TRIF/IRF3/PKC, it negatively modulates mA3 mRNA via TLR4/MyD88/MAPK-signaling pathways. Additional studies on human peripheral blood mononuclear cells reveal that PKC differentially regulates IFN-α and LPS induction of human A3A, A3F, and A3G mRNA expression. In summary, we identified important signaling targets downstream of IFN-αR and TLR4 that mediate A3 mRNA induction by both LPS and IFN-α. Our results provide new insights into the signaling targets that could be manipulated to enhance the intracellular store of A3 and potentially enhance A3 antiviral function in the host.