Herpes simplex virus type 1 (HSV-1) is an important human pathogen and a leading cause of infectious blindness in the developed world. HSV-1 exploits heparan sulfate proteoglycans (HSPG) for attachment to cells. While the significance of heparan sulphate (HS) moieties in HSV-1 infection is well established, the role of specific proteoglycan core proteins in the infection process remains poorly understood. The objective of this study was to assess the roles of syndecan-1 and syndecan-2 core proteins in HSV-1 infection, both of which are expressed by many HSV-1 target cell types. Our results demonstrate that syndecan-1 and syndecan-2 gene silencing by RNA interference reduces HSV-1 entry, plaque formation and facilitates cell survival. Furthermore, HSV-1 infection increases syndecan-1 and syndecan-2 protein synthesis and a resultant increase in cell surface expression of HS. Our observations suggest that changes in syndecan-1 and syndecan-2 expression levels may be related to active viral infection. Taken together, our findings provide new insights into HSPG functions during HSV-1 entry and spread. INTRODUCTIONHerpes simplex virus type 1 (HSV-1) is a clinically important pathogen and a leading cause of infectious blindness in the developed world. HSV-1 productively infects epithelial cells and establishes latent infection in sensory ganglia for the life of the host (Kumaraguru & Rouse, 2002;Terasaka et al., 2010). Currently, no cure exists against HSV-1, which can be transmitted via asymptomatic shedding by latently infected individuals (Hill & Clement, 2009). Prevention of virus transmission to uninfected people is a real challenge compounded by our limited understanding of HSV-1-host cell interactions including virus entry, which is the first essential step for the establishment of an acute and/or latent infection.Enveloped viruses including HSV-1 penetrate host cells by inducing fusion between the virus envelope and the host cell membrane. HSV-1 entry is a stepwise process, which starts when HSV-1 envelope glycoproteins gB and gC attach to cell surface heparan sulfate proteoglycans (HSPGs) (Herold et al., 1991;Nicola et al., 2003;Trybala et al., 2000). This initial interaction enables HSV-1 glycoprotein D (gD) to bind to one of the known gD entry co-receptors. There are three classes of gD co-receptors that have been characterized: nectin-1 (HveC) and nectin-2 (HveB), which are both members of the immunoglobulin superfamily (Geraghty et al., 1998), herpesvirus entry mediator (HVEM) that belongs to the tumour necrosis factor receptor family (Montgomery et al., 1996), and 3-O-sulfated heparan sulfate (3-OS HS) which is a specifically modified form of heparan sulfate (HS) (Shukla et al., 1999b; O'Donnell et al., 2010). The binding of gD to one of its receptors leads to conformational changes in gD that allows it to activate a multiglycoprotein complex involving gB, gD, gH and gL that triggers the viral fusion with the host cell membrane (Atanasiu et al., 2007;Spear et al., 2000). This fusion mechanism is utilized...

Our findings provide the first direct evidence for the crucial role of ductal secretion in protecting the pancreas from acute pancreatitis and strongly suggest that improved ductal function should be an important modality in prevention and treatment of the disease.

We have developed a simple, noninvasive model of acute necrotizing pancreatitis in rats by intraperitoneal injection of 3 g/kg L-ornithine. Interestingly, we found that, compared with L-arginine, L-ornithine was even more effective at inducing pancreatitis. Large doses of L-arginine produce a toxic effect on the pancreas, at least in part, through L-ornithine.

Taken together, early mitochondrial injury caused by large doses of L-lysine may lead to the development of acute pancreatitis independently of pancreatic trypsinogen and NF-κB activation.

To better understand melanoma resistance to herpes simplex virus type 1 (HSV-1)-mediated oncolysis, traditional two-dimensional (2D) cultures and extracellular matrix (ECM) containing three-dimensional (3D) cultures of OCM1 and C918 uveal melanoma cells were infected with an HSV-1 strain that expresses the green fluorescent protein (GFP) marker during replication. Although 2D cultures were completely destroyed within a few days of HSV-1 inoculation, viable GFP-negative tumor cells remained detectable in 3D cultures for several weeks. Tumor cells with increased resistance to HSV-1 included cells that formed vasculogenic mimicry patterns and multicellular spheroids and cells that invaded Matrigel individually. Mechanisms of tumor resistance against HSV-1 in the 3D environment included impaired virus spread in the ECM and ECM-mediated inhibition of viral replication after viral entry into tumor cells. Observations also suggested that HSV-1 established quiescent infection in some tumor cells present in multicellular spheroids and that this could revert to productive viral infection when the tumor growth pattern changed. These findings indicate that 3D tumor cell cultures can be used to identify distinct tumor cell populations with increased resistance to HSV-1 and to explore mechanisms of ECM-mediated tumor resistance to oncolytic virotherapy.

Pilocytic astrocytoma (PA) is the most common pediatric brain tumor. A recurrent feature of PA is deregulation of the mitogen activated protein kinase (MAPK) pathway most often through KIAA1549-BRAF fusion, but also by other BRAF- or RAF1-gene fusions and point mutations (e.g. BRAFV600E). These features may serve as diagnostic and prognostic markers, and also facilitate development of targeted therapy. The aims of this study were to characterize the genetic alterations underlying the development of PA in six tumor cases, and evaluate methods for fusion oncogene detection. Using a combined analysis of RNA sequencing and copy number variation data we identified a new BRAF fusion involving the 5’ gene fusion partner GTF2I (7q11.23), not previously described in PA. The new GTF2I-BRAF 19–10 fusion was found in one case, while the other five cases harbored the frequent KIAA1549-BRAF 16–9 fusion gene. Similar to other BRAF fusions, the GTF2I-BRAF fusion retains an intact BRAF kinase domain while the inhibitory N-terminal domain is lost. Functional studies on GTF2I-BRAF showed elevated MAPK pathway activation compared to BRAFWT. Comparing fusion detection methods, we found Fluorescence in situ hybridization with BRAF break apart probe as the most sensitive method for detection of different BRAF rearrangements (GTF2I-BRAF and KIAA1549-BRAF). Our finding of a new BRAF fusion in PA further emphasis the important role of B-Raf in tumorigenesis of these tumor types. Moreover, the consistency and growing list of BRAF/RAF gene fusions suggests these rearrangements to be informative tumor markers in molecular diagnostics, which could guide future treatment strategies.

HVEM is expressed in the cornea and TG and therefore may serve as an HSV entry receptor in these tissues. Furthermore, these findings raise the possibility that changes in HVEM expression following ocular HSV-1 infection can modulate HSV spread and infection-induced inflammation in the cornea and TG.

A patient with acute myelomonocytic leukemia (AML) developed nephrotic syndrome. The renal biopsy showed focal glomerulosclerosis by light microscopy. Electron microscopy and immunofluorescence revealed electron-dense deposits, IgG and C′3 in the glomerular mesangium. A 21S circulating immune complex (CIC) present in the patient’s serum and the renal biopsy eluate contained immunochemically identical materials. The isolated antibodies from the 21S CIC and the eluate showed restricted reactivity against autologous AML cells. Immunodiífusion studies demonstrated common antigenicity between the 21S CIC antigen, the eluted antigen and between autologous AML cell membrane antigens.