Type I Interferon-Sensitive Recombinant Newcastle Disease Virus for Oncolytic Virotherapy

Newcastle disease virus (NDV), an avian paramyxovirus, is tumor selective and intrinsically oncolytic because of its potent ability to induce apoptosis. Several studies have demonstrated that NDV is selectively cytotoxic to tumor cells but not normal cells due to defects in the interferon (IFN) antiviral responses of tumor cells. Many naturally occurring strains of NDV have an intact IFN-antagonistic function and can still replicate in normal human cells. To avoid potential toxicity issues with NDV, especially in cancer patients with immunosuppression, safe NDV-oncolytic vectors are needed. We compared the cell killing abilities of (i) a recombinant NDV (rNDV) strain, Beaudette C, containing an IFN-antagonistic, wild-type V protein (rBC), (ii) an isogenic recombinant virus with a mutant V protein (rBC-Edit virus) that induces increased IFN in infected cells and whose replication is restricted in normal human cells, and (iii) a recombinant LaSota virus with a virulent F protein cleavage site that is as interferon sensitive as rBC-Edit virus (LaSota V.F. virus). Our results indicated that the tumor-selective replication of rNDV is determined by the differential regulation of IFN-α and downstream antiviral genes induced by IFN-α, especially through the IRF-7 pathway. In a nude mouse model of human fibrosarcoma, we show that the IFN-sensitive NDV variants are as effective as IFN-resistant rBC virus in clearing the tumor burden. In addition, mice treated with rNDV exhibited no signs of toxicity to the viruses. These findings indicate that augmentation of innate immune responses by NDV results in selective oncolysis and offer a novel and safe virotherapy platform.Several naturally occurring or engineered oncolytic viruses are emerging as novel tools for selective growth in and killing of a variety of tumor cells (1, 21, 34, 41). It has been consistently reported that during tumor evolution, diminished interferon (IFN) responsiveness coevolves as a frequent genetic defect (4, 31, 32, 41). Any defects in responsiveness to interferon will afford permissiveness of tumors for replication of oncolytic viruses by blunting the antiviral innate immune system. Thus, it was suggested that oncolytic viruses could be engineered to induce strong IFN response and/or to be defective in antagonizing the IFN signaling. This would result in virus replication in tumor cells with IFN defects but in reduced or crippled virus replication in normal cells, with the absence of toxicity (42). A variety of oncolytic viruses have been engineered to exploit tumor-specific genetic defects (3, 12, 24, 42, 46) and shown to be potent oncolytic agents.Newcastle disease virus (NDV), an avian paramyxovirus, is a promising broad-spectrum oncolytic agent (27, 29, 30, 37). Nonengineered, naturally occurring strains of NDV such as 73-T (6), MTH68 (7), PV701 (28, 35), and NDV-HUJ (11) have been successfully employed in several clinical studies for tumor regression. NDV is inherently oncolytic and tumor selective, sparing normal cells (9, 15, 37). The tumor selectivity of NDV is considered to be due to a defective IFN response in tumor cells (10, 23, 37). NDV is a strong inducer of type I IFN in many types of cells (18). In normal cells, a robust IFN-mediated antiviral response limits the replication of NDV (9, 23). This known sensitivity of NDV to cellular antiviral mechanisms affords a wide safety margin for its use in humans.Recent studies have indicated that improved therapeutic vectors of NDV could be engineered through reverse genetics for enhanced oncolytic efficacy from an increased anti-tumor response and interleukin 2 (IL-2) receptor-mediated targeting (5, 9, 44, 46). Therefore, we reasoned that recombinant NDVs (rNDVs) that are susceptible to cellular innate immune responses would be safer and more effective oncolytic agents. Even though NDV is an avian virus and induces a strong IFN response in normal human cells, it still expresses IFN-antagonizing activity. Ablation of the expression of V protein, which is responsible for this anti-IFN activity, may further reduce the ability of NDV to infect and kill normal human cells without affecting tumor cell infection and lysis. Here, we describe the relative oncolytic efficacies of three rNDV strains differing in IFN antagonism. The rNDV variants with an IFN-sensitive phenotype had parallel therapeutic efficacies in xenotransplanted human fibrosarcoma cells in a nude mouse model and offer great potential as recombinant vectors in therapy of human malignancies.     

PCR-RFLP analysis of fliC,fimH and 16S rRNA genes in Salmonella Typhimurium isolates of varied origin

Restricted fragment length polymorphism (RFLP) was used in analyses on the typing and heterogeneity, typeability and polymorphism of the 16S rRNA, fliC and fimH genes in Salmonella Typhimurium isolates of varied origin. The digestion of PCR products with restriction enzymes EcoRV, ClaI, HaeIII and ScaI (fliC genes), HincII, ClaI, EcoRV and MluI (fimH genes) and EcoRI, SmaI and HaeIII (16S rRNA genes) generated two to four bands of ranging in size from 100 to 1,104 bp. Of all the restriction profiles obtained, only the ClaI profile for fimH could be used to classify Salmonella Typhimurium isolates into different groups. According to this profile, pattern A with uncut fimH was observed in eight isolates (36.36 %) and pattern B with 755- and 253-bp bands was observed in 14 isolates (63.63 %). No pattern was allotted for a special region or source. These results demonstrate that PCR-RFLP based on these genes showed good typeability but low discriminatory power. Moreover, the highly conserved nature of fliC, fimH and 16S rRNA illustrated in our study suggests the importance of these genes as immunization and diagnostic factors in Salmonella Typhimurium. Simultaneously, our results also illustrate the potential of ClaI-based fimH analysis as a marker for the sub-serotype level differentiation of Salmonella Typhimurium isolates.     

Glycome profiling by lectin microarray reveals dynamic glycan alterations during epidermal stem cell aging

Aging in the epidermis is marked by a gradual decline in barrier function, impaired wound healing, hair loss, and an increased risk of cancer. This could be due to age‐related changes in the properties of epidermal stem cells and defective interactions with their microenvironment. Currently, no biochemical tools are available to detect and evaluate the aging of epidermal stem cells. The cellular glycosylation is involved in cell–cell communications and cell–matrix adhesions in various physiological and pathological conditions. Here, we explored the changes of glycans in epidermal stem cells as a potential biomarker of aging. Using lectin microarray, we performed a comprehensive glycan profiling of freshly isolated epidermal stem cells from young and old mouse skin. Epidermal stem cells exhibited a significant difference in glycan profiles between young and old mice. In particular, the binding of a mannose‐binder rHeltuba was decreased in old epidermal stem cells, whereas that of an α2‐3Sia‐binder rGal8N increased. These glycan changes were accompanied by upregulation of sialyltransferase, St3gal2 and St6gal1 and mannosidase Man1a genes in old epidermal stem cells. The modification of cell surface glycans by overexpressing these glycogenes leads to a defect in the regenerative ability of epidermal stem cells in culture. Hence, our study suggests the age‐related global alterations in cellular glycosylation patterns and its potential contribution to the stem cell function. These glycan modifications detected by lectins may serve as molecular markers for aging, and further functional studies will lead us to a better understanding of the process of skin aging.     

GEN-SNiP: An Online Tool to Find Polymorphisms in a Genome

An online tool named GEN-SNiP that identifies variations in a set of test DNA sequences with respect to a standard reference sequence is developed and deployed successfully. The tool generates a list of substitutions, insertions and deletions for each test sequences, determined by the reference sequence. In the key batch mode feature, the tool allows multiple sequences to be compared and contrasted even when small insertions and deletions are present, with results sent to the user via email. Other distinguishing features of the tool are grouping of continuous deletions or insertions in the test sequence into a single entity for better output handling, displaying of the alignment of test and reference sequence and the input sequence. The tool has been reported as unique in recent literature.     

Ligand Based Virtual Screening Using Self-organizing Maps

The Protein Journal - Conventional drug discovery methods rely primarily on in-vitro experiments with a target molecule and an extensive set of small molecules to choose the suitable ligand. The...     

Characterisation of a Gold Nanorod Sol–Gel Utilising Inter-particle Coupling to Yield High Refractive Index Sensitivity

The development of gold nanorod plasmonic sol?Cgel polymer is presented and characterised with respect to its sensitivity to refractive index change. Structural characterisation of the polymer was conducted using Raman microscopy and energy dispersion spectroscopy while plasmonic function was investigated using UV/VIS spectroscopy. Refractive index sensitivities utilising the peak wavelength shift of the localised surface plasmon resonance were shown to be of the order of 2,338?nm per refractive index unit; in addition, peak absorbance was considered as an alternative measure. Furthermore, demonstration of sensitivity to biomolecule interaction has been shown as a model study. Strong photoluminescence was observed during Raman studies that restricts the potential use of the polymer as a surface-enhanced Raman substrate.     

Critical review of applications of iron and steel slags for carbon sequestration and environmental remediation

Reviews in Environmental Science and Bio/Technology - One of the major concerns faced by the iron and steel industry, other than the abundant emission of carbon dioxide into the atmosphere, is the...