Vesicular stomatitis virus (VSV) therapy of tumors

Vesicular stomatitis virus (VSV) is an essentially nonpathogenic negative-stranded RNA virus, the replication of which is extremely sensitive to the antiviral effects of interferon (IFN). We demonstrate here that VSV selectively induces the cytolysis of numerous transformed human cell lines in vitro, with all the morphological characteristics of apoptotic cell death. Importantly, VSV can also potently inhibit the growth of p53-null C6 glioblastoma tumors in vivo without infecting and replicating in normal tissue. With our previous findings demonstrating that primary cells containing the double-stranded RNA-activated protein kinase PKR and a functional IFN system are not permissive to VSV replication, these results suggest that signaling by IFN may be defective in many malignancies. Thus VSV might be useful in novel therapeutic strategies for targeting neoplastic disease.     

Homologs of the Brugia malayi diagnostic antigen BmR1 are present in other filarial parasites but induce different humoral immune responses

BACKGROUND: The recombinant antigen BmR1 has been extensively employed in both ELISA and immunochromatographic rapid dipstick (Brugia Rapid) formats for the specific and sensitive detection of IgG4 antibodies against the lymphatic filarial parasites Brugia malayi and Brugia timori. In sera of individuals infected with Wuchereria bancrofti the IgG4 reactivity to BmR1 is variable, and cross-reactivity of sera from individuals infected with Onchocerca volvulus or Loa loa was observed only in single cases. In order to characterize the homologs of the BmR1 antigen in W. bancrofti (Wb-BmR1), O. volvulus (Ov-BmR1) and L. loa (Ll-BmR1) the cDNA sequences were identified, the protein expressed and the antibody reactivity of patients' sera was studied. METHODS: PCR methodology was used to identify the cDNA sequences from cDNA libraries and/or genomic DNA of W. bancrofti, O. volvulus and L. loa. The clones obtained were sequenced and compared to the cDNA sequence of BmR1. Ov-BmR1 and Ll-BmR1 were expressed in E. coli and tested using an IgG4-ELISA with 262 serum samples from individuals with or without B. malayi, W. bancrofti, O. volvulus and L. loa infections or various other parasitic infections. BmR1, Ov-BmR1 and Ll-BmR1 were also tested for reactivity with the other three IgG subclasses in patients' sera. RESULTS: Wb-BmR1 was found to be identical to BmR1. Ov-BmR1 and Ll-BmR1 were found to be identical to each other and share 99.7% homology with BmR1. The pattern of IgG4 recognition of all serum samples to BmR1, Ov-BmR1 and Ll-BmR1 were identical. This included weak IgG4 reactivities demonstrated by L. loa- and O. volvulus-infected patients tested with Ov-BmR1 and Ll-BmR1 (or BmR1). With respect to reactivity to other IgG subclasses, sera from O. volvulus- and L. loa-infected patients showed positive reactions (when tested with BmR1, Ov-BmR1 or Ll-BmR1 antigens) only with IgG1. No reactivity was observed with IgG2 or with IgG3. Similarly, ELISAs to detect reactivity to other anti-filarial IgG subclasses antibodies showed that sera from individuals infected with B. malayi or W. bancrofti (active infections as well as patients with chronic disease) were positive with BmR1 only for IgG1 and were negative when tested with IgG2 and with IgG3 subclasses. CONCLUSIONS: This study demonstrates that homologs of the BmR1 antigen are present in W. bancrofti, O. volvulus and L. loa and that these antigens are highly conserved. Recognition of this antigen by patients' sera is similar with regard to IgG1, IgG2 and IgG3, but different for IgG4 antibodies. We conclude that the BmR1 antigen is suitable for detection of IgG4 antibodies in brugian filariasis. However, its homologs are not suitable for IgG4-based diagnosis of other filarial infections.     

Otomycosis — a clinico-mycological study and efficacy of mercurochrome in its treatment

A total of 110 patients of symptomatic otomycosis was investigated, prospectively. Aural swabs were collected on 1st, 7th and 14th day and examined by direct microscopy and culture for fungi. Of these, 80 patients found to be having pure fungal infection, were taken up for mycological and therapeutic study. Fungi belonging to genus Aspergillus were isolated in 76 (95.0%) patients of which Aspergillus niger was the commonest isolate in 46 (57.5%), followed by A. flavus in 27 (33.7%), A. fumigatus in 3 (3.7%), Candida species in 3 (3.7%) and Mucor in 1 (1.2%). The patients were of all age groups but majority were between 21 and 30 years and the male-female ratio was equal. Of the total of 40 male patients, twenty-one were Sikhs using turban. Before developing the symptoms, forty five patients used oil, mixture of oil and garlic juice, antibiotics, steroids, antiseptics or wax solvent as ear drops. Only two patients were diabetic! No patient had fungal infection elsewhere in the body. The patients were called for regular follow-up for three weeks. In forty cases mercurochrome was applied as the antifungal agent after cleaning the external auditory canal, in twenty-three clotrimazole and in rest of the seventeen patients miconazole was used. On 7th day, only 11 (13.7%) patients grew different fungi in culture. They became symptom-free on 14th day and no fungal material could be seen on otoscopy, direct microscopy or culture. Mercurochrome was found to be most effective in these patients.     

Facile one-pot synthesis of novel dispirooxindole-pyrrolidine derivatives and their antimicrobial and anticancer activity against A549 human lung adenocarcinoma cancer cell line

Novel dispirooxindole-pyrrolidine derivatives have been synthesized through 1,3-dipolar cycloaddition of an azomethine ylide generated from isatin and sarcosine with the dipolarophile 3-(1H-indol-3-yl)-3-oxo-2-(2-oxoindolin-3-ylidene)propanenitrile, and also spiro compound of acenaphthenequinone obtained by the same optimized reaction condition. Synthesized compounds were evaluated for their antimicrobial activity and all the compounds shown significant activity. Anticancer activity was evaluated against A549 human lung adenocarcinoma cancer cell lines. Compounds 7b, 7g, 7i and 7r exhibit very good anticancer activity 62.96%, 62.03%, 67.67% and 60.22%, respectively, at the dose of 200 μg/mL and compound 7i shows IC₅₀ value in 50 μg/mL.     

Comparative analysis of species-specific ligand recognition in Toll-like receptor 8 signaling: a hypothesis

Toll-like receptors (TLRs) play a central role in the innate immune response by recognizing conserved structural patterns in a variety of microbes. TLRs are classified into six families, of which TLR7 family members include TLR7, 8, and 9, which are localized to endolysosomal compartments recognizing viral infection in the form of foreign nucleic acids. In our current study, we focused on TLR8, which has been shown to recognize different types of ligands such as viral or bacterial ssRNA as well as small synthetic molecules. The primary sequences of rodent and non-rodent TLR8s are similar, but the antiviral compound (R848) that activates the TLR8 pathway is species-specific. Moreover, the factors underlying the receptor's species-specificity remain unknown. To this end, comparative homology modeling, molecular dynamics simulations refinement, automated docking and computational mutagenesis studies were employed to probe the intermolecular interactions between this anti-viral compound and TLR8. Furthermore, comparative analyses of modeled TLR8 (rodent and non-rodent) structures have shown that the variation mainly occurs at LRR14-15 (undefined region); hence, we hypothesized that this variation may be the primary reason for the exhibited species-specificity. Our hypothesis was further bolstered by our docking studies, which clearly showed that this undefined region was in close proximity to the ligand-binding site and thus may play a key role in ligand recognition. In addition, the interface between the ligand and TLR8s varied depending upon the amino acid charges, free energy of binding, and interaction surface. Therefore, our current work provides a hypothesis for previous in vivo studies in the context of TLR signaling.     

Caspase dependent programmed cell death in developing embryos: a potential target for therapeutic intervention against pathogenic nematodes

Background

Successful embryogenesis is a critical rate limiting step for the survival and transmission of parasitic worms as well as pathology mediated by them. Hence, blockage of this important process through therapeutic induction of apoptosis in their embryonic stages offers promise for developing effective anti-parasitic measures against these extra cellular parasites. However, unlike in the case of protozoan parasites, induction of apoptosis as a therapeutic approach is yet to be explored against metazoan helminth parasites.

Methodology/Principal Findings

For the first time, here we developed and evaluated flow cytometry based assays to assess several conserved features of apoptosis in developing embryos of a pathogenic filarial nematode Setaria digitata, in-vitro as well as ex-vivo. We validated programmed cell death in developing embryos by using immuno-fluorescence microscopy and scoring expression profile of nematode specific proteins related to apoptosis [e.g. CED-3, CED-4 and CED-9]. Mechanistically, apoptotic death of embryonic stages was found to be a caspase dependent phenomenon mediated primarily through induction of intracellular ROS. The apoptogenicity of some pharmacological compounds viz. DEC, Chloroquine, Primaquine and Curcumin were also evaluated. Curcumin was found to be the most effective pharmacological agent followed by Primaquine while Chloroquine displayed minimal effect and DEC had no demonstrable effect. Further, demonstration of induction of apoptosis in embryonic stages by lipid peroxidation products [molecules commonly associated with inflammatory responses in filarial disease] and demonstration of in-situ apoptosis of developing embryos in adult parasites in a natural bovine model of filariasis have offered a framework to understand anti-fecundity host immunity operational against parasitic helminths.

Conclusions/Significance

Our observations have revealed for the first time, that induction of apoptosis in developing embryos can be a potential approach for therapeutic intervention against pathogenic nematodes and flow cytometry can be used to address different issues of biological importance during embryogenesis of parasitic worms.     

Structural Modification and Aggregation of Mucin by Chromium(III) Complexes

Abstract

Metal ions binding to proteins regulate the functions of proteins and may also lead to structural changes. In this communication we demonstrate the interaction and subsequent conformational changes induced in pig gastric mucin (PGM) upon binding to certain chromium(III) complexes like, [Cr(salen)(H₂O)₂](ClO₄) (1), [Cr(en)₃]Cl₃ (2) and [Cr(EDTA)(H₂O)]Na (3) which vary in charge and ionic character. Complexes 1 and 3 have been shown to interact coordinately with PGM whereas complex 2 binds through electrostatic interaction and hydrogen bonding. Steady state fluorescence experiment reveals that at lower concentration of complex 2 there is partial quenching of the tyrosine emission, whereas at higher concentration of the complex the emission intensity is enhanced. On the other hand with complexes 1 and 3 a decrease in fluorescence intensity was observed. PGM viscosity was found to decrease in the presence of complex 1 and 3 due to the formation of flexible fibres through coordinate interaction. Complex 2 was found to facilitate metal induced intertangling of PGM fibres which tends to stabilize the interaction and leads to sol-gel transition with subsequent increase in viscosity. A significant change in CD spectrum of PGM was observed in the presence of complex 2 where random coil spectrum became typical of a α-helical structure with 80% alpha helix content. In the case of complexes 1 and 3 only minor changes in the amplitude of the spectrum were observed. Histochemical analysis supports the contention that complex 2 favors the oligomerisation of PGM and leads to the formation of aggregated mass of macromolecules.     

Differently Environment Stable Bio-Silver Nanoparticles: Study on Their Optical Enhancing and Antibacterial Properties

Generally, limited research is extended in studying stability and applicational properties of silver nanoparticles (Ag NPs) synthesized by adopting ‘green chemistry’ protocol. In this work, we report on the synthesis of stable Ag NPs using plant-derived materials such as leaf extract of Neem (Azadirachta indica) and biopolymer pectin from apple peel. In addition, the applicational properties of Ag NPs such as surface-enhanced Raman scattering (SERS) and antibacterial efficiencies were also investigated. As-synthesized nanoparticles (NPs) were characterized using various instrumentation techniques. Both the plant materials (leaf extract and biopolymer) favored the synthesis of well-defined NPs capped with biomaterials. The NPs were spherical in shape with an average particle size between 14-27 nm. These bio-NPs exhibited colloidal stability in most of the suspended solutions such as water, electrolyte solutions (NaCl; NaNO₃), biological solution (bovine serum albumin), and in different pH solutions (pH 7; 9) for a reasonable time period of 120 hrs. Both the bio-NPs were observed to be SERS active through displaying intrinsic SERS signals of the Raman probe molecule (Nile blue A). The NPs were effective against the Escherichia coli bacterium when tested in nutrient broth and agar medium. Scanning and high-resolution transmission electron microscopy (SEM and HRTEM) images confirmed cellular membrane damage of nanoparticle treated E. coli cells. These environmental friendly template Ag NPs can be used as an antimicrobial agent and also for SERS based analytical applications.