Effect of the Deletion of Genes Encoding Proteins of the Extracellular Virion Form of Vaccinia Virus on Vaccine Immunogenicity and Protective Effectiveness in the Mouse Model

Antibodies to both infectious forms of vaccinia virus, the mature virion (MV) and the enveloped virion (EV), as well as cell-mediated immune response appear to be important for protection against smallpox. EV virus particles, although more labile and less numerous than MV, are important for dissemination and spread of virus in infected hosts and thus important in virus pathogenesis. The importance of the EV A33 and B5 proteins for vaccine induced immunity and protection in a murine intranasal challenge model was evaluated by deletion of both the A33R and B5R genes in a vaccine-derived strain of vaccinia virus. Deletion of either A33R or B5R resulted in viruses with a small plaque phenotype and reduced virus yields, as reported previously, whereas deletion of both EV protein-encoding genes resulted in a virus that formed small infection foci that were detectable and quantifiable only by immunostaining and an even more dramatic decrease in total virus yield in cell culture. Deletion of B5R, either as a single gene knockout or in the double EV gene knockout virus, resulted in a loss of EV neutralizing activity, but all EV gene knockout viruses still induced a robust neutralizing activity against the vaccinia MV form of the virus. The effect of elimination of A33 and/or B5 on the protection afforded by vaccination was evaluated by intranasal challenge with a lethal dose of either vaccinia virus WR or IHD-J, a strain of vaccinia virus that produces relatively higher amounts of EV virus. The results from multiple experiments, using a range of vaccination doses and virus challenge doses, and using mortality, morbidity, and virus dissemination as endpoints, indicate that the absence of A33 and B5 have little effect on the ability of a vaccinia vaccine virus to provide protection against a lethal intranasal challenge in a mouse model.     

Transbilayer organization of membrane cholesterol at low concentrations: Implications in health and disease

Cholesterol is an essential and representative lipid in higher eukaryotic cellular membranes and is often found distributed nonrandomly in domains in biological membranes. A large body of literature exists on the organization of cholesterol in plasma membranes or membranes with high cholesterol content. However, very little is known about organization of cholesterol in membranes containing low amounts of cholesterol such as the endoplasmic reticulum or inner mitochondrial membranes. In this review, we have traced the discovery and subsequent development of the concept of transbilayer cholesterol dimers (domains) in membranes at low concentrations. We have further discussed the role of membrane curvature and thickness on the transbilayer organization of cholesterol. Interestingly, this type of cholesterol organization could be relevant in cellular sorting and trafficking, and in pathological conditions.     

Biosorption and Reuse Potential of a Blue Green Alga for the Removal of Hazardous Reactive Dyes from Aqueous Solutions

The adsorption potential of a nonliving alga Nostoc comminutum for the removal of hazardous dyes from aqueous solutions was assessed. The algal biomass in its native form exhibited the highest dye removal efficiency at a pH of 1 and at a contact time of 50 min. The effect of various chemical pretreatments was studied in order to assess the role of surface chemistry and the underlying mechanism. Combined with Fourier transform infrared (FTIR) studies, it was concluded that the carboxylic and amine groups played a dominant role in the dye binding process. pH studies further revealed that besides the electrostatic mechanism, other physical interactions might be operative, which is also revealed from the Dubinin-Radushkevich (D-R) isotherm model. Kinetic studies indicated that the adsorption process followed the second-order kinetics and particle diffusion mechanisms were operative. Thermodynamic studies revealed that the adsorption of two dyes onto the algal biomass was feasible, spontaneous, and exothermic under the studied conditions. Microwave irradiation was proposed as a green method for the regeneration and reuse of the biomass. A 16% loss in the regeneration efficiency of the biosorbent was observed, which reveals its stability and reuse potential. Column experiments with real textile wastewater established the practicality of the developed system. Finally, a comparative study revealed the efficacy of the biosorbent with other previously reported biosorbents for dye removal.     

Intraspecific strains of Pythium aphanidermatum induced disease resistance in ginger and response of host proteins

Intraspecific strains of Pythium aphanidermatum induced resistance in ginger against rhizome rot and activated biosynthesis of selected host proteins. Pre-inoculation of plants with IR strain (avirulent) or co-inoculation with SR2 (virulent) caused significant reduction in disease severity. Analysis of protein profiles of ginger leaves of inoculated and non-inoculated plants by SDS-PAGE and Image Master VDS-ID Gel Analysis version : 3.0 revealed that some specific defence proteins/stress proteins increased in inoculated plants. Five such proteins having molecular weight 56, 32, 27, 18 and 14 kDa were detected in leaves of plant treated with IR + SR2 strains. On the contrary, mycelial protein profiles and submerged growth of strains were studied separately and together. Mycelia of IR, SR2 and IR + SR2 exhibited 26, 23 and 25 protein bands, respectively although, 21 bands were common between IR and SR2. Growth of SR2 in synthetic medium was much higher than that of IR, but the growth of two strains together was lower than SR2 alone. To characterise strains, their differential growth response to DL-beta-aminobutyric acid (BABA), a known defence activator of ginger was also tested. Results suggested that at least 5 specific defence proteins/stress proteins were involved in microbially induced resistance in ginger and inducer strains were distinct in their specific protein profiles and sensitivity to BABA.     

Structural transition in micelles: novel insight into microenvironmental changes in polarity and dynamics

Structural transitions involving shape changes play an important role in cellular physiology. Such transition can be conveniently induced in charged micelles by increasing ionic strength of the medium. Shape changes have recently been shown to result in altered packing and lowering of micellar polarity. As a consequence of reduced polarity, the ionization states of micelle-bound molecules vary in micelles of different shape. The changes in micellar organization and dynamics due to structural transition can be effectively monitored utilizing the red edge excitation shift (REES). These changes are influenced by the position (location) of the probe in the micelle, i.e., the region of the micelle being monitored. Changes in organization and dynamics of probes and peptides upon structural transition are discussed with representative examples. We envisage that the reduction in micellar polarity and tighter packing upon structural transition represent important factors in the incorporation of drugs in micelles (nano-carriers), since micellar polarity plays a crucial role in the incorporation of drugs.     

Intricacies of hedgehog signaling pathways: a perspective in tumorigenesis

The hedgehog (HH) signaling pathway is a crucial negotiator of developmental proceedings in the embryo governing a diverse array of processes including cell proliferation, differentiation, and tissue patterning. The overall activity of the pathway is significantly curtailed after embryogenesis as well as in adults, yet it retains many of its functional capacities. However, aberration in HH signaling mediates the initiation, proliferation and continued sustenance of malignancy in different tissues to varying degrees through different mechanisms. In this review, we provide an overview of the role of constitutively active aberrant HH signaling pathway in different types of human cancer and the underlying molecular and genetic mechanisms that drive tumorigenesis in that particular tissue. An insight into the various modes of anomalous HH signaling in different organs will provide a comprehensive knowledge of the pathway in these tissues and open a window for individually tailored, tissue-specific therapeutic interventions. The synergistic cross talking of HH pathway with many other regulatory molecules and developmentally inclined signaling pathways may offer many avenues for pharmacological advances. Understanding the molecular basis of abnormal HH signaling in cancer will provide an opportunity to inhibit the deregulated pathway in many aggressive and therapeutically challenging cancers where promising options are not available.     

Micropropagation of Withania coagulans (Stocks) Dunal: A Critically Endangered Medicinal Herb

An efficient micropropagation protocol has been developed for Withania coagulans, a highly endangered medicinal herb and an important natural source of withanolides. Prolific multiplication of axillary buds occurred from the nodal segments taken from adult plant, and cultured on MS medium enriched with BA (0.5 mg l^?1), Kn (0.5 mg l^?1) and PG (0.5 mg l^?1). Nodal segments and shoot tips of elongated microshoots also behaved the same way in cultures and formed multiple shoots through axillary bud multiplication. Addition of PG (0.5 mg l^?1) in the regeneration medium significantly improved induction and elongation of shoot buds. Elongated shoots were placed on filter paper bridges soaked in MS medium with CC (10 mg l^?1) and PG (0.5 mg l^?1) for the initial 7 days’ pulse treatment and thereafter, they were transferred to rooting medium containing IBA (0.25 mg l^?1) + PAA (0.5 mg l^?1) + CC (2 mg l^?1). This protocol has the capacity of producing 1000 plants from one nodal segment after 4 subcultures of 2 weeks each.     

Virus-induced gene silencing: A versatile tool for discovery of gene functions in plants

Virus-induced gene silencing (VIGS) is a technology that exploits an antiviral defense mechanism in plants as a tool for plant reverse genetics. VIGS circumvents the need for plant transformation, is methodologically simple and yields rapid results. Various VIGS vectors have been developed and have helped to unravel the functions of genes involved in processes such as disease resistance, abiotic stress, cellular signaling and secondary metabolite biosynthesis.