Productive Hepatitis C Virus Infection of Stem Cell-Derived Hepatocytes Reveals a Critical Transition to Viral Permissiveness during Differentiation

Primary human hepatocytes isolated from patient biopsies represent the most physiologically relevant cell culture model for hepatitis C virus (HCV) infection, but these primary cells are not readily accessible, display individual variability, and are largely refractory to genetic manipulation. Hepatocyte-like cells differentiated from pluripotent stem cells provide an attractive alternative as they not only overcome these shortcomings but can also provide an unlimited source of noncancer cells for both research and cell therapy. Despite its promise, the permissiveness to HCV infection of differentiated human hepatocyte-like cells (DHHs) has not been explored. Here we report a novel infection model based on DHHs derived from human embryonic (hESCs) and induced pluripotent stem cells (iPSCs). DHHs generated in chemically defined media under feeder-free conditions were subjected to infection by both HCV derived in cell culture (HCVcc) and patient-derived virus (HCVser). Pluripotent stem cells and definitive endoderm were not permissive for HCV infection whereas hepatic progenitor cells were persistently infected and secreted infectious particles into culture medium. Permissiveness to infection was correlated with induction of the liver-specific microRNA-122 and modulation of cellular factors that affect HCV replication. RNA interference directed toward essential cellular cofactors in stem cells resulted in HCV-resistant hepatocyte-like cells after differentiation. The ability to infect cultured cells directly with HCV patient serum, to study defined stages of viral permissiveness, and to produce genetically modified cells with desired phenotypes all have broad significance for host-pathogen interactions and cell therapy

Biotyping of Vibrio cholerae O1: time to redefine the scheme

Considering the recent emergence of "hybrid biotype" and "El Tor variant", we propose to redefine the biotyping scheme for Vibrio cholerae O1 serogroup. The existing biotyping scheme has limitations and causes confusion as many of the hybrid biotype and El Tor variant strains have phenotypic and genetic changes. A revised biotyping scheme will play a significant role to understand the ecology, epidemiology and nature of infection of V. cholerae O1 strains in future

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Not AvailableUnder global warming and as well as increase inCO2 concentration, the crop production is likely to be affected significantly by influencing the crop physiological processes. In this study, the crop growth, yield, water productivity and water footprints of maize were worked out with 1 OC and 2 OC increase in prevailing ambient temperature from the base line data 1983-2010at present (370 ppm) and 550 ppm CO2 concentrations using Decision Support System of Agro technology Transfer (DSSAT 4.5) model. The result of the model was validated with field experimental data of Dhenkanal, Odisha. Monitored ecosystem CO2 emissions and sequestration by agricultural crops, gross primary productivity, ecosystem respiration, net ecosystem exchange and energy balances of rice based cropping system (rice-okra-tomato).The effect of climate change with respect to rainfall fluctuations on the groundwater water table and groundwater recharge was analysed. The available data set of rainfall and water table clearly reveals the uneven and erratic pattern and effect of climate change. To compensate the crop evapo-transpiration loss in view of the climate change, pressurized irrigation system was implemented in canal command and groundwater irrigated areas to enhance water use efficiency in vegetable crops. Location specific groundwater recharge techniques suitable for geo-hydrological conditions were developed and tested for their performance in terms of recharge rate and area of influence.Not Availabl