Dengue Virus Ensures Its Fusion in Late Endosomes Using Compartment-Specific Lipids

Many enveloped viruses invade cells via endocytosis and use different environmental factors as triggers for virus-endosome fusion that delivers viral genome into cytosol. Intriguingly, dengue virus (DEN), the most prevalent mosquito-borne virus that infects up to 100 million people each year, fuses only in late endosomes, while activation of DEN protein fusogen glycoprotein E is triggered already at pH characteristic for early endosomes. Are there any cofactors that time DEN fusion to virion entry into late endosomes? Here we show that DEN utilizes bis(monoacylglycero)phosphate, a lipid specific to late endosomes, as a co-factor for its endosomal acidification-dependent fusion machinery. Effective virus fusion to plasma- and intracellular- membranes, as well as to protein-free liposomes, requires the target membrane to contain anionic lipids such as bis(monoacylglycero)phosphate and phosphatidylserine. Anionic lipids act downstream of low-pH-dependent fusion stages and promote the advance from the earliest hemifusion intermediates to the fusion pore opening. To reach anionic lipid-enriched late endosomes, DEN travels through acidified early endosomes, but we found that low pH-dependent loss of fusogenic properties of DEN is relatively slow in the presence of anionic lipid-free target membranes. We propose that anionic lipid-dependence of DEN fusion machinery protects it against premature irreversible restructuring and inactivation and ensures viral fusion in late endosomes, where the virus encounters anionic lipids for the first time during entry. Currently there are neither vaccines nor effective therapies for DEN, and the essential role of the newly identified DEN-bis(monoacylglycero)phosphate interactions in viral genome escape from the endosome suggests a novel target for drug design

Ayahuasca Lodges in the Peruvian Amazon: A Valid Alternative for Ethno-development?

The purpose of this text is to understand how ayahuasca tourism affects local communities from an ethno-development and postcolonial studies approach. Our extensive ethnographic field research in Northeastern Peru has led us to encompass a view in which humans and plants establish complex relationships. In this text, we criticize the way Western ontologies situate plants as objects for consumption. The history of plant exploitation in the Amazon is long and it starts at the beginning of the twentieth century with the Rubber Boom. Presently, during the first decade of our twenty-first century, the Peruvian Amazon has become a new spiritual Mecca for Western tourists seeking enlightenment and healing. The sudden arrival of tourists caused a significant impact on local cultures and economies. Indigenous, mestizo and foreigner entrepreneurs embraced the opportunity to market the knowledge of medicinal and magic plants as a service from the Indigenous cultures. In this context, ayahuasca lodges emerged as healing spaces dedicated to organizing ceremonies with the psychoactive beverage as well as purges and diets with other medicinal plants. With the compilation of narratives and the construction of case studies, we intend to portray the subtle social dynamics between local and foreigner working to build their practices “between worlds”. Each group engages the global trends of ayahuasca spirituality through their own particular ways of connecting with plants. The chapter ends with a reflection about the impact of ayahuasca tourism on the protection and promotion of Indigenous and mestizo autonomy, advocating the strengthening of the postcolonial and ethno-developmental perspectives in the studies concerning ayahuasca.Fil: Echazú, Ana Gretel. Universidade Federal do Rio Grande do Norte; BrasilFil: Flores, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones en Ciencias Sociales y Humanidades. Universidad Nacional de Salta. Facultad de Humanidades. Instituto de Investigaciones en Ciencias Sociales y Humanidades; Argentin