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Dengue virus, an RNA virus belonging to the genus Flavivirus, affects 50 million individuals annually, and approximately 500,000-1,000,000 of these infections lead to dengue hemorrhagic fever or dengue shock syndrome. With no licensed vaccine or specific antiviral treatments available to prevent dengue infection, dengue is considered a major public health problem in subtropical and tropical regions. The virus, like other enveloped viruses, uses the host's cellular enzymes to synthesize its structural (C, E, and prM/M) and nonstructural proteins (NS1-5) and, subsequently, to glycosylate these proteins to produce complete and functional glycoproteins. The structural glycoproteins, specifically the E protein, are known to interact with the host's carbohydrate receptors through the viral proteins' N-glycosylation sites and thus mediate the viral invasion of cells. This review focuses on the involvement of dengue glycoproteins in the course of infection and the virus' exploitation of the host's glycans, especially the interactions between host receptors and carbohydrate moieties. We also discuss the recent developments in antiviral therapies that target these processes and interactions, focusing specifically on the use of carbohydrate-binding agents derived from plants, commonly known as lectins, to inhibit the progression of infection.

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Introduction: Complete inactivation of virus is crucial before samples are manipulated outside of biological containment areas or general cleaning. There are several control methods that could decrease the risk from viral contamination on surfaces, which include chemical disinfectants, heating sterilisation, and ultraviolet germicidal irradiation depending on the nature and properties of the materials to be sterilised.To date, there are limited studies reporting the effectiveness of physical inactivation methods of dengue virus. Therefore, this study was designed to evaluate the effectiveness of two physical inactivation methods, which are heat-and ultraviolet-inactivation, against dengue virus. Material and methods:All dengue virus serotypes were subjected to heat treatment at various temperatures and exposed to UV light (wavelength of 250-270 nm) at a distance of approximately 75 cm in a Class II Biosafety cabinet (ESCO) at room temperature. The effectiveness of inactivation methods was tested using viability testing on Vero cells and immunofluorescence assay. Results:Dengue virus can be effectively inactivated by heat treatment at 56°C for at least 30 minutes or at higher temperature. On the other hand, the virus required 45 minutes or longer of ultraviolet light exposure at 75 cm distance from the source to be completely inactivated. Conclusion:The results indicated that DENV can be effectively inactivated using high temperature, i.e. 56°C or above, and UV light irradiation. This result would serve as guidelines in proper decontamination and control of dengue virus in laboratory settings, provided proper conditions are met.

Blood-brain barrier (BBB) is a selective barrier formed by the endothelial cells that line cerebral microvessels. It serves as a physical barrier due to the presence of complex tight junctions between adjacent endothelial cells which limits the paracellular movement of most molecules across the BBB. Many in vitro models of the BBB have been established to mimic these in vivo properties with limited success. In this study, we described the properties of a cell-based murine in vitro BBB model in five configurations constructed using immortalized cell lines in a 12-well format Transwell system: murine brain endothelial cells (bEnd.3) grown in a monoculture, or as co-culture in contact with astrocytes, or without contact with astrocytes or neurons, and triple coculture combining the three cell lines. We found that only contact and triple co-culture model closely mimic the in vivo BBB tightness as evaluated by apparent permeability (Papp) of sucrose and albumin producing the lowest Papp values of 0.56 ± 0.16 x 10 -6 cms -1 and 3.30 ± 0.51 x 10 -6 cms -1 , respectively, obtained in triple co-culture model. Co-culturing of bEnd.3 with astrocytes increased the expression of occludin as shown by western blot analysis, and immunohistochemistry showed an increase in peripheral localization of occludin and claudin-5.In addition, we found conditioned media were able to increase in vitro BBB model tightness through the modulation of tight junction proteins localization. We conclude that the presence of astrocytes and neurons in close proximity to brain endothelial cells is essential to produce a tight in vitro BBB model.

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