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The Filoviridae family comprises of Ebola and Marburg viruses, which are known to cause lethal hemorrhagic fever. However, there is no effective anti-viral therapy or licensed vaccines currently available for these human pathogens. The envelope glycoprotein (GP) of Ebola virus, which mediates entry into target cells, is cytotoxic and this effect maps to a highly glycosylated mucin-like region in the surface subunit of GP (GP1). However, the mechanism underlying this cytotoxic property of GP is unknown. To gain insight into the basis of this GP-induced cytotoxicity, HEK293T cells were transiently transfected with full-length and mucin-deleted (Δmucin) Ebola GP plasmids and GP localization was examined relative to the nucleus, endoplasmic reticulum (ER), Golgi, early and late endosomes using deconvolution fluorescent microscopy. Full-length Ebola GP was observed to accumulate in the ER. In contrast, GPΔmucin was uniformly expressed throughout the cell and did not localize in the ER. The Ebola major matrix protein VP40 was also co-expressed with GP to investigate its influence on GP localization. GP and VP40 co-expression did not alter GP localization to the ER. Also, when VP40 was co-expressed with the nucleoprotein (NP), it localized to the plasma membrane while NP accumulated in distinct cytoplasmic structures lined with vimentin. These latter structures are consistent with aggresomes and may serve as assembly sites for filoviral nucleocapsids. Collectively, these data suggest that full-length GP, but not GPΔmucin, accumulates in the ER in close proximity to the nuclear membrane, which may underscore its cytotoxic property.

Background Inhibiting transport of virions within the female reproductive tract is an attractive mechanism for transmission prevention. The mucosal environment varies with menstrual cycle and concurrent bacterial vaginosis (BV). Previous studies of transport within mucosal samples have focused on cervico-vaginal samples in exclusion. Severe BV corresponds to increased incidence of female-to-male HIV-1 transmission although the mechanism remains unclear.

Background Currently, there is much debate on whether epithelial thinning from hormonal contraceptives can increase HIV acquisition. Previously, we illustrated that HIV can penetrate to depths in squamous epithelium where it can interact with target cells, such as CD4+ T-cells and macrophages. Using a similar approach, we show that epithelial thinning affects virus penetration, along with target cell and cellular junction distribution.

Methods Monocyte derived macrophages (MDMs) were isolated from PBMCs, while Monomac-1 cells were obtained from DSMZ. Expression of CD4, HIV-1 co-receptors and FcRs were analysed by FACS staining. Antibody inhibition was determined by p24 release. FcRs involvement was determined using blocking antibodies. Cytokine release was quantified by in house multiplex bead immunoassay. Antibody and immune-complex binding to HIV and FcRs were assessed using an optical SPR Imager. HIV intracellular trafficking was studied by fluorescent microscopy.

Background Vaccination strategies capable of eliciting neutralizing antibody responses to HIV remain elusive despite extensive efforts. Alternative antibody functions offer opportunities for protection without necessarily achieving broad neutralization breadth. Viral immune exclusion through aggregation has been proposed as an alternative protection pathway, but mechanisms for studying this phenomenon at the scale necessary for clinical trials have not been explored.