HVEM of the human immunodeficiency virus
The human immunodeficiency virus (HIV-1), the causative agent of the acquired immunodeficiency syndrome, is a retrovirus. HIV-1 infects host cells by fusing with the plasma membrane and injecting viral RNA into the cytoplasm. Viral RNA induces the synthesis of viral DNA that is integrated into the host genome. Viral progeny are secreted by budding from the plasma membrane. Only two periods in the life cycle of the virus are amenable for examining morphological interactions between HIV-1 and host cells: during infection, before the virus disassembles prior to viral DNA production, and morphogenesis of HIV-1, as structural components are assembled at the host plasma membrane. Although these periods are critical for the success of HIV-1 they have not been widely investigated at the electron-microscope level. To address this we have used high-voltage electron microscopy (HVEM) to analyze the spatial and morphological associations between HIV-1 and host cells during infection and morphogenesis.