Investigation of HIV-1 Assembly and Release Using Modern Fluorescence Imaging Techniques

The replication of HIV-1, like that of all viruses, is intimately connected with cellular structures and pathways. For many years, bulk biochemical and cell biological methods were the main approaches employed to investigate interactions between HIV-1 and its host cell. However, during the past decade advancements in fluorescence imaging technologies opened new possibilities for the direct visualization of individual steps occurring throughout the viral replication cycle. Electron microscopy (EM) methods, which have traditionally been employed for the study of viruses, are complemented by fluorescence microscopy (FM) techniques that allow us to follow the dynamics of virus-cell interaction. Subdiffraction fluorescence microscopy, as well as correlative EM/FM approaches, are narrowing the fundamental gap between the high structural resolution provided by EM and the high temporal resolution and throughput accomplished by FM. The application of modern microscopy to the study of HIV-1-host cell interactions has provided insights into the biology of the virus which could not easily, or not at all, have been gained by other methods. Here, we review how modern fluorescence imaging techniques enhanced our knowledge of the dynamic and structural changes involved in HIV-1 particle formation.