nn7b00275_si_009.avi (1.87 MB)
Single-Particle Tracking of Human Immunodeficiency Virus Type 1 Productive Entry into Human Primary Macrophages
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posted on 2017-04-03, 00:00 authored by Qin Li, Wei Li, Wen Yin, Jia Guo, Zhi-Ping Zhang, Dejun Zeng, Xiaowei Zhang, Yuntao Wu, Xian-En Zhang, Zongqiang CuiMacrophages are one of the major
targets of human immunodeficiency virus (HIV-1), but the viral entry
pathway remains poorly understood in these cells. Noninvasive virus
labeling and single-virus tracking are effective tools for studying
virus entry. Here, we constructed a quantum dot (QD)-encapsulated
infectious HIV-1 particle to track viral entry at a single-particle
level in live human primary macrophages. QDs were encapsulated in
HIV-1 virions by incorporating viral accessory protein Vpr-conjugated
QDs during virus assembly. With the HIV-1 particles encapsulating
QDs, we monitored the early phase of viral infection in real time
and observed that, during infection, HIV-1 was endocytosed in a clathrin-mediated
manner; the particles were translocated into Rab5A-positive endosomes,
and the core was released into the cytoplasm by viral envelope-mediated
endosomal fusion. Drug inhibition assays verified that endosome fusion
contributes to HIV-1 productive infection in primary macrophages.
Additionally, we observed that a dynamic actin cytoskeleton is critical
for HIV-1 entry and intracellular migration in primary macrophages.
HIV-1 dynamics and infection could be blocked by multiple different
actin inhibitors. Our study revealed a productive entry pathway in
macrophages that requires both endosomal function and actin dynamics,
which may assist in the development of inhibitors to block the HIV
entry in macrophages.