Fluorescence Microscopy of the HIV-1 Envelope

Human immunodeficiency virus (HIV) infection constitutes a major health and social issue worldwide. HIV infects cells by fusing its envelope with the target cell plasma membrane. This process is mediated by the viral Env glycoprotein and depends on the envelope lipid composition. Fluorescent microscopy has been employed to investigate the envelope properties, and the processes of viral assembly and fusion, but the application of this technique to the study of HIV is still limited by a number of factors, such as the small size of HIV virions or the difficulty to label the envelope components. Here, we review fluorescence imaging studies of the envelope lipids and proteins, focusing on labelling strategies and model systems. PC was awarded a contract from the Basque Government Postdoctoral Programme (POS_2019_2_0022). JLN acknowledges financial support by the Spanish Government (BIO2015-64421-R (MINECO/AEI/FEDER UE) and RTI2018-095624-B-C21 (MCIU/AEI/FEDER UE) Grants) and the Basque Government (IT1196-19 Grant). CE acknowledges support from the Wolfson Imaging Centre Oxford (Christoffer Lagerholm), the Wolfson Foundation (18272), the Medical Research Council (MC_UU_12010/unit programmes G0902418 and MC_UU_12025), MRC/BBSRC/ESPRC (grant number MR/K01577X/1), the Wellcome Trust (104924/14/Z/14, 100262Z/12/Z, 098274/Z/12/Z and Strategic Award 091911 (107457/Z/15/Z, Advanced Micron Bioimaging Unit)), the Deutsche Forschungsgemeinschaft (Research unit 1905, Jena Excellence Cluster “Balance of the Microverse”, project no. 3162113987 – SFB 1278 (project C05), the Newton-Katip Celebi Institutional Links grant (352333122), and internal University of Oxford funding (EPA Cephalosporin Fund and John Fell Fund).