LC3B conjugation machinery promotes autophagy-independent HIV-1 entry in CD4⁺ T lymphocytes

ABSTRACT

HIV-1 entry into CD4⁺ T lymphocytes relies on the viral and cellular membranes’ fusion, leading to viral capsid delivery in the target cell cytoplasm. Atg8/LC3B conjugation to lipids, process named Atg8ylation mainly studied in the context of macroautophagy/autophagy, occurs transiently in the early stages of HIV-1 replication in CD4⁺ T lymphocytes. Despite numerous studies investigating the HIV-1-autophagy interplays, the Atg8ylation impact in these early stages of infection remains unknown. Here we found that HIV-1 exposure leads to the rapid LC3B enrichment toward the target cell plasma membrane, in close proximity with the incoming viral particles. Furthermore, we demonstrated that Atg8ylation is a key event facilitating HIV-1 entry in target CD4⁺ T cells. Interestingly, this effect is independent of canonical autophagy as ATG13 silencing does not prevent HIV-1 entry. Together, our results provide an unconventional role of LC3B conjugation subverted by HIV-1 to achieve a critical step of its replication cycle.

Abbreviations: BafA1: bafilomycin A1; BlaM: beta-lactamase; CD4⁺ TL: CD4⁺ T lymphocytes; PtdIns3K-BECN1 complex: BECN1-containing class III phosphatidylinositol 3-kinase complex; Env: HIV-1 envelope glycoproteins; HIV-1: type 1 human immunodeficiency virus; PM: plasma membrane; PtdIns3P: phosphatidylinositol-3-phosphate; VLP: virus-like particle.

KEYWORDS:

• Atg8ylation
• CD4⁺ T lymphocyte
• HIV-1
• LC3B
• virus entry

Acknowledgements

We thank Dr. Philippe Benaroch (Institut Curie INSERM U932, Paris) for the Env-mutated pNL4.3.Gag-mCherry (R5 tropic). We thank Dr. Caroline Goujon (IRIM UMR 9004 CNRS UM, Montpellier) for having provided us the pBlaM-Vpr plasmid. The following reagent was obtained through the NIH HIV Reagent Program, Division of AIDS, NIAID, NIH: Jurkat LTR-GFP CCR5⁺ Cells (JLTRG-R5), ARP-11586, contributed by Dr. Olaf Kutsch. We acknowledge the imaging facility MRI, member of the national infrastructure “France-BioImaging infrastructure” supported by the French National Research Agency (ANR-10-INBS-04, «Investments for the future»)”. We are grateful to S. Lyonnais and the CEMIPAI BSL-3 facility for the HIV-1 live-cell imaging experiments. We warmly thank Sam Howells for the manuscript proofreading. This work was supported by the “ANRS - Maladies Infectieuses Emergentes », by SIDACTION, by the Centre National de la Recherche Scientifique (CNRS) and by the University of Montpellier.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplemental data

Supplemental data for this article can be accessed online at https://doi.org/10.1080/15548627.2024.2338573.

Additional information

Funding

The work was supported by the Agence Nationale de Recherches sur le Sida et les Hépatites Virales [244097]; Agence Nationale de Recherches sur le Sida et les Hépatites Virales [176196]; Agence Nationale de la Recherche [CE17-0054-02]; Sidaction [2021-1-AEQ-12958]; Sidaction [2022-1-FJC-13342].