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Enhancement of endocytic uptake of HIV-1 virions into CD4-negative epithelial cells by HIV-1 gp41 via its interaction with POB1

Cellular & Molecular Immunology volume 14, pages 568–571 (2017)Cite this article

We previously used recombinant soluble gp41 (rsgp41) as a target to screen a human bone marrow cDNA library by the yeast two-hybrid assay, and we identified an HIV-1 gp41-binding protein, human POB1 (the partner of RalBP1). We found that the gp41-binding site was located at the C-terminal region (aa462-521) of POB1 and the POB1-binding site was on the N-terminal heptad repeat (NHR) region of HIV-1 gp411. However, it is unclear whether this interaction has any effect on HIV-1 entry into the host cell. Here, we showed that gp41 could co-immunoprecipitate with POB1 and co-localize with POB1 in NRK cells transfected with pEYFP-N1-rsgp41 and pECFP-N1-POB1. HIV-1 gp41 effectively promoted the internalization of epidermal growth factor (EGF), whereas both gp41 and EGF significantly enhanced the entry of HIV-1 virions into CD4-negative A431 epithelial cells. This enhancement was attenuated by the endocytosis inhibitor, chlorpromazine. These results indicate that HIV-1 gp41 promotes viral endocytosis in a CD4-independent manner by interacting with the host protein POB1, suggesting a new role for gp41 in the endocytic uptake of virions into CD4-negative epithelial cells and providing a new target for the development of therapeutics and prophylactics against HIV/AIDS.

POB1 is involved in the process of receptor-mediated EGF internalization2. The A431 cell line, which was derived from a female with epidermal carcinoma and carries large numbers of EGF-binding sites, has been widely used as a model cell line for studying the regulation of EGF and signal transduction (epidermal growth factor receptor)4. Therefore, we used this cell line to investigate whether HIV-1 gp41 affects EGF internalization. A431 cells that were transfected with pcDNA3-rsgp41-EGFP (control: pcDNA3-EGFP) plasmid were treated with EGF-Rh and observed with a laser-scanning confocal microscope. As shown in Figure 1c, the internalization of EGF-Rh in A431 cells expressing both gp41 and EGFP was significantly higher than that in A431 cells expressing EGFP alone, thus suggesting that gp41 enhances EGF internalization in A431 cells. We then tested whether the HIV-1 envelope glycoprotein (Env) consisting of native gp120 and gp41 subunits can also affect EGF internalization using CHO-Env cells expressing HIV-1 Env upon stimulation with sodium butyrate5. Flow cytometric analysis revealed that EGF-Alexa internalization was significantly enhanced in CHO-Env cells after stimulation with sodium butyrate (Figure 1di), whereas no apparent EGF internalization was observed in CHO-C cells lacking HIV-1 Env under the same conditions (Figure 1dii), thus suggesting that the native gp41 in Env can also enhance EGF internalization.

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References

  1. Chao L, Lu L, Yang H, Zhu Y, Li Y, Wang Q et al . Identification of a human protein-derived HIV-1 fusion inhibitor targeting the gp41 fusion core structure . PLoS One 2013 ; 8 : e66156.

    Article  CAS  Google Scholar 

  2. Ikeda M, Ishida O, Hinoi T, Kishida S, Kikuchi A . Identification and characterization of a novel protein interacting with Ral-binding protein 1, a putative effector protein of Ral . J Biol Chem 1998 ; 273 : 814 – 821.

    Article  CAS  Google Scholar 

  3. Zhou C, Lu L, Tan S, Jiang S, Chen YH . HIV-1 glycoprotein 41 ectodomain induces activation of the CD74 protein-mediated extracellular signal-regulated kinase/mitogen-activated protein kinase pathway to enhance viral infection . J Biol Chem 2011 ; 286 : 44869 – 44877.

    Article  CAS  Google Scholar 

  4. Graness A, Hanke S, Boehmer FD, Presek P, Liebmann C . Protein-tyrosine-phosphatase-mediated epidermal growth factor (EGF) receptor transinactivation and EGF receptor-independent stimulation of mitogen-activated protein kinase by bradykinin in A431 cells . Biochem J 2000 ; 347 : 441 – 447.

    Article  CAS  Google Scholar 

  5. Weiss CD, Barnett SW, Cacalano N, Killeen N, Littman DR, J.M. Studies of HIV-1 envelope glycoprotein-mediated fusion using a simple fluorescence assay . AIDS 1996 ; 10 : 241 – 246.

    Article  CAS  Google Scholar 

  6. Chan DC, Kim PS . HIV entry and its inhibition . Cell 1998 ; 93 : 681 – 684.

    Article  CAS  Google Scholar 

  7. Schneider-Schaulies J, Schneider-Schaulies S . Viral infections and sphingolipids . Handb Exp Pharmacol 2013 ; 216 : 321 – 340.

    Article  CAS  Google Scholar 

  8. Jiang S, Lin K, Strick N, Neurath AR . HIV-1 inhibition by a peptide . Nature 1993 ; 365 : 113.

    Article  CAS  Google Scholar 

  9. Wild CT, Shugars DC, Greenwell TK, McDanal CB, Matthews TJ . Peptides corresponding to a predictive alpha-helical domain of human immunodeficiency virus type 1 gp41 are potent inhibitors of virus infection . Proc Natl Acad Sci USA 1994 ; 91 : 9770 – 9774.

    Article  CAS  Google Scholar 

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Acknowledgements

We thank Dr Lijun Chao for critical reading and revisions of this manuscript. This work was supported by the following grants: 2012ZX10001-009 and NSFC-81271823 to Ying-Hua Chen, the National 973 Program of China 2012CB519001 to Shibo Jiang NSFC-81373456 to Lu Lu, and the Shanghai Pujiang Program (13PJD004 to Lu Lu).

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Author notes

  1. Yue Tan, Junyi Wang and Shan Su: These authors contributed equally to this work.

  2. Prof. Ying-Hua Chen, Tel: +86-10-62772267; E-mail: chenyh@mail.tsinghua.edu.cn

  3. Prof. Lu Lu, Tel: +86-21-54237671; E-mail: lul@fudan.edu.cn

Authors and Affiliations

  1. Laboratory of Immunology, School of Life Sciences, Beijing Key Laboratory for Protein Therapeutics, Protein Science Laboratory of the Ministry of Education, Tsinghua University, Beijing, 100084, People’s Republic of China

    Yue Tan, Junyi Wang & Ying-Hua Chen

  2. Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Shanghai Public Health Clinical Center and Shanghai Medical College, Fudan University, Shanghai, 200433, People’s Republic of China

    Shan Su, Qian Wang, Shibo Jiang & Lu Lu

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Tan, Y., Wang, J., Su, S. et al. Enhancement of endocytic uptake of HIV-1 virions into CD4-negative epithelial cells by HIV-1 gp41 via its interaction with POB1. Cell Mol Immunol 14, 568–571 (2017). https://doi.org/10.1038/cmi.2015.38

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