Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Stimulating the RIG-I pathway to kill cells in the latent HIV reservoir following viral reactivation

Abstract

The persistence of latent HIV proviruses in long-lived CD4+ T cells despite antiretroviral therapy (ART)1,2,3 is a major obstacle to viral eradication4,5,6. Because current candidate latency-reversing agents (LRAs) induce HIV transcription, but fail to clear these cellular reservoirs7,8, new approaches for killing these reactivated latent HIV reservoir cells are urgently needed. HIV latency depends upon the transcriptional quiescence of the integrated provirus and the circumvention of immune defense mechanisms4,5,6,9. These defenses include cell-intrinsic innate responses that use pattern-recognition receptors (PRRs) to detect viral pathogens, and that subsequently induce apoptosis of the infected cell10. Retinoic acid (RA)-inducible gene I (RIG-I, encoded by DDX58) forms one class of PRRs that mediates apoptosis and the elimination of infected cells after recognition of viral RNA11,12,13,14. Here we show that acitretin, an RA derivative approved by the US Food and Drug Administration (FDA), enhances RIG-I signaling ex vivo, increases HIV transcription, and induces preferential apoptosis of HIV-infected cells. These effects are abrogated by DDX58 knockdown. Acitretin also decreases proviral DNA levels in CD4+ T cells from HIV-positive subjects on suppressive ART, an effect that is amplified when combined with suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor. Pharmacological enhancement of an innate cellular-defense network could provide a means by which to eliminate reactivated cells in the latent HIV reservoir.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Acitretin induces HIV expression and reduces cellular HIV DNA in CD4+ T cells.
Figure 2: Acitretin preferentially induces apoptosis in HIV-infected cells.
Figure 3: Acitretin increases the expression of RIG-I-signaling-pathway proteins, including MAVS, IRF3, phosphorylated IRF3 (p-IRF3), and BAX, and increases the production of IFN-β and CXCL10 in cells infected with HIV.
Figure 4: shRNA knockdown of RIG-I expression markedly inhibits acitretin enhancement of apoptosis, induction of IFN-β and CXCL10 production and preferential depletion of HIV-DNA+ cells.

Similar content being viewed by others

References

  1. Wong, J.K. et al. Recovery of replication-competent HIV despite prolonged suppression of plasma viremia. Science 278, 1291–1295 (1997).

    Article  CAS  Google Scholar 

  2. Finzi, D. et al. Identification of a reservoir for HIV-1 in patients on highly active antiretroviral therapy. Science 278, 1295–1300 (1997).

    Article  CAS  Google Scholar 

  3. Chun, T.W. et al. Presence of an inducible HIV-1 latent reservoir during highly active antiretroviral therapy. Proc. Natl. Acad. Sci. USA 94, 13193–13197 (1997).

    Article  CAS  Google Scholar 

  4. Deeks, S.G., Lewin, S.R. & Havlir, D.V. The end of AIDS: HIV infection as a chronic disease. Lancet 382, 1525–1533 (2013).

    Article  PubMed Central  Google Scholar 

  5. Passaes, C.P. & Sáez-Cirión, A. HIV cure research: advances and prospects. Virology 454–455, 340–352 (2014).

    Article  Google Scholar 

  6. Ruelas, D.S. & Greene, W.C. An integrated overview of HIV-1 latency. Cell 155, 519–529 (2013).

    Article  CAS  PubMed Central  Google Scholar 

  7. Archin, N.M. et al. Administration of vorinostat disrupts HIV-1 latency in patients on antiretroviral therapy. Nature 487, 482–485 (2012).

    Article  CAS  PubMed Central  Google Scholar 

  8. Deng, K. et al. Broad CTL response is required to clear latent HIV-1 due to dominance of escape mutations. Nature 517, 381–385 (2015).

    Article  CAS  PubMed Central  Google Scholar 

  9. Badley, A.D., Sainski, A., Wightman, F. & Lewin, S.R. Altering cell death pathways as an approach to cure HIV infection. Cell Death Dis. 4, e718 (2013).

    Article  CAS  PubMed Central  Google Scholar 

  10. Kell, A.M. & Gale, M. Jr. RIG-I in RNA virus recognition. Virology 479–480, 110–121 (2015).

    Article  Google Scholar 

  11. Huang, S.L., Shyu, R.Y., Yeh, M.Y. & Jiang, S.Y. Cloning and characterization of a novel retinoid-inducible gene 1 (RIG1) deriving from human gastric cancer cells. Mol. Cell. Endocrinol. 159, 15–24 (2000).

    Article  CAS  Google Scholar 

  12. Goubau, D. et al. Antiviral immunity via RIG-I-mediated recognition of RNA bearing 5′ diphosphates. Nature 514, 372–375 (2014).

    Article  CAS  PubMed Central  Google Scholar 

  13. Chattopadhyay, S. et al. Viral apoptosis is induced by IRF-3-mediated activation of BAX. EMBO J. 29, 1762–1773 (2010).

    Article  CAS  PubMed Central  Google Scholar 

  14. Broz, P. & Monack, D.M. Newly described pattern recognition receptors team up against intracellular pathogens. Nat. Rev. Immunol. 13, 551–565 (2013).

    Article  CAS  Google Scholar 

  15. Schlee, M. Master sensors of pathogenic RNA—RIG-I like receptors. Immunobiology 218, 1322–1335 (2013).

    Article  CAS  Google Scholar 

  16. Berg, R.K. et al. Genomic HIV RNA induces innate immune responses through RIG-I-dependent sensing of secondary-structured RNA. PLoS One 7, e29291 (2012).

    Article  CAS  PubMed Central  Google Scholar 

  17. Wang, Y., Wang, X., Li, J., Zhou, Y. & Ho, W. RIG-I activation inhibits HIV replication in macrophages. J. Leukoc. Biol. 94, 337–341 (2013).

    Article  CAS  PubMed Central  Google Scholar 

  18. Solis, M. et al. RIG-I-mediated antiviral signaling is inhibited in HIV-1 infection by a protease-mediated sequestration of RIG-I. J. Virol. 85, 1224–1236 (2011).

    Article  CAS  Google Scholar 

  19. Doehle, B.P., Hladik, F., McNevin, J.P., McElrath, M.J. & Gale, M. Jr. Human immunodeficiency virus type 1 mediates global disruption of innate antiviral signaling and immune defenses within infected cells. J. Virol. 83, 10395–10405 (2009).

    Article  CAS  PubMed Central  Google Scholar 

  20. Britto, A.M. et al. Expression levels of the innate response gene RIG-I and its regulators RNF125 and TRIM25 in HIV-1-infected adult and pediatric individuals. AIDS 27, 1879–1885 (2013).

    Article  CAS  Google Scholar 

  21. Cassani, B., Villablanca, E.J., De Calisto, J., Wang, S. & Mora, J.R. Vitamin A and immune regulation: role of retinoic acid in gut-associated dendritic cell education, immune protection and tolerance. Mol. Aspects Med. 33, 63–76 (2012).

    Article  CAS  Google Scholar 

  22. Raverdeau, M. & Mills, K.H. Modulation of T cell and innate immune responses by retinoic acid. J. Immunol. 192, 2953–2958 (2014).

    Article  CAS  Google Scholar 

  23. Dietze, E.C. et al. CBP–p300 induction is required for retinoic acid sensitivity in human mammary cells. Biochem. Biophys. Res. Commun. 302, 841–848 (2003).

    Article  CAS  Google Scholar 

  24. Kawasaki, H. et al. Distinct roles of the co-activators p300 and CBP in retinoic-acid-induced F9 cell differentiation. Nature 393, 284–289 (1998).

    Article  CAS  Google Scholar 

  25. Ortiz, N.E., Nijhawan, R.I. & Weinberg, J.M. Acitretin. Dermatol. Ther. 26, 390–399 (2013).

    Article  Google Scholar 

  26. Buccheri, L., Katchen, B.R., Karter, A.J. & Cohen, S.R. Acitretin therapy is effective for psoriasis associated with human immunodeficiency virus infection. Arch. Dermatol. 133, 711–715 (1997).

    Article  CAS  Google Scholar 

  27. Clouse, K.A. et al. Monokine regulation of human immunodeficiency virus–1 expression in a chronically infected human T cell clone. J. Immunol. 142, 431–438 (1989).

    CAS  PubMed  Google Scholar 

  28. Marcu, M.G. et al. Curcumin is an inhibitor of p300 histone acetyltransferase. Med. Chem. 2, 169–174 (2006).

    Article  CAS  Google Scholar 

  29. Lassen, K.G., Hebbeler, A.M., Bhattacharyya, D., Lobritz, M.A. & Greene, W.C. A flexible model of HIV-1 latency permitting evaluation of many primary CD4 T cell reservoirs. PLoS One 7, e30176 (2012).

    Article  CAS  PubMed Central  Google Scholar 

  30. Pace, M.J. et al. Directly infected resting CD4+ T cells can produce HIV Gag without spreading infection in a model of HIV latency. PLoS Pathog. 8, e1002818 (2012).

    Article  CAS  PubMed Central  Google Scholar 

  31. Bullen, C.K., Laird, G.M., Durand, C.M., Siliciano, J.D. & Siliciano, R.F. New ex vivo approaches distinguish effective and ineffective single agents for reversing HIV-1 latency in vivo. Nat. Med. 20, 425–429 (2014).

    Article  CAS  PubMed Central  Google Scholar 

  32. Peisley, A., Wu, B., Xu, H., Chen, Z.J. & Hur, S. Structural basis for ubiquitin-mediated antiviral signal activation by RIG-I. Nature 509, 110–114 (2014).

    Article  CAS  PubMed Central  Google Scholar 

  33. Kawai, T. et al. IPS-1, an adaptor triggering RIG-I- and MDA5-mediated type I interferon induction. Nat. Immunol. 6, 981–988 (2005).

    Article  CAS  Google Scholar 

  34. Yoneyama, M. et al. The RNA helicase RIG-I has an essential function in double-stranded RNA-induced innate antiviral responses. Nat. Immunol. 5, 730–737 (2004).

    Article  CAS  Google Scholar 

  35. Sumpter, R. Jr. et al. Regulating intracellular antiviral defense and permissiveness to hepatitis C virus RNA replication through a cellular RNA helicase, RIG-I. J. Virol. 79, 2689–2699 (2005).

    Article  CAS  PubMed Central  Google Scholar 

  36. Samanta, M., Iwakiri, D., Kanda, T., Imaizumi, T. & Takada, K. EB virus–encoded RNAs are recognized by RIG-I and activate signaling to induce type I IFN. EMBO J. 25, 4207–4214 (2006).

    Article  CAS  PubMed Central  Google Scholar 

  37. Rehwinkel, J. Exposing viruses: RNA patterns sensed by RIG-I-like receptors. J. Clin. Immunol. 30, 491–495 (2010).

    Article  CAS  Google Scholar 

  38. Wu, B. et al. Molecular imprinting as a signal-activation mechanism of the viral RNA sensor RIG-I. Mol. Cell 55, 511–523 (2014).

    Article  CAS  PubMed Central  Google Scholar 

  39. Yoshida, T. et al. Bax-inhibiting peptide derived from mouse and rat Ku70. Biochem. Biophys. Res. Commun. 321, 961–966 (2004).

    Article  CAS  Google Scholar 

  40. Wiegand, U.W. & Chou, R.C. Pharmacokinetics of acitretin and etretinate. J. Am. Acad. Dermatol. 39, S25–S33 (1998).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We thank the study participants, without whom this research could not have been performed. We thank S. Deeks, H. Gunthard, C. Lopez, and H. Hatano for their helpful comments and support, and M. Vu for assistance with participant recruitment. We thank J.C.W. Carroll for graphics arts, S. Ordway for editorial assistance, and S. Wilcox for administrative assistance. We thank the US National Institutes of Health (NIH) AIDS Reagent Program, Division of AIDS, NIAID, NIH for cell lines, plasmid, and reagents. This work was supported by the NIH (grants 1R21AI104445-01A1 (P.L.), R56 AI116342 and R21 AI116218 (J.K.W.)), the Department of Veterans Affairs Merit Review Award 5101 BX001048 (J.K.W.), the UCSF–Gladstone Center for AIDS Research Virology Core P30AI027763 (W.C.G. and J.K.W.), U19 AI096113 (W.C.G.) and research supported as part of the amfAR Institute for HIV Cure Research with grant number 109301(W.G., J.K.W., and P.L.).

Author information

Authors and Affiliations

Authors

Contributions

P.L. contributed to designing the research, performing the experiments, interpreting the data, and writing the paper. P. Kaiser assisted with experiments and contributed to interpreting the data and writing the paper. H.W.L. contributed to recruiting subjects with HIV for the study. P. Kim and S.A.Y. assisted with experiments. D.V.H. and W.C.G. provided key suggestions and contributed to interpreting the data. W.C.G. also contributed to writing the paper. J.K.W. contributed to recruiting subjects with HIV for the study, interpreting the data, and writing the paper.

Corresponding author

Correspondence to Peilin Li.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Text and Figures

Supplementary Figures 1–4 and Supplementary Table 1 (PDF 4130 kb)

Source data

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Li, P., Kaiser, P., Lampiris, H. et al. Stimulating the RIG-I pathway to kill cells in the latent HIV reservoir following viral reactivation. Nat Med 22, 807–811 (2016). https://doi.org/10.1038/nm.4124

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nm.4124

This article is cited by

Search

Quick links

Nature Briefing: Translational Research

Sign up for the Nature Briefing: Translational Research newsletter — top stories in biotechnology, drug discovery and pharma.

Get what matters in translational research, free to your inbox weekly. Sign up for Nature Briefing: Translational Research