Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2016 Aug:10:45-54.
doi: 10.1016/j.ebiom.2016.06.037. Epub 2016 Jun 26.

Tyrosine-sulfated V2 peptides inhibit HIV-1 infection via coreceptor mimicry

Raffaello Cimbro  1 , Francis C Peterson  2 , Qingbo Liu  1 , Christina Guzzo  1 , Peng Zhang  1 , Huiyi Miao  1 , Donald Van Ryk  1 , Xavier Ambroggio  3 , Darrell E Hurt  3 , Luca De Gioia  4 , Brian F Volkman  2 , Michael A Dolan  3 , Paolo Lusso  5
Affiliations

Tyrosine-sulfated V2 peptides inhibit HIV-1 infection via coreceptor mimicry

Raffaello Cimbro et al. EBioMedicine. 2016 Aug.

Abstract

Tyrosine sulfation is a post-translational modification that facilitates protein-protein interaction. Two sulfated tyrosines (Tys173 and Tys177) were recently identified within the second variable (V2) loop of the major HIV-1 envelope glycoprotein, gp120, and shown to contribute to stabilizing the intramolecular interaction between V2 and the third variable (V3) loop. Here, we report that tyrosine-sulfated peptides derived from V2 act as structural and functional mimics of the CCR5 N-terminus and potently block HIV-1 infection. Nuclear magnetic and surface plasmon resonance analyses indicate that a tyrosine-sulfated V2 peptide (pV2α-Tys) adopts a CCR5-like helical conformation and directly interacts with gp120 in a CD4-dependent fashion, competing with a CCR5 N-terminal peptide. Sulfated V2 mimics, but not their non-sulfated counterparts, inhibit HIV-1 entry and fusion by preventing coreceptor utilization, with the highly conserved C-terminal sulfotyrosine, Tys177, playing a dominant role. Unlike CCR5 N-terminal peptides, V2 mimics inhibit a broad range of HIV-1 strains irrespective of their coreceptor tropism, highlighting the overall structural conservation of the coreceptor-binding site in gp120. These results document the use of receptor mimicry by a retrovirus to occlude a key neutralization target site and provide leads for the design of therapeutic strategies against HIV-1.

Keywords: Coreceptors; Envelope; HIV-1; Immune evasion; Inhibitors; Molecular mimicry; Peptides; Trimer.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Nuclear magnetic and surface plasmon resonance analyses of the interaction of a tyrosine-sulfated V2 mimetic peptide with monomeric and trimeric HIV-1 gp120. (a) 2D NOESY spectrum of a tyrosine-sulfated 18-mer V2 mimic, pV2α-Tys, at 0.8 mM. The peptide sequence is indicated at the bottom for reference. (b) 2D trNOESY spectrum of 0.8 mM pV2α-Tys in the presence of 20 μM CD4:gp120 complex. Monomeric gp120 was derived from the CCR5-tropic isolate BaL. (c) 1D slices from the 2D NOESY spectra of 0.8 mM pV2α-Tys corresponding to 7.26 ppm in the ω2 dimension (Tys177 Hδ). Tys177 NOE signals are shown for pV2α-Tys alone (bottom) or in the presence of sCD4, gp120 or the sCD4:gp120 complex as illustrated in the cartoons. (d) Surface plasmon resonance (SPR) analysis of the interaction of the tyrosine-sulfated V2 mimic pV2α-Tys with monomeric HIV-1 gp120 (strain BaL). (e) Surface plasmon resonance analysis of the interaction of the tyrosine-sulfated V2 mimic pV2α-Tys with a soluble cleaved gp140 trimer (BG505 SOSIP.664). The tyrosine-sulfated V2 mimic was immobilized on the surface of the sensor, while gp120 and the SOSIP trimer were used in the flow phase at increasing concentrations either in the unliganded form or after treatment with a CD4 mimic (CD4-M48U).
Fig. 2
Fig. 2
Competition of a tyrosine-sulfated V2 mimetic peptide with a sulfated CCR5 N-terminal peptide for gp120 binding. Overlay of 2D trNOESY spectra of 0.4 mM pV2α-Tys in the presence of 20 μM CD4:gp120 complex before (orange) and after (green) displacement by a molar excess of a tyrosine-sulfated CCR5 N-terminal peptide, pCCR5-Tys, at 1.6 mM. The peptide sequence is indicated at the bottom for reference.
Fig. 3
Fig. 3
NMR characterization of a tyrosine-sulfated V2 mimetic peptide bound to HIV-1 gp120. (a) NOE peaks between the Hb and Hd of Tys173, Phe176 and Tys177 of free pV2a-Tys in a region of the NOESY spectrum that corresponds to the dashed box from Fig. 1D. (b) The same region of the trNOESY spectrum of pV2a-Tys in the presence of 20 μM CD4:gp120 peaks shows stronger NOE signals for Tys173, Phe176 and Tys177 side chains include new NOEs (black arrows) linking Hb of Tys173 and Hd of Tys177. (c) Sequential NH to NH NOEs in the trNOESY spectrum of 0.8 mM pV2a-Tys in the presence of 20 μM CD4:gp120 are consistent with helical conformations. (d) Ensemble of 20 structures of the bound conformation of pV2a-Tys calculated from trNOE distance constraints. Residues 170–182 are shown for clarity. (e) NOEs connecting the side chains of Tys173 and Tys177 (shown in Fig. 1b) define a helical turn.
Fig. 4
Fig. 4
Broad-spectrum inhibition of HIV-1 infection, entry and CCR5 utilization by tyrosine-sulfated V2 mimics. (a) Dose-dependent inhibitory effect of the V2 mimic pV2α-Tys and the CCR5 mimic pCCR5-Tys on cell-free infection of primary human CD4+ T cells by HIV-1, strain BaL; the respective non-sulfated homologous peptides, pV2α and pCCR5, were tested in parallel, as was a control scrambled sulfated peptide (pSCR-Tys). (b) Effect of pV2α-Tys or pCCR5-Tys (both at 50 μM) on HIV-1 BaL entry into activated primary human CD4+ T cells; the gp41-derived peptide T20, a pure HIV-1 entry inhibitor, was used as a control at 50 μg/mL. (c) Dose-dependent inhibitory effect of pV2α-Tys or pCCR5-Tys on binding of a soluble cleaved gp140 trimer (BG505 SOSIP.664) to human CCR5 expressed on the surface of canine thymocytes after pre-activation with sCD4; the scrambled sulfated peptide pSCR-Tys and an anti-CCR5 mAb (2D6) were used as negative and positive controls, respectively. (d) Effect of pV2α-Tys or pCCR5-Tys (both at 50 μM) on soluble CD4-activated fusion between HIV-1 BaL envelope-expressing cells and CCR5+ CD4− cells; the entry inhibitor T20 was used as a control at 50 μg/mL. (e) Dominant role of Tys177 in HIV-1 blockade. Dose-dependent inhibitory effect of peptide pV2α and its modified versions bearing either double (pV2α-Tys) or single (Tys173 and Tys177) sulfated tyrosines on cell-free infection by HIV-1 BaL in primary CD4+ T cells. (f) Broad spectrum of HIV-1 inhibition by tyrosine-sulfated V2 mimetic peptides. Peptides pV2α-Tys (clade B), pV2αΕ-Tys (clade E), or pCCR5-Tys (each at 50 μM) were tested on cell-free infection of purified CD4+ T cells by different strains of HIV-1. Eight primary isolates minimally passaged in vitro (92US714, 92HT599, 07USLR, 07USPC and 07USSG, subtype B; 97ZA009 and 98IN017, subtype C; 93BR019, subtype F) and 4 laboratory-expanded strains (BaL, JR-FL, ADA, IIIB, all subtype B) were tested. The coreceptor-usage phenotype of the various HIV-1 isolates is indicated below the strain designations.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Alsahafi N., Debbeche O., Sodroski J., Finzi A. Effects of the I559P gp41 change on the conformation and function of the human immunodeficiency virus (HIV-1) membrane envelope glycoprotein trimer. PLoS One. 2015;10 - PMC - PubMed
    1. Auerbach D.J., Lin Y., Miao H., Cimbro R., DiFiore M.J., Gianolini M.E., Furci L., Biswas P., Fauci A.S., Lusso P. Identification of the platelet-derived chemokine CXCL4/PF-4 as a broad-spectrum HIV-1 inhibitor. Proc. Natl. Acad. Sci. U. S. A. 2012;109:9569–9574. - PMC - PubMed
    1. Bartesaghi A., Merk A., Borgnia M.J., Milne J.L., Subramaniam S. Prefusion structure of trimeric HIV-1 envelope glycoprotein determined by cryo-electron microscopy. Nat. Struct. Mol. Biol. 2013;20:1352–1357. - PMC - PubMed
    1. Burton D.R., Ahmed R., Barouch D.H., Butera S.T., Crotty S., Godzik A., Kaufmann D.E., McElrath M.J., Nussenzweig M.C., Pulendran B., Scanlan C.N., Schief W.R., Silvestri G., Streeck H., Walker B.D., Walker L.M., Ward A.B., Wilson I.A., Wyatt R. A blueprint for HIV vaccine discovery. Cell Host Microbe. 2012;12:396–407. - PMC - PubMed
    1. Cao J., Sullivan N., Desjardin E., Parolin C., Robinson J., Wyatt R., Sodroski J. Replication and neutralization of human immunodeficiency virus type 1 lacking the V1 and V2 variable loops of the gp120 envelope glycoprotein. J. Virol. 1997;71:9808–9812. - PMC - PubMed

MeSH terms