Conformational activation and disulfide exchange in HIV-1 Env induce cell-free lytic/fusogenic transformation and enhance infection.

IF 4 2区 医学 Q2 VIROLOGY
Journal of Virology Pub Date : 2025-03-18 Epub Date: 2025-02-06 DOI:10.1128/jvi.01471-24
Charles G Ang, Nadia L Hyatt, Giang Le Minh, Monisha Gupta, Manali Kadam, Philip J Hogg, Amos B Smith, Irwin M Chaiken
{"title":"Conformational activation and disulfide exchange in HIV-1 Env induce cell-free lytic/fusogenic transformation and enhance infection.","authors":"Charles G Ang, Nadia L Hyatt, Giang Le Minh, Monisha Gupta, Manali Kadam, Philip J Hogg, Amos B Smith, Irwin M Chaiken","doi":"10.1128/jvi.01471-24","DOIUrl":null,"url":null,"abstract":"<p><p>Disulfide exchange is underexplored as a mechanism influencing HIV-1 entry. Prior studies demonstrated that redox enzyme inhibition can prevent HIV-1 infection but with limited mechanistic explanation. We hypothesize that ligand-driven rearrangement (\"conformational activation\") enables enzyme-mediated disulfide exchange in Env residues (\"disulfide trigger\") that promotes fusion transformations, enhancing virus entry. We tested soluble CD4 and CD4-binding site entry inhibitors as conformational activators and the ubiquitous redox enzyme thioredoxin-1 (Trx1) as disulfide trigger. We found that combination treatment caused fusion-like Env transformation and pseudovirus lysis, independent of cells. Notably, only compounds associated with gp120 shedding caused lysis when paired with Trx1. In each case, lysis was prevented by adding the fusion inhibitor T20, demonstrating that six-helix bundle formation is required as in virus-cell fusion. In contrast to conformationally activating ligands, neither the ground state stabilizer BMS-806 with Trx1 nor Trx1 alone caused lysis. Order of addition experiments reinforced conformational activation/disulfide trigger as a sequential process, with virus/activator preincubation transiently enhancing lysis and virus/Trx1 preincubation reducing lysis. Lastly, addition of exogenous Trx1 to typical pseudovirus infections exhibited dose-dependent enhancement of infection. Altogether, these data support conformational activation and disulfide triggering as a mechanism that can induce and enhance the fusogenic transformation of Env.IMPORTANCEHIV remains a global epidemic despite effective anti-retroviral therapies (ART) that suppress viral replication. Damage from early-stage infection and immune cell depletion lingers, as ART enables only partial immune system recovery, making prevention of initial virus entry preferable. In this study, we investigate disulfide exchange and its facilitating conformational rearrangements as underexplored, but critical, events in the HIV entry process. The HIV envelope (Env) protein effects cell entry by conformational rearrangement and pore formation upon interaction with immune cell surface proteins, but this transformation can be induced by Env's conformational activation and disulfide exchange by redox enzymes, which then integrates into established processes of HIV entry. The significance of this research is in identifying Env's conformational activation as a mechanistic requirement for initiating fusion by triggering disulfide exchange. This will aid the development of novel preventative strategies against HIV entry, particularly in the context of HIV-enhanced inflammation and comorbidities with redox mechanisms.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0147124"},"PeriodicalIF":4.0000,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11915811/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Virology","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1128/jvi.01471-24","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/2/6 0:00:00","PubModel":"Epub","JCR":"Q2","JCRName":"VIROLOGY","Score":null,"Total":0}
引用次数: 0

Abstract

Disulfide exchange is underexplored as a mechanism influencing HIV-1 entry. Prior studies demonstrated that redox enzyme inhibition can prevent HIV-1 infection but with limited mechanistic explanation. We hypothesize that ligand-driven rearrangement ("conformational activation") enables enzyme-mediated disulfide exchange in Env residues ("disulfide trigger") that promotes fusion transformations, enhancing virus entry. We tested soluble CD4 and CD4-binding site entry inhibitors as conformational activators and the ubiquitous redox enzyme thioredoxin-1 (Trx1) as disulfide trigger. We found that combination treatment caused fusion-like Env transformation and pseudovirus lysis, independent of cells. Notably, only compounds associated with gp120 shedding caused lysis when paired with Trx1. In each case, lysis was prevented by adding the fusion inhibitor T20, demonstrating that six-helix bundle formation is required as in virus-cell fusion. In contrast to conformationally activating ligands, neither the ground state stabilizer BMS-806 with Trx1 nor Trx1 alone caused lysis. Order of addition experiments reinforced conformational activation/disulfide trigger as a sequential process, with virus/activator preincubation transiently enhancing lysis and virus/Trx1 preincubation reducing lysis. Lastly, addition of exogenous Trx1 to typical pseudovirus infections exhibited dose-dependent enhancement of infection. Altogether, these data support conformational activation and disulfide triggering as a mechanism that can induce and enhance the fusogenic transformation of Env.IMPORTANCEHIV remains a global epidemic despite effective anti-retroviral therapies (ART) that suppress viral replication. Damage from early-stage infection and immune cell depletion lingers, as ART enables only partial immune system recovery, making prevention of initial virus entry preferable. In this study, we investigate disulfide exchange and its facilitating conformational rearrangements as underexplored, but critical, events in the HIV entry process. The HIV envelope (Env) protein effects cell entry by conformational rearrangement and pore formation upon interaction with immune cell surface proteins, but this transformation can be induced by Env's conformational activation and disulfide exchange by redox enzymes, which then integrates into established processes of HIV entry. The significance of this research is in identifying Env's conformational activation as a mechanistic requirement for initiating fusion by triggering disulfide exchange. This will aid the development of novel preventative strategies against HIV entry, particularly in the context of HIV-enhanced inflammation and comorbidities with redox mechanisms.

求助全文
约1分钟内获得全文 求助全文
来源期刊
Journal of Virology
Journal of Virology 医学-病毒学
CiteScore
10.10
自引率
7.40%
发文量
906
审稿时长
1 months
期刊介绍: Journal of Virology (JVI) explores the nature of the viruses of animals, archaea, bacteria, fungi, plants, and protozoa. We welcome papers on virion structure and assembly, viral genome replication and regulation of gene expression, genetic diversity and evolution, virus-cell interactions, cellular responses to infection, transformation and oncogenesis, gene delivery, viral pathogenesis and immunity, and vaccines and antiviral agents.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信