1
|
Symmonds J, Gaufin T, Xu C, Raehtz KD, Ribeiro RM, Pandrea I, Apetrei C. Making a Monkey out of Human Immunodeficiency Virus/Simian Immunodeficiency Virus Pathogenesis: Immune Cell Depletion Experiments as a Tool to Understand the Immune Correlates of Protection and Pathogenicity in HIV Infection. Viruses 2024; 16:972. [PMID: 38932264 DOI: 10.3390/v16060972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 05/31/2024] [Accepted: 06/12/2024] [Indexed: 06/28/2024] Open
Abstract
Understanding the underlying mechanisms of HIV pathogenesis is critical for designing successful HIV vaccines and cure strategies. However, achieving this goal is complicated by the virus's direct interactions with immune cells, the induction of persistent reservoirs in the immune system cells, and multiple strategies developed by the virus for immune evasion. Meanwhile, HIV and SIV infections induce a pandysfunction of the immune cell populations, making it difficult to untangle the various concurrent mechanisms of HIV pathogenesis. Over the years, one of the most successful approaches for dissecting the immune correlates of protection in HIV/SIV infection has been the in vivo depletion of various immune cell populations and assessment of the impact of these depletions on the outcome of infection in non-human primate models. Here, we present a detailed analysis of the strategies and results of manipulating SIV pathogenesis through in vivo depletions of key immune cells populations. Although each of these methods has its limitations, they have all contributed to our understanding of key pathogenic pathways in HIV/SIV infection.
Collapse
Affiliation(s)
- Jen Symmonds
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Department of Infectious Diseases and Microbiology, School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Thaidra Gaufin
- Tulane National Primate Research Center, Tulane University, Covington, LA 70433, USA
| | - Cuiling Xu
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Division of Infectious Diseases, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Kevin D Raehtz
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Division of Infectious Diseases, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Ruy M Ribeiro
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Ivona Pandrea
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Department of Infectious Diseases and Microbiology, School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Cristian Apetrei
- Department of Infectious Diseases and Microbiology, School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Division of Infectious Diseases, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| |
Collapse
|
2
|
Tebit DM, Nickel G, Gibson R, Rodriguez M, Hathaway NJ, Bain K, Reyes-Rodriguez AL, Ondoa P, Heeney JL, Li Y, Bongorno J, Canaday D, McDonald D, Bailey JA, Arts EJ. Replicative fitness and pathogenicity of primate lentiviruses in lymphoid tissue, primary human and chimpanzee cells: relation to possible jumps to humans. EBioMedicine 2024; 100:104965. [PMID: 38215691 PMCID: PMC10827413 DOI: 10.1016/j.ebiom.2023.104965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 12/20/2023] [Accepted: 12/28/2023] [Indexed: 01/14/2024] Open
Abstract
BACKGROUND Simian immunodeficiency viruses (SIV) have been jumping between non-human primates in West/Central Africa for thousands of years and yet, the HIV-1 epidemic only originated from a primate lentivirus over 100 years ago. METHODS This study examined the replicative fitness, transmission, restriction, and cytopathogenicity of 22 primate lentiviruses in primary human lymphoid tissue and both primary human and chimpanzee peripheral blood mononuclear cells. FINDINGS Pairwise competitions revealed that SIV from chimpanzees (cpz) had the highest replicative fitness in human or chimpanzee peripheral blood mononuclear cells, even higher fitness than HIV-1 group M strains responsible for worldwide epidemic. The SIV strains belonging to the "HIV-2 lineage" (including SIVsmm, SIVmac, SIVagm) had the lowest replicative fitness. SIVcpz strains were less inhibited by human restriction factors than the "HIV-2 lineage" strains. SIVcpz efficiently replicated in human tonsillar tissue but did not deplete CD4+ T-cells, consistent with the slow or nonpathogenic disease observed in most chimpanzees. In contrast, HIV-1 isolates and SIV of the HIV-2 lineage were pathogenic to the human tonsillar tissue, almost independent of the level of virus replication. INTERPRETATION Of all primate lentiviruses, SIV from chimpanzees appears most capable of infecting and replicating in humans, establishing HIV-1. SIV from other Old World monkeys, e.g. the progenitor of HIV-2, replicate slowly in humans due in part to restriction factors. Nonetheless, many of these SIV strains were more pathogenic than SIVcpz. Either SIVcpz evolved into a more pathogenic virus while in humans or a rare SIVcpz, possibly extinct in chimpanzees, was pathogenic immediately following the jump into human. FUNDING Support for this study to E.J.A. was provided by the NIH/NIAID R01 AI49170 and CIHR project grant 385787. Infrastructure support was provided by the NIH CFAR AI36219 and Canadian CFI/Ontario ORF 36287. Efforts of J.A.B. and N.J.H. was provided by NIH AI099473 and for D.H.C., by VA and NIH AI AI080313.
Collapse
Affiliation(s)
- Denis M Tebit
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, OH, USA; Global Biomed Scientific, LLC, P.O. Box 2368, Forest, VA, USA
| | - Gabrielle Nickel
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Richard Gibson
- Department of Microbiology and Immunology, Western University, Ontario, Canada
| | - Myriam Rodriguez
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Nicolas J Hathaway
- Department of Pathology and Laboratory Medicine, Warren Alpert Medical School, Brown University, Providence, RI, USA
| | - Katie Bain
- Department of Microbiology and Immunology, Western University, Ontario, Canada
| | - Angel L Reyes-Rodriguez
- Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Pascal Ondoa
- African Society for Laboratory Medicine, Addis Ababa, Ethiopia; Department of Global Health, Institute of Global Health and Development, University of Amsterdam, Amsterdam, the Netherlands
| | - Jonathan L Heeney
- Laboratory of Viral Zoonotics, Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Yue Li
- Department of Microbiology and Immunology, Western University, Ontario, Canada
| | - Jennifer Bongorno
- Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - David Canaday
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - David McDonald
- Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Jeffrey A Bailey
- Department of Pathology and Laboratory Medicine, Warren Alpert Medical School, Brown University, Providence, RI, USA
| | - Eric J Arts
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, OH, USA; Department of Microbiology and Immunology, Western University, Ontario, Canada.
| |
Collapse
|
3
|
Kumar MR, Fray EJ, Bender AM, Zitzmann C, Ribeiro RM, Perelson AS, Barouch DH, Siliciano JD, Siliciano RF. Biphasic decay of intact SHIV genomes following initiation of antiretroviral therapy complicates analysis of interventions targeting the reservoir. Proc Natl Acad Sci U S A 2023; 120:e2313209120. [PMID: 37844236 PMCID: PMC10614214 DOI: 10.1073/pnas.2313209120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 09/05/2023] [Indexed: 10/18/2023] Open
Abstract
The latent reservoir for HIV-1 in resting CD4+ T cells persists despite antiretroviral therapy (ART) and precludes cure. Reservoir-targeting interventions are evaluated in ART-treated macaques infected with simian immunodeficiency virus (SIV) or simian-human immunodeficiency virus (SHIV). Efficacy is determined by reservoir measurements before and after the intervention. However, most proviruses persisting in the setting of ART are defective. In addition, intact HIV-1 and SIV genomes undergo complex, multiphasic decay observable when new infection events are blocked by ART. Intervention-induced elimination of latently infected cells must be distinguished from natural decay. Here, we address these issues for SHIV. We describe an intact proviral DNA assay that allows digital counting of SHIV genomes lacking common fatal defects. We show that intact SHIV genomes in circulating CD4+ T cells undergo biphasic decay during the first year of ART, with a rapid first phase (t1/2 = 30.1 d) and a slower second phase (t1/2 = 8.1 mo) that is still more rapid that the slow decay observed in people with HIV-1 on long-term ART (t1/2 = 3.7 y). In SHIV models, most interventions are tested during 2nd phase decay. Natural 2nd phase decay must be considered in evaluating interventions as most infected cells present at this time do not become part of the stable reservoir. In addition, for interventions tested during 2nd phase decay, a caveat is that the intervention may not be equally effective in people with HIV on long-term ART whose reservoirs are dominated by latently infected cells with a slower decay rate.
Collapse
Affiliation(s)
- Mithra R. Kumar
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD21205
| | - Emily J. Fray
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD21205
| | - Alexandra M. Bender
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD21205
| | | | | | | | - Dan H. Barouch
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Boston, MA02215
| | - Janet D. Siliciano
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD21205
| | - Robert F. Siliciano
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD21205
- HHMI, Baltimore, MD21205
| |
Collapse
|
4
|
Le Hingrat Q, Sette P, Xu C, Rahmberg AR, Tarnus L, Annapureddy H, Kleinman A, Brocca-Cofano E, Sivanandham R, Sivanandham S, He T, Capreri DJ, Ma D, Estes JD, Brenchley JM, Apetrei C, Pandrea I. Prolonged experimental CD4 + T-cell depletion does not cause disease progression in SIV-infected African green monkeys. Nat Commun 2023; 14:979. [PMID: 36813761 PMCID: PMC9946951 DOI: 10.1038/s41467-023-36379-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 01/23/2023] [Indexed: 02/24/2023] Open
Abstract
CD4+ T-cell depletion is a hallmark of HIV infection, leading to impairment of cellular immunity and opportunistic infections, but its contribution to SIV/HIV-associated gut dysfunction is unknown. Chronically SIV-infected African Green Monkeys (AGMs) partially recover mucosal CD4+ T-cells, maintain gut integrity and do not progress to AIDS. Here we assess the impact of prolonged, antibody-mediated CD4 + T-cell depletion on gut integrity and natural history of SIV infection in AGMs. All circulating CD4+ T-cells and >90% of mucosal CD4+ T-cells are depleted. Plasma viral loads and cell-associated viral RNA in tissues are lower in CD4+-cell-depleted animals. CD4+-cell-depleted AGMs maintain gut integrity, control immune activation and do not progress to AIDS. We thus conclude that CD4+ T-cell depletion is not a determinant of SIV-related gut dysfunction, when gastrointestinal tract epithelial damage and inflammation are absent, suggesting that disease progression and resistance to AIDS are independent of CD4+ T-cell restoration in SIVagm-infected AGMs.
Collapse
Affiliation(s)
- Quentin Le Hingrat
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.,Division of Infectious Diseases, Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Paola Sette
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.,Division of Infectious Diseases, Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Cuiling Xu
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.,Division of Infectious Diseases, Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Andrew R Rahmberg
- Barrier Immunity Section, Lab of Viral Diseases, Division of Intramural Research, NIAID, NIH, Bethesda, MD, USA
| | - Lilas Tarnus
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.,Division of Infectious Diseases, Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Haritha Annapureddy
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Adam Kleinman
- Division of Infectious Diseases, Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Egidio Brocca-Cofano
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Ranjit Sivanandham
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Sindhuja Sivanandham
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Tianyu He
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Daniel J Capreri
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Dongzhu Ma
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.,Division of Infectious Diseases, Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jacob D Estes
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Portland, OR, USA.,Division of Pathobiology and Immunology, Oregon National Primate Research Center, Oregon Health & Science University, Portland, OR, USA
| | - Jason M Brenchley
- Barrier Immunity Section, Lab of Viral Diseases, Division of Intramural Research, NIAID, NIH, Bethesda, MD, USA
| | - Cristian Apetrei
- Division of Infectious Diseases, Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.,Department of Infectious Diseases and Microbiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - Ivona Pandrea
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA. .,Department of Infectious Diseases and Microbiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.
| |
Collapse
|
5
|
Reno TA, Tarnus L, Tracy R, Landay AL, Sereti I, Apetrei C, Pandrea I. The Youngbloods. Get Together. Hypercoagulation, Complement, and NET Formation in HIV/SIV Pathogenesis. FRONTIERS IN VIROLOGY 2022. [DOI: 10.3389/fviro.2021.795373] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Chronic, systemic T-cell immune activation and inflammation (IA/INFL) have been reported to be associated with disease progression in persons with HIV (PWH) since the inception of the AIDS pandemic. IA/INFL persist in PWH on antiretroviral therapy (ART), despite complete viral suppression and increases their susceptibility to serious non-AIDS events (SNAEs). Increased IA/INFL also occur during pathogenic SIV infections of macaques, while natural hosts of SIVs that control chronic IA/INFL do not progress to AIDS, despite having persistent high viral replication and severe acute CD4+ T-cell loss. Moreover, natural hosts of SIVs do not present with SNAEs. Multiple mechanisms drive HIV-associated IA/INFL, including the virus itself, persistent gut dysfunction, coinfections (CMV, HCV, HBV), proinflammatory lipids, ART toxicity, comorbidities, and behavioral factors (diet, smoking, and alcohol). Other mechanisms could also significantly contribute to IA/INFL during HIV/SIV infection, notably, a hypercoagulable state, characterized by elevated coagulation biomarkers, including D-dimer and tissue factor, which can accurately identify patients at risk for thromboembolic events and death. Coagulation biomarkers strongly correlate with INFL and predict the risk of SNAE-induced end-organ damage. Meanwhile, the complement system is also involved in the pathogenesis of HIV comorbidities. Despite prolonged viral suppression, PWH on ART have high plasma levels of C3a. HIV/SIV infections also trigger neutrophil extracellular traps (NETs) formation that contribute to the elimination of viral particles and infected CD4+ T-cells. However, as SIV infection progresses, generation of NETs can become excessive, fueling IA/INFL, destruction of multiple immune cells subsets, and microthrombotic events, contributing to further tissue damages and SNAEs. Tackling residual IA/INFL has the potential to improve the clinical course of HIV infection. Therefore, therapeutics targeting new pathways that can fuel IA/INFL such as hypercoagulation, complement activation and excessive formation of NETs might be beneficial for PWH and should be considered and evaluated.
Collapse
|
6
|
Prasad AN, Woolsey C, Geisbert JB, Agans KN, Borisevich V, Deer DJ, Mire CE, Cross RW, Fenton KA, Broder CC, Geisbert TW. Resistance of Cynomolgus Monkeys to Nipah and Hendra Virus Disease Is Associated With Cell-Mediated and Humoral Immunity. J Infect Dis 2021; 221:S436-S447. [PMID: 32022850 DOI: 10.1093/infdis/jiz613] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND The henipaviruses, Hendra virus (HeV) and Nipah virus (NiV), are capable of causing severe and often lethal respiratory and/or neurologic disease in animals and humans. Given the sporadic nature of henipavirus outbreaks, licensure of vaccines and therapeutics for human use will likely require demonstration of efficacy in animal models that faithfully reproduce the human condition. Currently, the African green monkey (AGM) best mimics human henipavirus-induced disease. METHODS The pathogenic potential of HeV and both strains of NiV (Malaysia, Bangladesh) was assessed in cynomolgus monkeys and compared with henipavirus-infected historical control AGMs. Multiplex gene and protein expression assays were used to compare host responses. RESULTS In contrast to AGMs, in which henipaviruses cause severe and usually lethal disease, HeV and NiVs caused only mild or asymptomatic infections in macaques. All henipaviruses replicated in macaques with similar kinetics as in AGMs. Infection in macaques was associated with activation and predicted recruitment of cytotoxic CD8+ T cells, Th1 cells, IgM+ B cells, and plasma cells. Conversely, fatal outcome in AGMs was associated with aberrant innate immune signaling, complement dysregulation, Th2 skewing, and increased secretion of MCP-1. CONCLUSION The restriction factors identified in macaques can be harnessed for development of effective countermeasures against henipavirus disease.
Collapse
Affiliation(s)
- Abhishek N Prasad
- Galveston National Laboratory, University of Texas Medical Branch, Galveston.,Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston
| | - Courtney Woolsey
- Galveston National Laboratory, University of Texas Medical Branch, Galveston.,Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston
| | - Joan B Geisbert
- Galveston National Laboratory, University of Texas Medical Branch, Galveston.,Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston
| | - Krystle N Agans
- Galveston National Laboratory, University of Texas Medical Branch, Galveston.,Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston
| | - Viktoriya Borisevich
- Galveston National Laboratory, University of Texas Medical Branch, Galveston.,Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston
| | - Daniel J Deer
- Galveston National Laboratory, University of Texas Medical Branch, Galveston.,Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston
| | - Chad E Mire
- Galveston National Laboratory, University of Texas Medical Branch, Galveston.,Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston
| | - Robert W Cross
- Galveston National Laboratory, University of Texas Medical Branch, Galveston.,Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston
| | - Karla A Fenton
- Galveston National Laboratory, University of Texas Medical Branch, Galveston.,Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston
| | - Christopher C Broder
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, Maryland
| | - Thomas W Geisbert
- Galveston National Laboratory, University of Texas Medical Branch, Galveston.,Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston
| |
Collapse
|
7
|
Rouzine IM. An Evolutionary Model of Progression to AIDS. Microorganisms 2020; 8:microorganisms8111714. [PMID: 33142907 PMCID: PMC7692852 DOI: 10.3390/microorganisms8111714] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 10/30/2020] [Accepted: 10/30/2020] [Indexed: 11/16/2022] Open
Abstract
The time to the onset of AIDS symptoms in an HIV infected individual is known to correlate inversely with viremia and the level of immune activation. The correlation exists against the background of strong individual fluctuations demonstrating the existence of hidden variables depending on patient and virus parameters. At the moment, prognosis of the time to AIDS based on patient parameters is not possible. In addition, it is of paramount importance to understand the reason of progression to AIDS in untreated patients to be able to learn to control it by means other than anti-retroviral therapy. Here we develop a mechanistic mathematical model to predict the speed of progression to AIDS in individual untreated patients and patients treated with suboptimal therapy, based on a single-time measurement of several virological and immunological parameters. We show that the gradual increase in virus fitness during a chronic infection causes slow gradual depletion of CD4 T cells. Using the existing evolution models of HIV, we obtain general expressions predicting the time to the onset of AIDS symptoms in terms of the patient parameters, for low-viremia and high-viremia patients separately. We show that the evolution model of AIDS fits the existing data on virus-time correlations better than the alternative model of the deregulation of homeostatic response.
Collapse
Affiliation(s)
- Igor M Rouzine
- Laboratory of Computational and Quantitative Biology, 7238 CNRS-UPMC, Institut Biologie Paris-Seine, Sorbonne Université, Campus Pierre et Marie Curie, 75005 Paris, France
| |
Collapse
|
8
|
Nonhuman Primate Testing of the Impact of Different Regulatory T Cell Depletion Strategies on Reactivation and Clearance of Latent Simian Immunodeficiency Virus. J Virol 2020; 94:JVI.00533-20. [PMID: 32669326 DOI: 10.1128/jvi.00533-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 07/07/2020] [Indexed: 12/20/2022] Open
Abstract
Regulatory T cells (Tregs) may be key contributors to the HIV/SIV latent reservoir, since they harbor high levels of HIV/SIV; reverse CD4+ T cell immune activation status, increasing the pool of resting CD4+ T cells; and impair CD8+ T cell function, favoring HIV persistence. We tested the hypothesis that Treg depletion is a valid intervention toward an HIV cure by depleted Tregs in 14 rhesus macaque (RM) controllers infected with SIVsab, the virus that naturally infects sabaeus monkeys, through different strategies: administration of an anti-CCR4 immunotoxin, two doses of an anti-CD25 immunotoxin (interleukin-2 with diphtheria toxin [IL-2-DT]), or two combinations of both. All of these treatments resulted in significant depletion of the circulating Tregs (>70%) and their partial depletion in the gut (25%) and lymph nodes (>50%). The fractions of CD4+ T cells expressing Ki -67 increased up to 80% in experiments containing IL-2-DT and only 30% in anti-CCR4-treated RMs, paralleled by increases in the inflammatory cytokines. In the absence of ART, plasma virus rebounded to 103 vRNA copies/ml by day 10 after IL-2-DT administration. A large but transient boost of the SIV-specific CD8+ T cell responses occurred in IL-2-DT-treated RMs. Such increases were minimal in the RMs receiving anti-CCR4-based regimens. Five RMs received IL-2-DT on ART, but treatment was discontinued because of high toxicity and lymphopenia. As such, while all treatments depleted a significant proportion of Tregs, the side effects in the presence of ART prevent their clinical use and call for different Treg depletion approaches. Thus, based on our data, Treg targeting as a strategy for HIV cure cannot be discarded.IMPORTANCE Regulatory T cells (Tregs) can decisively contribute to the establishment and persistence of the HIV reservoir, since they harbor high levels of HIV/SIV, increase the pool of resting CD4+ T cells by reversing their immune activation status, and impair CD8+ T cell function, favoring HIV persistence. We tested multiple Treg depletion strategies and showed that all of them are at least partially successful in depleting Tregs. As such, Treg depletion appears to be a valid intervention toward an HIV cure, reducing the size of the reservoir, reactivating the virus, and boosting cell-mediated immune responses. Yet, when Treg depletion was attempted in ART-suppressed animals, the treatment had to be discontinued due to high toxicity and lymphopenia. Therefore, while Treg targeting as a strategy for HIV cure cannot be discarded, the methodology for Treg depletion has to be revisited.
Collapse
|
9
|
Raehtz KD, Barrenäs F, Xu C, Busman-Sahay K, Valentine A, Law L, Ma D, Policicchio BB, Wijewardana V, Brocca-Cofano E, Trichel A, Gale M, Keele BF, Estes JD, Apetrei C, Pandrea I. African green monkeys avoid SIV disease progression by preventing intestinal dysfunction and maintaining mucosal barrier integrity. PLoS Pathog 2020; 16:e1008333. [PMID: 32119719 PMCID: PMC7077871 DOI: 10.1371/journal.ppat.1008333] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 03/17/2020] [Accepted: 01/18/2020] [Indexed: 12/12/2022] Open
Abstract
Unlike HIV infection, SIV infection is generally nonpathogenic in natural hosts, such as African green monkeys (AGMs), despite life-long high viral replication. Lack of disease progression was reportedly based on the ability of SIV-infected AGMs to prevent gut dysfunction, avoiding microbial translocation and the associated systemic immune activation and chronic inflammation. Yet, the maintenance of gut integrity has never been documented, and the mechanism(s) by which gut integrity is preserved are unknown. We sought to investigate the early events of SIV infection in AGMs, specifically examining the impact of SIVsab infection on the gut mucosa. Twenty-nine adult male AGMs were intrarectally infected with SIVsab92018 and serially sacrificed at well-defined stages of SIV infection, preramp-up (1-3 days post-infection (dpi)), ramp-up (4-6 dpi), peak viremia (9-12 dpi), and early chronic SIV infection (46-55 dpi), to assess the levels of immune activation, apoptosis, epithelial damage and microbial translocation in the GI tract and peripheral lymph nodes. Tissue viral loads, plasma cytokines and plasma markers of gut dysfunction were also measured throughout the course of early infection. While a strong, but transient, interferon-based inflammatory response was observed, the levels of plasma markers linked to enteropathy did not increase. Accordingly, no significant increases in apoptosis of either mucosal enterocytes or lymphocytes, and no damage to the mucosal epithelium were documented during early SIVsab infection of AGMs. These findings were supported by RNAseq of the gut tissue, which found no significant alterations in gene expression that would indicate microbial translocation. Thus, for the first time, we confirmed that gut epithelial integrity is preserved, with no evidence of microbial translocation, in AGMs throughout early SIVsab infection. This might protect AGMs from developing intestinal dysfunction and the subsequent chronic inflammation that drives both HIV disease progression and HIV-associated comorbidities.
Collapse
Affiliation(s)
- Kevin D. Raehtz
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Fredrik Barrenäs
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Cuiling Xu
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Kathleen Busman-Sahay
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Portland, Oregon, United States of America
- Oregon National Primate Research Center, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Audrey Valentine
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Lynn Law
- Department of Immunology, University of Washington, Seattle, Washington, United States of America
- Center for Innate Immunity and Immune Diseases, University of Washington, Washington, United States of America
| | - Dongzhu Ma
- Department of Orthopedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Benjamin B. Policicchio
- Department of Infectious Diseases and Microbiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Viskam Wijewardana
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Egidio Brocca-Cofano
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Anita Trichel
- Division of Laboratory Animal Resources, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Michael Gale
- Department of Immunology, University of Washington, Seattle, Washington, United States of America
- Center for Innate Immunity and Immune Diseases, University of Washington, Washington, United States of America
- Washington National Primate Research Center, University of Washington, Seattle, Washington, United States of America
| | - Brandon F. Keele
- AIDS and Cancer Virus Program, Frederick National Laboratory of Cancer Research, Frederick, Maryland, United States of America
| | - Jacob D. Estes
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Portland, Oregon, United States of America
- Oregon National Primate Research Center, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Cristian Apetrei
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Infectious Diseases and Microbiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Ivona Pandrea
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Infectious Diseases and Microbiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| |
Collapse
|
10
|
Wetzel KS, Yi Y, Yadav A, Bauer AM, Bello EA, Romero DC, Bibollet-Ruche F, Hahn BH, Paiardini M, Silvestri G, Peeters M, Collman RG. Loss of CXCR6 coreceptor usage characterizes pathogenic lentiviruses. PLoS Pathog 2018; 14:e1007003. [PMID: 29659623 PMCID: PMC5919676 DOI: 10.1371/journal.ppat.1007003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 04/26/2018] [Accepted: 04/02/2018] [Indexed: 11/18/2022] Open
Abstract
Pandemic HIV-1 originated from the cross-species transmission of SIVcpz, which infects chimpanzees, while SIVcpz itself emerged following the cross-species transmission and recombination of monkey SIVs, with env contributed by the SIVgsn/mus/mon lineage that infects greater spot-nosed, mustached and mona monkeys. SIVcpz and HIV-1 are pathogenic in their respective hosts, while the phenotype of their SIVgsn/mus/mon ancestors is unknown. However, two well-studied SIV infected natural hosts, sooty mangabeys (SMs) and African green monkeys (AGMs), typically remain healthy despite high viral loads; these species express low levels of the canonical coreceptor CCR5, and recent work shows that CXCR6 is a major coreceptor for SIV in these hosts. It is not known what coreceptors were used by the precursors of SIVcpz, whether coreceptor use changed during emergence of the SIVcpz/HIV-1 lineage, and what T cell subsets express CXCR6 in natural hosts. Using species-matched coreceptors and CD4, we show here that SIVcpz uses only CCR5 for entry and, like HIV-1, cannot use CXCR6. In contrast, SIVmus efficiently uses both CXCR6 and CCR5. Coreceptor selectivity was determined by Env, with CXCR6 use abrogated by Pro326 in the V3 crown, which is absent in monkey SIVs but highly conserved in SIVcpz/HIV-1. To characterize which cells express CXCR6, we generated a novel antibody that recognizes CXCR6 of multiple primate species. Testing lymphocytes from SM, the best-studied natural host, we found that CXCR6 is restricted to CD4+ effector memory cells, and is expressed by a sub-population distinct from those expressing CCR5. Thus, efficient CXCR6 use, previously identified in SM and AGM infection, also characterizes a member of the SIV lineage that gave rise to SIVcpz/HIV-1. Loss of CXCR6 usage by SIVcpz may have altered its cell tropism, shifting virus from CXCR6-expressing cells that may support replication without disrupting immune function or homeostasis, towards CCR5-expressing cells with pathogenic consequences.
Collapse
Affiliation(s)
- Katherine S. Wetzel
- Departments of Medicine and Microbiology, University of Pennsylvania School of Medicine, Philadelphia, PA, United States of America
| | - Yanjie Yi
- Departments of Medicine and Microbiology, University of Pennsylvania School of Medicine, Philadelphia, PA, United States of America
| | - Anjana Yadav
- Departments of Medicine and Microbiology, University of Pennsylvania School of Medicine, Philadelphia, PA, United States of America
| | - Anya M. Bauer
- Departments of Medicine and Microbiology, University of Pennsylvania School of Medicine, Philadelphia, PA, United States of America
| | - Ezekiel A. Bello
- Departments of Medicine and Microbiology, University of Pennsylvania School of Medicine, Philadelphia, PA, United States of America
| | - Dino C. Romero
- Departments of Medicine and Microbiology, University of Pennsylvania School of Medicine, Philadelphia, PA, United States of America
| | - Frederic Bibollet-Ruche
- Departments of Medicine and Microbiology, University of Pennsylvania School of Medicine, Philadelphia, PA, United States of America
| | - Beatrice H. Hahn
- Departments of Medicine and Microbiology, University of Pennsylvania School of Medicine, Philadelphia, PA, United States of America
| | - Mirko Paiardini
- Division of Microbiology and Immunology, Yerkes National Primate Research Center, Atlanta, GA, United States of America
| | - Guido Silvestri
- Division of Microbiology and Immunology, Yerkes National Primate Research Center, Atlanta, GA, United States of America
| | - Martine Peeters
- UMI233-TransVIHMI/INSERM U1175, Institut de Recherche pour le Développement (IRD) and University of Montpellier, Montpellier, France
| | - Ronald G. Collman
- Departments of Medicine and Microbiology, University of Pennsylvania School of Medicine, Philadelphia, PA, United States of America
- * E-mail:
| |
Collapse
|
11
|
Joas S, Parrish EH, Gnanadurai CW, Lump E, Stürzel CM, Parrish NF, Learn GH, Sauermann U, Neumann B, Rensing KM, Fuchs D, Billingsley JM, Bosinger SE, Silvestri G, Apetrei C, Huot N, Garcia-Tellez T, Müller-Trutwin M, Hotter D, Sauter D, Stahl-Hennig C, Hahn BH, Kirchhoff F. Species-specific host factors rather than virus-intrinsic virulence determine primate lentiviral pathogenicity. Nat Commun 2018; 9:1371. [PMID: 29636452 PMCID: PMC5893559 DOI: 10.1038/s41467-018-03762-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 03/07/2018] [Indexed: 12/23/2022] Open
Abstract
HIV-1 causes chronic inflammation and AIDS in humans, whereas related simian immunodeficiency viruses (SIVs) replicate efficiently in their natural hosts without causing disease. It is currently unknown to what extent virus-specific properties are responsible for these different clinical outcomes. Here, we incorporate two putative HIV-1 virulence determinants, i.e., a Vpu protein that antagonizes tetherin and blocks NF-κB activation and a Nef protein that fails to suppress T cell activation via downmodulation of CD3, into a non-pathogenic SIVagm strain and test their impact on viral replication and pathogenicity in African green monkeys. Despite sustained high-level viremia over more than 4 years, moderately increased immune activation and transcriptional signatures of inflammation, the HIV-1-like SIVagm does not cause immunodeficiency or any other disease. These data indicate that species-specific host factors rather than intrinsic viral virulence factors determine the pathogenicity of primate lentiviruses.
Collapse
Affiliation(s)
- Simone Joas
- Institute of Molecular Virology, Ulm University Medical Center, 89081, Ulm, Germany
| | - Erica H Parrish
- Departments of Medicine and Microbiology, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, 372327, USA
| | - Clement W Gnanadurai
- Institute of Molecular Virology, Ulm University Medical Center, 89081, Ulm, Germany
- Department of Veterinary Pathology, University of Georgia, Athens, GA, 30602, USA
| | - Edina Lump
- Institute of Molecular Virology, Ulm University Medical Center, 89081, Ulm, Germany
| | - Christina M Stürzel
- Institute of Molecular Virology, Ulm University Medical Center, 89081, Ulm, Germany
| | - Nicholas F Parrish
- Departments of Medicine and Microbiology, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Gerald H Learn
- Departments of Medicine and Microbiology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | | | | | | | - Dietmar Fuchs
- Division of Biological Chemistry, Biocenter Innsbruck Medical University, Center for Chemistry and Biomedicine, A-6020, Innsbruck, Austria
| | - James M Billingsley
- Emory Vaccine Center and Yerkes National Primate Research Center, Emory University, Atlanta, GA, 30322, USA
| | - Steven E Bosinger
- Emory Vaccine Center and Yerkes National Primate Research Center, Emory University, Atlanta, GA, 30322, USA
| | - Guido Silvestri
- Emory Vaccine Center and Yerkes National Primate Research Center, Emory University, Atlanta, GA, 30322, USA
| | - Cristian Apetrei
- WA Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Nicolas Huot
- Institut Pasteur, Unité HIV, Inflammation and Persistence, Paris, 75015, France
- Vaccine Research Institute, Hôpital Henri Mondor, Créteil, 94010, France
| | | | | | - Dominik Hotter
- Institute of Molecular Virology, Ulm University Medical Center, 89081, Ulm, Germany
| | - Daniel Sauter
- Institute of Molecular Virology, Ulm University Medical Center, 89081, Ulm, Germany
| | | | - Beatrice H Hahn
- Departments of Medicine and Microbiology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, 89081, Ulm, Germany.
| |
Collapse
|
12
|
Policicchio BB, Sette P, Xu C, Haret-Richter G, Dunsmore T, Pandrea I, Ribeiro RM, Apetrei C. Emergence of resistance mutations in simian immunodeficiency virus (SIV)-infected rhesus macaques receiving non-suppressive antiretroviral therapy (ART). PLoS One 2018; 13:e0190908. [PMID: 29466356 PMCID: PMC5821307 DOI: 10.1371/journal.pone.0190908] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 12/21/2017] [Indexed: 01/31/2023] Open
Abstract
Two SIVmac251-infected rhesus macaques received tenofovir/emtricitabine with raltegravir intensification. Viral rebound occurred during treatment and sequencing of reverse transcriptase and integrase genes identified multiple resistance mutations. Similar to HIV infection, antiretroviral-resistance mutations may occur in SIV-infected nonhuman primates receiving nonsuppressive ART. As ART administration to nonhuman primates is currently dramatically expanding, fueled by both cure research and the study of HIV-related comorbidities, viral resistance should be factored in the study design and data interpretation.
Collapse
Affiliation(s)
- Benjamin Bruno Policicchio
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Infectious Diseases and Microbiology, Graduate School of Public Health, University of Pittsburgh, Pennsylvania, United States of America
| | - Paola Sette
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Cuiling Xu
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - George Haret-Richter
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Tammy Dunsmore
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Ivona Pandrea
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Infectious Diseases and Microbiology, Graduate School of Public Health, University of Pittsburgh, Pennsylvania, United States of America
- Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Ruy M. Ribeiro
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
- Laboratorio de Biomatemática, Faculdade de Medicina, Universidade de Lisbo, Lisboa, Portugal
| | - Cristian Apetrei
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Infectious Diseases and Microbiology, Graduate School of Public Health, University of Pittsburgh, Pennsylvania, United States of America
- Microbiology and Molecular Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
| |
Collapse
|
13
|
Pathogenic Correlates of Simian Immunodeficiency Virus-Associated B Cell Dysfunction. J Virol 2017; 91:JVI.01051-17. [PMID: 28931679 DOI: 10.1128/jvi.01051-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 09/12/2017] [Indexed: 01/08/2023] Open
Abstract
We compared and contrasted pathogenic (in pig-tailed macaques [PTMs]) and nonpathogenic (in African green monkeys [AGMs]) SIVsab infections to assess the significance of the B cell dysfunction observed in simian (SIV) and human immunodeficiency virus (HIV) infections. We report that the loss of B cells is specifically associated with the pathogenic SIV infection, while in the natural hosts, in which SIV is nonpathogenic, B cells rapidly increase in both lymph nodes (LNs) and intestine. SIV-associated B cell dysfunction associated with the pathogenic SIV infection is characterized by loss of naive B cells, loss of resting memory B cells due to their redistribution to the gut, increases of the activated B cells and circulating tissue-like memory B cells, and expansion of the B regulatory cells (Bregs). While circulating B cells are virtually restored to preinfection levels during the chronic pathogenic SIV infection, restoration is mainly due to an expansion of the "exhausted," virus-specific B cells, i.e., activated memory cells and tissue-like memory B cells. Despite of the B cell dysfunction, SIV-specific antibody (Ab) production was higher in the PTMs than in AGMs, with the caveat that rapid disease progression in PTMs was strongly associated with lack of anti-SIV Ab. Neutralization titers and the avidity and maturation of immune responses did not differ between pathogenic and nonpathogenic infections, with the exception of the conformational epitope recognition, which evolved from low to high conformations in the natural host. The patterns of humoral immune responses in the natural host are therefore more similar to those observed in HIV-infected subjects, suggesting that natural hosts may be more appropriate for modeling the immunization strategies aimed at preventing HIV disease progression. The numerous differences between the pathogenic and nonpathogenic infections with regard to dynamics of the memory B cell subsets point to their role in the pathogenesis of HIV/SIV infections and suggest that monitoring B cells may be a reliable approach for assessing disease progression.IMPORTANCE We report here that the HIV/SIV-associated B cell dysfunction (defined by loss of total and memory B cells, increased B regulatory cell [Breg] counts, and B cell activation and apoptosis) is specifically associated with pathogenic SIV infection and absent during the course of nonpathogenic SIV infection in natural nonhuman primate hosts. Alterations of the B cell population are not correlated with production of neutralizing antibodies, the levels of which are similar in the two species. Rapid progressive infections are associated with a severe impairment in SIV-specific antibody production. While we did not find major differences in avidity and maturation between the pathogenic and nonpathogenic SIV infections, we identified a major difference in conformational epitope recognition, with the nonpathogenic infection being characterized by an evolution from low to high conformations. B cell dysfunction should be considered in designing immunization strategies aimed at preventing HIV disease progression.
Collapse
|
14
|
CXCR6-Mediated Simian Immunodeficiency Virus SIVagmSab Entry into Sabaeus African Green Monkey Lymphocytes Implicates Widespread Use of Non-CCR5 Pathways in Natural Host Infections. J Virol 2017; 91:JVI.01626-16. [PMID: 27903799 DOI: 10.1128/jvi.01626-16] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 11/22/2016] [Indexed: 12/14/2022] Open
Abstract
African green monkeys (AGM) and sooty mangabeys (SM) are well-studied natural hosts of simian immunodeficiency virus (SIV) that do not progress to AIDS when infected with their species-specific viruses. Natural hosts of SIV express very low levels of the canonical entry coreceptor CCR5, and recent studies have shown that CCR5 is dispensable for SIV infection of SM in vivo and that blocking of CCR5 does not prevent ex vivo infection of peripheral blood mononuclear cells (PBMC) from SM or vervet AGM. In both hosts, CXCR6 is an efficient entry pathway in vitro Here we investigated the use of species-matched CXCR6 and other alternative coreceptors by SIVagmSab, which infects sabaeus AGM. We cloned sabaeus CD4 and 10 candidate coreceptors. Species-matched CXCR6, CCR5, and GPR15 mediated robust entry into transfected cells by pseudotypes carrying SIVagmSab92018ivTF Env, with lower-level entry through GPR1 and APJ. We cloned genetically divergent env genes from the plasma of two wild-infected sabaeus AGM and found similar patterns of coreceptor use. Titration experiments showed that CXCR6 and CCR5 were more efficient than other coreceptors when tested at limiting CD4/coreceptor levels. Finally, blocking of CXCR6 with its ligand CXCL16 significantly inhibited SIVagmSab replication in sabaeus PBMC and had a greater impact than did the CCR5 blocker maraviroc, confirming the use of CXCR6 in primary lymphocyte infection. These data suggest a new paradigm for SIV infection of natural host species, whereby a shared outcome of virus-host coevolution is the use of CXCR6 or other alternative coreceptors for entry, which may direct SIV toward CD4+ T cell subsets and anatomical sites that support viral replication without disrupting immune homeostasis and function. IMPORTANCE Natural hosts of SIV do not progress to AIDS, in stark contrast to pathogenic human immunodeficiency virus type 1 (HIV-1)-human and SIVmac-macaque infections. Identifying how natural hosts avoid immunodeficiency can elucidate key mechanisms of pathogenesis. It is known that despite high viral loads, natural hosts have a low frequency of CD4+ cells expressing the SIV coreceptor CCR5. In this study, we demonstrate the efficient use of the coreceptor CXCR6 by SIVagmSab to infect sabaeus African green monkey lymphocytes. In conjunction with studies of SIVsmm, which infects sooty mangabeys, and SIVagmVer, which infects vervet monkeys, our data suggest a unifying model whereby in natural hosts, in which the CCR5 expression level is low, the use of CXCR6 or other coreceptors to mediate infection may target SIV toward distinct cell populations that are able to support high-level viral replication without causing a loss of CD4+ T cell homeostasis and lymphoid tissue damage that lead to AIDS in HIV-1 and SIVmac infections.
Collapse
|
15
|
Immune activation in HIV infection: what can the natural hosts of simian immunodeficiency virus teach us? Curr Opin HIV AIDS 2016; 11:201-8. [PMID: 26845673 DOI: 10.1097/coh.0000000000000238] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE OF REVIEW The review summarizes studies in natural hosts, with a particular focus on the control of immune activation and new insights into viral reservoirs. We discuss why these findings are relevant for HIV research today. RECENT FINDINGS AIDS resistance in natural hosts is characterized by a rapid control of inflammatory processes in response to simian immunodeficiency virus infection despite persistent viremia. Although CD4 T cells are dramatically depleted in the intestine in primary infection, interleukin 17-producing T helper cells (Th17) are preserved and natural hosts lack microbial translocation. Thus, viral replication in the gut is not sufficient to explain mucosal damage, but additional factors are necessary. Natural hosts also display a lower infection rate of stem-cell memory, central memory and follicular helper T cells. The follicles are characterized by a lack of viral trapping and the viral replication in secondary lymphoid organs is rapidly controlled. Hence, the healthy status of natural hosts is associated with preserved lymphoid environments. SUMMARY Understanding the underlying mechanisms of preservation of Th17 and of the low contribution of stem-cell memory, central memory and follicular helper T cells to viral reservoirs could benefit the search for preventive and curative approaches of HIV. Altogether, the complementarity of the model helps to identify strategies aiming at restoring full capacity of the immune system and decreasing the size of the viral reservoirs.
Collapse
|
16
|
Notwithstanding Circumstantial Alibis, Cytotoxic T Cells Can Be Major Killers of HIV-1-Infected Cells. J Virol 2016; 90:7066-7083. [PMID: 27226367 PMCID: PMC4984658 DOI: 10.1128/jvi.00306-16] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 05/06/2016] [Indexed: 02/07/2023] Open
Abstract
Several experiments suggest that in the chronic phase of human immunodeficiency virus type 1 (HIV-1) infection, CD8+ cytotoxic T lymphocytes (CTL) contribute very little to the death of productively infected cells. First, the expected life span of productively infected cells is fairly long, i.e., about 1 day. Second, this life span is hardly affected by the depletion of CD8+ T cells. Third, the rate at which mutants escaping a CTL response take over the viral population tends to be slow. Our main result is that all these observations are perfectly compatible with killing rates that are much faster than one per day once we invoke the fact that infected cells proceed through an eclipse phase of about 1 day before they start producing virus. Assuming that the major protective effect of CTL is cytolytic, we demonstrate that mathematical models with an eclipse phase account for the data when the killing is fast and when it varies over the life cycle of infected cells. Considering the steady state corresponding to the chronic phase of the infection, we find that the rate of immune escape and the rate at which the viral load increases following CD8+ T cell depletion should reflect the viral replication rate, ρ. A meta-analysis of previous data shows that viral replication rates during chronic infection vary between 0.5 ≤ ρ ≤ 1 day−1. Balancing such fast viral replication requires killing rates that are several times larger than ρ, implying that most productively infected cells would die by cytolytic effects. IMPORTANCE Most current data suggest that cytotoxic T cells (CTL) mediate their control of human immunodeficiency virus type 1 (HIV-1) infection by nonlytic mechanisms; i.e., the data suggest that CTL hardly kill. This interpretation of these data has been based upon the general mathematical model for HIV infection. Because this model ignores the eclipse phase between the infection of a target cell and the start of viral production by that cell, we reanalyze the same data sets with novel models that do account for the eclipse phase. We find that the data are perfectly consistent with lytic control by CTL and predict that most productively infected cells are killed by CTL. Because the killing rate should balance the viral replication rate, we estimate both parameters from a large set of published experiments in which CD8+ T cells were depleted in simian immunodeficiency virus (SIV)-infected monkeys. This confirms that the killing rate can be much faster than is currently appreciated.
Collapse
|
17
|
The well-tempered SIV infection: Pathogenesis of SIV infection in natural hosts in the wild, with emphasis on virus transmission and early events post-infection that may contribute to protection from disease progression. INFECTION GENETICS AND EVOLUTION 2016; 46:308-323. [PMID: 27394696 DOI: 10.1016/j.meegid.2016.07.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Revised: 07/04/2016] [Accepted: 07/05/2016] [Indexed: 12/25/2022]
Abstract
African NHPs are infected by over 40 different simian immunodeficiency viruses. These viruses have coevolved with their hosts for long periods of time and, unlike HIV in humans, infection does not generally lead to disease progression. Chronic viral replication is maintained for the natural lifespan of the host, without loss of overall immune function. Lack of disease progression is not correlated with transmission, as SIV infection is highly prevalent in many African NHP species in the wild. The exact mechanisms by which these natural hosts of SIV avoid disease progression are still unclear, but a number of factors might play a role, including: (i) avoidance of microbial translocation from the gut lumen by preventing or repairing damage to the gut epithelium; (ii) control of immune activation and apoptosis following infection; (iii) establishment of an anti-inflammatory response that resolves chronic inflammation; (iv) maintenance of homeostasis of various immune cell populations, including NK cells, monocytes/macrophages, dendritic cells, Tregs, Th17 T-cells, and γδ T-cells; (v) restriction of CCR5 availability at mucosal sites; (vi) preservation of T-cell function associated with down-regulation of CD4 receptor. Some of these mechanisms might also be involved in protection of natural hosts from mother-to-infant SIV transmission during breastfeeding. The difficulty of performing invasive studies in the wild has prohibited investigation of the exact events surrounding transmission in natural hosts. Increased understanding of the mechanisms of SIV transmission in natural hosts, and of the early events post-transmission which may contribute to avoidance of disease progression, along with better comprehension of the factors involved in protection from SIV breastfeeding transmission in the natural hosts, could prove invaluable for the development of new prevention strategies for HIV.
Collapse
|
18
|
Li H, Wang S, Kong R, Ding W, Lee FH, Parker Z, Kim E, Learn GH, Hahn P, Policicchio B, Brocca-Cofano E, Deleage C, Hao X, Chuang GY, Gorman J, Gardner M, Lewis MG, Hatziioannou T, Santra S, Apetrei C, Pandrea I, Alam SM, Liao HX, Shen X, Tomaras GD, Farzan M, Chertova E, Keele BF, Estes JD, Lifson JD, Doms RW, Montefiori DC, Haynes BF, Sodroski JG, Kwong PD, Hahn BH, Shaw GM. Envelope residue 375 substitutions in simian-human immunodeficiency viruses enhance CD4 binding and replication in rhesus macaques. Proc Natl Acad Sci U S A 2016; 113:E3413-22. [PMID: 27247400 PMCID: PMC4914158 DOI: 10.1073/pnas.1606636113] [Citation(s) in RCA: 150] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Most simian-human immunodeficiency viruses (SHIVs) bearing envelope (Env) glycoproteins from primary HIV-1 strains fail to infect rhesus macaques (RMs). We hypothesized that inefficient Env binding to rhesus CD4 (rhCD4) limits virus entry and replication and could be enhanced by substituting naturally occurring simian immunodeficiency virus Env residues at position 375, which resides at a critical location in the CD4-binding pocket and is under strong positive evolutionary pressure across the broad spectrum of primate lentiviruses. SHIVs containing primary or transmitted/founder HIV-1 subtype A, B, C, or D Envs with genotypic variants at residue 375 were constructed and analyzed in vitro and in vivo. Bulky hydrophobic or basic amino acids substituted for serine-375 enhanced Env affinity for rhCD4, virus entry into cells bearing rhCD4, and virus replication in primary rhCD4 T cells without appreciably affecting antigenicity or antibody-mediated neutralization sensitivity. Twenty-four RMs inoculated with subtype A, B, C, or D SHIVs all became productively infected with different Env375 variants-S, M, Y, H, W, or F-that were differentially selected in different Env backbones. Notably, SHIVs replicated persistently at titers comparable to HIV-1 in humans and elicited autologous neutralizing antibody responses typical of HIV-1. Seven animals succumbed to AIDS. These findings identify Env-rhCD4 binding as a critical determinant for productive SHIV infection in RMs and validate a novel and generalizable strategy for constructing SHIVs with Env glycoproteins of interest, including those that in humans elicit broadly neutralizing antibodies or bind particular Ig germ-line B-cell receptors.
Collapse
Affiliation(s)
- Hui Li
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Shuyi Wang
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Rui Kong
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Wenge Ding
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Fang-Hua Lee
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Zahra Parker
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Eunlim Kim
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Gerald H Learn
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Paul Hahn
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Ben Policicchio
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA 15261
| | | | - Claire Deleage
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory, Frederick, MD 21702
| | - Xingpei Hao
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory, Frederick, MD 21702
| | - Gwo-Yu Chuang
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Jason Gorman
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Matthew Gardner
- Department of Infectious Disease, Scripps Research Institute, Jupiter, FL 33458
| | | | | | - Sampa Santra
- Center of Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Boston, MA 02215
| | - Cristian Apetrei
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA 15261
| | - Ivona Pandrea
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA 15261
| | - S Munir Alam
- Department of Medicine, Duke University, Durham, NC 27710
| | - Hua-Xin Liao
- Department of Medicine, Duke University, Durham, NC 27710
| | - Xiaoying Shen
- Department of Medicine, Duke University, Durham, NC 27710
| | | | - Michael Farzan
- Department of Infectious Disease, Scripps Research Institute, Jupiter, FL 33458
| | - Elena Chertova
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory, Frederick, MD 21702
| | - Brandon F Keele
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory, Frederick, MD 21702
| | - Jacob D Estes
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory, Frederick, MD 21702
| | - Jeffrey D Lifson
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory, Frederick, MD 21702
| | - Robert W Doms
- Department of Pathology, Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | | | | | - Joseph G Sodroski
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02215
| | - Peter D Kwong
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory, Frederick, MD 21702
| | - Beatrice H Hahn
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104;
| | - George M Shaw
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104;
| |
Collapse
|
19
|
Pandrea I, Xu C, Stock JL, Frank DN, Ma D, Policicchio BB, He T, Kristoff J, Cornell E, Haret-Richter GS, Trichel A, Ribeiro RM, Tracy R, Wilson C, Landay AL, Apetrei C. Antibiotic and Antiinflammatory Therapy Transiently Reduces Inflammation and Hypercoagulation in Acutely SIV-Infected Pigtailed Macaques. PLoS Pathog 2016; 12:e1005384. [PMID: 26764484 PMCID: PMC4713071 DOI: 10.1371/journal.ppat.1005384] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Accepted: 12/16/2015] [Indexed: 01/08/2023] Open
Abstract
Increased chronic immune activation and inflammation are hallmarks of HIV/SIV infection and are highly correlated with progression to AIDS and development of non-AIDS comorbidities, such as hypercoagulability and cardiovascular disease. Intestinal dysfunction resulting in microbial translocation has been proposed as a lead cause of systemic immune activation and hypercoagulability in HIV/SIV infection. Our goal was to assess the biological and clinical impact of a therapeutic strategy designed to reduce microbial translocation through reduction of the microbial content of the intestine (Rifaximin-RFX) and of gut inflammation (Sulfasalazine-SFZ). RFX is an intraluminal antibiotic that was successfully used in patients with hepatic encephalopathy. SFZ is an antiinflammatory drug successfully used in patients with mild to moderate inflammatory bowel disease. Both these clinical conditions are associated with increased microbial translocation, similar to HIV-infected patients. Treatment was administered for 90 days to five acutely SIV-infected pigtailed macaques (PTMs) starting at the time of infection; seven untreated SIVsab-infected PTMs were used as controls. RFX+SFZ were also administered for 90 days to three chronically SIVsab-infected PTMs. RFX+SFZ administration during acute SIVsab infection of PTMs resulted in: significantly lower microbial translocation, lower systemic immune activation, lower viral replication, better preservation of mucosal CD4+ T cells and significantly lower levels of hypercoagulation biomarkers. This effect was clear during the first 40 days of treatment and was lost during the last stages of treatment. Administration of RFX+SFZ to chronically SIVsab–infected PTMs had no discernible effect on infection. Our data thus indicate that early RFX+SFZ administration transiently improves the natural history of acute and postacute SIV infection, but has no effect during chronic infection. We report that administration of the intraluminal antibiotic Rifaximin and the gut-focused anti-inflammatory drug Sulfasalazine to acutely SIV-infected pigtailed macaques is associated with a transient disruption of the vicious circle of inflammation-microbial translocation-immune activation which is pathognomonic to pathogenic HIV/SIV infection and drives HIV disease progression and non-AIDS comorbidities in HIV-infected patients. This therapeutic approach resulted in transient lower microbial translocation, lower systemic immune activation, lower viral replication, better preservation of mucosal CD4+ T cells and lower levels of hypercoagulation biomarkers throughout acute SIV infection. Our results thus support the use of therapeutic approaches to reduce microbial translocation, improve the clinical outcome of HIV-infected patients receiving antiretroviral therapy and prevent non-AIDS comorbidities. Our results also reinforce the importance of early therapeutic management of HIV infection.
Collapse
Affiliation(s)
- Ivona Pandrea
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, Penssylvania, United States of America
- * E-mail:
| | - Cuiling Xu
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Jennifer L. Stock
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Daniel N. Frank
- Department of Medicine, University of Colorado, Aurora, Colorado, United States of America
| | - Dongzhu Ma
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Microbiology and Molecular Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, Penssylvania, United States of America
| | - Benjamin B. Policicchio
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Tianyu He
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Jan Kristoff
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Elaine Cornell
- Department of Pathology and Laboratory Medicine, University of Vermont, Burlington, Vermont, United States of America
| | - George S. Haret-Richter
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Anita Trichel
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Division of Laboratory Animal Resources, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Ruy M. Ribeiro
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Russell Tracy
- Department of Pathology and Laboratory Medicine, University of Vermont, Burlington, Vermont, United States of America
| | - Cara Wilson
- Department of Medicine, University of Colorado, Aurora, Colorado, United States of America
| | - Alan L. Landay
- Department of Immunology and Microbiology, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Cristian Apetrei
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Microbiology and Molecular Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, Penssylvania, United States of America
| |
Collapse
|
20
|
Simian Immunodeficiency Virus SIVagm Efficiently Utilizes Non-CCR5 Entry Pathways in African Green Monkey Lymphocytes: Potential Role for GPR15 and CXCR6 as Viral Coreceptors. J Virol 2015; 90:2316-31. [PMID: 26656714 DOI: 10.1128/jvi.02529-15] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 12/04/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED African green monkeys (AGM) are natural hosts of simian immunodeficiency virus (SIV), and infection in these animals is generally nonpathogenic, whereas infection of nonnatural hosts, such as rhesus macaques (RM), is commonly pathogenic. CCR5 has been described as the primary entry coreceptor for SIV in vivo, while human-derived CXCR6 and GPR15 also appear to be used in vitro. However, sooty mangabeys that are genetically deficient in CCR5 due to an out-of-frame deletion are infectible with SIVsmm, indicating that SIVsmm can use alternative coreceptors in vivo. In this study, we examined the CCR5 dependence of SIV strains derived from vervet AGM (SIVagmVer) and the ability of AGM-derived GPR15 and CXCR6 to serve as potential entry coreceptors. We found that SIVagmVer replicated efficiently in AGM and RM peripheral blood mononuclear cells (PBMC) in the presence of the CCR5 antagonist maraviroc, despite the fact that maraviroc was capable of blocking the CCR5-tropic strains SIVmac239, SIVsmE543-3, and simian-human immunodeficiency virus SHIV-AD8 in RM PBMC. We also found that AGM CXCR6 and AGM GPR15, to a lesser extent, supported entry of pseudotype viruses bearing SIVagm envelopes, including SIVagm transmitted/founder envelopes. Lastly, we found that CCR5, GPR15, and CXCR6 mRNAs were detected in AGM and RM memory CD4(+) T cells. These results suggest that GPR15 and CXCR6 are expressed on AGM CD4(+) T cells and are potential alternative coreceptors for SIVagm use in vivo. These data suggest that the use of non-CCR5 entry pathways may be a common feature of SIV replication in natural host species, with the potential to contribute to nonpathogenicity in these animals. IMPORTANCE African green monkeys (AGM) are natural hosts of SIV, and infection in these animals generally does not cause AIDS, whereas SIV-infected rhesus macaques (RM) typically develop AIDS. Although it has been reported that SIV generally uses CD4 and CCR5 to enter target cells in vivo, other molecules, such as GPR15 and CXCR6, also function as SIV coreceptors in vitro. In this study, we investigated whether SIV from vervet AGM can use non-CCR5 entry pathways, as has been observed in sooty mangabeys. We found that SIVagmVer efficiently replicated in AGM and RM peripheral blood mononuclear cells in the presence of the CCR5 antagonist maraviroc, suggesting that non-CCR5 entry pathways can support SIVagm entry. We found that AGM-derived GPR15 and CXCR6 support SIVagmVer entry in vitro and may serve as entry coreceptors for SIVagm in vivo, since their mRNAs were detected in AGM memory CD4(+) T cells, the preferred target cells of SIV.
Collapse
|
21
|
Hao XP, Lucero CM, Turkbey B, Bernardo ML, Morcock DR, Deleage C, Trubey CM, Smedley J, Klatt NR, Giavedoni LD, Kristoff J, Xu A, Del Prete GQ, Keele BF, Rao SS, Alvord WG, Choyke PL, Lifson JD, Brenchley JM, Apetrei C, Pandrea I, Estes JD. Experimental colitis in SIV-uninfected rhesus macaques recapitulates important features of pathogenic SIV infection. Nat Commun 2015; 6:8020. [PMID: 26282376 PMCID: PMC4544774 DOI: 10.1038/ncomms9020] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 07/08/2015] [Indexed: 02/07/2023] Open
Abstract
Mucosal damage to the gastrointestinal (GI) tract with resulting microbial translocation is hypothesized to significantly contribute to the heightened and persistent chronic inflammation and immune activation characteristic to HIV infection. Here we employ a non-human primate model of chemically induced colitis in SIV-uninfected rhesus macaques that we developed using dextran sulfate sodium (DSS), to directly test this hypothesis. DSS treatment results in GI barrier damage with associated microbial translocation, inflammation and immune activation. The progression and severity of colitis are longitudinally monitored by a magnetic resonance imaging approach. DSS treatment of SIV-infected African green monkeys, a natural host species for SIV that does not manifest GI tract damage or chronic immune activation during infection, results in colitis with elevated levels of plasma SIV RNA, sCD14, LPS, CRP and mucosal CD4+ T-cell loss. Together these results support the hypothesis that GI tract damage leading to local and systemic microbial translocation, and associated immune activation, are important determinants of AIDS pathogenesis.
Collapse
Affiliation(s)
- Xing Pei Hao
- Pathology and Histotechnology Laboratory, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, BG 539, Post Office Box B, Frederick, Maryland 21702, USA
| | - Carissa M. Lucero
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, BG 535, Post Office Box B, Frederick, Maryland 21702, USA
| | - Baris Turkbey
- Molecular Imaging Program, National Cancer Institute, Building 10, Room B3B69F, Bethesda, Maryland 20814, USA
| | - Marcelino L. Bernardo
- Molecular Imaging Program, National Cancer Institute, Building 10, Room B3B69F, Bethesda, Maryland 20814, USA
| | - David R. Morcock
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, BG 535, Post Office Box B, Frederick, Maryland 21702, USA
| | - Claire Deleage
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, BG 535, Post Office Box B, Frederick, Maryland 21702, USA
| | - Charles M. Trubey
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, BG 535, Post Office Box B, Frederick, Maryland 21702, USA
| | - Jeremy Smedley
- Laboratory Animal Science Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, BG 14D RM 233, 14 Service RD West, Bethesda, Maryland 20814, USA
- Washington National Primate Research Center, University of Washington, 1705 NE Pacific Street, Box 357330, Seattle, Washington 98195, USA
| | - Nichole R. Klatt
- Department of Pharmaceutics, WaNPRC, University of Washington, 3018 Western Avenue, Box 357331, Seattle, Washington 98121, USA
| | - Luis D. Giavedoni
- Department of Virology and Immunology, Southwest National Primate Research Center, Texas Biomedical Research Institute, 7620 NW Loop 410, San Antonio, Texas 78227, USA
| | - Jan Kristoff
- Center for Vaccine Research, University of Pittsburgh, 9044 BST3, 3501 Fifth Avenue, Pittsburgh, Pennsylvania 15261, USA
- School of Public Health, University of Pittsburgh, 9044 BST3, 3501 Fifth Avenue, Pittsburgh, Pennsylvania 15261, USA
| | - Amy Xu
- Center for Vaccine Research, University of Pittsburgh, 9044 BST3, 3501 Fifth Avenue, Pittsburgh, Pennsylvania 15261, USA
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, 9044 BST3, 3501 Fifth Avenue, Pittsburgh, Pennsylvania 15261, USA
| | - Gregory Q. Del Prete
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, BG 535, Post Office Box B, Frederick, Maryland 21702, USA
| | - Brandon F. Keele
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, BG 535, Post Office Box B, Frederick, Maryland 21702, USA
| | - Srinivas S. Rao
- Laboratory Animal Medicine, Vaccine Research Center, NIAID, NIH, BG 40, 40 Convent Drive, Bethesda, Maryland 20814, USA
| | - W. Gregory Alvord
- Statistical Consulting, Data Management Services, Inc., National Cancer Institute at Frederick, Post Office Box B, Frederick, Maryland 21702, USA
| | - Peter L. Choyke
- Molecular Imaging Program, National Cancer Institute, Building 10, Room B3B69F, Bethesda, Maryland 20814, USA
| | - Jeffrey D. Lifson
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, BG 535, Post Office Box B, Frederick, Maryland 21702, USA
| | - Jason M. Brenchley
- Immunopathogenesis Section, Lab of Molecular Microbiology, NIAID, NIH, BG 4 RM 201, 4 Memorial Drive, Bethesda, Maryland 20814, USA
| | - Cristian Apetrei
- Center for Vaccine Research, University of Pittsburgh, 9044 BST3, 3501 Fifth Avenue, Pittsburgh, Pennsylvania 15261, USA
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, 9044 BST3, 3501 Fifth Avenue, Pittsburgh, Pennsylvania 15261, USA
| | - Ivona Pandrea
- Center for Vaccine Research, University of Pittsburgh, 9044 BST3, 3501 Fifth Avenue, Pittsburgh, Pennsylvania 15261, USA
- Department of Pathology and School of Medicine, University of Pittsburgh, 9017 Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, Pennsylvania 15261, USA
| | - Jacob D. Estes
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, BG 535, Post Office Box B, Frederick, Maryland 21702, USA
| |
Collapse
|
22
|
Critical Role for the Adenosine Pathway in Controlling Simian Immunodeficiency Virus-Related Immune Activation and Inflammation in Gut Mucosal Tissues. J Virol 2015; 89:9616-30. [PMID: 26178986 DOI: 10.1128/jvi.01196-15] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 07/06/2015] [Indexed: 01/25/2023] Open
Abstract
UNLABELLED The role of the adenosine (ADO) pathway in human immunodeficiency virus type 1/simian immunodeficiency virus (HIV-1/SIV) infection remains unclear. We compared SIVsab-induced changes of markers related to ADO production (CD39 and CD73) and breakdown (CD26 and adenosine deaminase) on T cells from blood, lymph nodes, and intestine collected from pigtailed macaques (PTMs) and African green monkeys (AGMs) that experience different SIVsab infection outcomes. We also measured ADO and inosine (INO) levels in tissues by mass spectrometry. Finally, we assessed the suppressive effect of ADO on proinflammatory cytokine production after T cell receptor stimulation. The baseline level of both CD39 and CD73 coexpression on regulatory T cells and ADO levels were higher in AGMs than in PTMs. Conversely, high INO levels associated with dramatic increases in CD26 expression and adenosine deaminase activity were observed in PTMs during chronic SIV infection. Immune activation and inflammation markers in the gut and periphery inversely correlated with ADO and directly correlated with INO. Ex vivo administration of ADO significantly suppressed proinflammatory cytokine production by T cells in both species. In conclusion, the opposite dynamics of ADO pathway-related markers and contrasting ADO/INO levels in species with divergent proinflammatory responses to SIV infection support a key role of ADO in controlling immune activation/inflammation in nonprogressive SIV infections. Changes in ADO levels predominately occurred in the gut, suggesting that the ADO pathway may be involved in sparing natural hosts of SIVs from developing SIV-related gut dysfunction. Focusing studies of the ADO pathway on mucosal sites of viral replication is warranted. IMPORTANCE The mechanisms responsible for the severe gut dysfunction characteristic of progressive HIV and SIV infection in humans and macaques are not completely elucidated. We report that ADO may play a key role in controlling immune activation/inflammation in nonprogressive SIV infections by limiting SIV-related gut inflammation. Conversely, in progressive SIV infection, significant degradation of ADO occurs, possibly due to an early increase of ADO deaminase complexing protein 2 (CD26) and adenosine deaminase. Our study supports therapeutic interventions to offset alterations of this pathway during progressive HIV/SIV infections. These potential approaches to control chronic immune activation and inflammation during pathogenic SIV infection may prevent HIV disease progression.
Collapse
|
23
|
Abstract
UNLABELLED The role of the accessory viral Nef protein as a multifunctional manipulator of the host cell that is required for effective replication of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) in vivo is well established. It is unknown, however, whether Nef manipulates all or just specific subsets of CD4(+) T cells, which are the main targets of virus infection and differ substantially in their state of activation and importance for a functional immune system. Here, we analyzed the effect of Nef proteins differing in their T cell receptor (TCR)-CD3 downmodulation function in HIV-infected human lymphoid aggregate cultures and peripheral blood mononuclear cells. We found that Nef efficiently downmodulates TCR-CD3 in naive and memory CD4(+) T cells and protects the latter against apoptosis. In contrast, highly proliferative CD45RA(+) CD45RO(+) CD4(+) T cells were main producers of infectious virus but largely refractory to TCR-CD3 downmodulation. Such T cell subset-specific differences were also observed for Nef-mediated modulation of CD4 but not for enhancement of virion infectivity. Our results indicate that Nef predominantly modulates surface receptors on CD4(+) T cell subsets that are not already fully permissive for viral replication. As a consequence, Nef-mediated downmodulation of TCR-CD3, which distinguishes most primate lentiviruses from HIV type 1 (HIV-1) and its vpu-containing simian precursors, may promote a selective preservation of central memory CD4(+) T cells, which are critical for the maintenance of a functional immune system. IMPORTANCE The Nef proteins of human and simian immunodeficiency viruses manipulate infected CD4(+) T cells in multiple ways to promote viral replication and immune evasion in vivo. Here, we show that some effects of Nef are subset specific. Downmodulation of CD4 and TCR-CD3 is highly effective in central memory CD4(+) T cells, and the latter Nef function protects this T cell subset against apoptosis. In contrast, highly activated/proliferating CD4(+) T cells are largely refractory to receptor downmodulation but are main producers of infectious HIV-1. Nef-mediated enhancement of virion infectivity, however, was observed in all T cell subsets examined. Our results provide new insights into how primate lentiviruses manipulate their target cells and suggest that the TCR-CD3 downmodulation function of Nef may promote a selective preservation of memory CD4(+) T cells, which are critical for immune function, but has little effect on activated/proliferating CD4(+) T cells, which are the main targets for viral replication.
Collapse
|
24
|
Mandell DT, Kristoff J, Gaufin T, Gautam R, Ma D, Sandler N, Haret-Richter G, Xu C, Aamer H, Dufour J, Trichel A, Douek DC, Keele BF, Apetrei C, Pandrea I. Pathogenic features associated with increased virulence upon Simian immunodeficiency virus cross-species transmission from natural hosts. J Virol 2014; 88:6778-92. [PMID: 24696477 PMCID: PMC4054382 DOI: 10.1128/jvi.03785-13] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 03/27/2014] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED While simian immunodeficiency viruses (SIVs) are generally nonpathogenic in their natural hosts, dramatic increases in pathogenicity may occur upon cross-species transmission to new hosts. Deciphering the drivers of these increases in virulence is of major interest for understanding the emergence of new human immunodeficiency viruses (HIVs). We transmitted SIVsab from the sabaeus species of African green monkeys (AGMs) to pigtailed macaques (PTMs). High acute viral replication occurred in all SIVsab-infected PTMs, yet the outcome of chronic infection was highly variable, ranging from rapid progression to controlled infection, which was independent of the dynamics of acute viral replication, CD4(+) T cell depletion, or preinfection levels of microbial translocation. Infection of seven PTMs with plasma collected at necropsy from a rapid-progressor PTM was consistently highly pathogenic, with high acute and chronic viral replication, massive depletion of memory CD4(+) T cells, and disease progression in all PTMs. The plasma inoculum used for the serial passage did not contain adventitious bacterial or viral contaminants. Single-genome amplification showed that this inoculum was significantly more homogenous than the inoculum directly derived from AGMs, pointing to a strain selection in PTMs. In spite of similar peak plasma viral loads between the monkeys in the two passages, immune activation/inflammation levels dramatically increased in PTMs infected with the passaged virus. These results suggest that strain selection and a massive cytokine storm are major factors behind increased pathogenicity of SIV upon serial passage and adaptation of SIVs to new hosts following cross-species transmission. IMPORTANCE We report here that upon cross-species transmission and serial passage of SIVsab from its natural host, the sabaeus African green monkey (AGM), to a new host, the pigtailed macaque (PTM), viral adaptation and increased pathogenicity involve strain selection and a massive cytokine storm. These results permit the design of strategies aimed at preventing cross-species transmission from natural hosts of SIVs to humans in areas of endemicity. Furthermore, our study describes a new animal model for SIV infection. As the outcomes of SIVsab infection in PTMs, African green monkeys, and rhesus macaques are different, the use of these systems enables comparative studies between pathogenic, nonpathogenic, and elite-controlled infections, to gain insight into the mechanisms of SIV immunodeficiency and comorbidities.
Collapse
Affiliation(s)
- Daniel T Mandell
- Division of Microbiology, Tulane National Primate Research Center (TNPRC), Covington, Louisiana, USA
| | - Jan Kristoff
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Thaidra Gaufin
- Division of Microbiology, Tulane National Primate Research Center (TNPRC), Covington, Louisiana, USA
| | - Rajeev Gautam
- Division of Microbiology, Tulane National Primate Research Center (TNPRC), Covington, Louisiana, USA
| | - Dongzhu Ma
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Netanya Sandler
- Human Immunology Section, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - George Haret-Richter
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Cuiling Xu
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Hadega Aamer
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Jason Dufour
- Division of Veterinary Medicine, Tulane National Primate Research Center (TNPRC), Covington, Louisiana, USA
| | - Anita Trichel
- Division of Laboratory Animal Resources, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Daniel C Douek
- Human Immunology Section, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Brandon F Keele
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, Frederick, Maryland, USA
| | - Cristian Apetrei
- Division of Microbiology, Tulane National Primate Research Center (TNPRC), Covington, Louisiana, USA Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA Departments of Microbiology and Molecular Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Ivona Pandrea
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA Division of Comparative Pathology, Tulane National Primate Research Center (TNPRC), Covington, Louisiana, USA Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| |
Collapse
|
25
|
Kristoff J, Haret-Richter G, Ma D, Ribeiro RM, Xu C, Cornell E, Stock JL, He T, Mobley AD, Ross S, Trichel A, Wilson C, Tracy R, Landay A, Apetrei C, Pandrea I. Early microbial translocation blockade reduces SIV-mediated inflammation and viral replication. J Clin Invest 2014; 124:2802-6. [PMID: 24837437 DOI: 10.1172/jci75090] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 03/27/2014] [Indexed: 12/31/2022] Open
Abstract
Damage to the intestinal mucosa results in the translocation of microbes from the intestinal lumen into the circulation. Microbial translocation has been proposed to trigger immune activation, inflammation, and coagulopathy, all of which are key factors that drive HIV disease progression and non-HIV comorbidities; however, direct proof of a causal link is still lacking. Here, we have demonstrated that treatment of acutely SIV-infected pigtailed macaques with the drug sevelamer, which binds microbial lipopolysaccharide in the gut, dramatically reduces immune activation and inflammation and slightly reduces viral replication. Furthermore, sevelamer administration reduced coagulation biomarkers, confirming the contribution of microbial translocation in the development of cardiovascular comorbidities in SIV-infected nonhuman primates. Together, our data suggest that early control of microbial translocation may improve the outcome of HIV infection and limit noninfectious comorbidities associated with AIDS.
Collapse
|
26
|
|
27
|
Factors associated with siman immunodeficiency virus transmission in a natural African nonhuman primate host in the wild. J Virol 2014; 88:5687-705. [PMID: 24623416 DOI: 10.1128/jvi.03606-13] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED African green monkeys (AGMs) are naturally infected with simian immunodeficiency virus (SIV) at high prevalence levels and do not progress to AIDS. Sexual transmission is the main transmission route in AGM, while mother-to-infant transmission (MTIT) is negligible. We investigated SIV transmission in wild AGMs to assess whether or not high SIV prevalence is due to differences in mucosal permissivity to SIV (i.e., whether the genetic bottleneck of viral transmission reported in humans and macaques is also observed in AGMs in the wild). We tested 121 sabaeus AGMs (Chlorocebus sabaeus) from the Gambia and found that 53 were SIV infected (44%). By combining serology and viral load quantitation, we identified 4 acutely infected AGMs, in which we assessed the diversity of the quasispecies by single-genome amplification (SGA) and documented that a single virus variant established the infections. We thus show that natural SIV transmission in the wild is associated with a genetic bottleneck similar to that described for mucosal human immunodeficiency virus (HIV) transmission in humans. Flow cytometry assessment of the immune cell populations did not identify major differences between infected and uninfected AGM. The expression of the SIV coreceptor CCR5 on CD4+ T cells dramatically increased in adults, being higher in infected than in uninfected infant and juvenile AGMs. Thus, the limited SIV MTIT in natural hosts appears to be due to low target cell availability in newborns and infants, which supports HIV MTIT prevention strategies aimed at limiting the target cells at mucosal sites. Combined, (i) the extremely high prevalence in sexually active AGMs, (ii) the very efficient SIV transmission in the wild, and (iii) the existence of a fraction of multiparous females that remain uninfected in spite of massive exposure to SIV identify wild AGMs as an acceptable model of exposed, uninfected individuals. IMPORTANCE We report an extensive analysis of the natural history of SIVagm infection in its sabaeus monkey host, the African green monkey species endemic to West Africa. Virtually no study has investigated the natural history of SIV infection in the wild. The novelty of our approach is that we report for the first time that SIV infection has no discernible impact on the major immune cell populations in natural hosts, thus confirming the nonpathogenic nature of SIV infection in the wild. We also focused on the correlates of SIV transmission, and we report, also for the first time, that SIV transmission in the wild is characterized by a major genetic bottleneck, similar to that described for HIV-1 transmission in humans. Finally, we report here that the restriction of target cell availability is a major correlate of the lack of SIV transmission to the offspring in natural hosts of SIVs.
Collapse
|
28
|
Okoye AA, Picker LJ. CD4(+) T-cell depletion in HIV infection: mechanisms of immunological failure. Immunol Rev 2014; 254:54-64. [PMID: 23772614 DOI: 10.1111/imr.12066] [Citation(s) in RCA: 323] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The hallmark of acquired immunodeficiency syndrome (AIDS) pathogenesis is a progressive depletion of CD4(+) T-cell populations in close association with progressive impairment of cellular immunity and increasing susceptibility to opportunistic infections (OI). Disease progression in untreated human immunodeficiency virus (HIV) infection can take many years, and it was originally hypothesized to be a consequence of slow, viral-mediated CD4(+) T-cell destruction. However, massive CD4(+) memory T-cell destruction is now known to occur quite early in infection, almost always without overt immunodeficiency. In most individuals, this initial destruction is countered by CD4(+) memory T-cell regeneration that preserves CD4(+) T-cell numbers and functions above the threshold associated with overt immunodeficiency. This regeneration, which occurs in the setting of chronic immune activation and immune dysregulation does not, however, restore all functionally important CD4(+) T-cell populations and is not stable over the long term. Ultimately, CD4(+) memory T-cell homeostasis fails and critical effector populations decline below the level necessary to prevent OI. Thus, the onset of overt immune deficiency appears to be intimately linked with CD4(+) memory T-cell dynamics and reflects the complex interplay of direct viral cytopathogenicity and the indirect effects of persistent immune activation on CD4(+) memory T-cell proliferation, differentiation, and survival.
Collapse
Affiliation(s)
- Afam A Okoye
- Vaccine and Gene Therapy Institute and Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA.
| | | |
Collapse
|
29
|
Wijewardana V, Kristoff J, Xu C, Ma D, Haret-Richter G, Stock JL, Policicchio BB, Mobley AD, Nusbaum R, Aamer H, Trichel A, Ribeiro RM, Apetrei C, Pandrea I. Kinetics of myeloid dendritic cell trafficking and activation: impact on progressive, nonprogressive and controlled SIV infections. PLoS Pathog 2013; 9:e1003600. [PMID: 24098110 PMCID: PMC3789723 DOI: 10.1371/journal.ppat.1003600] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2013] [Accepted: 07/24/2013] [Indexed: 12/21/2022] Open
Abstract
We assessed the role of myeloid dendritic cells (mDCs) in the outcome of SIV infection by comparing and contrasting their frequency, mobilization, phenotype, cytokine production and apoptosis in pathogenic (pigtailed macaques, PTMs), nonpathogenic (African green monkeys, AGMs) and controlled (rhesus macaques, RMs) SIVagmSab infection. Through the identification of recently replicating cells, we demonstrated that mDC mobilization from the bone marrow occurred in all species postinfection, being most prominent in RMs. Circulating mDCs were depleted with disease progression in PTMs, recovered to baseline values after the viral peak in AGMs, and significantly increased at the time of virus control in RMs. Rapid disease progression in PTMs was associated with low baseline levels and incomplete recovery of circulating mDCs during chronic infection. mDC recruitment to the intestine occurred in all pathogenic scenarios, but loss of mucosal mDCs was associated only with progressive infection. Sustained mDC immune activation occurred throughout infection in PTMs and was associated with increased bystander apoptosis in blood and intestine. Conversely, mDC activation occurred only during acute infection in nonprogressive and controlled infections. Postinfection, circulating mDCs rapidly became unresponsive to TLR7/8 stimulation in all species. Yet, stimulation with LPS, a bacterial product translocated in circulation only in SIV-infected PTMs, induced mDC hyperactivation, apoptosis and excessive production of proinflammatory cytokines. After infection, spontaneous production of proinflammatory cytokines by mucosal mDCs increased only in progressor PTMs. We thus propose that mDCs promote tolerance to SIV in the biological systems that lack intestinal dysfunction. In progressive infections, mDC loss and excessive activation of residual mDCs by SIV and additional stimuli, such as translocated microbial products, enhance generalized immune activation and inflammation. Our results thus provide a mechanistic basis for the role of mDCs in the pathogenesis of AIDS and elucidate the causes of mDC loss during progressive HIV/SIV infections. Myeloid dendritic cells (mDCs) are potent antigen-presenting cells that regulate both innate and adaptive immune responses and act as “watch-dogs”, sensing and controlling aberrant immune activation; as such, they may significantly impact the outcome of HIV/SIV infection. By comparing and contrasting the frequency, function, migration to tissues and levels of activation and apoptosis in progressive, nonprogressive and elite-controlled SIV infections, we investigated the mechanisms responsible for mDC loss in HIV/SIV infection and their role in driving progression to AIDS. We report that progression to AIDS is associated with low mDC preinfection levels and depletion throughout infection, due to massive migration of these cells to mucosal sites and excessive cell death by apoptosis. We also show that residual mDCs from blood and intestine have a high capacity to produce proinflammatory cytokines, thus contributing to the increased immune activation and inflammation characteristic of progressive infections.
Collapse
Affiliation(s)
- Viskam Wijewardana
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Microbiology and Molecular Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Jan Kristoff
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Cuiling Xu
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Dongzhu Ma
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Microbiology and Molecular Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - George Haret-Richter
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Jennifer L. Stock
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Infectious Diseases and Microbiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Benjamin B. Policicchio
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Infectious Diseases and Microbiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Adam D. Mobley
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Rebecca Nusbaum
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Hadega Aamer
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Microbiology and Molecular Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Anita Trichel
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Ruy M. Ribeiro
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Cristian Apetrei
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Microbiology and Molecular Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Ivona Pandrea
- Center for Vaccine Research, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
| |
Collapse
|
30
|
Lack of B cell dysfunction is associated with functional, gp120-dominant antibody responses in breast milk of simian immunodeficiency virus-infected African green monkeys. J Virol 2013; 87:11121-34. [PMID: 23926338 DOI: 10.1128/jvi.01887-13] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The design of an effective vaccine to reduce the incidence of mother-to-child transmission (MTCT) of human immunodeficiency virus (HIV) via breastfeeding will require identification of protective immune responses that block postnatal virus acquisition. Natural hosts of simian immunodeficiency virus (SIV) sustain nonpathogenic infection and rarely transmit the virus to their infants despite high milk virus RNA loads. This is in contrast to HIV-infected women and SIV-infected rhesus macaques (RhMs), nonnatural hosts which exhibit higher rates of postnatal virus transmission. In this study, we compared the systemic and mucosal B cell responses of lactating, SIV-infected African green monkeys (AGMs), a natural host species, to that of SIV-infected RhMs and HIV-infected women. AGMs did not demonstrate hypergammaglobulinemia or accumulate circulating memory B cells during chronic SIV infection. Moreover, the milk of SIV-infected AGMs contained higher proportions of naive B cells than RhMs. Interestingly, AGMs exhibited robust milk and plasma Env binding antibody responses that were one to two logs higher than those in RhMs and humans and demonstrated autologous neutralizing responses in milk at 1 year postinfection. Furthermore, the plasma and milk Env gp120-binding antibody responses were equivalent to or predominant over Env gp140-binding antibody responses in AGMs, in contrast to that in RhMs and humans. The strong gp120-specific, functional antibody responses in the milk of SIV-infected AGMs may contribute to the rarity of postnatal transmission observed in natural SIV hosts.
Collapse
|
31
|
Klatt NR, Silvestri G, Hirsch V. Nonpathogenic simian immunodeficiency virus infections. Cold Spring Harb Perspect Med 2013; 2:a007153. [PMID: 22315718 DOI: 10.1101/cshperspect.a007153] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The simian immunodeficiency viruses (SIVs) are a diverse group of viruses that naturally infect a wide range of African primates, including African green monkeys (AGMs) and sooty mangabey monkeys (SMs). Although natural infection is widespread in feral populations of AGMs and SMs, this infection generally does not result in immunodeficiency. However, experimental inoculation of Asian macaques results in an immunodeficiency syndrome remarkably similar to human AIDS. Thus, natural nonprogressive SIV infections appear to represent an evolutionary adaptation between these animals and their primate lentiviruses. Curiously, these animals maintain robust virus replication but have evolved strategies to avoid disease progression. Adaptations observed in these primates include phenotypic changes to CD4(+) T cells, limited chronic immune activation, and altered mucosal immunity. It is probable that these animals have achieved a unique balance between T-cell renewal and proliferation and loss through activation-induced apoptosis, and virus-induced cell death. A clearer understanding of the mechanisms underlying the lack of disease progression in natural hosts for SIV infection should therefore yield insights into the pathogenesis of AIDS and may inform vaccine design.
Collapse
Affiliation(s)
- Nichole R Klatt
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | | | | |
Collapse
|
32
|
De Boer RJ, Perelson AS. Quantifying T lymphocyte turnover. J Theor Biol 2013; 327:45-87. [PMID: 23313150 PMCID: PMC3640348 DOI: 10.1016/j.jtbi.2012.12.025] [Citation(s) in RCA: 149] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Revised: 12/13/2012] [Accepted: 12/30/2012] [Indexed: 01/13/2023]
Abstract
Peripheral T cell populations are maintained by production of naive T cells in the thymus, clonal expansion of activated cells, cellular self-renewal (or homeostatic proliferation), and density dependent cell life spans. A variety of experimental techniques have been employed to quantify the relative contributions of these processes. In modern studies lymphocytes are typically labeled with 5-bromo-2'-deoxyuridine (BrdU), deuterium, or the fluorescent dye carboxy-fluorescein diacetate succinimidyl ester (CFSE), their division history has been studied by monitoring telomere shortening and the dilution of T cell receptor excision circles (TRECs) or the dye CFSE, and clonal expansion has been documented by recording changes in the population densities of antigen specific cells. Proper interpretation of such data in terms of the underlying rates of T cell production, division, and death has proven to be notoriously difficult and involves mathematical modeling. We review the various models that have been developed for each of these techniques, discuss which models seem most appropriate for what type of data, reveal open problems that require better models, and pinpoint how the assumptions underlying a mathematical model may influence the interpretation of data. Elaborating various successful cases where modeling has delivered new insights in T cell population dynamics, this review provides quantitative estimates of several processes involved in the maintenance of naive and memory, CD4(+) and CD8(+) T cell pools in mice and men.
Collapse
Affiliation(s)
- Rob J De Boer
- Theoretical Biology & Bioinformatics, Utrecht University, The Netherlands; Santa Fe Institute, Santa Fe, NM 87501, USA.
| | | |
Collapse
|
33
|
Ma D, Jasinska A, Kristoff J, Grobler JP, Turner T, Jung Y, Schmitt C, Raehtz K, Feyertag F, Martinez Sosa N, Wijewardana V, Burke DS, Robertson DL, Tracy R, Pandrea I, Freimer N, Apetrei C. SIVagm infection in wild African green monkeys from South Africa: epidemiology, natural history, and evolutionary considerations. PLoS Pathog 2013; 9:e1003011. [PMID: 23349627 PMCID: PMC3547836 DOI: 10.1371/journal.ppat.1003011] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Accepted: 09/20/2012] [Indexed: 11/18/2022] Open
Abstract
Pathogenesis studies of SIV infection have not been performed to date in wild monkeys due to difficulty in collecting and storing samples on site and the lack of analytical reagents covering the extensive SIV diversity. We performed a large scale study of molecular epidemiology and natural history of SIVagm infection in 225 free-ranging AGMs from multiple locations in South Africa. SIV prevalence (established by sequencing pol, env, and gag) varied dramatically between infant/juvenile (7%) and adult animals (68%) (p<0.0001), and between adult females (78%) and males (57%). Phylogenetic analyses revealed an extensive genetic diversity, including frequent recombination events. Some AGMs harbored epidemiologically linked viruses. Viruses infecting AGMs in the Free State, which are separated from those on the coastal side by the Drakensberg Mountains, formed a separate cluster in the phylogenetic trees; this observation supports a long standing presence of SIV in AGMs, at least from the time of their speciation to their Plio-Pleistocene migration. Specific primers/probes were synthesized based on the pol sequence data and viral loads (VLs) were quantified. VLs were of 10(4)-10(6) RNA copies/ml, in the range of those observed in experimentally-infected monkeys, validating the experimental approaches in natural hosts. VLs were significantly higher (10(7)-10(8) RNA copies/ml) in 10 AGMs diagnosed as acutely infected based on SIV seronegativity (Fiebig II), which suggests a very active transmission of SIVagm in the wild. Neither cytokine levels (as biomarkers of immune activation) nor sCD14 levels (a biomarker of microbial translocation) were different between SIV-infected and SIV-uninfected monkeys. This complex algorithm combining sequencing and phylogeny, VL quantification, serology, and testing of surrogate markers of microbial translocation and immune activation permits a systematic investigation of the epidemiology, viral diversity and natural history of SIV infection in wild African natural hosts.
Collapse
Affiliation(s)
- Dongzhu Ma
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Wonderlich ER, Barratt-Boyes SM. A dendrite in every pie: myeloid dendritic cells in HIV and SIV infection. Virulence 2012; 3:647-53. [PMID: 23154284 PMCID: PMC3545946 DOI: 10.4161/viru.22491] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Dendritic cells (DC) are a heterogeneous population of innate immune cells that are fundamental to initiating responses against invading pathogens and regulating immune responses. Myeloid DC (mDC) act as a bridge between the innate and adaptive immune response during virus infections but their role in immunity to human immunodeficiency virus (HIV) remains ill-defined. This review examines aspects of the mDC response to HIV and its simian counterpart, simian immunodeficiency virus (SIV), and emphasizes areas where our knowledge of mDC biology and function is incomplete. Defining the potentially beneficial and detrimental roles mDC play during pathogenic and stable infection of humans and nonhuman primates is crucial to our overall understanding of AIDS pathogenesis.
Collapse
|
35
|
Chahroudi A, Bosinger SE, Vanderford TH, Paiardini M, Silvestri G. Natural SIV hosts: showing AIDS the door. Science 2012; 335:1188-93. [PMID: 22403383 DOI: 10.1126/science.1217550] [Citation(s) in RCA: 195] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Many species of African nonhuman primates are naturally infected with simian immunodeficiency viruses (SIVs) in the wild and in captivity. In contrast to HIV-infected humans, these natural SIV hosts typically do not develop AIDS, despite chronic infection with a highly replicating virus. In this Review, we discuss the most recent advances on the mechanisms of protection from disease progression in natural SIV hosts, with emphasis on how they differ from pathogenic HIV/SIV infections of humans and rhesus macaques. These mechanisms include: (i) resolution of immune activation after acute infection, (ii) restricted pattern of target cell infection, and (iii) protection from mother-to-infant transmission. We highlight the areas that should be pursued in future studies, focusing on potential applications for the treatment and prevention of HIV infection.
Collapse
Affiliation(s)
- Ann Chahroudi
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | | | | | | | | |
Collapse
|
36
|
Memory CD4(+) T lymphocytes in the gastrointestinal tract are a major source of cell-associated simian immunodeficiency virus in chronic nonpathogenic infection of African green monkeys. J Virol 2012; 86:11380-5. [PMID: 22896600 DOI: 10.1128/jvi.01556-12] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Simian immunodeficiency virus (SIV) infection of natural hosts is characterized by nonpathogenic chronic viremia, maintenance of gastrointestinal epithelial barrier integrity, and low numbers of target cells. Assessment of cell-associated virus load in T cell subsets in multiple anatomic compartments of chronically SIV-infected sabeus African green monkeys (AGMs) revealed that gastrointestinal memory CD4(+) T lymphocytes are a major source of cell-associated virus and a significant contributor to SIV viremia in AGMs.
Collapse
|
37
|
Abstract
PURPOSE OF REVIEW A key factor driving AIDS-associated immunopathogenesis is chronic immune activation. Simian immunodeficiency virus (SIV) infection of African natural host species leads to high viremia, but low immune activation and absence of disease. Considerable progress in our understanding of pathological immune activation has come from comparative studies of SIV infection in pathogenic Asian macaque species and natural hosts. The focus of this review is to highlight recent work on the natural host model using high-throughput genomics. RECENT FINDINGS Several groups have independently conducted microarray gene expression profiling comparing in-vivo SIV infection in natural and non-natural hosts. A consistent finding between these studies is that both pathogenic SIV infection of macaques and nonpathogenic infections of natural hosts have strong induction of interferon-stimulated genes (ISGs) early on, but a key difference was that natural hosts down-modulated the interferon response rapidly after acute infection. The development of new genome-based resources for further study of the natural host model is discussed. SUMMARY Initial efforts using high-throughput biology to study SIV infection of natural hosts have effectively identified the ability of natural hosts to resolve interferon responses and immune activation. Further application of 'omic-based technologies coupled with integrative systems-based analysis should continue to yield progress.
Collapse
|
38
|
Mucosal simian immunodeficiency virus transmission in African green monkeys: susceptibility to infection is proportional to target cell availability at mucosal sites. J Virol 2012; 86:4158-68. [PMID: 22318138 DOI: 10.1128/jvi.07141-11] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
African green monkeys (AGMs) are naturally infected with a simian immunodeficiency virus (SIVagm) that is nonpathogenic in its host. Although SIVagm is common and widespread, little is known about the mechanisms that govern its transmission. Since the earliest virus-host interactions may provide key insights into the nonpathogenic phenotype of SIVagm, we developed a mucosal transmission model for this virus. Using plasma from an acutely infected AGM as the virus inoculum, we exposed adult and juvenile AGMs, as well as pigtailed macaques (PTMs) as a nonnatural host control, by mucosal routes to increasing titers of virus and compared the doses needed to establish a productive infection. Four juvenile and four adult AGMs as well as two PTMs were intrarectally (IR) exposed, while two additional adult female AGMs were intravaginally (IVAG) exposed. No animal became infected following exposure to 10(5) RNA copies. Both PTMs but none of the AGMs became infected following exposure to 10(6) RNA copies. Finally, all adult AGMs and two of the four juvenile AGMs became infected following exposure to 10(7) RNA copies, acquiring either one (2 IR infected juveniles, 1 IR infected adult, 2 IVAG infected adults) or two (3 IR infected adults) transmitted founder viruses. These results were consistent with immunophenotypic data, which revealed a significant correlation between the percentage of CD4(+) T cells expressing CCR5 in the mucosa and the susceptibility to infection, in terms of both the viral dose and the numbers of transmitted founder viruses. Moreover, studies of uninfected AGMs showed that the fraction of CCR5-expressing CD4(+) T cells increased significantly with age. These results indicate that (i) AGMs are readily infected with SIVagm by both intrarectal and intravaginal routes, (ii) susceptibility to infection is proportional to the number of available CCR5(+) CD4(+) target cells in the mucosa, and (iii) the paucity of CCR5(+) CD4(+) target cells in infant and juvenile AGMs may explain the near absence of vertical transmission.
Collapse
|
39
|
Immunovirological analyses of chronically simian immunodeficiency virus SIVmnd-1- and SIVmnd-2-infected mandrills (Mandrillus sphinx). J Virol 2011; 85:13077-87. [PMID: 21957286 DOI: 10.1128/jvi.05693-11] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Simian immunodeficiency virus (SIV) infection in African nonhuman primate (NHP) natural hosts is usually nonpathogenic, despite high levels of virus replication. We have previously shown that chronic SIV infection in sooty mangabeys (SMs) and African green monkeys (AGMs) is associated with low levels of immune activation and bystander T cell apoptosis. To compare these features with those observed in another natural host, the mandrill (MND), we conducted a cross-sectional survey of the 23 SIV-infected and 25 uninfected MNDs from the only semifree colony of mandrills available worldwide. Viral loads (VLs) were determined and phenotypic and functional analysis of peripheral blood- and lymph node-derived lymphocytes was performed. We found that mandrills chronically infected with SIVmnd-1 or SIVmnd-2 have similar levels of viral replication, and we observed a trend toward lower CD4+ T cell counts in chronically SIVmnd-2-infected MNDs than SIVmnd-1-infected MNDs. No correlation between CD4+ T cell counts and VLs in SIV-infected MNDs could be established. Of note, the levels of T cell activation, proliferation, and apoptosis were comparable between SIVmnd-1- and SIVmnd-2-infected MNDs and to those observed in uninfected animals, with the only exception being an increase in tumor necrosis factor alpha-producing CD8+ T cells in SIVmnd-2-infected MNDs. Overall, these findings recapitulate previous observations in SIV-infected SMs and AGMs and lend further evidence to the hypothesis that low levels of immune activation protect natural SIV hosts from disease progression.
Collapse
|
40
|
Pandrea I, Gaufin T, Gautam R, Kristoff J, Mandell D, Montefiori D, Keele BF, Ribeiro RM, Veazey RS, Apetrei C. Functional cure of SIVagm infection in rhesus macaques results in complete recovery of CD4+ T cells and is reverted by CD8+ cell depletion. PLoS Pathog 2011; 7:e1002170. [PMID: 21829366 PMCID: PMC3150280 DOI: 10.1371/journal.ppat.1002170] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 06/02/2011] [Indexed: 01/01/2023] Open
Abstract
Understanding the mechanism of infection control in elite controllers (EC) may shed light on the correlates of control of disease progression in HIV infection. However, limitations have prevented a clear understanding of the mechanisms of elite controlled infection, as these studies can only be performed at randomly selected late time points in infection, after control is achieved, and the access to tissues is limited. We report that SIVagm infection is elite-controlled in rhesus macaques (RMs) and therefore can be used as an animal model for EC HIV infection. A robust acute infection, with high levels of viral replication and dramatic mucosal CD4+ T cell depletion, similar to pathogenic HIV-1/SIV infections of humans and RMs, was followed by complete and durable control of SIVagm replication, defined as: undetectable VLs in blood and tissues beginning 72 to 90 days postinoculation (pi) and continuing at least 4 years; seroreversion; progressive recovery of mucosal CD4+ T cells, with complete recovery by 4 years pi; normal levels of T cell immune activation, proliferation, and apoptosis; and no disease progression. This “functional cure” of SIVagm infection in RMs could be reverted after 4 years of control of infection by depleting CD8 cells, which resulted in transient rebounds of VLs, thus suggesting that control may be at least in part immune mediated. Viral control was independent of MHC, partial APOBEC restriction was not involved in SIVagm control in RMs and Trim5 genotypes did not impact viral replication. This new animal model of EC lentiviral infection, in which complete control can be predicted in all cases, permits research on the early events of infection in blood and tissues, before the defining characteristics of EC are evident and when host factors are actively driving the infection towards the EC status. A small proportion of HIV-infected patients control viral replication and disease progression in the absence of any antiretroviral treatment. Understanding the mechanisms of viral control in these elite controllers may help to identify new therapeutic approaches in order to control HIV infection. However, elite controllers are identified AFTER control is established, therefore it is difficult to identify the virus and host factors that drive the infection to the controlled status. We identified an animal model (the rhesus macaque infection with SIVagm) in which, after massive acute viral replication and CD4+ T cell depletion, SIV infection is controlled in 100% of cases during chronic infection. This “functional cure” of SIVagm infection in rhesus macaques results in a complete immune restoration after four years and can be reverted by depleting the cellular immune responses in vivo. An animal model of elite controlled lentiviral infection in which complete control can be predicted in all cases permits research on the early events of infection when host factors are actively driving the infection towards the controlled status to understand the pathogenesis of HIV/SIV infections and design of new approaches for controlling HIV infection.
Collapse
Affiliation(s)
- Ivona Pandrea
- Division of Comparative Pathology, Tulane National Primate Research Center, Covington, Louisiana, United States of America
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Thaidra Gaufin
- Division of Microbiology, Tulane National Primate Research Center, Covington, Louisiana, United States of America
| | - Rajeev Gautam
- Division of Microbiology, Tulane National Primate Research Center, Covington, Louisiana, United States of America
| | - Jan Kristoff
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Daniel Mandell
- Division of Microbiology, Tulane National Primate Research Center, Covington, Louisiana, United States of America
| | - David Montefiori
- Department of Surgery, Duke University, Durham, North Carolina, United States of America
| | - Brandon F. Keele
- SAIC Frederick, Inc, NCI, NIH, Frederick, Maryland, United States of America
| | - Ruy M. Ribeiro
- Los Alamos National Laboratory, Los Alamos New Mexico, United States of America
| | - Ronald S. Veazey
- Division of Comparative Pathology, Tulane National Primate Research Center, Covington, Louisiana, United States of America
| | - Cristian Apetrei
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Division of Microbiology, Tulane National Primate Research Center, Covington, Louisiana, United States of America
- Department of Microbiology and Molecular Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
| |
Collapse
|
41
|
Hodges-Mameletzis I, De Bree GJ, Rowland-Jones SL. An underestimated lentivirus model: what can HIV-2 research contribute to the development of an effective HIV-1 vaccine? Expert Rev Anti Infect Ther 2011; 9:195-206. [PMID: 21342067 DOI: 10.1586/eri.10.176] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The development of an HIV-1 vaccine that would be effective against all existing subtypes and circulating recombinant forms remains one of the great scientific and public health challenges of our generation. One of the major barriers to HIV-1 vaccine development is a lack of understanding of the correlates of protective immunity against the virus. In this context, research has focused on the rare phenomenon of spontaneous control of HIV-1 infection, in groups referred to as 'long-term nonprogressors' and 'elite controllers', together with models of nonprogressive sooty mangabey simian immunodeficiency (SIV) infection in African nonhuman primate hosts such as sooty mangabeys and African green monkeys, in which the majority of animals tolerate high levels of viral replication without development of immunodeficiency or disease. Much less attention has been given to humans infected with the nonpandemic strain HIV-2, derived from the SIV in West Africa, most of whom behave as long-term nonprogressors or viral controllers, while a minority develop disease clinically indistinguishable from AIDS caused by HIV-1. This apparent dichotomous outcome is, based on the evidence accumulated to date, more clearly related to the host immune response than the good clinical outcome of HIV-1 controllers. We propose that complementing research into HIV-1 controllers and nonpathogenic SIV models with the prioritization of HIV-2 research could enhance the HIV-1 vaccine research effort. The absence of disease progression or detectable plasma viral replication in the presence of an effective immune response in most patients living with HIV-2 represents an opportunity to unravel the virus' evolutionary adaptation in human hosts and to establish the correlates of such a protective response.
Collapse
|
42
|
Althaus CL, De Boer RJ. Implications of CTL-mediated killing of HIV-infected cells during the non-productive stage of infection. PLoS One 2011; 6:e16468. [PMID: 21326882 PMCID: PMC3034731 DOI: 10.1371/journal.pone.0016468] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Accepted: 12/20/2010] [Indexed: 11/23/2022] Open
Abstract
Patients infected with HIV exhibit orders of magnitude differences in their set-point levels of the plasma viral load. As to what extent this variation is due to differences in the efficacy of the cytotoxic T lymphocyte (CTL) response in these patients is unclear. Several studies have shown that HIV-infected CD4+ T cells also present viral epitopes that are recognized by CTLs before the productive stage of infection, i.e., during the intracellular eclipse phase before the infected cell starts to produce new viral particles. Here, we use mathematical modeling to investigate the potential impact of early killing of HIV-infected cells on viral replication. We suggest that the majority of CTL-mediated killing could occur during the viral eclipse phase, and that the killing of virus-producing cells could be substantially lower at later stages due to MHC-I-down-regulation. Such a mechanism is in agreement with several experimental observations that include CD8+ T cell depletion and antiretroviral drug treatment. This indicates a potentially important role of CTL-mediated killing during the non-productive stage of HIV-infected cells.
Collapse
|
43
|
Apetrei C, Gaufin T, Gautam R, Vinton C, Hirsch V, Lewis M, Brenchley J, Pandrea I. Pattern of SIVagm infection in patas monkeys suggests that host adaptation to simian immunodeficiency virus infection may result in resistance to infection and virus extinction. J Infect Dis 2010; 202 Suppl 3:S371-6. [PMID: 20887227 DOI: 10.1086/655970] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Patas monkeys were not reported to carry species‐specific simian immunodeficiency virus (SIV), but cross‐species transmission of SIVagm to patas monkeys occurred in the wild. We report that patas monkeys share immunophenotypic features with natural hosts of SIV; that is, low levels of CD4+ T cells and low CCR5 expression on CD4+ T cells. In 1 patas monkey with undetectable levels of CD4+ T cells, experimental exposure to SIVagm did not result in infection. The other experimentally infected patas monkeys showed an infection pattern similar to SIV infection in natural hosts. Thus, down‐regulation of CD4 and CCR5 expression on CD4+ T cells may effectively control human immunodeficiency virus acquisition and result in SIV extinction.
Collapse
Affiliation(s)
- Cristian Apetrei
- Division of Microbiology, Tulane National Primate Research Center, Covington, Louisiana, USA.
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Genetic identity and biological phenotype of a transmitted/founder virus representative of nonpathogenic simian immunodeficiency virus infection in African green monkeys. J Virol 2010; 84:12245-54. [PMID: 20881048 DOI: 10.1128/jvi.01603-10] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Understanding the lack of disease progression in nonpathogenic simian immunodeficiency virus (SIV) infections is essential for deciphering the immunopathogenesis of human AIDS. Yet, in vivo studies have been hampered by a paucity of infectious molecular clones (IMCs) of SIV suitable to dissect the viral and host factors responsible for the nonpathogenic phenotype. Here, we describe the identification, cloning, and biological analysis of the first transmitted/founder (T/F) virus representing a nonpathogenic SIV infection. Blood was collected at peak viremia from an acutely infected sabaeus monkey (Chlorocebus sabaeus) inoculated intravenously with an African green monkey SIV (SIVagm) strain (Sab92018) that had never been propagated in vitro. To generate IMCs, we first used conventional (bulk) PCR to amplify full-length viral genomes from peripheral blood mononuclear cell (PBMC) DNA. Although this yielded two intact SIVagmSab genomes, biological characterization revealed that both were replication defective. We then performed single-genome amplification (SGA) to generate partially overlapping 5' (n = 10) and 3' (n = 13) half genomes from plasma viral RNA. Analysis of these amplicons revealed clusters of nearly identical viral sequences representing the progeny of T/F viruses. Synthesis of the consensus sequence of one of these generated an IMC (Sab92018ivTF) that produced infectious CCR5-tropic virions and replicated to high titers in Molt-4 clone 8 cells and African green monkey PBMCs. Sab92018ivTF also initiated productive infection in sabaeus monkeys and faithfully recapitulated the replication kinetics and nonpathogenic phenotype of the parental Sab92018 strain. These results thus extend the T/F virus concept to nonpathogenic SIV infections and provide an important new tool to define viral determinants of disease nonprogression.
Collapse
|
45
|
Abstract
PURPOSE OF REVIEW To summarize our current understanding of the regulation of Th17 cells in pathogenic and nonpathogenic lentiviral infections. RECENT FINDINGS It has been shown that Th17 cells, a recently identified T helper-cell subset deemed critical for antimicrobial mucosal immunity, are preferentially depleted in the gastrointestinal tracts of human immunodeficiency virus (HIV)-infected humans and simian immunodeficiency virus (SIV)-infected rhesus and pigtailed (PTMs) macaques. In contrast, Th17 cells are preserved at healthy levels in monkey species that are natural hosts for SIV, such as sooty mangabeys or African green monkeys (AGMs), which maintain mucosal immunity and remain AIDS free. These findings suggest that preservation of Th17 cells (or lack thereof) may be central in determining the pathogenic or nonpathogenic outcome of HIV/SIV infection. SUMMARY A preferential depletion of mucosal Th17 cells is a feature that distinguishes pathogenic HIV infection of humans from nonprogressive SIV infection of sooty mangabeys and AGMs. The exact mechanism accounting for this different phenotype is still unclear. To understand how natural hosts for SIV preserve Th17 cells and mucosal immunity might be central to the development of therapeutic interventions aimed at improving mucosal immunity in HIV-infected individuals.
Collapse
|
46
|
Pandrea I, Apetrei C. Where the wild things are: pathogenesis of SIV infection in African nonhuman primate hosts. Curr HIV/AIDS Rep 2010; 7:28-36. [PMID: 20425055 PMCID: PMC2824118 DOI: 10.1007/s11904-009-0034-8] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
African nonhuman primates that are natural hosts of simian immunodeficiency virus (SIV) are generally spared from disease progression. Pathogenic and nonpathogenic SIV infections share some major features: high viral replication, massive acute depletion of mucosal CD4(+) T cells, and partial control of the virus by both adaptive and innate immune responses. A key distinction of natural SIV infections is rapid and active control of immune activation and apoptosis of T cells that contributes to the integrity of mucosal barrier and lack of microbial translocation. This allows partial recovery of CD4(+) T cells and preservation of the function of other immune cell subsets. A better understanding of the mechanisms underlying the lack of disease in natural hosts for SIV infection will likely provide important clues as to the therapy of HIV-1 infection.
Collapse
Affiliation(s)
- Ivona Pandrea
- Center for Vaccine Research and Department of Pathology, University of Pittsburgh, 9014 Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA, 15261-9045, USA.
| | | |
Collapse
|
47
|
Chan ML, Petravic J, Ortiz AM, Engram J, Paiardini M, Cromer D, Silvestri G, Davenport MP. Limited CD4+ T cell proliferation leads to preservation of CD4+ T cell counts in SIV-infected sooty mangabeys. Proc Biol Sci 2010; 277:3773-81. [PMID: 20591864 DOI: 10.1098/rspb.2010.0972] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) infections result in chronic virus replication and progressive depletion of CD4+ T cells, leading to immunodeficiency and death. In contrast, 'natural hosts' of SIV experience persistent infection with high virus replication but no severe CD4+ T cell depletion, and remain AIDS-free. One important difference between pathogenic and non-pathogenic infections is the level of activation and proliferation of CD4+ T cells. We analysed the relationship between CD4+ T cell number and proliferation in HIV, pathogenic SIV in macaques, and non-pathogenic SIV in sooty mangabeys (SMs) and mandrills. We found that CD4+ T cell proliferation was negatively correlated with CD4+ T cell number, suggesting that animals respond to the loss of CD4+ T cells by increasing the proliferation of remaining cells. However, the level of proliferation seen in pathogenic infections (SIV in rhesus macaques and HIV) was much greater than in non-pathogenic infections (SMs and mandrills). We then used a modelling approach to understand how the host proliferative response to CD4+ T cell depletion may impact the outcome of infection. This modelling demonstrates that the rapid proliferation of CD4+ T cells in humans and macaques associated with low CD4+ T cell levels can act to 'fuel the fire' of infection by providing more proliferating cells for infection. Natural host species, on the other hand, have limited proliferation of CD4+ T cells at low CD4+ T cell levels, which allows them to restrict the number of proliferating cells susceptible to infection.
Collapse
Affiliation(s)
- Ming Liang Chan
- Complex Systems in Biology Group, Centre for Vascular Research, University of New South Wales, Kensington, NSW, Australia
| | | | | | | | | | | | | | | |
Collapse
|
48
|
Abstract
Twenty-five years after the discovery of HIV as the cause of AIDS, tremendous progress has been made in reducing the morbidity and mortality associated with this disease. However, there is still neither a cure nor a vaccine for HIV infection. This shortcoming is likely a consequence of our incomplete understanding of the mechanisms of AIDS pathogenesis, particularly with regard to the interaction between the virus and the host immune system. In this article we review a series of recent advances in specific areas of HIV immunopathogenesis research: virus-host cell interactions; immune responses to HIV; chronic immune activation; and natural simian immunodeficiency virus infections. Finally, we discuss the potential implications of these findings for HIV/AIDS therapy and vaccines.
Collapse
Affiliation(s)
- Alexandra M Ortiz
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, 705 Stellar-Chance Laboratories, 422 Curie Boulevard, Philadelphia, PA 19104, USA
| | | |
Collapse
|
49
|
Gaufin T, Ribeiro RM, Gautam R, Dufour J, Mandell D, Apetrei C, Pandrea I. Experimental depletion of CD8+ cells in acutely SIVagm-infected African Green Monkeys results in increased viral replication. Retrovirology 2010; 7:42. [PMID: 20459829 PMCID: PMC2879233 DOI: 10.1186/1742-4690-7-42] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Accepted: 05/11/2010] [Indexed: 11/22/2022] Open
Abstract
Background In vivo CD8+ cell depletions in pathogenic SIV infections identified a key role for cellular immunity in controlling viral load (VL) and disease progression. However, similar studies gave discordant results in chronically-infected SMs, leading some authors to propose that in natural hosts, SIV replication is independent of cellular immunity. To assess the role of cellular immune responses in the control of SIV replication in natural hosts, we investigated the impact of CD8+ cell depletion during acute SIV infection in AGMs. Results Nine AGMs were infected with SIVagm.sab and were followed up to day 225 p.i. Four were intravenously infused with the cM-T807 antibody on days 0 (50 mg/kg), 6, and 13 (10 mg/kg, respectively) post infection (p.i.). CD8+ cells were depleted for up to 28 days p.i. in peripheral blood and LNs in all treated AGMs. Partial CD8+ T cell depletion occurred in the intestine. SIVagm VLs peaked at similar levels in both groups (107-108 RNA copies/ml). However, while VLs were controlled in undepleted AGMs, reaching set-point levels (104-105 RNA copies/ml) by day 28 p.i., high VLs (>106 RNA copies/ml) were maintained by day 21 p.i. in CD8-depleted AGMs. By day 42 p.i., VLs were comparable between the two groups. The levels of immune activation and proliferation remained elevated up to day 72 p.i. in CD8-depleted AGMs and returned to preinfection levels in controls by day 28 p.i. None of the CD8-depleted animals progressed to AIDS. Conclusion CD8+ cells are responsible for a partial control of postacute viral replication in SIVagm.sab-infected AGMs. In contrast to macaques, the SIVagm-infected AGMs are able to control viral replication after recovery of the CD8+ T cells and avoid disease progression.
Collapse
Affiliation(s)
- Thaidra Gaufin
- Division of Microbiology, Tulane National Primate Research Center, Covington, LA 70433, USA
| | | | | | | | | | | | | |
Collapse
|
50
|
Suppression of adaptive immune responses during primary SIV infection of sabaeus African green monkeys delays partial containment of viremia but does not induce disease. Blood 2010; 115:3070-8. [PMID: 20147699 DOI: 10.1182/blood-2009-10-245225] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
One of the most puzzling observations in HIV research is the lack of pathogenicity in most nonhuman primate species that are natural hosts of simian immunodeficiency virus (SIV) infection. Despite this, natural hosts experience a level of viremia similar to humans infected with HIV or macaques infected with SIV. To determine the role of adaptive immune responses in viral containment and lack of disease, we delayed the generation of cellular and humoral immune responses by administering anti-CD8- and anti-CD20 lymphocyte-depleting antibodies to sabaeus African green monkeys (Chlorocebus sabaeus) before challenge with SIV(sab9315BR). In vivo lymphocyte depletion during primary infection resulted in a brief elevation of viremia but not in disease. Based on the magnitude and timing of SIV-specific CD8(+) T-cell responses in the lymphocyte-depleted animals, CD8(+) T-cell responses appear to contribute to viral containment in natural hosts. We found no evidence for a contribution of humoral immune responses in viral containment. These studies indicate that natural hosts have developed mechanisms in addition to classic adaptive immune responses to cope with this lentiviral infection. Thus, adaptive immune responses in natural hosts appear to be less critical for viral containment than in HIV infection.
Collapse
|