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Nduati EW, Gorman MJ, Sein Y, Hermanus T, Yuan D, Oyaro I, Muema DM, Ndung’u T, Alter G, Moore PL. Coordinated Fc-effector and neutralization functions in HIV-infected children define a window of opportunity for HIV vaccination. AIDS 2021; 35:1895-1905. [PMID: 34115644 PMCID: PMC8462450 DOI: 10.1097/qad.0000000000002976] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 05/04/2021] [Accepted: 06/02/2021] [Indexed: 12/21/2022]
Abstract
OBJECTIVES Antibody function has been extensively studied in HIV-infected adults but is relatively understudied in children. Emerging data suggests enhanced development of broadly neutralizing antibodies (bNAbs) in children but Fc effector functions in this group are less well defined. Here, we profiled overall antibody function in HIV-infected children. DESIGN Plasma samples from a cross-sectional study of 50 antiretroviral therapy-naive children (aged 1-11 years) vertically infected with HIV-1 clade A were screened for HIV-specific binding antibody levels and neutralizing and Fc-mediated functions. METHODS Neutralization breadth was determined against a globally representative panel of 12 viruses. HIV-specific antibody levels were determined using a multiplex assay. Fc-mediated antibody functions measured were antibody-dependent: cellular phagocytosis (ADCP); neutrophil phagocytosis (ADNP); complement deposition (ADCD) and natural killer function (ADNK). RESULTS All children had HIV gp120-specific antibodies, largely of the IgG1 subtype. Fifty-four percent of the children exhibited more than 50% neutralization breadth, with older children showing significantly broader neutralization activity. Apart from ADCC, observed only in 16% children, other Fc-mediated functions were common (>58% children). Neutralization breadth correlated with Fc-mediated functions suggesting shared determinants of enhanced antibody function exist. CONCLUSIONS These results are consistent with previous observations that children may develop high levels of neutralization breadth. Furthermore, the striking association between neutralization breadth and Fc effector function suggests that HIV vaccination in children could yield multifunctional antibodies. Paediatric populations may therefore provide an ideal window of opportunity for HIV vaccination strategies.
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Affiliation(s)
| | | | - Yiakon Sein
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya
| | - Tandile Hermanus
- National Institute for Communicable Diseases of the National Health Laboratory Services, Johannesburg
| | - Dansu Yuan
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
| | - Ian Oyaro
- KEMRI Wellcome Trust Research Programme, Kilifi, Kenya
| | - Daniel M. Muema
- Africa Health Research Institute, Durban
- HIV Pathogenesis Programme, The Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa
| | - Thumbi Ndung’u
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
- Africa Health Research Institute, Durban
- HIV Pathogenesis Programme, The Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa
- Max Planck Institute for Infection Biology, Berlin, Germany
- Division of Infection and Immunity, University College London, London, UK
| | - Galit Alter
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
| | - Penny L. Moore
- National Institute for Communicable Diseases of the National Health Laboratory Services, Johannesburg
- Antibody Immunity Research Unit, University of the Witwatersrand, Johannesburg, South Africa
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Serwanga J, Ssemwanga D, Muganga M, Nakiboneka R, Nakubulwa S, Kiwuwa-Muyingo S, Morris L, Redd AD, Quinn TC, Kaleebu P. HIV-1 superinfection can occur in the presence of broadly neutralizing antibodies. Vaccine 2017; 36:578-586. [PMID: 29274699 DOI: 10.1016/j.vaccine.2017.11.075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 10/28/2017] [Accepted: 11/26/2017] [Indexed: 01/13/2023]
Abstract
BACKGROUND Superinfection of individuals already infected with HIV-1 suggests that pre-existing immune responses may not adequately protect against re-infection. We assessed high-risk female sex workers initially infected with HIV-1 clades A, D or A/D recombinants, to determine if HIV-1 broadly neutralizing antibodies were lacking prior to superinfection. METHODS Six superinfected female sex workers previously stratified by HIV-1 high-risk behavior, infecting virus clade and volunteer CD4 counts were evaluated at baseline (n = 5) and at 350 days post-superinfection (n = 6); one superinfected volunteer lacked pre-superinfection plasma. Retrospective plasmas were assessed for neutralization of a multi-clade panel of 12 HIV-1 viruses before superinfection, and then at quarterly intervals thereafter. Similarly stratified singly infected female sex workers were correspondingly assessed at baseline (n = 19) and 350 days after superinfection (n = 24). Neutralization of at least 50% of the 12 viruses (broad neutralization), and geometric means of the neutralization titers (IC50) were compared before and after superinfection; and were correlated with the volunteer HIV-1 superinfection status, CD4 counts, and pseudovirus clade. RESULTS Preexisting broad neutralization occurred in 80% (4/5) of the superinfected subjects with no further broadening by 350 days after superinfection. In one of the five subjects, HIV-1 superinfection occurred when broad neutralization was lacking; with subsequent broadening of neutralizing antibodies occuring within 9 months and plateauing by 30 months after detection of superinfection. Clade B and C pseudoviruses were more sensitive to neutralization (13; [87%]); and (12; [80%]) than the locally circulating clades A (10; [67%]) and D (6; [40%]), respectively (p = 0.025). Low antibody titers correlated with clade D viruses and with >500 CD4 T cell counts, but not with the superinfection status. CONCLUSION These data demonstrate that HIV-1 superinfection can occur both in the presence, and in the absence of broadly neutralizing antibodies.
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Affiliation(s)
- Jennifer Serwanga
- MRC/UVRI Uganda Research Unit on AIDS, c/o Uganda Virus Research Institute, Entebbe, Uganda.
| | - Deogratius Ssemwanga
- MRC/UVRI Uganda Research Unit on AIDS, c/o Uganda Virus Research Institute, Entebbe, Uganda
| | - Michael Muganga
- MRC/UVRI Uganda Research Unit on AIDS, c/o Uganda Virus Research Institute, Entebbe, Uganda
| | - Ritah Nakiboneka
- MRC/UVRI Uganda Research Unit on AIDS, c/o Uganda Virus Research Institute, Entebbe, Uganda
| | - Susan Nakubulwa
- MRC/UVRI Uganda Research Unit on AIDS, c/o Uganda Virus Research Institute, Entebbe, Uganda
| | - Sylvia Kiwuwa-Muyingo
- MRC/UVRI Uganda Research Unit on AIDS, c/o Uganda Virus Research Institute, Entebbe, Uganda
| | - Lynn Morris
- National Institute for Communicable Diseases, Johannesburg, South Africa; Center for the AIDS Program of Research in South Africa (CAPRISA), South Africa; University of the Witwatersrand, Johannesburg, South Africa
| | - Andrew D Redd
- Laboratory of Immunoregulation, Division of Intramural Research, NIAID, NIH, Bethesda, USA; Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Thomas C Quinn
- Laboratory of Immunoregulation, Division of Intramural Research, NIAID, NIH, Bethesda, USA; Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Pontiano Kaleebu
- MRC/UVRI Uganda Research Unit on AIDS, c/o Uganda Virus Research Institute, Entebbe, Uganda; London School of Hygiene and Tropical Medicine, Department of Clinical Research, London, UK
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3
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Ronen K, Dingens AS, Graham SM, Jaoko W, Mandaliya K, McClelland RS, Overbaugh J. Comprehensive Characterization of Humoral Correlates of Human Immunodeficiency Virus 1 Superinfection Acquisition in High-risk Kenyan Women. EBioMedicine 2017; 18:216-224. [PMID: 28427948 PMCID: PMC5405187 DOI: 10.1016/j.ebiom.2017.04.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 03/27/2017] [Accepted: 04/03/2017] [Indexed: 11/16/2022] Open
Abstract
HIV-1 superinfection, in which an infected individual acquires a second HIV-1 infection from a different partner, is one of the only settings in which HIV acquisition occurs in the context of a pre-existing immune response to natural HIV infection. There is evidence that initial infection provides some protection from superinfection, particularly after 6 months of initial infection, when development of broad immunity occurs. Comparison of the immune response of superinfected individuals at the time of superinfection acquisition to that of individuals who remain singly infected despite continued exposure can shed light on immune correlates of HIV acquisition to inform prophylactic vaccine design. We evaluated a panel of humoral immune responses in the largest published group of superinfected individuals (n = 21), compared to a set of 3:1 matched singly infected controls from the same cohort. The immune functions studied included plasma neutralization, plasma and cervical antibody-dependent cellular cytotoxicity, and plasma IgG and IgA binding to a panel of 18 envelope antigens, including correlates of HIV acquisition in the RV144 vaccine trial, IgG binding to V1V2 and IgA binding to gp140. Association between each immune function and HIV superinfection was evaluated using conditional logistic regression. No significant associations were detected between any of the immune functions and superinfection acquisition. This study constitutes the most comprehensive and detailed characterization of multiple immune correlates of superinfection to date. The results suggest that immune responses not commonly measured in current HIV studies may be important in protection from HIV infection, and these or a more robust humoral response than that seen in naturally infected women may be needed for a protective vaccine. We conducted a case-control study of the association between humoral immune functions and HIV superinfection (SI). Neutralization, antibody-dependent cellular cytotoxicity, and IgG and IgA binding to Env antigens were interrogated. We found no significant associations between SI acquisition and neutralizing or non-neutralizing antibody activity.
HIV superinfection (repeat infection from a second partner) is a unique situation in which infection occurs in the presence of a pre-existing HIV-specific immune response. Identification of immune deficits in superinfected individuals prior to superinfection can shed light on immune functions associated with HIV acquisition, and help inform prophylactic vaccine development. We compared various antibody measures in superinfected women vs. women who remained singly infected. We found no evidence that deficits in any of the measures analyzed were associated with superinfection risk. This suggests a prophylactic vaccine may need to elicit stronger or different immune responses than those investigated here.
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Affiliation(s)
- Keshet Ronen
- Human Biology Division, Fred Hutch Cancer Research Center, 1100 Fairview Ave N., Seattle, WA 98109, USA; Department of Global Health, University of Washington, 325 9th Avenue, Seattle, WA 98104, USA; Department of Epidemiology, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA
| | - Adam S Dingens
- Human Biology Division, Fred Hutch Cancer Research Center, 1100 Fairview Ave N., Seattle, WA 98109, USA; Department of Epidemiology, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA; Molecular and Cellular Biology Program, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA
| | - Susan M Graham
- Department of Global Health, University of Washington, 325 9th Avenue, Seattle, WA 98104, USA; Department of Epidemiology, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA; Department of Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA
| | - Walter Jaoko
- Department of Medical Microbiology, University of Nairobi, P.O. Box 30197-00100, Nairobi, Kenya
| | - Kishor Mandaliya
- Department of Global Health, University of Washington, 325 9th Avenue, Seattle, WA 98104, USA
| | - R Scott McClelland
- Department of Global Health, University of Washington, 325 9th Avenue, Seattle, WA 98104, USA; Department of Epidemiology, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA; Department of Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA; Institute of Tropical and Infectious Disease, University of Nairobi, P.O. Box 30197-00100, Nairobi, Kenya
| | - Julie Overbaugh
- Human Biology Division, Fred Hutch Cancer Research Center, 1100 Fairview Ave N., Seattle, WA 98109, USA; Public Health Sciences Division, Fred Hutch Cancer Research Center, 1100 Fairview Ave N., Seattle, WA 98109, USA.
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4
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Boyd DF, Sharma A, Humes D, Cheng-Mayer C, Overbaugh J. Adapting SHIVs In Vivo Selects for Envelope-Mediated Interferon-α Resistance. PLoS Pathog 2016; 12:e1005727. [PMID: 27399306 PMCID: PMC4939950 DOI: 10.1371/journal.ppat.1005727] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 06/05/2016] [Indexed: 02/07/2023] Open
Abstract
Lentiviruses are able to establish persistent infection in their respective hosts despite a potent type-I interferon (IFN-I) response following transmission. A number of IFN-I-induced host factors that are able to inhibit lentiviral replication in vitro have been identified, and these studies suggest a role for IFN-induced factors as barriers to cross-species transmission. However, the ability of these factors to inhibit viral replication in vivo has not been well characterized, nor have the viral determinants that contribute to evasion or antagonism of the host IFN-I response. In this study, we hypothesized that the host IFN-I response serves as a strong selective pressure in the context of SIV/HIV chimeric virus (SHIV) infection of macaques and sought to identify the viral determinants that contribute to IFN-I resistance. We assessed the ability of SHIVs encoding HIV-1 sequences adapted by serial passage in macaques versus SHIVs encoding HIV sequences isolated directly from infected individuals to replicate in the presence of IFNα in macaque lymphocytes. We demonstrate that passage in macaques selects for IFNα resistant viruses that have higher replication kinetics and increased envelope content. SHIVs that encode HIV-1 sequences derived directly from infected humans were sensitive to IFNα -induced inhibition whereas SHIVs obtained after passage in macaques were not. This evolutionary process was directly observed in viruses that were serially passaged during the first few months of infection-a time when the IFNα response is high. Differences in IFNα sensitivity mapped to HIV-1 envelope and were associated with increased envelope levels despite similar mRNA expression, suggesting a post-transcriptional mechanism. These studies highlight critical differences in IFNα sensitivity between HIV-1 sequences in infected people and those used in SHIV models.
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Affiliation(s)
- David F. Boyd
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Pathobiology Graduate Program, University of Washington, Seattle, Washington, United States of America
| | - Amit Sharma
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Daryl Humes
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | | | - Julie Overbaugh
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
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5
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Mutations in HIV-1 envelope that enhance entry with the macaque CD4 receptor alter antibody recognition by disrupting quaternary interactions within the trimer. J Virol 2014; 89:894-907. [PMID: 25378497 DOI: 10.1128/jvi.02680-14] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
UNLABELLED Chimeric simian immunodeficiency virus (SIV)/human immunodeficiency virus (HIV) (SHIV) infection of macaques is commonly used to model HIV type 1 (HIV-1) transmission and pathogenesis in humans. Despite the fact that SHIVs encode SIV antagonists of the known macaque host restriction factors, these viruses require additional adaptation for replication in macaques to establish a persistent infection. Additional adaptation may be required in part because macaque CD4 (mCD4) is a suboptimal receptor for most HIV-1 envelope glycoprotein (Env) variants. This requirement raises the possibility that adaptation of HIV-1 Env to the macaque host leads to selection of variants that lack important biological and antigenic properties of the viruses responsible for the HIV-1 pandemic in humans. Here, we investigated whether this adaptation process leads to changes in the antigenicity and structure of HIV-1 Env. For this purpose, we examined how two independent mutations that enhance mCD4-mediated entry, A204E and G312V, impact antibody recognition in the context of seven different parental HIV-1 Env proteins from diverse subtypes. We also examined HIV-1 Env variants from three SHIVs that had been adapted for increased replication in macaques. Our results indicate that these different macaque-adapted variants had features in common, including resistance to antibodies directed to quaternary epitopes and sensitivity to antibodies directed to epitopes in the variable domains (V2 and V3) that are buried in the parental, unadapted Env proteins. Collectively, these findings suggest that adaptation to mCD4 results in conformational changes that expose epitopes in the variable domains and disrupt quaternary epitopes in the native Env trimer. IMPORTANCE These findings indicate the antigenic consequences of adapting HIV-1 Env to mCD4. They also suggest that to best mimic HIV-1 infection in humans when using the SHIV/macaque model, HIV-1 Env proteins should be identified that use mCD4 as a functional receptor and preserve quaternary epitopes characteristic of HIV-1 Env.
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6
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Finton KAK, Friend D, Jaffe J, Gewe M, Holmes MA, Larman HB, Stuart A, Larimore K, Greenberg PD, Elledge SJ, Stamatatos L, Strong RK. Ontogeny of recognition specificity and functionality for the broadly neutralizing anti-HIV antibody 4E10. PLoS Pathog 2014; 10:e1004403. [PMID: 25254371 PMCID: PMC4177983 DOI: 10.1371/journal.ppat.1004403] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 08/16/2014] [Indexed: 01/07/2023] Open
Abstract
The process of antibody ontogeny typically improves affinity, on-rate, and thermostability, narrows polyspecificity, and rigidifies the combining site to the conformer optimal for binding from the broader ensemble accessible to the precursor. However, many broadly-neutralizing anti-HIV antibodies incorporate unusual structural elements and recognition specificities or properties that often lead to autoreactivity. The ontogeny of 4E10, an autoreactive antibody with unexpected combining site flexibility, was delineated through structural and biophysical comparisons of the mature antibody with multiple potential precursors. 4E10 gained affinity primarily by off-rate enhancement through a small number of mutations to a highly conserved recognition surface. Controverting the conventional paradigm, the combining site gained flexibility and autoreactivity during ontogeny, while losing thermostability, though polyspecificity was unaffected. Details of the recognition mechanism, including inferred global effects due to 4E10 binding, suggest that neutralization by 4E10 may involve mechanisms beyond simply binding, also requiring the ability of the antibody to induce conformational changes distant from its binding site. 4E10 is, therefore, unlikely to be re-elicited by conventional vaccination strategies.
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Affiliation(s)
- Kathryn A. K. Finton
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Della Friend
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - James Jaffe
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Mesfin Gewe
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Margaret A. Holmes
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - H. Benjamin Larman
- Department of Genetics, Harvard University Medical School, and Division of Genetics, Howard Hughes Medical Institute, Brigham and Women's Hospital, Boston, Massachusetts, United States of America
| | - Andrew Stuart
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America
| | - Kevin Larimore
- Department of Immunology, University of Washington, Seattle, Washington, United States of America
| | - Philip D. Greenberg
- Department of Immunology, University of Washington, Seattle, Washington, United States of America
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
- Program in Immunology, Cancer Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Stephen J. Elledge
- Department of Genetics, Harvard University Medical School, and Division of Genetics, Howard Hughes Medical Institute, Brigham and Women's Hospital, Boston, Massachusetts, United States of America
| | - Leonidas Stamatatos
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Roland K. Strong
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- * E-mail:
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Chaitaveep N, Utachee P, Nakamura S, Chuenchitra T, Ekpo P, Takeda N, Pattanapanyasat K, Kameoka M. Characterization of human immunodeficiency virus type 1 CRF01_AE env genes derived from recently infected Thai individuals. Microbes Infect 2014; 16:142-52. [PMID: 24513704 DOI: 10.1016/j.micinf.2013.10.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 10/08/2013] [Accepted: 10/17/2013] [Indexed: 11/15/2022]
Abstract
Transmitted/founder virus is responsible for the establishment of human immunodeficiency virus type 1 (HIV-1) infection and induces primary anti-HIV-1 immune responses; therefore, it is important to study the viral population to understand the early events of HIV-1 infection. We amplified HIV-1 env genes from sera derived from recently infected Thai individuals, and established envelope glycoproteins (Env)-recombinant viruses. Generated Env-recombinant viruses were tested for their neutralization susceptibility to neutralizing human monoclonal antibodies (NHMAbs) and entry inhibitors, as well as being subjected to genotypic analysis. Most recombinant viruses were susceptible to neutralization by NHMAbs to Env gp41, whereas approximately one-third of the recombinant viruses were susceptible to a NHMAb against the CD4 binding site of gp120. In addition, all env genes were classified into CRF01_AE genes and showed low genetic divergence. Taken together with our previous studies on CRF01_AE env genes derived from chronically infected Thai individuals, these results suggested that the immunological and genetic characteristics of CRF01_AE Env derived from recently infected Thai individuals were different from those derived from chronically infected individuals.
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8
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Early development of broadly neutralizing antibodies in HIV-1-infected infants. Nat Med 2014; 20:655-8. [PMID: 24859529 PMCID: PMC4060046 DOI: 10.1038/nm.3565] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 04/14/2014] [Indexed: 02/07/2023]
Abstract
Eliciting protective neutralizing antibodies (NAbs) against HIV-1 is daunting because of the extensive genetic and antigenic diversity of HIV-1. Moreover, broad and potent responses are uncommon even during persistent infection, with only a subset of adults developing broadly neutralizing antibodies (bNAbs) that recognize variants from different HIV-1 clades1–8. It is not known whether bNAbs can also arise in HIV-1-infected infants, who typically progress to disease faster than adults9, presumably in part due to an immature immune system10. Here, we show that bNAbs develop at least as commonly in infants as in adults. Cross-clade NAb responses were detected in 20/28 infected infants, in some cases, within 1 year of infection. Among infants with the top quartile of responses, neutralization of Tier 2–3 variants from multiple clades was detected at 20 months post-infection. These findings suggest that, even in early life, there is sufficient B-cell functionality to mount bNAbs against HIV-1. Additionally, the relatively early appearance of bNAbs in infants may provide a unique setting for understanding the pathways of B-cell maturation leading to bNAbs.
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9
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Abstract
The development of an effective vaccine has been hindered by the enormous diversity of human immunodeficiency virus-1 (HIV-1) and its ability to escape a myriad of host immune responses. In addition, conserved vulnerable regions on the HIV-1 envelope glycoprotein are often poorly immunogenic and elicit broadly neutralizing antibody responses (BNAbs) in a minority of HIV-1-infected individuals and only after several years of infection. All of the known BNAbs demonstrate high levels of somatic mutations and often display other unusual traits, such as a long heavy chain complementarity determining region 3 (CDRH3) and autoreactivity that can be limited by host tolerance controls. Nonetheless, the demonstration that HIV-1-infected individuals can make potent BNAbs is encouraging, and recent progress in isolating such antibodies and mapping their immune pathways of development is providing new strategies for vaccination.
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Affiliation(s)
- John R Mascola
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, USA.
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10
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Jennifer M, Leslie G, Maxwel MO, Ruth N, Julie O. HIV-1 maternal and infant variants show similar sensitivity to broadly neutralizing antibodies, but sensitivity varies by subtype. AIDS 2013; 27:1535-44. [PMID: 23856624 PMCID: PMC4080909 DOI: 10.1097/qad.0b013e32835faba5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
RATIONALE To protect against HIV infection, passively transferred and/or vaccine-elicited neutralizing antibodies (NAbs) need to effectively target diverse subtypes that are transmitted globally. These variants are a limited subset of those present during chronic infection and display some unique features. In the case of mother-to-child transmission (MTCT), transmitted variants tend to be resistant to neutralization by maternal autologous NAbs. METHOD To investigate whether variants transmitted during MTCT are generally resistant to HIV-1-specific NAbs, 107 maternal or infant variants representing the dominant HIV-1 subtypes were tested against six recently identified HIV-1-specific broadly neutralizing monoclonal antibodies (bNAbs), NIH45-46W, VRC01, PGT128, PGT121, PG9 and PGT145. RESULTS Infant and maternal variants did not differ in their neutralization sensitivity to individual bNAbs, nor did viruses from transmitting versus nontransmitting mothers, although there was a trend for viruses from transmitting mothers to be less sensitive overall. No single bNAb neutralized all viruses, but a combination of bNAbs that target distinct epitopes covered 100% of the variants tested. Compared with heterosexually transmitted variants, vertically transmitted variants were significantly more sensitive to neutralization by PGT128 and PGT121 (P=0.03 in both cases), but there were no differences for the other bNAbs. Overall, subtype A variants were significantly more sensitive to NIH45-46 (P=0.04), VRC01 (P=0.002) and PGT145 (P=0.03) compared with the nonsubtype A and less sensitive to PGT121 than subtype Cs (P=0.0001). CONCLUSION A combination of bNAbs against distinct epitopes may be needed to provide maximum coverage against viruses in different modes of transmission and diverse subtypes.
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Affiliation(s)
- Mabuka Jennifer
- Division of Human Biology and Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, US 98109
- Program of Pathobiology, Department of Global Health, University of Washington, Seattle, WA
| | - Goo Leslie
- Division of Human Biology and Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, US 98109
- Program of Pathobiology, Department of Global Health, University of Washington, Seattle, WA
| | - Majiwa O. Maxwel
- Division of Human Biology and Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, US 98109
- Program of Pathobiology, Department of Global Health, University of Washington, Seattle, WA
| | - Nduati Ruth
- Department of Pediatrics, University of Nairobi, Nairobi, Kenya
| | - Overbaugh Julie
- Division of Human Biology and Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, US 98109
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11
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Leaman DP, Zwick MB. Increased functional stability and homogeneity of viral envelope spikes through directed evolution. PLoS Pathog 2013; 9:e1003184. [PMID: 23468626 PMCID: PMC3585149 DOI: 10.1371/journal.ppat.1003184] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Accepted: 12/21/2012] [Indexed: 11/19/2022] Open
Abstract
The functional HIV-1 envelope glycoprotein (Env) trimer, the target of anti-HIV-1 neutralizing antibodies (Abs), is innately labile and coexists with non-native forms of Env. This lability and heterogeneity in Env has been associated with its tendency to elicit non-neutralizing Abs. Here, we use directed evolution to overcome instability and heterogeneity of a primary Env spike. HIV-1 virions were subjected to iterative cycles of destabilization followed by replication to select for Envs with enhanced stability. Two separate pools of stable Env variants with distinct sequence changes were selected using this method. Clones isolated from these viral pools could withstand heat, denaturants and other destabilizing conditions. Seven mutations in Env were associated with increased trimer stability, primarily in the heptad repeat regions of gp41, but also in V1 of gp120. Combining the seven mutations generated a variant Env with superior homogeneity and stability. This variant spike moreover showed resistance to proteolysis and to dissociation by detergent. Heterogeneity within the functional population of hyper-stable Envs was also reduced, as evidenced by a relative decrease in a proportion of virus that is resistant to the neutralizing Ab, PG9. The latter result may reflect a change in glycans on the stabilized Envs. The stabilizing mutations also increased the proportion of secreted gp140 existing in a trimeric conformation. Finally, several Env-stabilizing substitutions could stabilize Env spikes from HIV-1 clades A, B and C. Spike stabilizing mutations may be useful in the development of Env immunogens that stably retain native, trimeric structure. A vaccine is needed to prevent HIV/AIDS but eliciting potent neutralizing antibodies (Abs) against primary isolates has been a major stumbling block. The target of HIV-1 neutralizing antibodies is the native envelope glycoprotein (Env) trimer that is displayed on the surface of the virus. Virion associated Env typically elicits antibodies that cannot neutralize primary viruses. However, because native Env trimers can dissociate and coexist with non-fusogenic forms of Env interpreting these results are difficult. Here, we used directed evolution to select for virions that display native Env with increased stability and homogeneity. HIV-1 virions were subjected to increasingly harsh treatments that destabilize Env trimers, and the variants that survived each treatment were expanded. We could identify seven different mutations in Env that increased its stability of function in the face of multiple destabilizing treatments. When these mutations were combined, the resulting mutant Env trimers were far more stable than the original Env protein. Incorporating trimer-stabilizing mutations into Env-based immunogens should facilitate vaccine research by mitigating the confounding effects of non-native byproducts of Env decay. A similar approach may be used on other pathogens with potential vaccine targets that are difficult to isolate and maintain in a native form.
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Affiliation(s)
- Daniel P. Leaman
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
| | - Michael B. Zwick
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America
- * E-mail:
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Murphy MK, Yue L, Pan R, Boliar S, Sethi A, Tian J, Pfafferot K, Karita E, Allen SA, Cormier E, Goepfert PA, Borrow P, Robinson JE, Gnanakaran S, Hunter E, Kong XP, Derdeyn CA. Viral escape from neutralizing antibodies in early subtype A HIV-1 infection drives an increase in autologous neutralization breadth. PLoS Pathog 2013; 9:e1003173. [PMID: 23468623 PMCID: PMC3585129 DOI: 10.1371/journal.ppat.1003173] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Accepted: 12/19/2012] [Indexed: 01/07/2023] Open
Abstract
Antibodies that neutralize (nAbs) genetically diverse HIV-1 strains have been recovered from a subset of HIV-1 infected subjects during chronic infection. Exact mechanisms that expand the otherwise narrow neutralization capacity observed during early infection are, however, currently undefined. Here we characterized the earliest nAb responses in a subtype A HIV-1 infected Rwandan seroconverter who later developed moderate cross-clade nAb breadth, using (i) envelope (Env) glycoproteins from the transmitted/founder virus and twenty longitudinal nAb escape variants, (ii) longitudinal autologous plasma, and (iii) autologous monoclonal antibodies (mAbs). Initially, nAbs targeted a single region of gp120, which flanked the V3 domain and involved the alpha2 helix. A single amino acid change at one of three positions in this region conferred early escape. One immunoglobulin heavy chain and two light chains recovered from autologous B cells comprised two mAbs, 19.3H-L1 and 19.3H-L3, which neutralized the founder Env along with one or three of the early escape variants carrying these mutations, respectively. Neither mAb neutralized later nAb escape or heterologous Envs. Crystal structures of the antigen-binding fragments (Fabs) revealed flat epitope contact surfaces, where minimal light chain mutation in 19.3H-L3 allowed for additional antigenic interactions. Resistance to mAb neutralization arose in later Envs through alteration of two glycans spatially adjacent to the initial escape signatures. The cross-neutralizing nAbs that ultimately developed failed to target any of the defined V3-proximal changes generated during the first year of infection in this subject. Our data demonstrate that this subject's first recognized nAb epitope elicited strain-specific mAbs, which incrementally acquired autologous breadth, and directed later B cell responses to target distinct portions of Env. This immune re-focusing could have triggered the evolution of cross-clade antibodies and suggests that exposure to a specific sequence of immune escape variants might promote broad humoral responses during HIV-1 infection.
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Affiliation(s)
- Megan K. Murphy
- Immunology and Molecular Pathogenesis Graduate Program, Emory University, Atlanta, Georgia, United States of America
- Emory Vaccine Center at Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
| | - Ling Yue
- Emory Vaccine Center at Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
| | - Ruimin Pan
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York, United States of America
| | - Saikat Boliar
- Emory Vaccine Center at Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
| | - Anurag Sethi
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Jianhui Tian
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Katja Pfafferot
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | | | - Susan A. Allen
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia, United States of America
- Departments of Epidemiology and Global Health, Emory University, Atlanta, Georgia, United States of America
| | - Emmanuel Cormier
- International AIDS Vaccine Initiative, Human Immunology Laboratory, Imperial College, London, United Kingdom
| | - Paul A. Goepfert
- Departments of Medicine and Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Persephone Borrow
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - James E. Robinson
- Department of Pediatrics, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - S. Gnanakaran
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Eric Hunter
- Emory Vaccine Center at Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia, United States of America
| | - Xiang-Peng Kong
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York, United States of America
| | - Cynthia A. Derdeyn
- Emory Vaccine Center at Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia, United States of America
- * E-mail:
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OuYang Y, Sun J, Huang Y, Lu L, Xu W, Hu X, Hong K, Jiang S, Shao Y, Ma L. Neutralization sensitivity of HIV-1 subtype B' clinical isolates from former plasma donors in China. Virol J 2013; 10:10. [PMID: 23289760 PMCID: PMC3599083 DOI: 10.1186/1743-422x-10-10] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 12/27/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND HIV-1 subtype B' isolates have been predominantly circulating in China. Their intra- and inter-subtype neutralization sensitivity to autologous and heterologous plasmas has not been well studied. RESULTS Twelve HIV-1 B' clinical isolates obtained from patients were tested for their intra- and inter-subtype neutralization sensitivity to the neutralization antibodies in the plasmas from patients infected by HIV-1 B' and CRF07_BC subtypes, respectively. We found that the plasmas from the HIV-1 B'-infected patients could potently neutralize heterologous viruses of subtype B' with mean ID50 titer (1/x) of about 67, but they were not effective in neutralizing autologous viruses of subtype B' with mean ID50 titer (1/x) of about 8. The plasmas from HIV-1 CRF07_BC-infected patients exhibited weak inter-subtype neutralization activity against subtype B' viruses with ID50 titer (1/x) is about 22. The neutralization sensitivity of HIV-1 B' isolates was inversely correlated with the neutralizing activity of plasmas from HIV-1 B'-infected patients (Spearman's r = -0.657, P = 0.020), and with the number of potential N-glycosylation site (PNGS) in V1-V5 region (Spearman's r = -0.493, P = 0.034), but positively correlated with the viral load (Spearman's r = 0.629, P = 0.028). It had no correlation with the length of V1-V5 regions or the CD4+ T cell count. Virus AH259V has low intra-subtype neutralization sensitivity, it can be neutralized by 17b (IC50: 10μg/ml) and 447-52D (IC50: 1.6μg/ml), and the neutralizing antibodies (nAbs) in plasma AH259P are effective in neutralizing infection by the primary HIV-1 isolates with different subtypes with ID50 titers (1/x) in the range of 32-396. CONCLUSIONS These findings suggest that the HIV-1 subtype B' viruses may mutate under the immune pressure, thus becoming resistant to the autologous nAbs, possibly by changing the number of PNGS in the V1-V5 region of the viral gp120. Some of primary HIV-1 isolates are able to induce both intra- and inter-subtype cross-neutralizing antibody responses.
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Affiliation(s)
- Yabo OuYang
- State Key Laboratory for Infection Disease Prevention and Control, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention (China-CDC), Beijing, China
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14
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Archary D, Rong R, Gordon ML, Boliar S, Madiga M, Gray ES, Dugast AS, Hermanus T, Goulder PJR, Coovadia HM, Werner L, Morris L, Alter G, Derdeyn CA, Ndung'u T. Characterization of anti-HIV-1 neutralizing and binding antibodies in chronic HIV-1 subtype C infection. Virology 2012; 433:410-20. [PMID: 22995189 PMCID: PMC3488441 DOI: 10.1016/j.virol.2012.08.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 06/14/2012] [Accepted: 08/23/2012] [Indexed: 01/08/2023]
Abstract
Neutralizing (nAbs) and high affinity binding antibodies may be critical for an efficacious HIV-1 vaccine. We characterized virus-specific nAbs and binding antibody responses over 21 months in eight HIV-1 subtype C chronically infected individuals with heterogeneous rates of disease progression. Autologous nAb titers of study exit plasma against study entry viruses were significantly higher than contemporaneous responses at study entry (p=0.002) and exit (p=0.01). NAb breadth and potencies against subtype C viruses were significantly higher than for subtype A (p=0.03 and p=0.01) or B viruses (p=0.03; p=0.05) respectively. Gp41-IgG binding affinity was higher than gp120-IgG (p=0.0002). IgG-FcγR1 affinity was significantly higher than FcγRIIIa (p<0.005) at study entry and FcγRIIb (p<0.05) or FcγRIIIa (p<0.005) at study exit. Evolving IgG binding suggests alteration of immune function mediated by binding antibodies. Evolution of nAbs was a potential marker of HIV-1 disease progression.
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Affiliation(s)
- Derseree Archary
- HIV Pathogenesis Programme, Doris Duke Medical Research Institute, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa
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15
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Baalwa J, Wang S, Parrish NF, Decker JM, Keele BF, Learn GH, Yue L, Ruzagira E, Ssemwanga D, Kamali A, Amornkul PN, Price MA, Kappes JC, Karita E, Kaleebu P, Sanders E, Gilmour J, Allen S, Hunter E, Montefiori DC, Haynes BF, Cormier E, Hahn BH, Shaw GM. Molecular identification, cloning and characterization of transmitted/founder HIV-1 subtype A, D and A/D infectious molecular clones. Virology 2012; 436:33-48. [PMID: 23123038 DOI: 10.1016/j.virol.2012.10.009] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Revised: 09/25/2012] [Accepted: 10/05/2012] [Indexed: 11/18/2022]
Abstract
We report the molecular identification, cloning and initial biological characterization of 12 full-length HIV-1 subtype A, D and A/D recombinant transmitted/founder (T/F) genomes. T/F genomes contained intact canonical open reading frames and all T/F viruses were replication competent in primary human T-cells, although subtype D virus replication was more efficient (p<0.05). All 12 viruses utilized CCR5 but not CXCR4 as a co-receptor for entry and exhibited a neutralization profile typical of tier 2 primary virus strains, with significant differences observed between subtype A and D viruses with respect to sensitivity to monoclonal antibodies VRC01, PG9 and PG16 and polyclonal subtype C anti-HIV IgG (p<0.05 for each). The present report doubles the number of T/F HIV-1 clones available for pathogenesis and vaccine research and extends their representation to include subtypes A, B, C and D.
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Affiliation(s)
- Joshua Baalwa
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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16
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Kwong PD, Mascola JR. Human antibodies that neutralize HIV-1: identification, structures, and B cell ontogenies. Immunity 2012; 37:412-25. [PMID: 22999947 PMCID: PMC4706166 DOI: 10.1016/j.immuni.2012.08.012] [Citation(s) in RCA: 373] [Impact Index Per Article: 31.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Revised: 08/03/2012] [Accepted: 08/24/2012] [Indexed: 02/07/2023]
Abstract
Antibodies that neutralize diverse strains of HIV-1 develop in ∼20% of HIV-1-infected individuals, and isolation and structural characterization of these antibodies are revealing how they recognize the envelope glycoprotein spike. Broadly reactive neutralizing antibodies utilize just a few sites of spike vulnerability and converge on select modes of recognition. These antibodies have unusual features: uncommonly long complementarity-determining loops, extensive somatic mutation, or both. Recent advances in next-generation sequencing of antibody-gene transcripts are providing genetic records of the development of neutralizing antibodies. These records inform an understanding of the naive B cell repertoire, of somatic mutation, and of the resulting antibody features that are critical to effective HIV-1 neutralization; based on these, we propose an ontogeny and structure-based system of antibody classification. The human immune system is capable of developing antibodies that broadly neutralize HIV-1--and an increasingly detailed view is accumulating for how effective immunity against HIV-1 can be generated.
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Affiliation(s)
- Peter D. Kwong
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - John R. Mascola
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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17
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A combination of broadly neutralizing HIV-1 monoclonal antibodies targeting distinct epitopes effectively neutralizes variants found in early infection. J Virol 2012; 86:10857-61. [PMID: 22837204 DOI: 10.1128/jvi.01414-12] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Neutralizing antibody protection against HIV-1 may require broad and potent antibodies targeting multiple epitopes. We tested 7 monoclonal antibodies (MAbs) against 45 viruses of diverse subtypes from early infection. The CD4 binding site MAb NIH45-46W was most broad and potent (91% coverage; geometric mean 50% inhibitory concentration [IC(50)], 0.09 μg/ml). Combining NIH45-46W and a V3-specific MAb, PGT128, neutralized 96% of viruses, while PGT121, another V3-specific MAb, neutralized the remainder. Thus, 2 or 3 antibody specificities may prevent infection by most HIV-1 variants.
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18
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Silibinin inhibits HIV-1 infection by reducing cellular activation and proliferation. PLoS One 2012; 7:e41832. [PMID: 22848626 PMCID: PMC3404953 DOI: 10.1371/journal.pone.0041832] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 06/25/2012] [Indexed: 12/17/2022] Open
Abstract
Purified silymarin-derived natural products from the milk thistle plant (Silybum marianum) block hepatitis C virus (HCV) infection and inhibit T cell proliferation in vitro. An intravenous formulation of silibinin (SIL), a major component of silymarin, displays anti-HCV effects in humans and also inhibits T-cell proliferation in vitro. We show that SIL inhibited replication of HIV-1 in TZM-bl cells, PBMCs, and CEM cells in vitro. SIL suppression of HIV-1 coincided with dose-dependent reductions in actively proliferating CD19+, CD4+, and CD8+ cells, resulting in fewer CD4+ T cells expressing the HIV-1 co-receptors CXCR4 and CCR5. SIL inhibition of T-cell growth was not due to cytotoxicity measured by cell cycle arrest, apoptosis, or necrosis. SIL also blocked induction of the activation markers CD38, HLA-DR, Ki67, and CCR5 on CD4+ T cells. The data suggest that SIL attenuated cellular functions involved in T-cell activation, proliferation, and HIV-1 infection. Silymarin-derived compounds provide cytoprotection by suppressing virus infection, immune activation, and inflammation, and as such may be relevant for both HIV mono-infected and HIV/HCV co-infected subjects.
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19
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Mabuka J, Nduati R, Odem-Davis K, Peterson D, Overbaugh J. HIV-specific antibodies capable of ADCC are common in breastmilk and are associated with reduced risk of transmission in women with high viral loads. PLoS Pathog 2012; 8:e1002739. [PMID: 22719248 PMCID: PMC3375288 DOI: 10.1371/journal.ppat.1002739] [Citation(s) in RCA: 180] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 04/23/2012] [Indexed: 01/25/2023] Open
Abstract
There are limited data describing the functional characteristics of HIV-1 specific antibodies in breast milk (BM) and their role in breastfeeding transmission. The ability of BM antibodies to bind HIV-1 envelope, neutralize heterologous and autologous viruses and direct antibody-dependent cell cytotoxicity (ADCC) were analyzed in BM and plasma obtained soon after delivery from 10 non-transmitting and 9 transmitting women with high systemic viral loads and plasma neutralizing antibodies (NAbs). Because subtype A is the dominant subtype in this cohort, a subtype A envelope variant that was sensitive to plasma NAbs was used to assess the different antibody activities. We found that NAbs against the subtype A heterologous virus and/or the woman's autologous viruses were rare in IgG and IgA purified from breast milk supernatant (BMS)--only 4 of 19 women had any detectable NAb activity against either virus. Detected NAbs were of low potency (median IC50 value of 10 versus 647 for the corresponding plasma) and were not associated with infant infection (p = 0.58). The low NAb activity in BMS versus plasma was reflected in binding antibody levels: HIV-1 envelope specific IgG titers were 2.2 log(10) lower (compared to 0.59 log(10) lower for IgA) in BMS versus plasma. In contrast, antibodies capable of ADCC were common and could be detected in the BMS from all 19 women. BMS envelope-specific IgG titers were associated with both detection of IgG NAbs (p = 0.0001) and BMS ADCC activity (p = 0.014). Importantly, BMS ADCC capacity was inversely associated with infant infection risk (p = 0.039). Our findings indicate that BMS has low levels of envelope specific IgG and IgA with limited neutralizing activity. However, this small study of women with high plasma viral loads suggests that breastmilk ADCC activity is a correlate of transmission that may impact infant infection risk.
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Affiliation(s)
- Jennifer Mabuka
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Program of Pathobiology, Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Ruth Nduati
- Department of Pediatrics, University of Nairobi, Nairobi, Kenya
| | - Katherine Odem-Davis
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Dylan Peterson
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Julie Overbaugh
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
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20
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HIV gp120 H375 is unique to HIV-1 subtype CRF01_AE and confers strong resistance to the entry inhibitor BMS-599793, a candidate microbicide drug. Antimicrob Agents Chemother 2012; 56:4257-67. [PMID: 22615295 DOI: 10.1128/aac.00639-12] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
BMS-599793 is a small molecule entry inhibitor that binds to human immunodeficiency virus type 1 (HIV-1) gp120, resulting in the inhibition of CD4-dependent entry into cells. Since BMS-599793 is currently considered a candidate microbicide drug, we evaluated its efficacy against a number of primary patient HIV isolates from different subtypes and circulating recombinant forms (CRFs) and showed that activity varied between ∼3 ρM and 7 μM at 50% effective concentrations (EC(50)s). Interestingly, CRF01_AE HIV-1 isolates consistently demonstrated natural resistance against this compound. Genotypic analysis of >1,600 sequences (Los Alamos HIV sequence database) indicated that a single amino acid polymorphism in Env, H375, may account for the observed BMS-599793 resistance in CRF01_AE HIV-1. Results of site-directed mutagenesis experiments confirmed this hypothesis, and in silico drug docking simulations identified a drug resistance mechanism at the molecular level. In addition, CRF01_AE viruses were shown to be resistant to multiple broadly neutralizing monoclonal antibodies. Thus, our results not only provide insight into how Env polymorphisms may contribute to entry inhibitor resistance but also may help to elucidate how HIV can evade some broadly neutralizing antibodies. Furthermore, the high frequency of H375 in CRF01_AE HIV-1, and its apparent nonoccurrence in other subtypes, could serve as a means for rapid identification of CRF01_AE infections.
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21
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Abstract
We studied neutralization of CRF02_AG HIV-1-infected plasma samples. In contrast to previous reports, these samples neutralized CRF02_AG viruses better than other viruses. This included six of eight CRF02_AG viruses previously designated resistant (tier 2/3 or 3). Only viruses 253-11 and 278-50 remained highly resistant, but they were sensitive to membrane-proximal external region (MPER)-specific monoclonal antibodies, suggesting neutralization targets for even these viruses. We propose using high-neutralizing-within-subtype samples for evaluation of neutralization resistance of viruses.
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22
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Cortez V, Odem-Davis K, McClelland RS, Jaoko W, Overbaugh J. HIV-1 superinfection in women broadens and strengthens the neutralizing antibody response. PLoS Pathog 2012; 8:e1002611. [PMID: 22479183 PMCID: PMC3315492 DOI: 10.1371/journal.ppat.1002611] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Accepted: 02/14/2012] [Indexed: 12/16/2022] Open
Abstract
Identifying naturally-occurring neutralizing antibodies (NAb) that are cross-reactive against all global subtypes of HIV-1 is an important step toward the development of a vaccine. Establishing the host and viral determinants for eliciting such broadly NAbs is also critical for immunogen design. NAb breadth has previously been shown to be positively associated with viral diversity. Therefore, we hypothesized that superinfected individuals develop a broad NAb response as a result of increased antigenic stimulation by two distinct viruses. To test this hypothesis, plasma samples from 12 superinfected women each assigned to three singly infected women were tested against a panel of eight viruses representing four different HIV-1 subtypes at matched time points post-superinfection (~5 years post-initial infection). Here we show superinfected individuals develop significantly broader NAb responses post-superinfection when compared to singly infected individuals (RR = 1.68, CI: 1.23-2.30, p = 0.001). This was true even after controlling for NAb breadth developed prior to superinfection, contemporaneous CD4+ T cell count and viral load. Similarly, both unadjusted and adjusted analyses showed significantly greater potency in superinfected cases compared to controls. Notably, two superinfected individuals were able to neutralize variants from four different subtypes at plasma dilutions >1∶300, suggesting that their NAbs exhibit elite activity. Cross-subtype breadth was detected within a year of superinfection in both of these individuals, which was within 1.5 years of their initial infection. These data suggest that sequential infections lead to augmentation of the NAb response, a process that may provide insight into potential mechanisms that contribute to the development of antibody breadth. Therefore, a successful vaccination strategy that mimics superinfection may lead to the development of broad NAbs in immunized individuals.
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Affiliation(s)
- Valerie Cortez
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, Washington, United States of America
- Department of Epidemiology, University of Washington, Seattle, Washington, United States of America
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Katherine Odem-Davis
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - R. Scott McClelland
- Department of Epidemiology, University of Washington, Seattle, Washington, United States of America
| | - Walter Jaoko
- Department of Medical Microbiology, University of Nairobi, Nairobi, Kenya
| | - Julie Overbaugh
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- * E-mail:
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23
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The neutralization sensitivity of viruses representing human immunodeficiency virus type 1 variants of diverse subtypes from early in infection is dependent on producer cell, as well as characteristics of the specific antibody and envelope variant. Virology 2012; 427:25-33. [PMID: 22369748 DOI: 10.1016/j.virol.2012.02.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Revised: 10/22/2011] [Accepted: 02/03/2012] [Indexed: 12/27/2022]
Abstract
Neutralization properties of human immunodeficiency virus (HIV-1) are often defined using pseudoviruses grown in transformed cells, which are not biologically relevant HIV-1 producer cells. Little information exists on how these viruses compare to viruses produced in primary lymphocytes, particularly for globally relevant HIV-1 strains. Therefore, replication-competent chimeras encoding envelope variants from the dominant HIV-1 subtypes (A, C, and D) obtained early after infection were generated and the neutralization properties explored. Pseudoviruses generated in 293T cells were the most sensitive to antibody neutralization. Replicating viruses generated in primary lymphocytes were most resistant to neutralization by plasma antibodies and most monoclonal antibodies (b12, 4E10, 2F5, VRC01). These differences were not associated with differences in envelope content. Surprisingly, the virus source did not impact neutralization sensitivity of most viruses to PG9. These findings suggest that producer cell type has a major effect on neutralization sensitivity, but in an antibody dependent manner.
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24
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HIV-1 neutralization coverage is improved by combining monoclonal antibodies that target independent epitopes. J Virol 2012; 86:3393-7. [PMID: 22258252 DOI: 10.1128/jvi.06745-11] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
HIV-1 neutralizing monoclonal antibodies (MAbs) define key targets for vaccine development and are being considered for passive prevention of infection. We analyzed the interaction of MAbs to two independent epitopes on the viral envelope glycoprotein. Potently neutralizing MAbs to the CD4 binding site and V1V2 region displayed no in vitro cross-competition and displayed additive, though not synergistic, neutralization activity. Predicted neutralization coverage of a combination of two MAbs reached 97% on a 208-isolate panel.
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25
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Engineering, expression, purification, and characterization of stable clade A/B recombinant soluble heterotrimeric gp140 proteins. J Virol 2011; 86:128-42. [PMID: 22031951 DOI: 10.1128/jvi.06363-11] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The envelope glycoprotein (Env) of human immunodeficiency virus type 1 (HIV-1) is composed of two noncovalently associated subunits: an extracellular subunit (gp120) and a transmembrane subunit (gp41). The functional unit of Env on the surface of infectious virions is a trimer of gp120/gp41 heterodimers. Env is the target of anti-HIV neutralizing antibodies. A considerable effort has been invested in the engineering of recombinant soluble forms of the virion-associated Env trimer as vaccine candidates to elicit anti-HIV neutralizing antibody responses. These soluble constructs contain three gp120 subunits and the extracellular segments of the corresponding gp41 subunits. The individual gp120/gp41 protomers on these soluble trimers are identical in amino acid sequence (homotrimers). Here, we engineered novel soluble trimeric gp140 proteins that are formed by the association of gp140 protomers that differ in amino acid sequence and glycosylation patterns (heterotrimers). Specifically, we engineered soluble heterotrimeric proteins composed of clade A and clade B Env protomers. The clade A gp140 protomers were derived from viruses isolated during acute infection (Q168a2, Q259d2.17, and Q461e2), whereas the clade B gp140 protomers were derived from a virus isolated during chronic infection (SF162). The amino acid sequence divergence between the clade A and the clade B Envs is approximately 24%. Neutralization epitopes in the CD4 binding sites and coreceptor binding sites, as well as the membrane-proximal external region (MPER), were differentially expressed on the heterotrimeric and homotrimeric proteins. The heterotrimeric gp140s elicited broader anti-tier 1 isolate neutralizing antibody responses than did the homotrimeric gp140s.
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Lovelace E, Xu H, Blish CA, Strong R, Overbaugh J. The role of amino acid changes in the human immunodeficiency virus type 1 transmembrane domain in antibody binding and neutralization. Virology 2011; 421:235-44. [PMID: 22029936 DOI: 10.1016/j.virol.2011.09.032] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Revised: 09/27/2011] [Accepted: 09/30/2011] [Indexed: 10/16/2022]
Abstract
The detailed interactions between antibodies and the HIV-1 envelope protein that lead to neutralization are not well defined. Here, we show that several conservative substitutions in the envelope gp41 led to a ~100 fold increase in neutralization sensitivity to monoclonal antibodies (MAbs) that target gp41: 4E10 and 2F5. Substitution at position 675 alone did not impact neutralization susceptibility to MAbs that recognize more distal sites in gp120 (b12, VRC01, PG9). However, changes at position 675 in conjunction with Thr to Ala at position 569 increased the neutralization sensitivity to all gp41 and gp120 MAbs and plasma, in some cases by more than 1000-fold. Interestingly, the T569A change had a dramatic effect on b12 binding, but no effect on neutralization sensitivity. This finding suggests that antibody neutralization may occur through a multi-step pathway that includes distinct changes in envelope conformation that may affect binding but not neutralization susceptibility.
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Affiliation(s)
- Erica Lovelace
- Divisions of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
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27
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Morris L, Chen X, Alam M, Tomaras G, Zhang R, Marshall DJ, Chen B, Parks R, Foulger A, Jaeger F, Donathan M, Bilska M, Gray ES, Abdool Karim SS, Kepler TB, Whitesides J, Montefiori D, Moody MA, Liao HX, Haynes BF. Isolation of a human anti-HIV gp41 membrane proximal region neutralizing antibody by antigen-specific single B cell sorting. PLoS One 2011; 6:e23532. [PMID: 21980336 PMCID: PMC3184076 DOI: 10.1371/journal.pone.0023532] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2011] [Accepted: 07/19/2011] [Indexed: 11/19/2022] Open
Abstract
Broadly neutralizing antibodies are not commonly produced in HIV-1 infected individuals nor by experimental HIV-1 vaccines. When these antibodies do occur, it is important to be able to isolate and characterize them to provide clues for vaccine design. CAP206 is a South African subtype C HIV-1-infected individual previously shown to have broadly neutralizing plasma antibodies targeting the envelope gp41 distal membrane proximal external region (MPER). We have now used a fluoresceinated peptide tetramer antigen with specific cell sorting to isolate a human neutralizing monoclonal antibody (mAb) against the HIV-1 envelope gp41 MPER. The isolated recombinant mAb, CAP206-CH12, utilized a portion of the distal MPER (HXB2 amino acid residues, 673-680) and neutralized a subset of HIV-1 pseudoviruses sensitive to CAP206 plasma antibodies. Interestingly, this mAb was polyreactive and used the same germ-line variable heavy (V(H)1-69) and variable kappa light chain (V(K)3-20) gene families as the prototype broadly neutralizing anti-MPER mAb, 4E10 (residues 672-680). These data indicate that there are multiple immunogenic targets in the C-terminus of the MPER of HIV-1 gp41 envelope and suggests that gp41 neutralizing epitopes may interact with a restricted set of naive B cells during HIV-1 infection.
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Affiliation(s)
- Lynn Morris
- Duke Human Vaccine Institute and Departments of Medicine, Surgery and Immunology, Duke University School of Medicine, Durham, North Carolina, United States of America.
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Revilla A, Delgado E, Christian EC, Dalrymple J, Vega Y, Carrera C, González-Galeano M, Ocampo A, de Castro RO, Lezaún MJ, Rodríguez R, Mariño A, Ordóñez P, Cilla G, Cisterna R, Santamaría JM, Prieto S, Rakhmanova A, Vinogradova A, Ríos M, Pérez-Álvarez L, Nájera R, Montefiori DC, Seaman MS, Thomson MM. Construction and phenotypic characterization of HIV type 1 functional envelope clones of subtypes G and F. AIDS Res Hum Retroviruses 2011; 27:889-901. [PMID: 21226626 DOI: 10.1089/aid.2010.0177] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Subtype G has been estimated to represent the fourth most prevalent clade in the HIV-1 pandemic and subtype F is widely circulating in parts of South America (frequently within BF recombinant forms) and in Romania. However, functional envelope clones of these subtypes are lacking, which are needed for studies on antibody-mediated neutralization, coreceptor usage, and efficiency of viral entry inhibitor drugs. Here we report the construction, neutralization properties, and coreceptor usage of HIV-1 functional envelope clones of subtypes G (n = 15) and F (n = 7). These clones were obtained through RT-PCR amplification of HIV-1 gp160 from plasma RNA, and were used for pseudovirus production. All 15 subtype G-enveloped pseudoviruses were resistant to neutralization by gp120-targeted broadly neutralizing monoclonal antibodies (MAbs) b12 and 2G12, while a majority were neutralized by gp41-targeted MAbs 2F5 and 4E10. With regard to the subtype F envelopes, all seven pseudoviruses were resistant to 2F5 and b12, six were resistant to G12, and six were neutralized by 4E10. Coreceptor usage testing revealed that 21 of 22 envelopes were CCR5-tropic, including all 15 subtype G envelopes, seven of which were from patients with CD4(+) T cell counts <200/ml. These results confirm the broadly neutralizing activity of 4E10 on envelope clones across all tested group M clades, including subtypes G and F, reveal the resistance of most subtype F-enveloped pseudoviruses to broadly neutralizing MAbs b12, 2G12, and 2F5, and suggest that, similarly to subtype C, CXCR4 tropism is uncommon in subtype G, even at advanced stages of infection.
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Affiliation(s)
- Ana Revilla
- Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Elena Delgado
- Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Elizabeth C. Christian
- Division of Viral Pathogenesis, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Justin Dalrymple
- Division of Viral Pathogenesis, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Yolanda Vega
- Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Cristina Carrera
- Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - María González-Galeano
- Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Antonio Ocampo
- Complejo Hospitalario Xeral-Cíes, Vigo, Pontevedra, Spain
| | | | | | | | - Ana Mariño
- Hospital Arquitecto Marcide, Ferrol, A Coruña, Spain
| | | | | | | | | | | | - Aza Rakhmanova
- Botkin's Infectious Diseases Hospital, St. Petersburg, Russia
| | | | - Maritza Ríos
- National Reference Center of HIV/AIDS, Public Health Institute of Chile, Santiago, Chile
| | - Lucía Pérez-Álvarez
- Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Rafael Nájera
- Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - David C. Montefiori
- Department of Surgery, Laboratory for AIDS Vaccine Research and Development, Duke University Medical Center, Durham, North Carolina
| | - Michael S. Seaman
- Division of Viral Pathogenesis, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Michael M. Thomson
- Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
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Binding interactions between soluble HIV envelope glycoproteins and quaternary-structure-specific monoclonal antibodies PG9 and PG16. J Virol 2011; 85:7095-107. [PMID: 21543501 DOI: 10.1128/jvi.00411-11] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PG9 and PG16 are antibodies isolated from a subject infected with HIV-1 and display broad anti-HIV neutralizing activities. They recognize overlapping epitopes, which are preferentially expressed on the membrane-anchored trimeric form of the HIV envelope glycoprotein (Env). PG9 and PG16 were reported not to bind to soluble mimetics of Env. The engineering of soluble Env proteins on which the PG9 and PG16 epitopes are optimally exposed will support efforts to elicit broad anti-HIV neutralizing antibodies by immunization. Here, we identified several soluble gp140 Env proteins that are recognized by PG9 and PG16, and we investigated the molecular details of those binding interactions. The IgG versions of PG9 and PG16 recognize the soluble trimeric gp140 form less efficiently than the corresponding monomeric gp140 form. In contrast, the Fab versions of PG9 and PG16 recognized the monomeric and trimeric gp140 forms with identical binding kinetics and with binding affinities similar to the high binding affinity of the anti-V3 antibody 447D to its epitope. Our data also indicate that, depending on the Env backbone, the interactions of PG9 and PG16 with gp140 may be facilitated by the presence of the gp41 ectodomain and are independent of the proper enzymatic cleavage of gp140 into gp120 and gp41. The identification of soluble Env proteins that express the PG9 and PG16 epitopes and the detailed characterization of the molecular interactions between these two antibodies and their ligands provide important and novel information that will assist in improving the engineering of future Env immunogens.
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Gray ES, Madiga MC, Hermanus T, Moore PL, Wibmer CK, Tumba NL, Werner L, Mlisana K, Sibeko S, Williamson C, Abdool Karim SS, Morris L. The neutralization breadth of HIV-1 develops incrementally over four years and is associated with CD4+ T cell decline and high viral load during acute infection. J Virol 2011; 85:4828-40. [PMID: 21389135 PMCID: PMC3126191 DOI: 10.1128/jvi.00198-11] [Citation(s) in RCA: 370] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Accepted: 02/24/2011] [Indexed: 11/20/2022] Open
Abstract
An understanding of how broadly neutralizing activity develops in HIV-1-infected individuals is needed to guide vaccine design and immunization strategies. Here we used a large panel of 44 HIV-1 envelope variants (subtypes A, B, and C) to evaluate the presence of broadly neutralizing antibodies in serum samples obtained 3 years after seroconversion from 40 women enrolled in the CAPRISA 002 acute infection cohort. Seven of 40 participants had serum antibodies that neutralized more than 40% of viruses tested and were considered to have neutralization breadth. Among the samples with breadth, CAP257 serum neutralized 82% (36/44 variants) of the panel, while CAP256 serum neutralized 77% (33/43 variants) of the panel. Analysis of longitudinal samples showed that breadth developed gradually starting from year 2, with the number of viruses neutralized as well as the antibody titer increasing over time. Interestingly, neutralization breadth peaked at 4 years postinfection, with no increase thereafter. The extent of cross-neutralizing activity correlated with CD4(+) T cell decline, viral load, and CD4(+) T cell count at 6 months postinfection but not at later time points, suggesting that early events set the stage for the development of breadth. However, in a multivariate analysis, CD4 decline was the major driver of this association, as viral load was not an independent predictor of breadth. Mapping of the epitopes targeted by cross-neutralizing antibodies revealed that in one individual these antibodies recognized the membrane-proximal external region (MPER), while in two other individuals, cross-neutralizing activity was adsorbed by monomeric gp120 and targeted epitopes that involved the N-linked glycan at position 332 in the C3 region. Serum antibodies from the other four participants targeted quaternary epitopes, at least 2 of which were PG9/16-like and depended on the N160 and/or L165 residue in the V2 region. These data indicate that fewer than 20% of HIV-1 subtype C-infected individuals develop antibodies with cross-neutralizing activity after 3 years of infection and that these antibodies target different regions of the HIV-1 envelope, including as yet uncharacterized epitopes.
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Affiliation(s)
- Elin S. Gray
- AIDS Virus Research Unit, National Institute for Communicable Diseases, Johannesburg, South Africa
| | - Maphuti C. Madiga
- AIDS Virus Research Unit, National Institute for Communicable Diseases, Johannesburg, South Africa
| | - Tandile Hermanus
- AIDS Virus Research Unit, National Institute for Communicable Diseases, Johannesburg, South Africa
| | - Penny L. Moore
- AIDS Virus Research Unit, National Institute for Communicable Diseases, Johannesburg, South Africa
- University of Witwatersrand, Johannesburg, South Africa
| | - Constantinos Kurt Wibmer
- AIDS Virus Research Unit, National Institute for Communicable Diseases, Johannesburg, South Africa
- University of Witwatersrand, Johannesburg, South Africa
| | - Nancy L. Tumba
- AIDS Virus Research Unit, National Institute for Communicable Diseases, Johannesburg, South Africa
| | - Lise Werner
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa
| | - Koleka Mlisana
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa
| | - Sengeziwe Sibeko
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa
| | - Carolyn Williamson
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Salim S. Abdool Karim
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa
| | - Lynn Morris
- AIDS Virus Research Unit, National Institute for Communicable Diseases, Johannesburg, South Africa
- University of Witwatersrand, Johannesburg, South Africa
| | - and the CAPRISA002 Study Team
- AIDS Virus Research Unit, National Institute for Communicable Diseases, Johannesburg, South Africa
- University of Witwatersrand, Johannesburg, South Africa
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
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The breadth and potency of passively acquired human immunodeficiency virus type 1-specific neutralizing antibodies do not correlate with the risk of infant infection. J Virol 2011; 85:5252-61. [PMID: 21411521 DOI: 10.1128/jvi.02216-10] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Although a major goal of human immunodeficiency virus type 1 (HIV-1) vaccine efforts is to elicit broad and potent neutralizing antibodies (NAbs), there are no data that directly demonstrate a role for such NAbs in protection from HIV-1 infection in exposed humans. The setting of mother-to-child transmission provides an opportunity to examine whether NAbs provide protection from HIV-1 infection because infants acquire passive antibodies from their mothers prior to exposure to HIV-1 through breastfeeding. We evaluated the characteristics of HIV-1-specific NAbs in 100 breast-fed infants of HIV-1-positive mothers who were HIV-1 negative at birth and monitored them until age 2. A panel of eight viruses that included variants representative of those in the study region as well as more diverse strains was used to determine the breadth of the infant NAbs. From their mothers, infants acquired broad and potent NAbs that were capable of recognizing heterologous circulating HIV-1 variants of diverse subtypes, but the presence of NAbs of broad HIV-1 specificity was not associated with transmission risk. There was also no correlation between responses to any particular virus tested, which included a range of diverse variants that demonstrated different neutralization profiles, including recognition by specific antibodies with known epitope targets. The eight viruses tested exhibited neutralization profiles to a variety of monoclonal antibodies (2F5, PG9, and VRC01) similar to those of viruses present in pregnant women in the cohort. These results suggest that the breadth and potency of the heterologous antibody response in exposed infants, measured against a virus panel comprised of variants typical of those circulating in the population, does not predict protection.
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Adaptation of subtype a human immunodeficiency virus type 1 envelope to pig-tailed macaque cells. J Virol 2011; 85:4409-20. [PMID: 21325401 DOI: 10.1128/jvi.02244-10] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The relevance of simian/human immunodeficiency virus (SHIV) infection of macaques to HIV-1 infection in humans depends on how closely SHIVs mimic HIV-1 transmission, pathogenesis, and diversity. Circulating HIV-1 strains are predominantly subtypes C and A and overwhelmingly require CCR5 for entry, yet most SHIVs incorporate CXCR4-using subtype B envelopes (Envs). While pathogenic subtype C-based SHIVs have been constructed, the subtype A-based SHIVs (SHIV-As) constructed to date have been unable to replicate in macaque cells. To understand the barriers to SHIV-A replication in macaque cells, HIVA(Q23)/SIV(vif) was constructed by engineering a CCR5-tropic subtype A provirus to express SIV vif, which counters the macaque APOBEC3G restriction. HIVA(Q23)/SIV(vif) replicated poorly in pig-tailed macaque (Ptm) lymphocytes, but viruses were adapted to Ptm lymphocytes. Two independent mutations in gp120, G312V (V3 loop) and A204E (C2 region), were identified that increased peak virus levels by >100-fold. Introduction of G312V and A204E to multiple subtype A Envs and substitution of G312 and A204 with other residues increased entry into Ptm cells by 10- to 100-fold. G312V and A204E Env variants continued to require CCR5 for entry but were up to 50- and 200-fold more sensitive to neutralization by IgG1b12 and soluble CD4 and had a 5- to 50-fold increase in their ability to utilize Ptm CD4 compared to their wild-type counterparts. These findings identify the inefficient use of Ptm CD4 as an unappreciated restriction to subtype A HIV-1 replication in Ptm cells and reveal amino acid changes to gp120 that can overcome this barrier.
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Mikell I, Sather DN, Kalams SA, Altfeld M, Alter G, Stamatatos L. Characteristics of the earliest cross-neutralizing antibody response to HIV-1. PLoS Pathog 2011; 7:e1001251. [PMID: 21249232 PMCID: PMC3020924 DOI: 10.1371/journal.ppat.1001251] [Citation(s) in RCA: 253] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Accepted: 12/08/2010] [Indexed: 12/24/2022] Open
Abstract
Recent cross-sectional analyses of HIV-1+ plasmas have indicated that broadly cross-reactive neutralizing antibody responses are developed by 10%-30% of HIV-1+ subjects. The timing of the initial development of such anti-viral responses is unknown. It is also unknown whether the emergence of these responses coincides with the appearance of antibody specificities to a single or multiple regions of the viral envelope glycoprotein (Env). Here we analyzed the cross-neutralizing antibody responses in longitudinal plasmas collected soon after and up to seven years after HIV-1 infection. We find that anti-HIV-1 cross-neutralizing antibody responses first become evident on average at 2.5 years and, in rare cases, as early as 1 year following infection. If cross-neutralizing antibody responses do not develop during the first 2-3 years of infection, they most likely will not do so subsequently. Our results indicate a potential link between the development of cross-neutralizing antibody responses and specific activation markers on T cells, and with plasma viremia levels. The earliest cross-neutralizing antibody response targets a limited number of Env regions, primarily the CD4-binding site and epitopes that are not present on monomeric Env, but on the virion-associated trimeric Env form. In contrast, the neutralizing activities of plasmas from subjects that did not develop cross-neutralizing antibody responses target epitopes on monomeric gp120 other than the CD4-BS. Our study provides information that is not only relevant to better understanding the interaction of the human immune system with HIV but may guide the development of effective immunization protocols. Since antibodies to complex epitopes that are present on the virion-associated envelope spike appear to be key components of earliest cross-neutralizing activities of HIV-1+ plasmas, then emphasis should be made to elicit similar antibodies by vaccination.
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Affiliation(s)
- Iliyana Mikell
- Seattle BioMed, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - D. Noah Sather
- Seattle BioMed, Seattle, Washington, United States of America
| | - Spyros A. Kalams
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Marcus Altfeld
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Boston, Massachusetts, United States of America
| | - Galit Alter
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Boston, Massachusetts, United States of America
| | - Leonidas Stamatatos
- Seattle BioMed, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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Gnanakaran S, Daniels MG, Bhattacharya T, Lapedes AS, Sethi A, Li M, Tang H, Greene K, Gao H, Haynes BF, Cohen MS, Shaw GM, Seaman MS, Kumar A, Gao F, Montefiori DC, Korber B. Genetic signatures in the envelope glycoproteins of HIV-1 that associate with broadly neutralizing antibodies. PLoS Comput Biol 2010; 6:e1000955. [PMID: 20949103 PMCID: PMC2951345 DOI: 10.1371/journal.pcbi.1000955] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Accepted: 09/10/2010] [Indexed: 11/27/2022] Open
Abstract
A steady increase in knowledge of the molecular and antigenic structure of the gp120 and gp41 HIV-1 envelope glycoproteins (Env) is yielding important new insights for vaccine design, but it has been difficult to translate this information to an immunogen that elicits broadly neutralizing antibodies. To help bridge this gap, we used phylogenetically corrected statistical methods to identify amino acid signature patterns in Envs derived from people who have made potently neutralizing antibodies, with the hypothesis that these Envs may share common features that would be useful for incorporation in a vaccine immunogen. Before attempting this, essentially as a control, we explored the utility of our computational methods for defining signatures of complex neutralization phenotypes by analyzing Env sequences from 251 clonal viruses that were differentially sensitive to neutralization by the well-characterized gp120-specific monoclonal antibody, b12. We identified ten b12-neutralization signatures, including seven either in the b12-binding surface of gp120 or in the V2 region of gp120 that have been previously shown to impact b12 sensitivity. A simple algorithm based on the b12 signature pattern was predictive of b12 sensitivity/resistance in an additional blinded panel of 57 viruses. Upon obtaining these reassuring outcomes, we went on to apply these same computational methods to define signature patterns in Env from HIV-1 infected individuals who had potent, broadly neutralizing responses. We analyzed a checkerboard-style neutralization dataset with sera from 69 HIV-1-infected individuals tested against a panel of 25 different Envs. Distinct clusters of sera with high and low neutralization potencies were identified. Six signature positions in Env sequences obtained from the 69 samples were found to be strongly associated with either the high or low potency responses. Five sites were in the CD4-induced coreceptor binding site of gp120, suggesting an important role for this region in the elicitation of broadly neutralizing antibody responses against HIV-1.
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Affiliation(s)
- S. Gnanakaran
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Marcus G. Daniels
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Tanmoy Bhattacharya
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
- Santa Fe Institute, Santa Fe, New Mexico, United States of America
| | - Alan S. Lapedes
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Anurag Sethi
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
- Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Ming Li
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Haili Tang
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Kelli Greene
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Hongmei Gao
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Barton F. Haynes
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Myron S. Cohen
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - George M. Shaw
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Michael S. Seaman
- Division of Viral Pathogenesis, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States of America
| | - Amit Kumar
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Feng Gao
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - David C. Montefiori
- Department of Surgery, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Bette Korber
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
- Santa Fe Institute, Santa Fe, New Mexico, United States of America
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Gilbert P, Wang M, Wrin T, Petropoulos C, Gurwith M, Sinangil F, D'Souza P, Rodriguez-Chavez IR, DeCamp A, Giganti M, Berman PW, Self SG, Montefiori DC. Magnitude and breadth of a nonprotective neutralizing antibody response in an efficacy trial of a candidate HIV-1 gp120 vaccine. J Infect Dis 2010; 202:595-605. [PMID: 20608874 DOI: 10.1086/654816] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND A candidate vaccine consisting of human immunodeficiency virus type 1 (HIV-1) subunit gp120 protein was found previously to be nonprotective in an efficacy trial (Vax004) despite strong antibody responses against the vaccine antigens. Here we assessed the magnitude and breadth of neutralizing antibody responses in Vax004. METHODS Neutralizing antibodies were measured against highly sensitive (tier 1) and moderately sensitive (tier 2) strains of HIV-1 subtype B in 2 independent assays. Vaccine recipients were stratified by sex, race, and high versus low behavioral risk of HIV-1 acquisition. RESULTS Most vaccine recipients mounted potent neutralizing antibody responses against HIV-1(MN) and other tier 1 viruses. Occasional weak neutralizing activity was detected against tier 2 viruses. The response against tier 1 and tier 2 viruses was significantly stronger in women than in men. Race and behavioral risk of HIV-1 acquisition had no significant effect on the response. Prior vaccination had little effect on the neutralizing antibody response that arose after infection. CONCLUSIONS Weak overall neutralizing antibody responses against tier 2 viruses is consistent with a lack of protection in this trial. The magnitude and breadth of neutralization reported here should be useful for identifying improved vaccines.
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Affiliation(s)
- Peter Gilbert
- Vaccine Infectious Disease Institute, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
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Cavrois M, Neidleman J, Galloway N, Derdeyn CA, Hunter E, Greene WC. Measuring HIV fusion mediated by envelopes from primary viral isolates. Methods 2010; 53:34-8. [PMID: 20554044 DOI: 10.1016/j.ymeth.2010.05.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Revised: 05/19/2010] [Accepted: 05/26/2010] [Indexed: 11/19/2022] Open
Abstract
Over the course of infection, the human immunodeficiency virus type 1 (HIV-1) continuously adapts in part to evade the host's neutralizing antibody response. Antibodies often target the HIV envelope proteins that mediate HIV fusion to its cellular targets. HIV virions pseudotyped with primary envelopes have often been used to explore the fusogenic properties of these envelopes. Unfortunately, these pseudotyped virions fuse with greatly reduced efficiency to primary cells. Here, we describe a relatively simple strategy to clone primary envelopes into a provirus and increase the sensitivity of the virion-based fusion assay.
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Affiliation(s)
- Marielle Cavrois
- Gladstone Institute of Virology and Immunology, San Francisco, CA 94158, USA.
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Enhanced exposure of human immunodeficiency virus type 1 primary isolate neutralization epitopes through binding of CD4 mimetic compounds. J Virol 2010; 84:7558-68. [PMID: 20504942 DOI: 10.1128/jvi.00227-10] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
N-(4-Chlorophenyl)-N'-(2,2,6,6-tetramethyl-piperidin-4-yl)-oxalamide (NBD-556) is a low-molecular-weight compound that reportedly blocks the interaction between human immunodeficiency virus type 1 (HIV-1) gp120 and its receptor CD4. We investigated whether the enhancement of binding of anti-gp120 monoclonal antibodies (MAbs) toward envelope (Env) protein with NBD-556 are similar to those of soluble CD4 (sCD4) by comparing the binding profiles of the individual MAbs to Env-expressing cell surfaces. In flow cytometric analyses, the binding profiles of anti-CD4-induced epitope (CD4i) MAbs toward NBD-556-pretreated Env-expressing cell surfaces were similar to the binding profiles toward sCD4-pretreated cell surfaces. To investigate the binding position of NBD-556 on gp120, we induced HIV-1 variants that were resistant to NBD-556 and sCD4 in vitro. At passage 21 in the presence of 50 microM NBD-556, two amino acid substitutions (S375N in C3 and A433T in C4) were identified. On the other hand, in the selection with sCD4, seven mutations (E211G, P212L, V255E, N280K, S375N, G380R, and G431E) appeared during the passages. The profiles of the mutations after the selections with NBD-556 and sCD4 were very similar in their three-dimensional positions. Moreover, combinations of NBD-556 with anti-gp120 MAbs showed highly synergistic interactions against HIV-1. We further found that after enhancing the neutralizing activity by adding NBD-556, the contemporaneous virus became highly sensitive to antibodies in the patient's plasma. These findings suggest that small compounds such as NBDs may enhance the neutralizing activities of CD4i and anti-V3 antibodies in vivo.
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Nie J, Zhang C, Liu W, Wu X, Li F, Wang S, Liang F, Song A, Wang Y. Genotypic and phenotypic characterization of HIV-1 CRF01_AE env molecular clones from infections in China. J Acquir Immune Defic Syndr 2010; 53:440-50. [PMID: 20090544 DOI: 10.1097/qai.0b013e3181cb8300] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Although a great number of HIV-1 pseudoviruses have been generated for neutralization assays, circulating recombinant forms, such as CRF01_AE, are not included. Given the increasing prevalence of CRF01_AE, the establishment of a pool of CRF01_AE env isolates for the evaluation of potential HIV vaccines is needed. MATERIALS AND METHODS Full-length env genes were cloned from HIV-1 CRF01_AE-infected plasma samples collected in China and used to establish Env-pseudotyped viruses. The neutralization phenotypes of the pseudoviruses were characterized by testing against broadly neutralizing monoclonal antibodies, coreceptor antagonists, and 42 plasma samples that include 3 main prevalent HIV-1 subtypes in China. RESULTS Thirty-four genetically distinct CRF01_AE env genes were cloned and used to generate pseudotyped viruses. Of the 34 pseudoviruses, 32 used CCR5 as a coreceptor and 2 used CXCR4. The majority of pseudoviruses were resistant to the neutralizing antibodies IgG1b12 and 2G12 and susceptible to 2F5 and 4E10. There was significant variation of the neutralization susceptibility of pseudoviruses against 42 HIV-1-positive plasma samples. Based on their overall neutralization susceptibilities, the 34 CRF01_AE pseudoviruses were classified into 3 tiers: high, medium, and low. CONCLUSION The CRF01_AE pseudovirus isolates should be included in the panel of pseudoviruses used to assess vaccine-elicited neutralizing antibodies.
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Affiliation(s)
- Jianhui Nie
- Department of Cell Biology, National Institute for the Control of Pharmaceutical and Biological Products, Beijing, China
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Neutralizing antibodies against HIV-1: can we elicit them with vaccines and how much do we need? Curr Opin HIV AIDS 2010; 4:347-51. [PMID: 20048696 DOI: 10.1097/coh.0b013e32832f4a4d] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
PURPOSE OF REVIEW This review describes some of the major obstacles that have impeded progress in the development of an effective neutralizing antibody-based HIV-1 vaccine and explains why it may be possible to overcome these obstacles. A renewed interest in the B-cell response in HIV-1-infected individuals is emphasized. RECENT FINDINGS New assay technologies and access to large numbers of clinical specimens have permitted a detailed assessment of the neutralizing antibody response in HIV-1-infected individuals. Recent studies have demonstrated that B cells can be stimulated to generate high titers of broadly cross-reactive neutralizing antibodies against multiple genetic subtypes of the virus. Preliminary evidence suggests that some of these antibodies are directed against epitopes in the CD4 binding site on monomeric gp120, whereas many others are directed against epitopes that remain to be identified. SUMMARY The rationale for pursuing an effective neutralizing antibody-based HIV-1 vaccine is strengthened by the recent demonstration of potent neutralizing antibody responses in a subset of HIV-1-infected individuals. Information on how this response develops and what epitopes are targeted could provide the insights that are needed to design improved vaccine strategies.
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Blish CA, Sather DN, Sellhorn G, Stamatatos L, Sun Y, Srivastava I, Barnett SW, Cleveland B, Overbaugh J, Hu SL. Comparative immunogenicity of subtype a Human Immunodeficiency Virus type 1 envelope exhibiting differential exposure of conserved neutralization epitopes. J Virol 2010; 84:2573-84. [PMID: 20015987 PMCID: PMC2820908 DOI: 10.1128/jvi.01687-09] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2009] [Accepted: 12/07/2009] [Indexed: 11/20/2022] Open
Abstract
Development of broadly cross-reactive neutralizing antibodies (NAbs) remains a major goal of HIV-1 vaccine development, but most candidate envelope immunogens have had limited ability to cross-neutralize heterologous strains. To evaluate the immunogenicity of subtype A variants of HIV-1, rabbits were immunized with pairs of closely related subtype A envelopes from the same individual. In each immunogen pair, one variant was readily neutralized by a variety of monoclonal antibodies and plasma antibodies, while the other was neutralization resistant, suggesting differences in the exposures of key epitopes. The breadth of the antibody response was evaluated against subtype A, B, C, and D variants of HIV-1. The specificity of the immunogen-derived neutralizing antibody response was also compared to that of the infected individuals from whom these variants were cloned. None of the immunogens produced broad neutralizing antibodies in immunized animals, and most of the neutralizing antibodies were directed to the variable loops, particularly the V3 loop. No detectable antibodies to either of the potentially exposed conserved epitopes, the membrane proximal external region, or the CD4 binding site were found with immunized rabbits. In contrast, relatively little of the neutralizing activity within the plasma samples of the infected individuals was directed to linear epitopes within the variable loops. These data indicate that immunogens designed to expose conserved regions did not enhance generation of broadly neutralizing antibodies in comparison with the immunogens that failed to expose those regions using this immunization approach.
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Affiliation(s)
- Catherine A Blish
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109-1024, USA.
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41
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Lagenaur LA, Villarroel VA, Bundoc V, Dey B, Berger EA. sCD4-17b bifunctional protein: extremely broad and potent neutralization of HIV-1 Env pseudotyped viruses from genetically diverse primary isolates. Retrovirology 2010; 7:11. [PMID: 20158904 PMCID: PMC2843639 DOI: 10.1186/1742-4690-7-11] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Accepted: 02/16/2010] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND We previously described a potent recombinant HIV-1 neutralizing protein, sCD4-17b, composed of soluble CD4 attached via a flexible polypeptide linker to an SCFv of the 17b human monoclonal antibody directed against the highly conserved CD4-induced bridging sheet of gp120 involved in coreceptor binding. The sCD4 moiety of the bifunctional protein binds to gp120 on free virions, thereby enabling the 17b SCFv moiety to bind and block the gp120/coreceptor interaction required for entry. The previous studies using the MAGI-CCR5 assay system indicated that sCD4-17b (in concentrated cell culture medium, or partially purified) potently neutralized several genetically diverse HIIV-1 primary isolates; however, at the concentrations tested it was ineffective against several other strains despite the conservation of binding sites for both CD4 and 17b. To address this puzzle, we designed variants of sCD4-17b with different linker lengths, and tested the neutralizing activities of the immunoaffinity purified proteins over a broader concentration range against a large number of genetically diverse HIV-1 primary isolates, using the TZM-bl Env pseudotype assay system. We also examined the sCD4-17b sensitivities of isogenic viruses generated from different producer cell types. RESULTS We observed that immunoaffinity purified sCD4-17b effectively neutralized HIV-1 pseudotypes, including those from HIV-1 isolates previously found to be relatively insensitive in the MAGI-CCR5 assay. The potencies were equivalent for the original construct and a variant with a longer linker, as observed with both pseudotype particles and infectious virions; by contrast, a construct with a linker too short to enable simultaneous binding of the sCD4 and 17b SCFv moieties was much less effective. sCD4-17b displayed potent neutralizing activity against 100% of nearly 4 dozen HIV-1 primary isolates from diverse genetic subtypes (clades A, B, C, D, F, and circulating recombinant forms AE and AG). The neutralization breadth and potency were superior to what have been reported for the broadly neutralizing monoclonal antibodies IgG b12, 2G12, 2F5, and 4E10. The activity of sCD4-17b was found to be similar against isogenic virus particles from infectious molecular clones derived either directly from the transfected producer cell line or after a single passage through PBMCs; this contrasted with the monoclonal antibodies, which were less potent against the PMBC-passaged viruses. CONCLUSIONS The results highlight the extremely potent and broad neutralizing activity of sCD4-17b against genetically diverse HIV-1 primary isolates. The bifunctional protein has potential applications for antiviral approaches to combat HIV infection.
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Affiliation(s)
- Laurel A Lagenaur
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Vadim A Villarroel
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Virgilio Bundoc
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Barna Dey
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Edward A Berger
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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Bosch KA, Rainwater S, Jaoko W, Overbaugh J. Temporal analysis of HIV envelope sequence evolution and antibody escape in a subtype A-infected individual with a broad neutralizing antibody response. Virology 2010; 398:115-24. [PMID: 20034648 DOI: 10.1016/j.virol.2009.11.032] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Revised: 10/28/2009] [Accepted: 11/18/2009] [Indexed: 11/29/2022]
Abstract
The origin of broadly neutralizing HIV-specific antibodies and their relation to HIV evolution are not well defined. Here we examined virus evolution and neutralizing antibody escape in a subtype A infected individual with a broad, cross subtype, antibody response. The majority of envelope variants isolated over the first approximately 5 years after infection were poorly neutralized by contemporaneous plasma that neutralized variants from earlier in infection, consistent with a dynamic process of escape. The majority of variants could be neutralized by later plasma, suggesting these evolving variants may have contributed to the elicitation of new antibody responses. However, some variants from later in infection were recognized by plasma from earlier in infection, including one notably neutralization-sensitive variant that was sensitive due to a proline at position 199 in V2. These studies suggest a complex pattern of virus evolution in this individual with a broad NAb response, including persistence of neutralization-sensitive viruses.
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Affiliation(s)
- Katherine A Bosch
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
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Abstract
PURPOSE OF REVIEW To summarize our current understanding of the restricted diversity and biological characteristics of newly transmitted HIV-1 variants. RECENT FINDINGS Transmission of HIV-1 involves a reduction in viral diversity, supporting the concept of a genetic bottleneck. In most cases, transmission appears to be mediated by a single infectious unit. Transmission of multiple variants has also been observed and is associated with factors that compromise the genital mucosa. The biological characteristics of the newly transmitted variants are influenced by the mode of transmission and perhaps the viral subtype. For sexual transmission, the integrity of the mucosal barrier is likely to impose a major restriction on the infecting virus, whereas mother-to-child transmission is also influenced by the presence of maternal antibody. SUMMARY Transmission of HIV-1 is complex, multimodal, and poorly understood, but one common feature appears to be a window of opportunity when the infection is localized and viral diversity is limited; at this time the virus is at its most vulnerable. A better understanding of the restrictions inflicted upon transmitting HIV-1 should therefore lead to improved biomedical interventions that have the potential to protect against HIV infection.
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Breadth of human immunodeficiency virus-specific neutralizing activity in sera: clustering analysis and association with clinical variables. J Virol 2009; 84:1631-6. [PMID: 19923174 DOI: 10.1128/jvi.01482-09] [Citation(s) in RCA: 263] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Induction of antibodies that neutralize a broad range of human immunodeficiency virus type 1 (HIV-1) isolates is a major goal of vaccine development. To study natural examples of broad neutralization, we analyzed sera from 103 HIV-1-infected subjects. Among progressor patients, 20% of sera neutralized more than 75% of a panel of 20 diverse viral isolates. Little activity was observed in sera from long-term nonprogressors (elite controllers). Breadth of neutralization was correlated with viral load, but not with CD4 count, history of past antiretroviral use, age, gender, race/ethnicity, or route of exposure. Clustering analysis of sera by a novel method identified a statistically robust subgrouping of sera that demonstrated broad and potent neutralization activity.
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45
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Sellhorn G, Caldwell Z, Mineart C, Stamatatos L. Improving the expression of recombinant soluble HIV Envelope glycoproteins using pseudo-stable transient transfection. Vaccine 2009; 28:430-6. [PMID: 19857451 DOI: 10.1016/j.vaccine.2009.10.028] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2009] [Revised: 10/01/2009] [Accepted: 10/07/2009] [Indexed: 11/24/2022]
Abstract
The Envelope glycoprotein (Env) of the human immunodeficiency virus (HIV) is the target of neutralizing antibodies (NAbs). So far, HIV Env-derived immunogens have not been able to elicit broad neutralizing antibody responses against primary isolates. Identifying conditions that will permit the efficient production of different soluble HIV Env proteins will facilitate a high throughput comparative analysis of the immunogenicity of diverse Env constructs, potentially identifying Env forms that are more conducive to the elicitation of anti-HIV NAbs. Here we compared different cell types, transfection reagents, transfection conditions and different DNA expression vectors on soluble HIV Envelope expression levels. We identified optimal expression conditions and developed a protocol to streamline and maximize production of diverse HIV Env constructs. Using this optimized platform, milligram quantities of purified soluble HIV Env trimer can be routinely achieved in a rapid and cost-effective manner.
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Affiliation(s)
- George Sellhorn
- Seattle Biomedical Research Institute, Seattle, WA 98109, United States
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46
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Piantadosi A, Panteleeff D, Blish CA, Baeten JM, Jaoko W, McClelland RS, Overbaugh J. Breadth of neutralizing antibody response to human immunodeficiency virus type 1 is affected by factors early in infection but does not influence disease progression. J Virol 2009; 83:10269-74. [PMID: 19640996 PMCID: PMC2748011 DOI: 10.1128/jvi.01149-09] [Citation(s) in RCA: 148] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Accepted: 07/21/2009] [Indexed: 01/27/2023] Open
Abstract
The determinants of a broad neutralizing antibody (NAb) response and its effect on human immunodeficiency virus type 1 (HIV-1) disease progression are not well defined, partly because most prior studies of a broad NAb response were cross-sectional. We examined correlates of NAb response breadth among 70 HIV-infected, antiretroviral-naïve Kenyan women from a longitudinal seroincident cohort. NAb response breadth was measured 5 years after infection against five subtype A viruses and one subtype B virus. Greater NAb response breadth was associated with a higher viral load set point and greater HIV-1 env diversity early in infection. However, greater NAb response breadth was not associated with a delayed time to a CD4(+) T-cell count of <200, antiretroviral therapy, or death. Thus, a broad NAb response results from a high level of antigenic stimulation early in infection, which likely accounts for prior observations that greater NAb response breadth is associated with a higher viral load later in infection.
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Affiliation(s)
- Anne Piantadosi
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109-1024, USA
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47
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Blish CA, Jalalian-Lechak Z, Rainwater S, Nguyen MA, Dogan OC, Overbaugh J. Cross-subtype neutralization sensitivity despite monoclonal antibody resistance among early subtype A, C, and D envelope variants of human immunodeficiency virus type 1. J Virol 2009; 83:7783-8. [PMID: 19474105 PMCID: PMC2708608 DOI: 10.1128/jvi.00673-09] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Accepted: 05/18/2009] [Indexed: 11/20/2022] Open
Abstract
The human immunodeficiency virus type 1 (HIV-1) variants that are transmitted to newly infected individuals are the primary targets of interventions, such as vaccines and microbicides, aimed at preventing new infections. Newly acquired subtype A, B, and C variants have been the focus of neutralization studies, although many of these viruses, particularly of subtypes A and B, represent viruses circulating more than a decade ago. In order to better represent the global diversity of transmitted HIV-1 variants, an additional 31 sexually transmitted Kenyan HIV-1 env genes, representing several recent infections with subtype A, as well as subtypes A/D, C, and D, were cloned, and their neutralization profiles were characterized. Most env variants were resistant to neutralization by the monoclonal antibodies (MAbs) b12, 4E10, 2F5, and 2G12, suggesting that targeting the epitopes of these MAbs may not be effective against variants that are spreading in areas of endemicity. However, significant cross-subtype neutralization by plasma was observed, indicating that there may be other epitopes, not yet defined by the limited available MAbs, which could be recognized more broadly.
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Affiliation(s)
- Catherine A Blish
- Division of Human Biology, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. North, Seattle, WA 98109-1024, USA
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48
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Ho O, Larsen K, Polacino P, Li Y, Anderson D, Song R, Ruprecht RM, Hu SL. Pathogenic infection of Macaca nemestrina with a CCR5-tropic subtype-C simian-human immunodeficiency virus. Retrovirology 2009; 6:65. [PMID: 19602283 PMCID: PMC2720380 DOI: 10.1186/1742-4690-6-65] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Accepted: 07/14/2009] [Indexed: 12/22/2022] Open
Abstract
Background Although pig-tailed macaques (Macaca nemestrina) have been used in AIDS research for years, less is known about the early immunopathogenic events in this species, as compared to rhesus macaques (Macaca mulatta). Similarly, the events in early infection are well-characterized for simian immunodeficiency viruses (SIV), but less so for chimeric simian-human immunodeficiency viruses (SHIV), although the latter have been widely used in HIV vaccine studies. Here, we report the consequences of intrarectal infection with a CCR5-tropic clade C SHIV-1157ipd3N4 in pig-tailed macaques. Results Plasma and cell-associated virus was detectable in peripheral blood and intestinal tissues of all four pig-tailed macaques following intrarectal inoculation with SHIV-1157ipd3N4. We also observed a rapid and irreversible loss of CD4+ T cells at multiple mucosal sites, resulting in a marked decrease of CD4:CD8 T cell ratios 0.5–4 weeks after inoculation. This depletion targeted subsets of CD4+ T cells expressing the CCR5 coreceptor and having a CD28-CD95+ effector memory phenotype, consistent with the R5-tropism of SHIV-1157ipd3N4. All three animals that were studied beyond the acute phase seroconverted as early as week 4, with two developing cross-clade neutralizing antibody responses by week 24. These two animals also demonstrated persistent plasma viremia for >48 weeks. One of these animals developed AIDS, as shown by peripheral blood CD4+ T-cell depletion starting at 20 weeks post inoculation. Conclusion These findings indicate that SHIV-1157ipd3N4-induced pathogenesis in pig-tailed macaques followed a similar course as SIV-infected rhesus macaques. Thus, R5 SHIV-C-infection of pig-tailed macaques could provide a useful and relevant model for AIDS vaccine and pathogenesis research.
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Affiliation(s)
- On Ho
- Department of Pharmaceutics, University of Washington, Seattle, 98195, USA.
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49
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The differential binding and activity of PRO 2000 against diverse HIV-1 envelopes. J Acquir Immune Defic Syndr 2009; 51:125-9. [PMID: 19349871 DOI: 10.1097/qai.0b013e31819f9e31] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE PRO 2000 is a polyanionic microbicide that binds directly to the glycoprotein 120 (gp120) envelope protein to inhibit HIV-1 entry. We studied the breadth of PRO 2000 activity against HIV-1 derived from recently transmitted R5 viruses. We also investigated the interaction of this compound with X4 and R5 HIV-1 envelope glycoproteins using an epitope-mapping strategy. METHODS The anti-HIV activity of PRO 2000 against subtype B and C Env-pseudotyped viruses was assessed in saline and cervicovaginal lavage fluid. Competitive binding assays were performed with X4 and R5 monomeric and virus-associated gp120. RESULTS PRO 2000 was found to be active against recently transmitted subtype B and C viruses tested in vitro, however, at 1 microg/mL in saline, activity against subtype C was decreased compared with subtype B. Epitope mapping using anti-V3 region antibodies showed that PRO 2000 binds to the V3 region of monomeric and virus-associated X4 gp120 with a higher affinity than to V3 of R5 gp120. In contrast, the interaction of PRO 2000 with the CD4-binding site was similar for both X4 and R5 monomeric and virus-associated gp120. CONCLUSIONS PRO 2000 has significant activity against recently transmitted viruses, although some activity is lost at low concentrations. Epitope binding studies suggest that this broad activity is due to direct and indirect interactions with multiple gp120 sites rather than V3 binding alone.
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50
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Virus entry via the alternative coreceptors CCR3 and FPRL1 differs by human immunodeficiency virus type 1 subtype. J Virol 2009; 83:8353-63. [PMID: 19553323 DOI: 10.1128/jvi.00780-09] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) infects target cells by binding to CD4 and a chemokine receptor, most commonly CCR5. CXCR4 is a frequent alternative coreceptor (CoR) in subtype B and D HIV-1 infection, but the importance of many other alternative CoRs remains elusive. We have analyzed HIV-1 envelope (Env) proteins from 66 individuals infected with the major subtypes of HIV-1 to determine if virus entry into highly permissive NP-2 cell lines expressing most known alternative CoRs differed by HIV-1 subtype. We also performed linear regression analysis to determine if virus entry via the major CoR CCR5 correlated with use of any alternative CoR and if this correlation differed by subtype. Virus pseudotyped with subtype B Env showed robust entry via CCR3 that was highly correlated with CCR5 entry efficiency. By contrast, viruses pseudotyped with subtype A and C Env proteins were able to use the recently described alternative CoR FPRL1 more efficiently than CCR3, and use of FPRL1 was correlated with CCR5 entry. Subtype D Env was unable to use either CCR3 or FPRL1 efficiently, a unique pattern of alternative CoR use. These results suggest that each subtype of circulating HIV-1 may be subject to somewhat different selective pressures for Env-mediated entry into target cells and suggest that CCR3 may be used as a surrogate CoR by subtype B while FPRL1 may be used as a surrogate CoR by subtypes A and C. These data may provide insight into development of resistance to CCR5-targeted entry inhibitors and alternative entry pathways for each HIV-1 subtype.
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