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Landry SJ, Mettu RR, Kolls JK, Aberle JH, Norton E, Zwezdaryk K, Robinson J. Structural Framework for Analysis of CD4+ T-Cell Epitope Dominance in Viral Fusion Proteins. Biochemistry 2023; 62:2517-2529. [PMID: 37554055 PMCID: PMC10483696 DOI: 10.1021/acs.biochem.3c00335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 07/31/2023] [Indexed: 08/10/2023]
Abstract
Antigen conformation shapes CD4+ T-cell specificity through mechanisms of antigen processing, and the consequences for immunity may rival those from conformational effects on antibody specificity. CD4+ T cells initiate and control immunity to pathogens and cancer and are at least partly responsible for immunopathology associated with infection, autoimmunity, and allergy. The primary trigger for CD4+ T-cell maturation is the presentation of an epitope peptide in the MHC class II antigen-presenting protein (MHCII), most commonly on an activated dendritic cell, and then the T-cell responses are recalled by subsequent presentations of the epitope peptide by the same or other antigen-presenting cells. Peptide presentation depends on the proteolytic fragmentation of the antigen in an endosomal/lysosomal compartment and concomitant loading of the fragments into the MHCII, a multistep mechanism called antigen processing and presentation. Although the role of peptide affinity for MHCII has been well studied, the role of proteolytic fragmentation has received less attention. In this Perspective, we will briefly summarize evidence that antigen resistance to unfolding and proteolytic fragmentation shapes the specificity of the CD4+ T-cell response to selected viral envelope proteins, identify several remarkable examples in which the immunodominant CD4+ epitopes most likely depend on the interaction of processing machinery with antigen conformation, and outline how knowledge of antigen conformation can inform future efforts to design vaccines.
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Affiliation(s)
- Samuel J. Landry
- Department
of Biochemistry and Molecular Biology, Tulane
University School of Medicine, New Orleans, Louisiana 70112, United States
| | - Ramgopal R. Mettu
- Department
of Computer Science, Tulane University, New Orleans, Louisiana 70118, United States
| | - Jay K. Kolls
- John
W. Deming Department of Internal Medicine, Center for Translational
Research in Infection and Inflammation, Tulane University School of Medicine, New Orleans, Louisiana 70112, United States
| | - Judith H. Aberle
- Center
for Virology, Medical University of Vienna, 1090 Vienna, Austria
| | - Elizabeth Norton
- Department
of Microbiology & Immunology, Tulane
University School of Medicine, New Orleans, Louisiana 70112, United States
| | - Kevin Zwezdaryk
- Department
of Microbiology & Immunology, Tulane
University School of Medicine, New Orleans, Louisiana 70112, United States
| | - James Robinson
- Department
of Pediatrics, Tulane University School
of Medicine, New Orleans, Louisiana 70112, United States
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2
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Pereira LMS, França EDS, Costa IB, Jorge EVO, Mattos PJDSM, Freire ABC, Ramos FLDP, Monteiro TAF, Macedo O, Sousa RCM, Dos Santos EJM, Freitas FB, Costa IB, Vallinoto ACR. HLA-B*13, B*35 and B*39 Alleles Are Closely Associated With the Lack of Response to ART in HIV Infection: A Cohort Study in a Population of Northern Brazil. Front Immunol 2022; 13:829126. [PMID: 35371095 PMCID: PMC8966405 DOI: 10.3389/fimmu.2022.829126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Accepted: 02/23/2022] [Indexed: 11/13/2022] Open
Abstract
Introduction Immune reconstitution failure after HIV treatment is a multifactorial phenomenon that may also be associated with a single polymorphism of human leukocyte antigen (HLA); however, few reports include patients from the Brazilian Amazon. Our objective was to evaluate the association of the immunogenic profile of the “classical” HLA-I and HLA-II loci with treatment nonresponse in a regional cohort monitored over 24 months since HIV diagnosis. Materials and Methods Treatment-free participants from reference centers in the state of Pará, Brazil, were enrolled. Infection screening was performed using enzyme immunoassays (Murex AG/AB Combination DiaSorin, UK) and confirmed by immunoblots (Bio-Manguinhos, FIOCRUZ). Plasma viral load was quantified by real-time PCR (ABBOTT, Chicago, Illinois, USA). CD4+/CD8+ T lymphocyte quantification was performed by immunophenotyping and flow cytometry (BD Biosciences, San Jose, CA, USA). Infection was monitored via test and logistics platforms (SISCEL and SICLOM). Therapeutic response failure was inferred based on CD4+ T lymphocyte quantification after 1 year of therapy. Loci A, B and DRB1 were genotyped using PCR-SSO (One Lambda Inc., Canoga Park, CA, USA). Statistical tests were applied using GENEPOP, GraphPad Prism 8.4.3 and BioEstat 5.3. Results Of the 270 patients monitored, 134 responded to treatment (CD4+ ≥ 500 cells/µL), and 136 did not respond to treatment (CD4+ < 500 cells/µL). The allele frequencies of the loci were similar to heterogeneous populations. The allelic profile of locus B was statistically associated with treatment nonresponse, and the B*13, B*35 and B*39 alleles had the greatest probabilistic influence. The B*13 allele had the highest risk of treatment nonresponse, and carriers of the allele had a detectable viral load and a CD4+ T lymphocyte count less than 400 cells/µL with up to 2 years of therapy. The B*13 allele was associated with a switch in treatment regimens, preferably to efavirenz (EFZ)-based regimens, and among those who switched regimens, half had a history of coinfection with tuberculosis. Conclusions The allelic variants of the B locus are more associated with non-response to therapy in people living with HIV (PLHIV) from a heterogeneous population in the Brazilian Amazon.
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Affiliation(s)
| | | | - Iran Barros Costa
- Epstein-Barr Virus Laboratory, Virology Unit, Evandro Chagas Institute, Ananindeua, Brazil
| | | | | | | | | | | | - Olinda Macedo
- Retrovirus Laboratory, Virology Unit, Evandro Chagas Institute, Ananindeua, Brazil
| | - Rita Catarina Medeiros Sousa
- Epstein-Barr Virus Laboratory, Virology Unit, Evandro Chagas Institute, Ananindeua, Brazil.,School of Medicine, Federal University of Pará, Belém, Brazil
| | - Eduardo José Melo Dos Santos
- Laboratory of Human and Medical Genetics, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil.,Graduate Program in Biology of Infectious and Parasitic Agents, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil
| | | | - Igor Brasil Costa
- Epstein-Barr Virus Laboratory, Virology Unit, Evandro Chagas Institute, Ananindeua, Brazil.,Graduate Program in Biology of Infectious and Parasitic Agents, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil
| | - Antonio Carlos Rosário Vallinoto
- Virology Laboratory, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil.,Graduate Program in Biology of Infectious and Parasitic Agents, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil
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3
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Moyano A, Blanch-Lombarte O, Tarancon-Diez L, Pedreño-Lopez N, Arenas M, Alvaro T, Casado C, Olivares I, Vera M, Rodriguez C, Del Romero J, López-Galíndez C, Ruiz-Mateos E, Prado JG, Pernas M. Immunoescape of HIV-1 in Env-EL9 CD8 + T cell response restricted by HLA-B*14:02 in a Non progressor who lost twenty-seven years of HIV-1 control. Retrovirology 2022; 19:6. [PMID: 35346235 PMCID: PMC8962528 DOI: 10.1186/s12977-022-00591-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 03/01/2022] [Indexed: 12/16/2022] Open
Abstract
Background Long-Term Non-Progressors (LTNPs) are untreated Human Immunodeficiency virus type 1 (HIV-1) infected individuals able to control disease progression for prolonged periods. However, the LTNPs status is temporary, as viral load increases followed by decreases in CD4 + T-cell counts. Control of HIV-1 infection in LTNPs viremic controllers, have been associated with effective immunodominant HIV-1 Gag-CD8 + T-cell responses restricted by protective HLA-B alleles. Individuals carrying HLA-B*14:02 control HIV-1 infection is related to an immunodominant Env-CD8 + T-cell response. Limited data are available on the contribution of HLA-B*14:02 CD8 + T -cells in LTNPs. Results In this study, we performed a virological and immunological detailed analysis of an HLA-B*14:02 LNTP individual that lost viral control (LVC) 27 years after HIV-1 diagnosis. We analysed viral evolution and immune escape in HLA-B*14:02 restricted CD8 + T -cell epitopes and identified viral evolution at the Env-EL9 epitope selecting the L592R mutation. By IFN-γ ELISpot and immune phenotype, we characterized HLA- B*14:02 HIV-1 CD8 + T cell responses targeting, Gag-DA9 and Env-EL9 epitopes before and after LVC. We observed an immunodominant response against the Env-EL9 epitope and a decreased of the CD8 T + cell response over time with LVC. Loss of Env-EL9 responses was concomitant with selecting K588R + L592R mutations at Env-EL9. Finally, we evaluated the impact of Env-EL9 escape mutations on HIV-1 infectivity and Env protein structure. The K588R + L592R escape variant was directly related to HIV-1 increase replicative capacity and stability of Env at the LVC. Conclusions These findings support the contribution of immunodominant Env-EL9 CD8 + T-cell responses and the imposition of immune escape variants with higher replicative capacity associated with LVC in this LNTP. These data highlight the importance of Env-EL9 specific-CD8 + T-cell responses restricted by the HLA-B*14:02 and brings new insights into understanding long-term HIV-1 control mediated by Env mediated CD8 + T-cell responses. Supplementary Information The online version contains supplementary material available at 10.1186/s12977-022-00591-7.
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Affiliation(s)
- Ana Moyano
- Virología Molecular, Laboratorio de Referencia e Investigación en Retrovirus, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Carretera de Pozuelo a Majadahonda Km 2, 28220, Madrid, Spain.,Max Von Pettenkofer Institute and Gene Center, Virology, National Reference Center for Retroviruses, Faculty of Medicine, LMU München, Munich, Germany
| | - Oscar Blanch-Lombarte
- IrsiCaixa AIDS Research Institute, Crta Canyet SN, Badalona, 08916, Barcelona, Spain.,Autonomous University of Barcelona, Cerdanyola del Vallès, Barcelona, Spain
| | - Laura Tarancon-Diez
- Institute of Biomedicine of Seville (IBiS)/Virgen del Rocío University Hospital, CSIC, University of Seville, Seville, Spain.,Molecular Immunobiology Laboratory, Immunology Section, Hospital Gregorio Marañón, Madrid, Spain
| | - Nuria Pedreño-Lopez
- Virología Molecular, Laboratorio de Referencia e Investigación en Retrovirus, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Carretera de Pozuelo a Majadahonda Km 2, 28220, Madrid, Spain.,IrsiCaixa AIDS Research Institute, Crta Canyet SN, Badalona, 08916, Barcelona, Spain
| | - Miguel Arenas
- Department of Biochemistry, Genetics and Immunology, University of Vigo, 36310, Vigo, Spain.,CINBIO, University of Vigo, 36310, Vigo, Spain.,Galicia Sur Health Research Institute (IIS Galicia Sur), 36310, Vigo, Spain
| | - Tamara Alvaro
- Virología Molecular, Laboratorio de Referencia e Investigación en Retrovirus, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Carretera de Pozuelo a Majadahonda Km 2, 28220, Madrid, Spain
| | - Concepción Casado
- Virología Molecular, Laboratorio de Referencia e Investigación en Retrovirus, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Carretera de Pozuelo a Majadahonda Km 2, 28220, Madrid, Spain
| | - Isabel Olivares
- Virología Molecular, Laboratorio de Referencia e Investigación en Retrovirus, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Carretera de Pozuelo a Majadahonda Km 2, 28220, Madrid, Spain
| | - Mar Vera
- Centro Sanitario Sandoval. Hospital Clínico San Carlos, IdISSC, Madrid, Spain
| | - Carmen Rodriguez
- Centro Sanitario Sandoval. Hospital Clínico San Carlos, IdISSC, Madrid, Spain
| | - Jorge Del Romero
- Centro Sanitario Sandoval. Hospital Clínico San Carlos, IdISSC, Madrid, Spain
| | - Cecilio López-Galíndez
- Virología Molecular, Laboratorio de Referencia e Investigación en Retrovirus, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Carretera de Pozuelo a Majadahonda Km 2, 28220, Madrid, Spain
| | - Ezequiel Ruiz-Mateos
- Institute of Biomedicine of Seville (IBiS)/Virgen del Rocío University Hospital, CSIC, University of Seville, Seville, Spain
| | - Julia G Prado
- IrsiCaixa AIDS Research Institute, Crta Canyet SN, Badalona, 08916, Barcelona, Spain. .,Germans Trias I Pujol Research Institute (IGTP), Badalona, Spain.
| | - María Pernas
- Virología Molecular, Laboratorio de Referencia e Investigación en Retrovirus, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Carretera de Pozuelo a Majadahonda Km 2, 28220, Madrid, Spain.
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4
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Blanch-Lombarte O, Santos JR, Peña R, Jiménez-Moyano E, Clotet B, Paredes R, Prado JG. HIV-1 Gag mutations alone are sufficient to reduce darunavir susceptibility during virological failure to boosted PI therapy. J Antimicrob Chemother 2020; 75:2535-2546. [PMID: 32556165 PMCID: PMC7443716 DOI: 10.1093/jac/dkaa228] [Citation(s) in RCA: 5] [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: 02/03/2020] [Revised: 04/21/2020] [Accepted: 05/03/2020] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Virological failure (VF) to boosted PIs with a high genetic barrier is not usually linked to the development of resistance-associated mutations in the protease gene. METHODS From a cohort of 520 HIV-infected subjects treated with lopinavir/ritonavir or darunavir/ritonavir monotherapy, we retrospectively identified nine patients with VF. We sequenced the HIV-1 Gag-protease region and generated clonal virus from plasma samples. We characterized phenotypically clonal variants in terms of replicative capacity and susceptibility to PIs. Also, we used VESPA to identify signature mutations and 3D molecular modelling information to detect conformational changes in the Gag region. RESULTS All subjects analysed harboured Gag-associated polymorphisms in the absence of resistance mutations in the protease gene. Most Gag changes occurred outside Gag cleavage sites. VESPA analyses identified K95R and R286K (P < 0.01) as signature mutations in Gag present at VF. In one out of four patients with clonal analysis available, we identified clonal variants with high replicative capacity and 8- to 13-fold reduction in darunavir susceptibility. These clonal variants harboured K95R, R286K and additional mutations in Gag. Low susceptibility to darunavir was dependent on the Gag sequence context. All other clonal variants analysed preserved drug susceptibility and virus replicative capacity. CONCLUSIONS Gag mutations may reduce darunavir susceptibility in the absence of protease mutations while preserving viral fitness. This effect is Gag-sequence context dependent and may occur during boosted PI failure.
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Affiliation(s)
- Oscar Blanch-Lombarte
- IrsiCaixa AIDS Research Institute, Badalona, Spain
- Germans Trias i Pujol Research Institute (IGTP), Badalona, Spain and Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
| | - José R Santos
- Lluita contra la SIDA Foundation, Hospital Universitari Germans Trias i Pujol, Badalona, Spain
- Infectious Diseases Department, Hospital Universitari Germans Trias i Pujol, Badalona, Spain
| | - Ruth Peña
- IrsiCaixa AIDS Research Institute, Badalona, Spain
| | | | - Bonaventura Clotet
- IrsiCaixa AIDS Research Institute, Badalona, Spain
- Faculty of Medicine, University of Vic - Central University of Catalonia (UVic-UCC), Vic, Spain
| | - Roger Paredes
- IrsiCaixa AIDS Research Institute, Badalona, Spain
- Faculty of Medicine, University of Vic - Central University of Catalonia (UVic-UCC), Vic, Spain
| | - Julia G Prado
- IrsiCaixa AIDS Research Institute, Badalona, Spain
- Germans Trias i Pujol Research Institute (IGTP), Badalona, Spain and Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
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5
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Olvera A, Noguera-Julian M, Kilpelainen A, Romero-Martín L, Prado JG, Brander C. SARS-CoV-2 Consensus-Sequence and Matching Overlapping Peptides Design for COVID19 Immune Studies and Vaccine Development. Vaccines (Basel) 2020; 8:E444. [PMID: 32781672 PMCID: PMC7565482 DOI: 10.3390/vaccines8030444] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 07/28/2020] [Accepted: 07/31/2020] [Indexed: 12/30/2022] Open
Abstract
Synthetic antigens based on consensus sequences that represent circulating viral isolates are sensitive, time saving and cost-effective tools for in vitro immune monitoring and to guide immunogen design. When based on a representative sequence database, such consensus sequences can effectively be used to test immune responses in exposed and infected individuals at the population level. To accelerate immune studies in SARS-CoV-2 infection, we here describe a SARS-CoV-2 2020 consensus sequence (CoV-2-cons) which is based on more than 1700 viral genome entries in NCBI and encompasses all described SARS-CoV-2 open reading frames (ORF), including recently described frame-shifted and length variant ORF. Based on these sequences, we created curated overlapping peptide (OLP) lists containing between 1500 to 3000 peptides of 15 and 18 amino acids in length, overlapping by 10 or 11 residues, as ideal tools for the assessment of SARS-CoV-2-specific T cell immunity. In addition, CoV-2-cons sequence entropy values are presented along with variant sequences to provide increased coverage of the most variable sections of the viral genome. The identification of conserved protein fragments across the coronavirus family and the corresponding OLP facilitate the identification of T cells potentially cross-reactive with related viruses. This new CoV-2-cons sequence, together with the peptides sets, should provide the basis for SARS-CoV-2 antigen synthesis to facilitate comparability between ex-vivo immune analyses and help to accelerate research on SARS-CoV-2 immunity and vaccine development.
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Affiliation(s)
- Alex Olvera
- IrsiCaixa AIDS Research Institute-HIVACAT, Hospital Universitari Germans Trias i Pujol, 08916 Badalona, Spain; (A.O.); (M.N.-J.); (A.K.); (L.R.-M.)
- Faculty of Sciences and Technology, Universitat de Vic-Central de Catalunya (UVic-UCC), 08500 Vic, Spain
| | - Marc Noguera-Julian
- IrsiCaixa AIDS Research Institute-HIVACAT, Hospital Universitari Germans Trias i Pujol, 08916 Badalona, Spain; (A.O.); (M.N.-J.); (A.K.); (L.R.-M.)
- Faculty of Medicine, Universitat de Vic-Central de Catalunya (UVic-UCC), 08500 Vic, Spain
| | - Athina Kilpelainen
- IrsiCaixa AIDS Research Institute-HIVACAT, Hospital Universitari Germans Trias i Pujol, 08916 Badalona, Spain; (A.O.); (M.N.-J.); (A.K.); (L.R.-M.)
| | - Luis Romero-Martín
- IrsiCaixa AIDS Research Institute-HIVACAT, Hospital Universitari Germans Trias i Pujol, 08916 Badalona, Spain; (A.O.); (M.N.-J.); (A.K.); (L.R.-M.)
| | - Julia G. Prado
- IrsiCaixa AIDS Research Institute-HIVACAT, Hospital Universitari Germans Trias i Pujol, 08916 Badalona, Spain; (A.O.); (M.N.-J.); (A.K.); (L.R.-M.)
- Germans Trias i Pujol Research Institute (IGTP), 08196 Barcelona, Spain
| | - Christian Brander
- IrsiCaixa AIDS Research Institute-HIVACAT, Hospital Universitari Germans Trias i Pujol, 08916 Badalona, Spain; (A.O.); (M.N.-J.); (A.K.); (L.R.-M.)
- Faculty of Medicine, Universitat de Vic-Central de Catalunya (UVic-UCC), 08500 Vic, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
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6
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Gomes STM, da Silva Graça Amoras E, Gomes ÉR, Queiroz MAF, Júnior ECS, de Vasconcelos Massafra JM, da Silva Lemos P, Júnior JLV, Ishak R, Vallinoto ACR. Immune escape mutations in HIV-1 controllers in the Brazilian Amazon region. BMC Infect Dis 2020; 20:546. [PMID: 32711474 PMCID: PMC7382849 DOI: 10.1186/s12879-020-05268-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 07/16/2020] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Human immunodeficiency virus (HIV-1) infection is characterized by high viral replication and a decrease in CD4+ T cells (CD4+TC), resulting in AIDS, which can lead to death. In elite controllers and viremia controllers, viral replication is naturally controlled, with maintenance of CD4+TC levels without the use of antiretroviral therapy (ART). METHODS The aim of the present study was to describe virological and immunological risk factors among HIV-1-infected individuals according to characteristics of progression to AIDS. The sample included 30 treatment-naive patients classified into three groups based on infection duration (> 6 years), CD4+TC count and viral load: (i) 2 elite controllers (ECs), (ii) 7 viremia controllers (VCs) and (iii) 21 nonviremia controllers (NVCs). Nested PCR was employed to amplify the virus genome, which was later sequenced using the Ion PGM platform for subtyping and analysis of immune escape mutations. RESULTS Viral samples were classified as HIV-1 subtypes B and F. Greater selection pressure on mutations was observed in the group of viremia controllers, with a higher frequency of immunological escape mutations in the genes investigated, including two new mutations in gag. The viral sequences of viremia controllers and nonviremia controllers did not differ significantly regarding the presence of immune escape mutations. CONCLUSION The results suggest that progression to AIDS is not dependent on a single variable but rather on a set of characteristics and pressures exerted by virus biology and interactions with immunogenetic host factors.
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Affiliation(s)
- Samara Tatielle Monteiro Gomes
- Laboratory of Virology, Biological Science Institute, Federal University of Pará (ICB/UFPA), Ananindeua, Brazil
- Graduate Program in Biology of Infectious and Parasitic Agents, Biological Science Institute, Federal University of Pará, Ananindeua, Brazil
| | | | - Érica Ribeiro Gomes
- Laboratory of Virology, Biological Science Institute, Federal University of Pará (ICB/UFPA), Ananindeua, Brazil
| | - Maria Alice Freitas Queiroz
- Laboratory of Virology, Biological Science Institute, Federal University of Pará (ICB/UFPA), Ananindeua, Brazil
| | - Edivaldo Costa Sousa Júnior
- Health Surveillance Department, Ministry of Health (IEC-SVS/MS), Evandro Chagas Institute, Ananindeua, Brazil
| | | | - Poliana da Silva Lemos
- Health Surveillance Department, Ministry of Health (IEC-SVS/MS), Evandro Chagas Institute, Ananindeua, Brazil
| | - João Lídio Vianez Júnior
- Health Surveillance Department, Ministry of Health (IEC-SVS/MS), Evandro Chagas Institute, Ananindeua, Brazil
| | - Ricardo Ishak
- Laboratory of Virology, Biological Science Institute, Federal University of Pará (ICB/UFPA), Ananindeua, Brazil
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7
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Ruiz A, Blanch-Lombarte O, Jimenez-Moyano E, Ouchi D, Mothe B, Peña R, Galvez C, Genescà M, Martinez-Picado J, Goulder P, Barnard R, Howell B, Clotet B, Prado JG. Antigen Production After Latency Reversal and Expression of Inhibitory Receptors in CD8+ T Cells Limit the Killing of HIV-1 Reactivated Cells. Front Immunol 2019; 9:3162. [PMID: 30723480 PMCID: PMC6349966 DOI: 10.3389/fimmu.2018.03162] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 12/21/2018] [Indexed: 12/22/2022] Open
Abstract
The so-called shock and kill therapies aim to combine HIV-1 reactivation by latency-reversing agents (LRA) with immune clearance to purge the HIV-1 reservoir. The clinical use of LRA has demonstrated detectable perturbations in the HIV-1 reservoir without measurable reductions to date. Consequently, fundamental questions concerning the limitations of the recognition and killing of LRA-reactivated cells by effector cells such as CD8+ T cells remain to be answered. Here, we developed a novel experimental framework where we combine the use of cytotoxic CD8+ T-cell lines and ex vivo CD8+ T cells from HIV-1-infected individuals with functional assays of LRA-inducible reactivation to delineate immune barriers to clear the reservoir. Our results demonstrate the potential for early recognition and killing of reactivated cells by CD8+ T cells. However, the potency of LRAs when crossing the barrier for antigen presentation in target cells, together with the lack of expression of inhibitory receptors in CD8+ T cells, are critical events to maximize the speed of recognition and the magnitude of the killing of LRA-inducible provirus. Taken together, our findings highlight direct limitations in LRA potency and CD8+ T cell functional status to succeed in the cure of HIV-1 infection.
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Affiliation(s)
- Alba Ruiz
- IrsiCaixa AIDS Research Institute, Badalona, Spain.,Germans Trias i Pujol Research Institute (IGTP), Universitat Autonoma de Barcelona, Badalona, Spain
| | - Oscar Blanch-Lombarte
- IrsiCaixa AIDS Research Institute, Badalona, Spain.,Germans Trias i Pujol Research Institute (IGTP), Universitat Autonoma de Barcelona, Badalona, Spain
| | | | - Dan Ouchi
- IrsiCaixa AIDS Research Institute, Badalona, Spain
| | - Beatriz Mothe
- IrsiCaixa AIDS Research Institute, Badalona, Spain.,Faculty of Medicine, University of Vic - Central University of Catalonia (UVic-UCC), Vic, Spain
| | - Ruth Peña
- IrsiCaixa AIDS Research Institute, Badalona, Spain
| | - Cristina Galvez
- IrsiCaixa AIDS Research Institute, Badalona, Spain.,Germans Trias i Pujol Research Institute (IGTP), Universitat Autonoma de Barcelona, Badalona, Spain
| | - Meritxell Genescà
- Department of Infectious Diseases, Hospital Universitari Vall d'Hebrón, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Javier Martinez-Picado
- IrsiCaixa AIDS Research Institute, Badalona, Spain.,Faculty of Medicine, University of Vic - Central University of Catalonia (UVic-UCC), Vic, Spain.,Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
| | - Philip Goulder
- Department of Paediatrics, University of Oxford, Oxford, United Kingdom
| | - Richard Barnard
- Department of Infectious Disease, Merck & Co. Inc. Kenilworth, NJ, United States
| | - Bonnie Howell
- Department of Infectious Disease, Merck & Co. Inc. Kenilworth, NJ, United States
| | - Bonaventura Clotet
- IrsiCaixa AIDS Research Institute, Badalona, Spain.,Faculty of Medicine, University of Vic - Central University of Catalonia (UVic-UCC), Vic, Spain
| | - Julia G Prado
- IrsiCaixa AIDS Research Institute, Badalona, Spain.,Germans Trias i Pujol Research Institute (IGTP), Universitat Autonoma de Barcelona, Badalona, Spain
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8
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Maintenance of AP-2-Dependent Functional Activities of Nef Restricts Pathways of Immune Escape from CD8 T Lymphocyte Responses. J Virol 2018; 92:JVI.01822-17. [PMID: 29237831 DOI: 10.1128/jvi.01822-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 12/02/2017] [Indexed: 01/28/2023] Open
Abstract
Nef-specific CD8+ T lymphocytes (CD8TL) are linked to extraordinary control of primate lentiviral replication, but the mechanisms underlying their efficacy remain largely unknown. The immunodominant, Mamu-B*017:01+-restricted Nef195-203MW9 epitope in SIVmac239 partially overlaps a sorting motif important for interactions with host AP-2 proteins and, hence, downmodulation of several host proteins, including Tetherin (CD317/BST-2), CD28, CD4, SERINC3, and SERINC5. We reasoned that CD8TL-driven evolution in this epitope might compromise Nef's ability to modulate these important molecules. Here, we used deep sequencing of SIV from nine B*017:01+ macaques throughout infection with SIVmac239 to characterize the patterns of viral escape in this epitope and then assayed the impacts of these variants on Nef-mediated modulation of multiple host molecules. Acute variation in multiple Nef195-203MW9 residues significantly compromised Nef's ability to downregulate surface Tetherin, CD4, and CD28 and reduced its ability to prevent SERINC5-mediated reduction in viral infectivity but did not impact downregulation of CD3 or major histocompatibility complex class I, suggesting the selective disruption of immunomodulatory pathways involving Nef AP-2 interactions. Together, our data illuminate a pattern of viral escape dictated by a selective balance to maintain AP-2-mediated downregulation while evading epitope-specific CD8TL responses. These data could shed light on mechanisms of both CD8TL-driven viral control generally and on Mamu-B*017:01-mediated viral control specifically.IMPORTANCE A rare subset of humans infected with HIV-1 and macaques infected with SIV can control the virus without aid of antiviral medications. A common feature of these individuals is the ability to mount unusually effective CD8 T lymphocyte responses against the virus. One of the most formidable aspects of HIV is its ability to evolve to evade immune responses, particularly CD8 T lymphocytes. We show that macaques that target a specific peptide in the SIV Nef protein are capable of better control of the virus and that, as the virus evolves to escape this response, it does so at a cost to specific functions performed by the Nef protein. Our results help show how the virus can be controlled by an immune response, which could help in designing effective vaccines.
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Sundaramurthi JC, Ashokkumar M, Swaminathan S, Hanna LE. HLA based selection of epitopes offers a potential window of opportunity for vaccine design against HIV. Vaccine 2017; 35:5568-5575. [PMID: 28888341 DOI: 10.1016/j.vaccine.2017.08.070] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 08/18/2017] [Accepted: 08/24/2017] [Indexed: 12/21/2022]
Abstract
The pace of progression to AIDS after HIV infection varies from individual to individual. While some individuals develop AIDS quickly, others are protected from the onset of disease for more than a decade (elite controllers and long term non-progressors). The mechanisms of protection are not yet clearly understood, though various factors including host genetics, immune components and virus attenuation have been elucidated partly. The influence of HLA alleles on HIV-1 infection and disease outcome has been studied extensively. Several HLA alleles are known to be associated with resistance to infection or delayed progression to AIDS after infection. Similarly, certain HLA alleles are reported to be associated with rapid progression to disease. Since HLA alleles influence the outcome of HIV infection differentially, selection of epitopes specifically recognized by protective alleles could serve asa rational means for HIV vaccine design. In this review article, we discuss existing knowledge on HLA alleles and their association with resistance/susceptibility to HIV and its relevance to vaccine design.
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Affiliation(s)
- Jagadish Chandrabose Sundaramurthi
- National Institute for Research in Tuberculosis (ICMR), (Formerly Tuberculosis Research Centre), Chetpet, Chennai 600031, Tamil Nadu, India
| | - Manickam Ashokkumar
- National Institute for Research in Tuberculosis (ICMR), (Formerly Tuberculosis Research Centre), Chetpet, Chennai 600031, Tamil Nadu, India
| | - Soumya Swaminathan
- National Institute for Research in Tuberculosis (ICMR), (Formerly Tuberculosis Research Centre), Chetpet, Chennai 600031, Tamil Nadu, India
| | - Luke Elizabeth Hanna
- National Institute for Research in Tuberculosis (ICMR), (Formerly Tuberculosis Research Centre), Chetpet, Chennai 600031, Tamil Nadu, India.
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Nomaguchi M, Doi N, Koma T, Adachi A. HIV-1 mutates to adapt in fluxing environments. Microbes Infect 2017; 20:610-614. [PMID: 28859896 DOI: 10.1016/j.micinf.2017.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Accepted: 08/23/2017] [Indexed: 01/11/2023]
Abstract
Human immunodeficiency virus type 1 (HIV-1) is specifically adapted for replication, persistence, transmission, and survival in humans. HIV-1 is highly mutable in nature, and well responds to a variety of environmental pressures by altering its genome sequences. In this review, we have described experimental evidence that demonstrates this phantasmagoric property of HIV-1.
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Affiliation(s)
- Masako Nomaguchi
- Department of Microbiology, Tokushima University Graduate School of Medical Science, Tokushima 770-8503, Japan
| | - Naoya Doi
- Department of Microbiology, Tokushima University Graduate School of Medical Science, Tokushima 770-8503, Japan
| | - Takaaki Koma
- Department of Microbiology, Tokushima University Graduate School of Medical Science, Tokushima 770-8503, Japan
| | - Akio Adachi
- Department of Microbiology, Tokushima University Graduate School of Medical Science, Tokushima 770-8503, Japan; Department of Microbiology, Kansai Medical University, Osaka 573-1010, Japan.
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11
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Jimenez-Moyano E, Ruiz A, Kløverpris HN, Rodriguez-Plata MT, Peña R, Blondeau C, Selwood DL, Izquierdo-Useros N, Moris A, Clotet B, Goulder P, Towers GJ, Prado JG. Nonhuman TRIM5 Variants Enhance Recognition of HIV-1-Infected Cells by CD8+ T Cells. J Virol 2016; 90:8552-62. [PMID: 27440884 PMCID: PMC5021395 DOI: 10.1128/jvi.00819-16] [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: 04/26/2016] [Accepted: 07/12/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Tripartite motif-containing protein 5 (TRIM5) restricts human immunodeficiency virus type 1 (HIV-1) in a species-specific manner by uncoating viral particles while activating early innate responses. Although the contribution of TRIM5 proteins to cellular immunity has not yet been studied, their interactions with the incoming viral capsid and the cellular proteasome led us to hypothesize a role for them. Here, we investigate whether the expression of two nonhuman TRIM5 orthologs, rhesus TRIM5α (RhT5) and TRIM-cyclophilin A (TCyp), both of which are potent restrictors of HIV-1, could enhance immune recognition of infected cells by CD8(+) T cells. We illustrate how TRIM5 restriction improves CD8(+) T-cell-mediated HIV-1 inhibition. Moreover, when TRIM5 activity was blocked by the nonimmunosuppressive analog of cyclosporine (CsA), sarcosine-3(4-methylbenzoate)-CsA (SmBz-CsA), we found a significant reduction in CD107a/MIP-1β expression in HIV-1-specific CD8(+) T cells. This finding underscores the direct link between TRIM5 restriction and activation of CD8(+) T-cell responses. Interestingly, cells expressing RhT5 induced stronger CD8(+) T-cell responses through the specific recognition of the HIV-1 capsid by the immune system. The underlying mechanism of this process may involve TRIM5-specific capsid recruitment to cellular proteasomes and increase peptide availability for loading and presentation of HLA class I antigens. In summary, we identified a novel function for nonhuman TRIM5 variants in cellular immunity. We hypothesize that TRIM5 can couple innate viral sensing and CD8(+) T-cell activation to increase species barriers against retrovirus infection. IMPORTANCE New therapeutics to tackle HIV-1 infection should aim to combine rapid innate viral sensing and cellular immune recognition. Such strategies could prevent seeding of the viral reservoir and the immune damage that occurs during acute infection. The nonhuman TRIM5 variants, rhesus TRIM5α (RhT5) and TRIM-cyclophilin A (TCyp), are attractive candidates owing to their potency in sensing HIV-1 and blocking its activity. Here, we show that expression of RhT5 and TCyp in HIV-1-infected cells improves CD8(+) T-cell-mediated inhibition through the direct activation of HIV-1-specific CD8(+) T-cell responses. We found that the potency in CD8(+) activation was stronger for RhT5 variants and capsid-specific CD8(+) T cells in a mechanism that relies on TRIM5-dependent particle recruitment to cellular proteasomes. This novel mechanism couples innate viral sensing with cellular immunity in a single protein and could be exploited to develop innovative therapeutics for control of HIV-1 infection.
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Affiliation(s)
| | - Alba Ruiz
- AIDS Research Institute, IrsiCaixa, Hospital Germans Trias i Pujol, Badalona, Spain
| | - Henrik N Kløverpris
- KwaZulu-Natal Research Institute for TB and HIV, University of KwaZulu-Natal, Durban, South Africa
| | | | - Ruth Peña
- AIDS Research Institute, IrsiCaixa, Hospital Germans Trias i Pujol, Badalona, Spain
| | - Caroline Blondeau
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - David L Selwood
- The Wolfson Institute for Biomedical Research, University College London, United Kingdom
| | | | - Arnaud Moris
- Sorbonne Universités, UPMC University Paris 6, INSERM U1135, CNRS ERL 8255, Center for Immunology and Microbial Infections-Paris, Paris, France
| | - Bonaventura Clotet
- AIDS Research Institute, IrsiCaixa, Hospital Germans Trias i Pujol, Badalona, Spain
| | - Philip Goulder
- Department of Paediatrics, University of Oxford, Oxford, United Kingdom
| | - Greg J Towers
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - Julia G Prado
- AIDS Research Institute, IrsiCaixa, Hospital Germans Trias i Pujol, Badalona, Spain
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CD8+ T Cell Breadth and Ex Vivo Virus Inhibition Capacity Distinguish between Viremic Controllers with and without Protective HLA Class I Alleles. J Virol 2016; 90:6818-6831. [PMID: 27194762 DOI: 10.1128/jvi.00276-16] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 05/11/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The mechanisms of viral control and loss of viral control in chronically infected individuals with or without protective HLA class I alleles are not fully understood. We therefore characterized longitudinally the immunological and virological features that may explain divergence in disease outcome in 70 HIV-1 C-clade-infected antiretroviral therapy (ART)-naive South African adults, 35 of whom possessed protective HLA class I alleles. We demonstrate that, over 5 years of longitudinal study, 35% of individuals with protective HLA class I alleles lost viral control compared to none of the individuals without protective HLA class I alleles (P = 0.06). Sustained HIV-1 control in patients with protective HLA class I alleles was characteristically related to the breadth of HIV-1 CD8(+) T cell responses against Gag and enhanced ability of CD8(+) T cells to suppress viral replication ex vivo In some cases, loss of virological control was associated with reduction in the total breadth of CD8(+) T cell responses in the absence of differences in HIV-1-specific CD8(+) T cell polyfunctionality or proliferation. In contrast, viremic controllers without protective HLA class I alleles possessed reduced breadth of HIV-1-specific CD8(+) T cell responses characterized by reduced ability to suppress viral replication ex vivo These data suggest that the control of HIV-1 in individuals with protective HLA class I alleles may be driven by broad CD8(+) T cell responses with potent viral inhibitory capacity while control among individuals without protective HLA class I alleles may be more durable and mediated by CD8(+) T cell-independent mechanisms. IMPORTANCE Host mechanisms of natural HIV-1 control are not fully understood. In a longitudinal study of antiretroviral therapy (ART)-naive individuals, we show that those with protective HLA class I alleles subsequently experienced virologic failure compared to those without protective alleles. Among individuals with protective HLA class I alleles, viremic control was associated with broad CD8(+) T cells that targeted the Gag protein, and CD8(+) T cells from these individuals exhibited superior virus inhibition capacity. In individuals without protective HLA class I alleles, HIV-1-specific CD8(+) T cell responses were narrow and poorly inhibited virus replication. These results suggest that broad, highly functional cytotoxic T cells (cytotoxic T lymphocytes [CTLs]) against the HIV-1 Gag protein are associated with control among those with protective HLA class I alleles and that loss of these responses eventually leads to viremia. A subset of individuals appears to have alternative, non-CTL mechanisms of viral control. These controllers may hold the key to an effective HIV vaccine.
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Consequences of HLA-B*13-Associated Escape Mutations on HIV-1 Replication and Nef Function. J Virol 2015; 89:11557-71. [PMID: 26355081 DOI: 10.1128/jvi.01955-15] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 08/31/2015] [Indexed: 01/05/2023] Open
Abstract
UNLABELLED HLA-B*13 is associated with superior in vivo HIV-1 viremia control. Protection is thought to be mediated by sustained targeting of key cytotoxic T lymphocyte (CTL) epitopes and viral fitness costs of CTL escape in Gag although additional factors may contribute. We assessed the impact of 10 published B*13-associated polymorphisms in Gag, Pol, and Nef, in 23 biologically relevant combinations, on HIV-1 replication capacity and Nef-mediated reduction of cell surface CD4 and HLA class I expression. Mutations were engineered into HIV-1NL4.3, and replication capacity was measured using a green fluorescent protein (GFP) reporter T cell line. Nef-mediated CD4 and HLA-A*02 downregulation was assessed by flow cytometry, and T cell recognition of infected target cells was measured via coculture with an HIV-specific luciferase reporter cell line. When tested individually, only Gag-I147L and Gag-I437L incurred replicative costs (5% and 17%, respectively), consistent with prior reports. The Gag-I437L-mediated replication defect was rescued to wild-type levels by the adjacent K436R mutation. A novel B*13 epitope, comprising 8 residues and terminating at Gag147, was identified in p24(Gag) (GQMVHQAIGag140-147). No other single or combination Gag, Pol, or Nef mutant impaired viral replication. Single Nef mutations did not affect CD4 or HLA downregulation; however, the Nef double mutant E24Q-Q107R showed 40% impairment in HLA downregulation with no evidence of Nef stability defects. Moreover, target cells infected with HIV-1-NefE24Q-Q107R were recognized better by HIV-specific T cells than those infected with HIV-1NL4.3 or single Nef mutants. Our results indicate that CTL escape in Gag and Nef can be functionally costly and suggest that these effects may contribute to long-term HIV-1 control by HLA-B*13. IMPORTANCE Protective effects of HLA-B*13 on HIV-1 disease progression are mediated in part by fitness costs of CTL escape mutations in conserved Gag epitopes, but other mechanisms remain incompletely known. We extend our knowledge of the impact of B*13-driven escape on HIV-1 replication by identifying Gag-K436R as a compensatory mutation for the fitness-costly Gag-I437L. We also identify Gag-I147L, the most rapidly and commonly selected B*13-driven substitution in HIV-1, as a putative C-terminal anchor residue mutation in a novel B*13 epitope. Most notably, we identify a novel escape-driven fitness defect: B*13-driven substitutions E24Q and Q107R in Nef, when present together, substantially impair this protein's ability to downregulate HLA class I. This, in turn, increases the visibility of infected cells to HIV-specific T cells. Our results suggest that B*13-associated escape mutations impair HIV-1 replication by two distinct mechanisms, that is, by reducing Gag fitness and dampening Nef immune evasion function.
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14
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Genome-Wide Association Studies of HIV-1 Host Control in Ethnically Diverse Chinese Populations. Sci Rep 2015; 5:10879. [PMID: 26039976 PMCID: PMC4454153 DOI: 10.1038/srep10879] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 05/07/2015] [Indexed: 02/05/2023] Open
Abstract
Genome-wide association studies (GWASs) have revealed several genetic loci associated with HIV-1 outcome following infection (e.g., HLA-C at 6p21.33) in multi-ethnic populations with genetic heterogeneity and racial/ethnic differences among Caucasians, African-Americans, and Hispanics. To systematically investigate the inherited predisposition to modulate HIV-1 infection in Chinese populations, we performed GWASs in three ethnically diverse HIV-infected patients groups (i.e., HAN, YUN, and XIN, N = 538). The reported loci at 6p21.33 was validated in HAN (e.g., rs9264942, P = 0.0018). An independent association signal (rs2442719, P = 7.85 × 10−7, HAN group) in the same region was observed. Imputation results suggest that haplotype HLA-B*13:02/C*06:02, which can partially account for the GWAS signal, is associated with lower viral load in Han Chinese. Moreover, several novel loci were identified using GWAS approach including the top association signals at 6q13 (KCNQ5, rs947612, P = 2.15 × 10−6), 6p24.1 (PHACTR1, rs202072, P = 3.8 × 10−6), and 11q12.3 (SCGB1D4, rs11231017, P = 7.39 × 10−7) in HAN, YUN, and XIN groups, respectively. Our findings imply shared or specific mechanisms for host control of HIV-1 in ethnically diverse Chinese populations, which may shed new light on individualized HIV/AIDS therapy in China.
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Multilayered HIV-1 gag-specific T-cell responses contribute to slow progression in HLA-A*30-B*13-C*06-positive patients. AIDS 2015; 29:993-1002. [PMID: 25756195 PMCID: PMC4444423 DOI: 10.1097/qad.0000000000000652] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Objective: The HLA-A∗30-B∗13-C∗06 haplotype is reported to be associated with slow disease progression in the HIV-1-infected Northern Han Chinese population, but the mechanism remains unknown. Design: Gag-specific T-cell responses and gag sequencing were performed in nine B′ clade HIV-1-infected HLA-A∗30-B∗13-C∗06-positive slow progressors to understand HLA-associated viral control. Methods: Interferon-γ ELISPOT assays were performed to determine the Gag-specific T-cell responses and cross-reactivity to variant peptides. Longitudinal HIV-1 gag sequencing was performed at the clonal level. Results: The overlapping peptides (OLP)-48: RQANFLGKIWPSHKGRPGNF (RL42 Gag434-453); OLP-2: GQLDRWEKIRLRPGGKKKYR (RL42 Gag11-30); OLP-15: VQNLQGQMVHQPISPRTLNA (RL42 Gag135-154) and OLP-16: HQPISPRTLNAWVKVVEEKA (RL42 Gag144-163) were dominant in HLA-A∗30-B∗13-C∗06-positive patients. A new epitope [HQPISPRTL (Gag144-152, HL9)] within OLP-15 and OLP-16 was identified. Results showed that strong cross-reactive responses to multiple immunodominant peptides were associated with better clinical outcomes. In addition, efficient cross-recognition of HL9 autologous variants developed in patients was associated with high CD4+ T-cell counts. However, two patients who had developed mutations to their dominant responses during the follow-up experienced decrease in CD4+ T-cell counts. It appears that Gag-specific T-cell responses against one or more unmutated epitopes or cross-recognition of autologous epitope variants contribute to slow disease progression in HLA-A∗30-B∗13-C∗06-positive patients. Conclusion: We conclude that a single ‘appropriate’ Gag-specific T-cell response appears to be sufficient to protect patients from disease progression. HLA-A∗30-B∗13-C∗06-positive individuals benefited from having a choice of numerous immunodominant gag epitopes for T cells to react. The study offers new insight for future design of T-cell-based HIV-1 vaccine.
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Acevedo-Sáenz L, Ochoa R, Rugeles MT, Olaya-García P, Velilla-Hernández PA, Diaz FJ. Selection pressure in CD8⁺ T-cell epitopes in the pol gene of HIV-1 infected individuals in Colombia. A bioinformatic approach. Viruses 2015; 7:1313-31. [PMID: 25803098 PMCID: PMC4379572 DOI: 10.3390/v7031313] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 02/23/2015] [Accepted: 02/24/2015] [Indexed: 01/24/2023] Open
Abstract
One of the main characteristics of the human immunodeficiency virus is its genetic variability and rapid adaptation to changing environmental conditions. This variability, resulting from the lack of proofreading activity of the viral reverse transcriptase, generates mutations that could be fixed either by random genetic drift or by positive selection. Among the forces driving positive selection are antiretroviral therapy and CD8+ T-cells, the most important immune mechanism involved in viral control. Here, we describe mutations induced by these selective forces acting on the pol gene of HIV in a group of infected individuals. We used Maximum Likelihood analyses of the ratio of non-synonymous to synonymous mutations per site (dN/dS) to study the extent of positive selection in the protease and the reverse transcriptase, using 614 viral sequences from Colombian patients. We also performed computational approaches, docking and algorithmic analyses, to assess whether the positively selected mutations affected binding to the HLA molecules. We found 19 positively-selected codons in drug resistance-associated sites and 22 located within CD8+ T-cell epitopes. A high percentage of mutations in these epitopes has not been previously reported. According to the docking analyses only one of those mutations affected HLA binding. However, algorithmic methods predicted a decrease in the affinity for the HLA molecule in seven mutated peptides. The bioinformatics strategies described here are useful to identify putative positively selected mutations associated with immune escape but should be complemented with an experimental approach to define the impact of these mutations on the functional profile of the CD8+ T-cells.
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Affiliation(s)
- Liliana Acevedo-Sáenz
- Grupo Inmunovirología, Facultad de Medicina, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, 050010, Colombia.
| | - Rodrigo Ochoa
- Programa de Estudio y Control de Enfermedades Tropicales-PECET, Universidad de Antioquia, Medellín, 050010, Colombia.
| | - Maria Teresa Rugeles
- Grupo Inmunovirología, Facultad de Medicina, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, 050010, Colombia.
| | | | - Paula Andrea Velilla-Hernández
- Grupo Inmunovirología, Facultad de Medicina, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, 050010, Colombia.
| | - Francisco J Diaz
- Grupo Inmunovirología, Facultad de Medicina, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, 050010, Colombia.
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Serwanga J, Nakiboneka R, Mugaba S, Magambo B, Ndembi N, Gotch F, Kaleebu P. Frequencies of Gag-restricted T-cell escape "footprints" differ across HIV-1 clades A1 and D chronically infected Ugandans irrespective of host HLA B alleles. Vaccine 2015; 33:1664-72. [PMID: 25728323 PMCID: PMC4374673 DOI: 10.1016/j.vaccine.2015.02.037] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 01/29/2015] [Accepted: 02/16/2015] [Indexed: 01/05/2023]
Abstract
A and D infected subjects even though they bear the same presenting HLA alleles, and live in the same environment. Escape mutations that are known to confer survival advantage were more frequent in clade A-infected subjects irrespective of host HLA alleles. There was no evidence to link this difference in outcome to the evaluated adaptive T-Cell responses (IFN-γ responses and polyfunctional responses) to those key structurally constrained Gag epitopes. However, we have demonstrated that there was significantly greater selective pressure on the Gag protein of clade A than that of clade D. The data are in line with the known faster disease progression in clade D than clade A infected individuals. The data also highlight that the current difficulties in formulating a global HIV vaccine design will be further challenged by clade associated differences in outcome.
Objective(s) We evaluated relationships between critical Gag T-cell escape mutations and concomitant T-cell responses to determine whether HLA-restricted Gag mutations that confer protection, occur at similar rates in a population infected with mixed HIV-1 clades A1 and D viruses. Methods Assessment of Gag selective pressure, and adaptive T-cell functions to KAFSPEVIPMF (KF11), ISPRTLNAW (ISW9) and TSTLQEQIGW (TW10) Gag epitopes were combined with host HLA to assess correlations with rates of critical epitope escape mutations in clades A1- (n = 23) and D- (n = 21) infected, untreated subjects. Infecting clades and selection pressure were determined from the gag sequences. Results Overall, Gag escape mutations A163X in KF11 were detected in 61% (14/23) A1- infected compared to 5% (1/21) in D-infected subjects (p = 0.00015). Gag mutations I147X in the ISW9 epitope were seen in 43%: (10/23) clade A compared to 5%: (1/21) clade D infected subjects, p = 0.007, Fisher's Exact test. Both mutations were more frequent in clade A1 infection. Frequencies of the measured epitope-specific T-cell responses were comparable across clades. Peptide binding affinities for the restricting HLA alleles did not differ across clades. Overall, selection pressure on the Gag protein was significantly greater in clade A than in clade D sequences. Conclusions These findings imply that HIV-1 vaccine strategies designed to target structurally constrained T-cell epitopes may be further challenged by clade-driven outcomes in specific HLA-restricted Gag epitopes. Equally, the data are line with slower HIV-1 disease progression in clade A infection; and raise hope that increased selective pressure on Gag may be protective irrespective of host HLA alleles.
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Affiliation(s)
| | | | - Susan Mugaba
- MRC/UVRI Uganda Research Unit on AIDS, Entebbe, Uganda
| | - Brian Magambo
- MRC/UVRI Uganda Research Unit on AIDS, Entebbe, Uganda
| | | | - Frances Gotch
- Department of Immunology, Imperial College, Chelsea & Westminster Hospital, London, United Kingdom
| | - Pontiano Kaleebu
- MRC/UVRI Uganda Research Unit on AIDS, Entebbe, Uganda; London School of Hygiene and Tropical Medicine, United Kingdom
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Carlson JM, Le AQ, Shahid A, Brumme ZL. HIV-1 adaptation to HLA: a window into virus-host immune interactions. Trends Microbiol 2015; 23:212-24. [PMID: 25613992 DOI: 10.1016/j.tim.2014.12.008] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 12/04/2014] [Accepted: 12/16/2014] [Indexed: 11/26/2022]
Abstract
HIV-1 develops specific mutations within its genome that allow it to escape detection by human leukocyte antigen (HLA) class I-restricted immune responses, notably those of CD8(+) cytotoxic T lymphocytes (CTL). HLA thus represents a major force driving the evolution and diversification of HIV-1 within individuals and at the population level. Importantly, the study of HIV-1 adaptation to HLA also represents an opportunity to identify what qualities constitute an effective immune response, how the virus in turn adapts to these pressures, and how we may harness this information to design HIV-1 vaccines that stimulate effective cellular immunity.
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Affiliation(s)
| | - Anh Q Le
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Aniqa Shahid
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Zabrina L Brumme
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada; British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada.
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19
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Highly pathogenic adapted HIV-1 strains limit host immunity and dictate rapid disease progression. AIDS 2014; 28:1261-72. [PMID: 24732774 DOI: 10.1097/qad.0000000000000293] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The study of HIV-1 rapid progressors has been limited to specific case reports. Nevertheless, identification and characterization of the viral and host factors involved in rapid progression are crucial when attempting to uncover the correlates of rapid disease outcome. DESIGN We carried out comparative functional analyses in rapid progressors (n = 46) and standard progressors (n = 46) early after HIV-1 seroconversion (≤1 year). The viral traits tested were viral replicative capacity, co-receptor usage, and genomic variation. Host CD8(+) T-cell responses, humoral activity, and HLA immunogenetic markers were also determined. RESULTS Our data demonstrate an unusual convergence of highly pathogenic HIV-1 strains in rapid progressors. Compared with standard progressors, rapid progressor viral strains show higher in-vitro replicative capacity (81.5 vs. 67.9%; P = 0.025) and greater X4/DM co-receptor usage (26.3 vs. 2.8%; P = 0.006) in early infection. Limited or absent functional HIV-1 CD8(+) T-cell responses and neutralizing activity were measured in rapid progressors. Moreover, the increase in common HLA allele-restricted CD8(+) T-cell escape mutations in rapid progressors acts as a signature of uncontrolled HIV-1 replication and early impairment of adaptive cellular responses. CONCLUSION Our data support a dominant role for viral factors in rapid progressors. Robust HIV-1 replication and intrinsic viral properties limit host adaptive immune responses, thus driving rapid disease progression.
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Payne RP, Branch S, Kløverpris H, Matthews PC, Koofhethile CK, Strong T, Adland E, Leitman E, Frater J, Ndung'u T, Hunter E, Haubrich R, Mothe B, Edwards A, Riddell L, Chen F, Harrigan PR, Brumme ZL, Mallal S, John M, Jooste JP, Shapiro R, Deeks SG, Walker BD, Brander C, Landis C, Carlson JM, Prado JG, Goulder PJR. Differential escape patterns within the dominant HLA-B*57:03-restricted HIV Gag epitope reflect distinct clade-specific functional constraints. J Virol 2014; 88:4668-78. [PMID: 24501417 PMCID: PMC3993828 DOI: 10.1128/jvi.03303-13] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 02/02/2014] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED HLA-B*57:01 and HLA-B*57:03, the most prevalent HLA-B*57 subtypes in Caucasian and African populations, respectively, are the HLA alleles most protective against HIV disease progression. Understanding the mechanisms underlying this immune control is of critical importance, yet they remain unclear. Unexplained differences are observed in the impact of the dominant cytotoxic T lymphocyte (CTL) response restricted by HLA-B*57:01 and HLA-B*57:03 in chronic infection on the Gag epitope KAFSPEVIPMF (KF11; Gag 162 to 172). We previously showed that the HLA-B*57:03-KF11 response is associated with a >1-log-lower viral setpoint in C clade virus infection and that this response selects escape mutants within the epitope. We first examined the relationship of KF11 responses in B clade virus-infected subjects with HLA-B*57:01 to immune control and observed that a detectable KF11 response was associated with a >1-log-higher viral load (P = 0.02). No evidence of HLA-B*57:01-KF11-associated selection pressure was identified in previous comprehensive analyses of >1,800 B clade virus-infected subjects. We then studied a B clade virus-infected cohort in Barbados, where HLA-B*57:03 is highly prevalent. In contrast to findings for B clade virus-infected subjects expressing HLA-B*57:01, we observed strong selection pressure driven by the HLA-B*57:03-KF11 response for the escape mutation S173T. This mutation reduces recognition of virus-infected cells by HLA-B*57:03-KF11 CTLs and is associated with a >1-log increase in viral load in HLA-B*57:03-positive subjects (P = 0.009). We demonstrate functional constraints imposed by HIV clade relating to the residue at Gag 173 that explain the differential clade-specific escape patterns in HLA-B*57:03 subjects. Further studies are needed to evaluate the role of the KF11 response in HLA-B*57:01-associated HIV disease protection. IMPORTANCE HLA-B*57 is the HLA class I molecule that affords the greatest protection against disease progression in HIV infection. Understanding the key mechanism(s) underlying immunosuppression of HIV is of importance in guiding therapeutic and vaccine-related approaches to improve the levels of HIV control occurring in nature. Numerous mechanisms have been proposed to explain the HLA associations with differential HIV disease outcome, but no consensus exists. These studies focus on two subtypes of HLA-B*57 prevalent in Caucasian and African populations, HLA-B*57:01 and HLA-B*57:03, respectively. These alleles appear equally protective against HIV disease progression. The CTL epitopes presented are in many cases identical, and the dominant response in chronic infection in each case is to the Gag epitope KF11. However, there the similarity ends. This study sought to better understand the reasons for these differences and what they teach us about which immune responses contribute to immune control of HIV infection.
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Affiliation(s)
- R. P. Payne
- Department of Paediatrics, University of Oxford, Oxford, United Kingdom
| | - S. Branch
- Ladymeade Reference Unit, Queen Elizabeth Hospital, Bridgetown, Barbados
| | - H. Kløverpris
- Department of Paediatrics, University of Oxford, Oxford, United Kingdom
- K-RITH, University of Kwa-Zulu Natal, Duran, South Africa
| | - P. C. Matthews
- Department of Paediatrics, University of Oxford, Oxford, United Kingdom
| | - C. K. Koofhethile
- Department of Paediatrics, University of Oxford, Oxford, United Kingdom
| | - T. Strong
- Department of Paediatrics, University of Oxford, Oxford, United Kingdom
| | - E. Adland
- Department of Paediatrics, University of Oxford, Oxford, United Kingdom
| | - E. Leitman
- Department of Paediatrics, University of Oxford, Oxford, United Kingdom
| | - J. Frater
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
- Oxford NIHR Biomedical Research Centre, Oxford, United Kingdom
| | - T. Ndung'u
- HIV Pathogenesis Program, Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa
| | - E. Hunter
- Emory Vaccine Center, Yerkes National Primate Research Centre, Emory University, Atlanta, Georgia, USA
- Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
| | - R. Haubrich
- Antiviral Research Center, University of California San Diego, San Diego, California, USA
| | - B. Mothe
- IrsiCaixa AIDS Research Institute-HIVCAT, Hospital Germans Trias i Pujol, Badalona, Spain
| | - A. Edwards
- Oxford Department of Genitourinary Medicine, The Churchill Hospital, Oxford, United Kingdom
| | - L. Riddell
- Department of Genitourinary Medicine, Northamptonshire Healthcare National Health Service Trust, Northampton General Hospital, Cliftonville, Northampton, United Kingdom
| | - F. Chen
- Department of Sexual Health, Royal Berkshire Hospital, Reading, United Kingdom
| | - P. R. Harrigan
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, British Columbia, Canada
| | - Z. L. Brumme
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, British Columbia, Canada
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - S. Mallal
- Centre for Clinical Immunology and Biomedical Statistics, Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, Western Australia, Australia
- Department of Clinical Immunology, Royal Perth Hospital, Perth, Western Australia, Australia
| | - M. John
- Centre for Clinical Immunology and Biomedical Statistics, Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, Western Australia, Australia
- Department of Clinical Immunology, Royal Perth Hospital, Perth, Western Australia, Australia
| | - J. P. Jooste
- Paediatric Department, Kimberley Hospital, Northern Cape, South Africa
| | - R. Shapiro
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, USA
| | - S. G. Deeks
- Department of Medicine, University of California, San Francisco, California, USA
| | - B. D. Walker
- HIV Pathogenesis Program, Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa
- Ragon Institute of MGH, MIT, and Harvard, AIDS Research Center, Charlestown, Massachusetts, USA
| | - C. Brander
- IrsiCaixa AIDS Research Institute-HIVCAT, Hospital Germans Trias i Pujol, Badalona, Spain
- Institució Catalana de Recerca i Estudis Avancats (ICREA), Barcelona, Spain
| | - C. Landis
- Ladymeade Reference Unit, Queen Elizabeth Hospital, Bridgetown, Barbados
| | - J. M. Carlson
- Microsoft Research, eScience Group, Los Angeles, California, USA
| | - J. G. Prado
- IrsiCaixa AIDS Research Institute-HIVCAT, Hospital Germans Trias i Pujol, Badalona, Spain
| | - P. J. R. Goulder
- Department of Paediatrics, University of Oxford, Oxford, United Kingdom
- HIV Pathogenesis Program, Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa
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Zhang J, Yang H, Li H, Liu F, Jia Q, Duan H, Niu Y, Bin P, Zheng Y, Dai Y. Peptide-binding motifs and characteristics for HLA -B*13:01 molecule. ACTA ACUST UNITED AC 2014; 81:442-8. [PMID: 23646949 DOI: 10.1111/tan.12114] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Revised: 01/28/2013] [Accepted: 03/18/2013] [Indexed: 11/28/2022]
Abstract
Trichloroethylene (TCE)-induced hypersensitivity dermatitis is one of the critical occupational diseases among workers in China. Our previous studies have identified a strong linkage between the disease and the HLA-B*13:01 allele. In this study, we searched for peptides bound to the HLA-B*13:01 molecule; 57 HLA-B*13:01-bound peptides in total were identified and 54 peptides were used to calculate frequency of amino acid residues to obtain binding motifs of HLA-B*13:01 molecule. The results showed P2, P3, and P9 were the primary binding anchor positions with the dominant anchor motifs of L, Q at P2, L at P9, D at P3. HLA-B*13:01-bound peptides were identified for the first time in our research, the results of which could contribute to the human leukocyte antigen (HLA)-binding peptides database.
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Affiliation(s)
- J Zhang
- Key laboratory of Chemical Safety and Health, Chinese Centre for Disease Control and Prevention, National Institute for Occupational Health and Poison Control, Chinese Centre for Disease Control and Prevention, Beijing, China
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Kløverpris HN, Payne RP, Sacha JB, Rasaiyaah JT, Chen F, Takiguchi M, Yang OO, Towers GJ, Goulder P, Prado JG. Early antigen presentation of protective HIV-1 KF11Gag and KK10Gag epitopes from incoming viral particles facilitates rapid recognition of infected cells by specific CD8+ T cells. J Virol 2013; 87:2628-38. [PMID: 23255798 PMCID: PMC3571362 DOI: 10.1128/jvi.02131-12] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2012] [Accepted: 12/11/2012] [Indexed: 02/07/2023] Open
Abstract
CD8(+) T cells are major players in antiviral immunity against human immunodeficiency virus type 1 (HIV-1) through recognition of viral epitopes presented on the surface of infected cells. However, the early events involving HIV-1 epitope presentation to CD8(+) T cells remain poorly understood but are nonetheless crucial for the rapid clearance of virus-infected cells. Here, we comprehensively studied the kinetics of antigen presentation of two protective epitopes, KF11Gag and KK10Gag, restricted by HLA alleles B*57:01 and B*27:05, respectively, and compared these to KY9Pol and VL9Vpr epitopes in a single cycle of HIV-1 replication. We consistently demonstrate differences in epitope presentation kinetics, with very early presentation, within 3 h postinfection, for the protective KF11Gag, KK10Gag epitopes, and KY9Pol but only late presentation for VL9Vpr. We show that this early presentation relies on the antigen being presented from incoming viral particles and is correlated with rapid CD8(+) T cell activation and clearance of virus-infected cells. Additionally, our data indicate a dose-response dependency between the levels of CD8(+) T cell activation and the amount of virus inoculum. These data reflect a proof of principle emphasizing the importance of identifying early-presented viral epitopes for rapid elimination of HIV-1-infected cells.
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Affiliation(s)
| | | | - Jonah B. Sacha
- Vaccine & Gene Therapy Institute, Oregon National Primate Research Center, Oregon Health & Science University, Portland, Oregon, USA
| | - Jane T. Rasaiyaah
- Medical Research Council Centre for Medical Molecular Virology, Division of Infection and Immunity, University College London, London, United Kingdom
| | - Fabian Chen
- Department of Sexual Health, Royal Berkshire Hospital, Reading, United Kingdom
| | | | - Otto O. Yang
- Departments of Medicine and Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Greg J. Towers
- Medical Research Council Centre for Medical Molecular Virology, Division of Infection and Immunity, University College London, London, United Kingdom
| | - Philip Goulder
- Department of Paediatrics, University of Oxford, United Kingdom
| | - Julia G. Prado
- AIDS Research Institute IrsiCaixa, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain
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Frequent and variable cytotoxic-T-lymphocyte escape-associated fitness costs in the human immunodeficiency virus type 1 subtype B Gag proteins. J Virol 2013; 87:3952-65. [PMID: 23365420 DOI: 10.1128/jvi.03233-12] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Cytotoxic-T-lymphocyte (CTL) escape mutations undermine the durability of effective human immunodeficiency virus type 1 (HIV-1)-specific CD8(+) T cell responses. The rate of CTL escape from a given response is largely governed by the net of all escape-associated viral fitness costs and benefits. The observation that CTL escape mutations can carry an associated fitness cost in terms of reduced virus replication capacity (RC) suggests a fitness cost-benefit trade-off that could delay CTL escape and thereby prolong CD8 response effectiveness. However, our understanding of this potential fitness trade-off is limited by the small number of CTL escape mutations for which a fitness cost has been quantified. Here, we quantified the fitness cost of the 29 most common HIV-1B Gag CTL escape mutations using an in vitro RC assay. The majority (20/29) of mutations reduced RC by more than the benchmark M184V antiretroviral drug resistance mutation, with impacts ranging from 8% to 69%. Notably, the reduction in RC was significantly greater for CTL escape mutations associated with protective HLA class I alleles than for those associated with nonprotective alleles. To speed the future evaluation of CTL escape costs, we also developed an in silico approach for inferring the relative impact of a mutation on RC based on its computed impact on protein thermodynamic stability. These data illustrate that the magnitude of CTL escape-associated fitness costs, and thus the barrier to CTL escape, varies widely even in the conserved Gag proteins and suggest that differential escape costs may contribute to the relative efficacy of CD8 responses.
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Ganusov VV, Neher RA, Perelson AS. Mathematical modeling of escape of HIV from cytotoxic T lymphocyte responses. JOURNAL OF STATISTICAL MECHANICS (ONLINE) 2013; 2013:P01010. [PMID: 24660019 PMCID: PMC3961578 DOI: 10.1088/1742-5468/2013/01/p01010] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Human immunodeficiency virus (HIV-1 or simply HIV) induces a persistent infection, which in the absence of treatment leads to AIDS and death in almost all infected individuals. HIV infection elicits a vigorous immune response starting about 2-3 weeks post infection that can lower the amount of virus in the body, but which cannot eradicate the virus. How HIV establishes a chronic infection in the face of a strong immune response remains poorly understood. It has been shown that HIV is able to rapidly change its proteins via mutation to evade recognition by virus-specific cytotoxic T lymphocytes (CTLs). Typically, an HIV-infected patient will generate 4-12 CTL responses specific for parts of viral proteins called epitopes. Such CTL responses lead to strong selective pressure to change the viral sequences encoding these epitopes so as to avoid CTL recognition. Indeed, the viral population "escapes" from about half of the CTL responses by mutation in the first year. Here we review experimental data on HIV evolution in response to CTL pressure, mathematical models developed to explain this evolution, and highlight problems associated with the data and previous modeling efforts. We show that estimates of the strength of the epitope-specific CTL response depend on the method used to fit models to experimental data and on the assumptions made regarding how mutants are generated during infection. We illustrate that allowing CTL responses to decay over time may improve the fit to experimental data and provides higher estimates of the killing efficacy of HIV-specific CTLs. We also propose a novel method for simultaneously estimating the killing efficacy of multiple CTL populations specific for different epitopes of HIV using stochastic simulations. Lastly, we show that current estimates of the efficacy at which HIV-specific CTLs clear virus-infected cells can be improved by more frequent sampling of viral sequences and by combining data on sequence evolution with experimentally measured CTL dynamics.
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Affiliation(s)
- Vitaly V Ganusov
- Department of Microbiology, University of Tennessee, Knoxville, TN 37996, USA
| | - Richard A Neher
- Max-Planck-Institute for Developmental Biology, 72070 Tübingen, Germany
| | - Alan S Perelson
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, MS K710 Los Alamos, 87545 NM, USA
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Mouzakis KD, Lang AL, Vander Meulen KA, Easterday PD, Butcher SE. HIV-1 frameshift efficiency is primarily determined by the stability of base pairs positioned at the mRNA entrance channel of the ribosome. Nucleic Acids Res 2012; 41:1901-13. [PMID: 23248007 PMCID: PMC3561942 DOI: 10.1093/nar/gks1254] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The human immunodeficiency virus (HIV) requires a programmed −1 ribosomal frameshift for Pol gene expression. The HIV frameshift site consists of a heptanucleotide slippery sequence (UUUUUUA) followed by a spacer region and a downstream RNA stem–loop structure. Here we investigate the role of the RNA structure in promoting the −1 frameshift. The stem–loop was systematically altered to decouple the contributions of local and overall thermodynamic stability towards frameshift efficiency. No correlation between overall stability and frameshift efficiency is observed. In contrast, there is a strong correlation between frameshift efficiency and the local thermodynamic stability of the first 3–4 bp in the stem–loop, which are predicted to reside at the opening of the mRNA entrance channel when the ribosome is paused at the slippery site. Insertion or deletions in the spacer region appear to correspondingly change the identity of the base pairs encountered 8 nt downstream of the slippery site. Finally, the role of the surrounding genomic secondary structure was investigated and found to have a modest impact on frameshift efficiency, consistent with the hypothesis that the genomic secondary structure attenuates frameshifting by affecting the overall rate of translation.
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Affiliation(s)
- Kathryn D Mouzakis
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
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26
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Temporal association of HLA-B*81:01- and HLA-B*39:10-mediated HIV-1 p24 sequence evolution with disease progression. J Virol 2012; 86:12013-24. [PMID: 22933291 DOI: 10.1128/jvi.00539-12] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
HLA-B*81:01 and HLA-B*39:10 alleles have been associated with viremic control in HIV-1 subtype C infection. Both alleles restrict the TL9 epitope in p24 Gag, and cytotoxic-T-lymphocyte (CTL)-mediated escape mutations in this epitope have been associated with an in vitro fitness cost to the virus. We investigated the timing and impact of mutations in the TL9 epitope on disease progression in five B*81:01- and two B*39:10-positive subtype C-infected individuals. Whereas both B*39:10 participants sampled at 2 months postinfection had viruses with mutations in the TL9 epitope, in three of the five (3/5) B*81:01 participants, TL9 escape mutations were only detected 10 months after infection, taking an additional 10 to 15 months to reach fixation. In the two remaining B*81:01 individuals, one carried a TL9 escape variant at 2 weeks postinfection, whereas no escape mutations were detected in the virus from the other participant for up to 33 months postinfection, despite CTL targeting of the epitope. In all participants, escape mutations in TL9 were linked to coevolving residues in the region of Gag known to be associated with host tropism. Late escape in TL9, together with coevolution of putative compensatory mutations, coincided with a spontaneous increase in viral loads in two individuals who were otherwise controlling the infection. These results provide in vivo evidence of the detrimental impact of B*81:01-mediated viral evolution, in a single Gag p24 epitope, on the control of viremia.
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Abstract
Evolution of RNA viruses occurs through disequilibria of collections of closely related mutant spectra or mutant clouds termed viral quasispecies. Here we review the origin of the quasispecies concept and some biological implications of quasispecies dynamics. Two main aspects are addressed: (i) mutant clouds as reservoirs of phenotypic variants for virus adaptability and (ii) the internal interactions that are established within mutant spectra that render a virus ensemble the unit of selection. The understanding of viruses as quasispecies has led to new antiviral designs, such as lethal mutagenesis, whose aim is to drive viruses toward low fitness values with limited chances of fitness recovery. The impact of quasispecies for three salient human pathogens, human immunodeficiency virus and the hepatitis B and C viruses, is reviewed, with emphasis on antiviral treatment strategies. Finally, extensions of quasispecies to nonviral systems are briefly mentioned to emphasize the broad applicability of quasispecies theory.
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Affiliation(s)
- Esteban Domingo
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), C/ Nicolás Cabrera, Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain.
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Abstract
Viral mutational escape from CD8(+) cytotoxic T lymphocytes (CTLs) is typically considered to be a dichotomous process and uncommon during chronic HIV-1 infection. Ex vivo passaging of HIV-1 from persons with chronic infection, however, revealed the evolution of many fixed substitutions within and around CTL-targeted regions, with an associated increase in replicative capacity. This indicates an evolution of mutations during chronic HIV-1 infection that trade replicative fitness for incomplete evasion of CTLs, or "partial escape."
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Uncommon pathways of immune escape attenuate HIV-1 integrase replication capacity. J Virol 2012; 86:6913-23. [PMID: 22496233 DOI: 10.1128/jvi.07133-11] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An attenuation of the HIV-1 replication capacity (RC) has been observed for immune-mediated escape mutations in Gag restricted by protective HLA alleles. However, the extent to which escape mutations affect other viral proteins during natural infection is not well understood. We generated recombinant viruses encoding plasma HIV-1 RNA integrase sequences from antiretroviral-naïve individuals with early (n = 88) and chronic (n = 304) infections and measured the in vitro RC of each. In contrast to data from previous studies of Gag, we observed little evidence that host HLA allele expression was associated with integrase RC. A modest negative correlation was observed between the number of HLA-B-associated integrase polymorphisms and RC in chronic infection (R = -0.2; P = 0.003); however, this effect was not driven by mutations restricted by protective HLA alleles. Notably, the integrase variants S119R, G163E, and I220L, which represent uncommon polymorphisms associated with HLA-C*05, -A*33, and -B*52, respectively, correlated with lower RC (all q < 0.2). We identified a novel C*05-restricted epitope (HTDNGSNF(114-121)) that likely contributes to the selection of the S119R variant, the polymorphism most significantly associated with lower RC in patient sequences. An NL4-3 mutant encoding the S119R polymorphism displayed a ~35%-reduced function that was rescued by a single compensatory mutation of A91E. Together, these data indicate that substantial HLA-driven attenuation of integrase is not a general phenomenon during HIV-1 adaptation to host immunity. However, uncommon polymorphisms selected by HLA alleles that are not conventionally regarded to be protective may be associated with impaired protein function. Vulnerable epitopes in integrase might therefore be considered for future vaccine strategies.
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Dalmau J, Codoñer FM, Erkizia I, Pino M, Pou C, Paredes R, Clotet B, Martinez-Picado J, Prado JG. In-depth characterization of viral isolates from plasma and cells compared with plasma circulating quasispecies in early HIV-1 infection. PLoS One 2012; 7:e32714. [PMID: 22393441 PMCID: PMC3290612 DOI: 10.1371/journal.pone.0032714] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Accepted: 01/30/2012] [Indexed: 11/20/2022] Open
Abstract
Background The use of in vitro models to unravel the phenotypic characteristics of circulating viral variants is key to understanding HIV-1 pathogenesis but limited by the availability of primary viral isolates from biological samples. However, overall in vivo genetic variability of HIV-1 within a subject may not be reflected in the viable viral population obtained after isolation. Although several studies have tried to determine whether viral populations expanded in vitro are representative of in vivo findings, the answer remains unclear due to the reduced number of clonal sequences analyzed or samples compared. In order to overcome previous experimental limitations, here we applied Deep Pyrosequencing (DPS) technology in combination with phenotypic experiments to analyze and compare with unprecedented detail the composition of viral isolates and in vivo quasispecies. Methodology/Principal Findings We amplified by DPS HIV-1 genomic regions covering gag, protease, integrase and env-V3 to characterize paired isolates from plasma and peripheral blood mononuclear cells and compare them with total plasma viral RNA in four recently HIV-1 infected subjects. Our study demonstrated the presence of unique haplotypes scattered between sample types with conservation of major variants. In addition, no differences in intra- and inter-population encoded protein variability were found between the different types of isolates or when these were compared to plasma viral RNA within subjects. Additionally, in vitro experiments demonstrated phenotypic similarities in terms of replicative capacity and co-receptor usage between viral isolates and plasma viral RNA. Conclusion This study is the first in-depth comparison and characterization of viral isolates from different sources and plasma circulating quasispecies using DPS in recently HIV-1 infected subjects. Our data supports the use of primary isolates regardless of their plasma or cellular origin to define genetic variability and biological traits of circulating HIV-1 quasispecies.
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Affiliation(s)
- Judith Dalmau
- AIDS Research Institute IrsiCaixa, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain
| | - Francisco M. Codoñer
- AIDS Research Institute IrsiCaixa, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain
- Lifesequencing SL, Parc Cientific Universitat de Valencia, Paterna, Valencia, Spain
| | - Itziar Erkizia
- AIDS Research Institute IrsiCaixa, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain
| | - Maria Pino
- AIDS Research Institute IrsiCaixa, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain
| | - Christian Pou
- AIDS Research Institute IrsiCaixa, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain
| | - Roger Paredes
- AIDS Research Institute IrsiCaixa, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain
- Fundació Lluita contra la SIDA, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain
| | - Bonaventura Clotet
- AIDS Research Institute IrsiCaixa, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain
- Fundació Lluita contra la SIDA, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain
| | - Javier Martinez-Picado
- AIDS Research Institute IrsiCaixa, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
- * E-mail: (JMP); (JGP)
| | - Julia G. Prado
- AIDS Research Institute IrsiCaixa, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain
- * E-mail: (JMP); (JGP)
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Goulder PJR, Prendergast AJ. Approaches towards avoiding lifelong antiretroviral therapy in paediatric HIV infection. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 719:25-37. [PMID: 22125032 DOI: 10.1007/978-1-4614-0204-6_3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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32
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Fitness costs and diversity of the cytotoxic T lymphocyte (CTL) response determine the rate of CTL escape during acute and chronic phases of HIV infection. J Virol 2011; 85:10518-28. [PMID: 21835793 DOI: 10.1128/jvi.00655-11] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
HIV-1 often evades cytotoxic T cell (CTL) responses by generating variants that are not recognized by CTLs. We used single-genome amplification and sequencing of complete HIV genomes to identify longitudinal changes in the transmitted/founder virus from the establishment of infection to the viral set point at 1 year after the infection. We found that the rate of viral escape from CTL responses in a given patient decreases dramatically from acute infection to the viral set point. Using a novel mathematical model that tracks the dynamics of viral escape at multiple epitopes, we show that a number of factors could potentially contribute to a slower escape in the chronic phase of infection, such as a decreased magnitude of epitope-specific CTL responses, an increased fitness cost of escape mutations, or an increased diversity of the CTL response. In the model, an increase in the number of epitope-specific CTL responses can reduce the rate of viral escape from a given epitope-specific CTL response, particularly if CD8+ T cells compete for killing of infected cells or control virus replication nonlytically. Our mathematical framework of viral escape from multiple CTL responses can be used to predict the breadth and magnitude of HIV-specific CTL responses that need to be induced by vaccination to reduce (or even prevent) viral escape following HIV infection.
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Chopera DR, Wright JK, Brockman MA, Brumme ZL. Immune-mediated attenuation of HIV-1. Future Virol 2011; 6:917-928. [PMID: 22393332 DOI: 10.2217/fvl.11.68] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Immune escape mutations selected by human leukocyte antigen class I-restricted CD8(+) cytotoxic T lymphocytes (CTLs) can result in biologically and clinically relevant costs to HIV-1 replicative fitness. This phenomenon may be exploited to design an HIV-1 vaccine capable of stimulating effective CTL responses against highly conserved, mutationally constrained viral regions, where immune escape could occur only at substantial functional costs. Such a vaccine might 'channel' HIV-1 evolution towards a less-fit state, thus lowering viral load set points, attenuating the infection course and potentially reducing the risk of transmission. A major barrier to this approach, however, is the accumulation of immune escape variants at the population level, possibly leading to the loss of immunogenic CTL epitopes and diminished vaccine-induced cellular immune responses as the epidemic progresses. Here, we review the evidence supporting CTL-driven replicative defects in HIV-1 and consider the implications of this work for CTL-based vaccines designed to attenuate the infection course.
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Irausquin SJ, Hughes AL. Conflicting selection pressures on T-cell epitopes in HIV-1 subtype B. INFECTION GENETICS AND EVOLUTION 2011; 11:483-8. [PMID: 21232634 DOI: 10.1016/j.meegid.2010.12.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 12/20/2010] [Accepted: 12/23/2010] [Indexed: 12/26/2022]
Abstract
Analysis of population-level polymorphism in eight coding genes of human immunodeficiency virus type 1 (HIV-1) subtype B revealed evidence not only of past purifying selection, but also of abundant slightly deleterious nonsynonymous variants subject to ongoing purifying selection. Both CD4 and CTL epitopes showed an excess of nonsynonymous variants that were singletons (occurring in just one sequence) in our dataset. Overall, median gene diversities at polymorphic nonsynonymous sites were highest at sites located in neither CD4 nor CTL epitopes, while polymorphic nonsynonymous sites in CD4 epitopes revealed the lowest median gene diversity. Our results support the hypothesis that there is an evolutionary conflict between immune escape and functional constraint on epitopes recognized by host T-cells, and suggest that amino acid sequences of CD4 epitopes are subject to particularly strong functional constraint.
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Affiliation(s)
- Stephanie Jiménez Irausquin
- Department of Biological Sciences, University of South Carolina, Coker Life Sciences Building, 700 Sumter St., Columbia, SC 29208, USA
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Verheyen J, Schweitzer F, Harrer EG, Knops E, Mueller SM, Däumer M, Eismann K, Bergmann S, Spriewald BM, Kaiser R, Harrer T. Analysis of immune selection as a potential cause for the presence of cleavage site mutation 431V in treatment-naive HIV type-1 isolates. Antivir Ther 2010; 15:907-12. [PMID: 20834103 DOI: 10.3851/imp1640] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION HIV type-1 (HIV-1) protease (PR) and cleavage site (CS) mutations accumulate in protease-inhibitor-resistant isolates. HIV-1 CS mutation 431V is the most frequent treatment-associated CS mutation; however, little is known about its origin in treatment-naive HIV-1 isolates. Recently, it has been shown that the CS mutation 431V is located within the human leukocyte antigen (HLA)-B*13-restricted cytotoxic T-lymphocyte (CTL) epitope RQANFLGKI (RI9). Therefore, we investigated whether the presence of CS mutation 431V might additionally be related to immune escape. METHODS CTL recognition of RI9 and of RI9 variants carrying the 431V or the 436R mutation was analysed by ELISPOT in nine HLA-B*13-positive HIV-1-infected patients. Treatment-naive HIV-1-infected patients with primary drug-resistant HIV-1 isolates (n=58) or carrying 431V (n=4) were genotyped for HLA class I alleles. RESULTS ELISPOT analysis showed different patterns of CTL recognition of RI9. CS mutation 431V could abrogate recognition by RI9-specific CTL in a subgroup of patients. Nevertheless, in our study, the occurrence of 431V in treatment-naive HIV-1 without primary drug resistance could not be explained by HLA-B*13-mediated immune selection. In patients with primary drug-resistant HIV-1 isolates, the frequency of HLA-B*13 was not increased and HLA-B*13 did not correlate with CS mutations 436R or 431V. CONCLUSIONS HIV-1 CS mutation 431V can abrogate CTL recognition, indicating interactions between development of drug resistance and the CTL response. However, we could not find evidence that the presence of 431V in treatment-naive HIV-1 isolates with and without primary drug resistance is related to immune selection by HLA-B*13 or other HLA class I alleles.
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Affiliation(s)
- Jens Verheyen
- Institute of Virology, University of Cologne, Germany.
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Kadolsky UD, Asquith B. Quantifying the impact of human immunodeficiency virus-1 escape from cytotoxic T-lymphocytes. PLoS Comput Biol 2010; 6:e1000981. [PMID: 21079675 PMCID: PMC2973816 DOI: 10.1371/journal.pcbi.1000981] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2010] [Accepted: 09/28/2010] [Indexed: 11/20/2022] Open
Abstract
HIV-1 escape from the cytotoxic T-lymphocyte (CTL) response leads to a weakening of viral control and is likely to be detrimental to the patient. To date, the impact of escape on viral load and CD4+ T cell count has not been quantified, primarily because of sparse longitudinal data and the difficulty of separating cause and effect in cross-sectional studies. We use two independent methods to quantify the impact of HIV-1 escape from CTLs in chronic infection: mathematical modelling of escape and statistical analysis of a cross-sectional cohort. Mathematical modelling revealed a modest increase in log viral load of 0.051 copies ml−1 per escape event. Analysis of the cross-sectional cohort revealed a significant positive association between viral load and the number of “escape events”, after correcting for length of infection and rate of replication. We estimate that a single CTL escape event leads to a viral load increase of 0.11 log copies ml−1 (95% confidence interval: 0.040–0.18), consistent with the predictions from the mathematical modelling. Overall, the number of escape events could only account for approximately 6% of the viral load variation in the cohort. Our findings indicate that although the loss of the CTL response for a single epitope results in a highly statistically significant increase in viral load, the biological impact is modest. We suggest that this small increase in viral load is explained by the small growth advantage of the variant relative to the wildtype virus. Escape from CTLs had a measurable, but unexpectedly low, impact on viral load in chronic infection. HIV, like many viruses, has evolved multiple strategies to evade immune surveillance. One of these strategies is the evolution of escape mutations which reduce the ability of the immune response to kill HIV-infected cells. But does HIV escape matter? Some believe that the accumulation of escape mutations leads to AIDS; many more believe escape is likely to be highly detrimental to human health. Yet, to date, it has not been possible to measure the impact of escape. We developed two independent methods to quantify the impact of escape on HIV viral load. Both methods showed that escape does lead to a detectable increase in viral load, but is unlikely to have a major impact on patient health as the increase is small. Indeed, only 6% of between-individual variation in viral load could be attributed to HIV escape. This work suggests that the current research focus on escape in chronic HIV infection might be out of proportion to its importance with other factors playing a more significant role in determining viral load.
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Affiliation(s)
- Ulrich D Kadolsky
- Department of Immunology, Division of Medicine, Imperial College London, London, United Kingdom.
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Early selection in Gag by protective HLA alleles contributes to reduced HIV-1 replication capacity that may be largely compensated for in chronic infection. J Virol 2010; 84:11937-49. [PMID: 20810731 DOI: 10.1128/jvi.01086-10] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Mutations that allow escape from CD8 T-cell responses are common in HIV-1 and may attenuate pathogenesis by reducing viral fitness. While this has been demonstrated for individual cases, a systematic investigation of the consequence of HLA class I-mediated selection on HIV-1 in vitro replication capacity (RC) has not been undertaken. We examined this question by generating recombinant viruses expressing plasma HIV-1 RNA-derived Gag-Protease sequences from 66 acute/early and 803 chronic untreated subtype B-infected individuals in an NL4-3 background and measuring their RCs using a green fluorescent protein (GFP) reporter CD4 T-cell assay. In acute/early infection, viruses derived from individuals expressing the protective alleles HLA-B*57, -B*5801, and/or -B*13 displayed significantly lower RCs than did viruses from individuals lacking these alleles (P < 0.05). Furthermore, acute/early RC inversely correlated with the presence of HLA-B-associated Gag polymorphisms (R = -0.27; P = 0.03), suggesting a cumulative effect of primary escape mutations on fitness during the first months of infection. At the chronic stage of infection, no strong correlations were observed between RC and protective HLA-B alleles or with the presence of HLA-B-associated polymorphisms restricted by protective alleles despite increased statistical power to detect these associations. However, RC correlated positively with the presence of known compensatory mutations in chronic viruses from B*57-expressing individuals harboring the Gag T242N mutation (n = 50; R = 0.36; P = 0.01), suggesting that the rescue of fitness defects occurred through mutations at secondary sites. Additional mutations in Gag that may modulate the impact of the T242N mutation on RC were identified. A modest inverse correlation was observed between RC and CD4 cell count in chronic infection (R = -0.17; P < 0.0001), suggesting that Gag-Protease RC could increase over the disease course. Notably, this association was stronger for individuals who expressed B*57, B*58, or B*13 (R = -0.27; P = 0.004). Taken together, these data indicate that certain protective HLA alleles contribute to early defects in HIV-1 fitness through the selection of detrimental mutations in Gag; however, these effects wane as compensatory mutations accumulate in chronic infection. The long-term control of HIV-1 in some persons who express protective alleles suggests that early fitness hits may provide lasting benefits.
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HLA-Cw*03-restricted CD8+ T-cell responses targeting the HIV-1 gag major homology region drive virus immune escape and fitness constraints compensated for by intracodon variation. J Virol 2010; 84:11279-88. [PMID: 20739527 DOI: 10.1128/jvi.01144-10] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The potential importance of HLA-C-restricted CD8+ cytotoxic T lymphocytes (CTL) in HIV infection remains undetermined. We studied the dominant HLA-Cw*03-restricted CTL response to YVDRFFKTL(296-304) (YL9), within the conserved major homology region (MHR) of the Gag protein, in 80 HLA-Cw*03-positive individuals with chronic HIV infection to better define the efficacy of the YL9 HLA-C-restricted response. The HLA-Cw*03 allele is strongly associated with HIV sequence changes from Thr-303 to Val, Ile, or Ala at position 8 within the YL9 epitope (P=1.62×10(-10)). In vitro studies revealed that introduction of the changes T303I and T303A into the YL9 epitope both significantly reduced CTL recognition and substantially reduced the viral replicative capacity. However, subsequent selection of the Val-303 variant, via intracodon variation from Ile-303 (I303V) or Ala-303 (A303V), restored both viral fitness and CTL recognition, as supported by our in vivo data. These results illustrate that HLA-C-restricted CTL responses are capable of driving viral immune escape within Gag, but in contrast to what was previously described for HLA-B-restricted Gag escape mutants, the common Cw*03-Gag-303V variant selected resulted in no detectable benefit to the host.
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Efficacious early antiviral activity of HIV Gag- and Pol-specific HLA-B 2705-restricted CD8+ T cells. J Virol 2010; 84:10543-57. [PMID: 20686036 DOI: 10.1128/jvi.00793-10] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The association between HLA-B 2705 and the immune control of human immunodeficiency virus type 1 (HIV-1) has previously been linked to the targeting of the HLA-B 2705-restricted Gag epitope KRWIILGLNK (KK10) by CD8(+) T cells. In order to better define the mechanisms of the HLA-B 2705 immune control of HIV, we first characterized the CD8(+) T-cell responses of nine highly active antiretroviral therapy (HAART)-naïve B 2705-positive subjects. Unexpectedly, we observed a strong response to an HLA-B 2705-restricted Pol epitope, KRKGGIGGY (KY9), in 8/9 subjects. The magnitude of the KY9 response was only marginally lower than that of the KK10-specific response (median, 695 versus 867 spot-forming cells [SFC]/million peripheral blood mononuclear cells [PBMCs]; not significant [NS]), and viral escape mutants were observed in both KY9 and KK10, resulting from selection pressure driven by the respective CD8(+) T-cell response. By comparing inhibitions of viral replication by CD8(+) T cells specific for the Gag KK10, Pol KY9, and Vpr VL9 HLA-B 2705-restricted epitopes, we observed a consistent hierarchy of antiviral efficacy (Gag KK10 > Pol KY9 > Vpr VL9). This hierarchy was associated with early recognition of HIV-1-infected cells, within 6 h of infection, by KK10- and KY9-specific CD8(+) T cells but not until 18 h postinfection by VL9-specific CD8(+) T cells. There was no association between antiviral efficacy and proliferative capacity, cytotoxicity, polyfunctionality, or T-cell receptor (TCR) avidity. These data are consistent with previous studies indicating an important role for the B 2705-Gag KK10 response in the control of HIV but also suggest a previously unrecognized role played by the subdominant Pol-specific KY9 response in HLA-B 2705-mediated control of HIV and that the recognition of HIV-infected cells by CD8(+) T cells early in the viral life cycle may be important for viral containment in HIV-infected individuals.
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Tang J, Malhotra R, Song W, Brill I, Hu L, Farmer PK, Mulenga J, Allen S, Hunter E, Kaslow RA. Human leukocyte antigens and HIV type 1 viral load in early and chronic infection: predominance of evolving relationships. PLoS One 2010; 5:e9629. [PMID: 20224785 PMCID: PMC2835758 DOI: 10.1371/journal.pone.0009629] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Accepted: 02/18/2010] [Indexed: 11/18/2022] Open
Abstract
Background During untreated, chronic HIV-1 infection, plasma viral load (VL) is a relatively stable quantitative trait that has clinical and epidemiological implications. Immunogenetic research has established various human genetic factors, especially human leukocyte antigen (HLA) variants, as independent determinants of VL set-point. Methodology/Principal Findings To identify and clarify HLA alleles that are associated with either transient or durable immune control of HIV-1 infection, we evaluated the relationships of HLA class I and class II alleles with VL among 563 seroprevalent Zambians (SPs) who were seropositive at enrollment and 221 seroconverters (SCs) who became seropositive during quarterly follow-up visits. After statistical adjustments for non-genetic factors (sex and age), two unfavorable alleles (A*3601 and DRB1*0102) were independently associated with high VL in SPs (p<0.01) but not in SCs. In contrast, favorable HLA variants, mainly A*74, B*13, B*57 (or Cw*18), and one HLA-A and HLA-C combination (A*30+Cw*03), dominated in SCs; their independent associations with low VL were reflected in regression beta estimates that ranged from −0.47±0.23 to −0.92±0.32 log10 in SCs (p<0.05). Except for Cw*18, all favorable variants had diminishing or vanishing association with VL in SPs (p≤0.86). Conclusions/Significance Overall, each of the three HLA class I genes had at least one allele that might contribute to effective immune control, especially during the early course of HIV-1 infection. These observations can provide a useful framework for ongoing analyses of viral mutations induced by protective immune responses.
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Affiliation(s)
- Jianming Tang
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America.
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Replicative capacity of human immunodeficiency virus type 1 transmitted from mother to child is associated with pediatric disease progression rate. J Virol 2010; 84:492-502. [PMID: 19828603 DOI: 10.1128/jvi.01743-09] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human immunodeficiency virus (HIV)-infected infants in the developing world typically progress to AIDS or death within the first 2 years of life. However, a minority progress relatively slowly. This study addresses the potential contribution of viral factors to HIV disease progression in eight infants selected from a well-characterized cohort of C clade HIV-infected infants, monitored prospectively from birth in Durban, South Africa. Three infants were defined as "progressors," and five were defined as "slow progressors." We observed that slow-progressor infants carry HIV isolates with significantly lower replicative capacity compared to virus from progressors. Furthermore, our data suggest a link between the attenuated viral phenotype and HLA-B* 57/5801 epitope-specific Gag mutational patterns of the transmitted virus and not to coreceptor usage or to the presence of Nef deletions or insertions. These data underline the importance of virus-host interactions and highlight the contribution of viral attenuation through Gag-specific CD8(+) T-cell escape mutations, among other factors, in the control of pediatric HIV infection.
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Sung FY, Jung CM, Wu CF, Lin CL, Liu CJ, Liaw YF, Tsai KS, Yu MW. Hepatitis B virus core variants modify natural course of viral infection and hepatocellular carcinoma progression. Gastroenterology 2009; 137:1687-97. [PMID: 19664630 DOI: 10.1053/j.gastro.2009.07.063] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Revised: 06/11/2009] [Accepted: 07/23/2009] [Indexed: 12/26/2022]
Abstract
BACKGROUND & AIMS We assessed the influence of genetic variants in the hepatitis B virus (HBV) core, which is a principal immunologic target, on the progression to hepatocellular carcinoma (HCC) in a cohort of 4841 male HBV carriers followed up for 16 years. METHODS First, baseline sera from 116 HCC cases and 154 controls nested within the cohort were used for sequencing of the HBV core gene to screen for variants with effects on HCC progression. By applying a high-throughput assay for detecting viral single nucleotide substitutions, we then used a longitudinal study (n = 1143) to examine whether 2 identified variants that lie in the region within or flanking epitopes affected the natural course of hepatitis B through investigating their relationships with time trends for viral load and clinical features. RESULTS In the nested case-control study, there were 6 core variants associated with decreased risk of HCC after accounting for viral genotype; 5 lie in the region within or flanking epitopes (P < .04). Each variant correlated with a 0.7- to 1-log decrease in viral load and hepatitis B virus e antigen negativity at baseline. The longitudinal study further showed that the appearance of 2 such variants (T1938C and T2045A) was preceded by long-term diminished viral load and decreased rate of liver abnormalities and was significantly less frequent in individuals with a prolonged immune clearance phase that associated with spectrum of liver disease than those in inactive carrier or reactivation phase. CONCLUSIONS HBV core variants affecting the kinetics of host-virus interplay may influence longitudinal viral load and HCC progression.
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Affiliation(s)
- Feng-Yu Sung
- Graduate Institute of Epidemiology, College of Public Health, National Taiwan University, Taipei, Taiwan
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Multiple T-cell epitopes overlap positively-selected residues in the p1 spacer protein of HIV-1 gag. AIDS 2009; 23:771-7. [PMID: 19287301 DOI: 10.1097/qad.0b013e32832995e0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVES The p1 region of HIV-1 gag contains the frameshift stem-loop, gag-pol transframe and a protease cleavage site that are crucial for viral assembly, replication and infectivity. Identifying and characterizing CD8+ epitopes that are under host immune selection in this region will help in designing effective vaccines for HIV-1. DESIGN An approach combining bioinformatical analysis and interferon gamma enzyme-linked immunosorbent spot (ELISPOT) assays is used to identify and characterize the epitopes. Potential human leukocyte antigen (HLA)-restricted epitopes were identified by correlating the positively-selected mutations with host HLA alleles. METHODS ELISPOT analysis with overlapping peptides was used to confirm and characterize the epitopes. RESULTS Four positively-selected residues were significantly associated with HLA class I alleles, including HLA B*1302 (K4R, P = 0.0008 and I5L, P = 0.0108), A*7401 (S9N, P = 0.0002) and A*30 genotypes (P7S, P = 0.009), suggesting epitopes restricted by these alleles are present in this region. ELISPOT analysis with patient peripheral blood mononuclear cells (PBMCs) identified seven novel epitopes restricted by the 3 alleles. Two types of epitopes were observed in this region based on the ELISPOT responses, Type I: the positively-selected variation does not affect CD8+ T-cell responses; and Type II: the CD8+ T-cell responses are determined by the epitope variants. CONCLUSION We identified and characterized seven novel CD8+ epitopes in the p1 spacer protein region. Classifying the effects of positively-selected variants on CD8+ T-cell responses will help in designing effective vaccines for HIV-1.
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