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Chikata T, Gatanaga H, Nguyen HT, Mizushima D, Zhang Y, Kuse N, Oka S, Takiguchi M. HIV-1 protective epitope-specific CD8 + T cells in HIV-1-exposed seronegative individuals. iScience 2023; 26:108089. [PMID: 37867946 PMCID: PMC10589889 DOI: 10.1016/j.isci.2023.108089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 08/08/2023] [Accepted: 09/26/2023] [Indexed: 10/24/2023] Open
Abstract
Although previous studies have reported HIV-1-specific T cell responses in HIV-1-exposed seronegative (HESN) individuals, there has been no detailed analysis of these T cells against HIV-1 infection. We investigated HIV-1-specific CD8+ T cell responses in 200 Japanese HESN men who have sex with men (MSM). T cell responses to 143 well-characterized HIV-1 epitope peptides were analyzed by intracellular cytokine staining assay consisting of 3-week cultures of PBMCs stimulated with peptides. HLA-B∗51:01-restricted Pol TI8-specific and HLA-A∗02:06-restricted Pol SV9-specific CD8+ T cells were identified in two and one individuals, respectively, whereas CD8+ T cells specific for other HLA-A∗02:06-restricted or HLA-B∗51:01 epitopes were not present in these individuals. These epitope-specific T cells recognized HIV-1-infected cells. Because these two epitopes were previously reported to be protective in HIV-1-infected individuals, these protective epitope-specific T cells might suppress HIV-1 replication in HESN-MSM individuals. The present study suggests the contribution of protective epitope-specific T cells to protection against HIV-1 infection.
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Affiliation(s)
- Takayuki Chikata
- Tokyo Laboratory and Division of International Collaboration Research, Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto 162-0052, Japan
| | - Hiroyuki Gatanaga
- AIDS Clinical Center, National Center for Global Health and Medicine, Shinjuku, Tokyo 162-8655, Japan
| | - Hung The Nguyen
- Tokyo Laboratory and Division of International Collaboration Research, Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto 162-0052, Japan
| | - Daisuke Mizushima
- AIDS Clinical Center, National Center for Global Health and Medicine, Shinjuku, Tokyo 162-8655, Japan
| | - Yu Zhang
- Tokyo Laboratory and Division of International Collaboration Research, Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto 162-0052, Japan
| | - Nozomi Kuse
- Tokyo Laboratory and Division of International Collaboration Research, Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto 162-0052, Japan
| | - Shinichi Oka
- AIDS Clinical Center, National Center for Global Health and Medicine, Shinjuku, Tokyo 162-8655, Japan
| | - Masafumi Takiguchi
- Tokyo Laboratory and Division of International Collaboration Research, Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto 162-0052, Japan
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2
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Hokello J, Tyagi P, Dimri S, Sharma AL, Tyagi M. Comparison of the Biological Basis for Non-HIV Transmission to HIV-Exposed Seronegative Individuals, Disease Non-Progression in HIV Long-Term Non-Progressors and Elite Controllers. Viruses 2023; 15:1362. [PMID: 37376660 DOI: 10.3390/v15061362] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 06/08/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
HIV-exposed seronegative individuals (HESIs) are a small fraction of persons who are multiply exposed to human immunodeficiency virus (HIV), but do not exhibit serological or clinical evidence of HIV infection. In other words, they are groups of people maintaining an uninfected status for a long time, even after being exposed to HIV several times. The long-term non-progressors (LTNPs), on the other hand, are a group of HIV-infected individuals (approx. 5%) who remain clinically and immunologically stable for an extended number of years without combination antiretroviral therapy (cART). Meanwhile, elite controllers are comprise a much lower number (0.5%) of HIV-infected persons who spontaneously and durably control viremia to below levels of detection for at least 12 months, even when using the most sensitive assays, such as polymerase chain reaction (PCR) in the absence of cART. Despite the fact that there is no universal agreement regarding the mechanisms by which these groups of individuals are able to control HIV infection and/or disease progression, there is a general consensus that the mechanisms of protection are multifaceted and include genetic, immunological as well as viral factors. In this review, we analyze and compare the biological factors responsible for the control of HIV in these unique groups of individuals.
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Affiliation(s)
- Joseph Hokello
- Department of Biology, Faculty of Science and Education, Busitema University, Tororo P.O. Box 236, Uganda
| | - Priya Tyagi
- Cherry Hill East High School, 1750 Kresson Rd, Cherry Hill, NJ 08003, USA
| | - Shelly Dimri
- George C. Marshall High School, Fairfax County Public Schools, 7731 Leesburg Pike, Falls Church, VA 22043, USA
| | | | - Mudit Tyagi
- Center for Translational Medicine, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
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3
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Can T Cells Abort SARS-CoV-2 and Other Viral Infections? Int J Mol Sci 2023; 24:ijms24054371. [PMID: 36901802 PMCID: PMC10002440 DOI: 10.3390/ijms24054371] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/14/2023] [Accepted: 02/20/2023] [Indexed: 02/25/2023] Open
Abstract
Despite the highly infectious nature of the SARS-CoV-2 virus, it is clear that some individuals with potential exposure, or even experimental challenge with the virus, resist developing a detectable infection. While a proportion of seronegative individuals will have completely avoided exposure to the virus, a growing body of evidence suggests a subset of individuals are exposed, but mediate rapid viral clearance before the infection is detected by PCR or seroconversion. This type of "abortive" infection likely represents a dead-end in transmission and precludes the possibility for development of disease. It is, therefore, a desirable outcome on exposure and a setting in which highly effective immunity can be studied. Here, we describe how early sampling of a new pandemic virus using sensitive immunoassays and a novel transcriptomic signature can identify abortive infections. Despite the challenges in identifying abortive infections, we highlight diverse lines of evidence supporting their occurrence. In particular, expansion of virus-specific T cells in seronegative individuals suggests abortive infections occur not only after exposure to SARS-CoV-2, but for other coronaviridae, and diverse viral infections of global health importance (e.g., HIV, HCV, HBV). We discuss unanswered questions related to abortive infection, such as: 'Are we just missing antibodies? Are T cells an epiphenomenon? What is the influence of the dose of viral inoculum?' Finally, we argue for a refinement of the current paradigm that T cells are only involved in clearing established infection; instead, we emphasise the importance of considering their role in terminating early viral replication by studying abortive infections.
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Al-kolla R, Grifoni A, Crotty S, Sette A, Gianella S, Dan J. Design and validation of HIV peptide pools for detection of HIV-specific CD4+ and CD8+ T cells. PLoS One 2022; 17:e0268370. [PMID: 35972938 PMCID: PMC9380920 DOI: 10.1371/journal.pone.0268370] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 08/01/2022] [Indexed: 11/18/2022] Open
Abstract
Reagents to monitor T cell responses to the entire HIV genome, based on well characterized epitopes, are missing. Evaluation of HIV-specific T cell responses is of importance to study natural infection, and therapeutic and vaccine interventions. Experimentally derived CD4+ and CD8+ HIV epitopes from the HIV molecular immunology database were developed into Class I and Class II HIV megapools (MPs). We assessed HIV responses in persons with HIV pre antiretroviral therapy (ART) (n = 17) and post-ART (n = 18) and compared these responses to 15 controls without HIV (matched by sex at birth, age, and ethnicity). Using the Activation Induced Marker (AIM) assay, we quantified HIV-specific total CD4+, memory CD4+, circulating T follicular helper, total CD8+ and memory CD8+ T cells. We also compared the Class I and Class II HIV MPs to commercially available HIV gag peptide pools. Overall, HIV Class II MP detected HIV-specific CD4+ T cells in 21/35 (60%) HIV positive samples and 0/15 HIV negative samples. HIV Class I MP detected an HIV-specific CD8+ T cells in 17/35 (48.6%) HIV positive samples and 0/15 HIV negative samples. Our innovative HIV MPs are reflective of the entire HIV genome, and its performance is comparable to other commercially available peptide pools. Here, we detected HIV-specific CD4+ and CD8+ T cell responses in people on and off ART, but not in people without HIV.
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Affiliation(s)
- Rita Al-kolla
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, California, United States of America
| | - Alba Grifoni
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, California, United States of America
| | - Shane Crotty
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, California, United States of America
- Division of Infectious Diseases and Global Public Health, Department of Medicine, University of California, San Diego, La Jolla, California, United States of America
- Consortium for HIV/AIDS Vaccine Development (CHAVD), The Scripps Research Institute, La Jolla, CA, United States of America
| | - Alessandro Sette
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, California, United States of America
- Division of Infectious Diseases and Global Public Health, Department of Medicine, University of California, San Diego, La Jolla, California, United States of America
| | - Sara Gianella
- Division of Infectious Diseases and Global Public Health, Department of Medicine, University of California, San Diego, La Jolla, California, United States of America
| | - Jennifer Dan
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, California, United States of America
- Division of Infectious Diseases and Global Public Health, Department of Medicine, University of California, San Diego, La Jolla, California, United States of America
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5
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Elias G, Meysman P, Bartholomeus E, De Neuter N, Keersmaekers N, Suls A, Jansens H, Souquette A, De Reu H, Emonds MP, Smits E, Lion E, Thomas PG, Mortier G, Van Damme P, Beutels P, Laukens K, Van Tendeloo V, Ogunjimi B. Preexisting memory CD4 T cells in naïve individuals confer robust immunity upon hepatitis B vaccination. eLife 2022; 11:68388. [PMID: 35074048 PMCID: PMC8824481 DOI: 10.7554/elife.68388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 01/07/2022] [Indexed: 11/22/2022] Open
Abstract
Antigen recognition through the T cell receptor (TCR) αβ heterodimer is one of the primary determinants of the adaptive immune response. Vaccines activate naïve T cells with high specificity to expand and differentiate into memory T cells. However, antigen-specific memory CD4 T cells exist in unexposed antigen-naïve hosts. In this study, we use high-throughput sequencing of memory CD4 TCRβ repertoire and machine learning to show that individuals with preexisting vaccine-reactive memory CD4 T cell clonotypes elicited earlier and higher antibody titers and mounted a more robust CD4 T cell response to hepatitis B vaccine. In addition, integration of TCRβ sequence patterns into a hepatitis B epitope-specific annotation model can predict which individuals will have an early and more vigorous vaccine-elicited immunity. Thus, the presence of preexisting memory T cell clonotypes has a significant impact on immunity and can be used to predict immune responses to vaccination. Immune cells called CD4 T cells help the body build immunity to infections caused by bacteria and viruses, or after vaccination. Receptor proteins on the outside of the cells recognize pathogens, foreign molecules called antigens, or vaccine antigens. Vaccine antigens are usually inactivated bacteria or viruses, or fragments of these pathogens. After recognizing an antigen, CD4 T cells develop into memory CD4 T cells ready to defend against future infections with the pathogen. People who have never been exposed to a pathogen, or have never been vaccinated against it, may nevertheless have preexisting memory cells ready to defend against it. This happens because CD4 T cells can recognize multiple targets, which enables the immune system to be ready to defend against both new and familiar pathogens. Elias, Meysman, Bartholomeus et al. wanted to find out whether having preexisting memory CD4 T cells confers an advantage for vaccine-induced immunity. Thirty-four people who were never exposed to hepatitis B or vaccinated against it participated in the study. These individuals provided blood samples before vaccination, with 2 doses of the hepatitis B vaccine, and at 3 time points afterward. Using next generation immune sequencing and machine learning techniques, Elias et al. analyzed the individuals’ memory CD4 T cells before and after vaccination. The experiments showed that preexisting memory CD4 T cells may determine vaccination outcomes, and people with more preexisting memory cells develop quicker and stronger immunity after vaccination against hepatitis B. This information may help scientists to better understand how people develop immunity to pathogens. It may guide them develop better vaccines or predict who will develop immunity after vaccination.
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Affiliation(s)
- George Elias
- Laboratory of Experimental Hematology (LEH), University of Antwerp
| | - Pieter Meysman
- Biomedical Informatics Research Network Antwerp, Department of Mathematics and Informatics, University of Antwerp
| | | | - Nicolas De Neuter
- Antwerp Unit for Data Analysis and Computation in Immunology and Sequencing, University of Antwerp
| | - Nina Keersmaekers
- Centre for Health Economics Research & Modeling Infectious Diseases, University of Antwerp
| | - Arvid Suls
- Antwerp Unit for Data Analysis and Computation in Immunology and Sequencing, University of Antwerp
| | - Hilde Jansens
- Department of Clinical Microbiology, Antwerp University Hospital
| | - Aisha Souquette
- Department of Immunology, St. Jude Children's Research Hospital
| | - Hans De Reu
- Laboratory of Experimental Hematology, University of Antwerp
| | | | - Evelien Smits
- Laboratory of Experimental Hematology, University of Antwerp
| | - Eva Lion
- Laboratory of Experimental Hematology, University of Antwerp
| | - Paul G Thomas
- Department of Immunology, St. Jude Children's Research Hospital
| | - Geert Mortier
- Antwerp Unit for Data Analysis and Computation in Immunology and Sequencing, University of Antwerp
| | - Pierre Van Damme
- Antwerp Unit for Data Analysis and Computation in Immunology and Sequencing, University of Antwerp
| | - Philippe Beutels
- Antwerp Unit for Data Analysis and Computation in Immunology and Sequencing, University of Antwerp
| | - Kris Laukens
- Antwerp Unit for Data Analysis and Computation in Immunology and Sequencing, University of Antwerp
| | - Viggo Van Tendeloo
- Janssen Research and Development, Immunosciences WWDA, Johnson and Johnson
| | - Benson Ogunjimi
- Antwerp Unit for Data Analysis and Computation in Immunology and Sequencing, University of Antwerp
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6
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Campion SL, Brenna E, Thomson E, Fischer W, Ladell K, McLaren JE, Price DA, Frahm N, McElrath JM, Cohen KW, Maenza JR, Walsh SR, Baden LR, Haynes BF, Korber B, Borrow P, McMichael AJ. Preexisting memory CD4+ T cells contribute to the primary response in an HIV-1 vaccine trial. J Clin Invest 2021; 131:e150823. [PMID: 34850742 PMCID: PMC8631594 DOI: 10.1172/jci150823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 10/07/2021] [Indexed: 11/17/2022] Open
Abstract
Naive and memory CD4+ T cells reactive with human immunodeficiency virus type 1 (HIV-1) are detectable in unexposed, unimmunized individuals. The contribution of preexisting CD4+ T cells to a primary immune response was investigated in 20 HIV-1-seronegative volunteers vaccinated with an HIV-1 envelope (Env) plasmid DNA prime and recombinant modified vaccinia virus Ankara (MVA) boost in the HVTN 106 vaccine trial (clinicaltrials.gov NCT02296541). Prevaccination naive or memory CD4+ T cell responses directed against peptide epitopes in Env were identified in 14 individuals. After priming with DNA, 40% (8/20) of the elicited responses matched epitopes detected in the corresponding preimmunization memory repertoires, and clonotypes were shared before and after vaccination in 2 representative volunteers. In contrast, there were no shared epitope specificities between the preimmunization memory compartment and responses detected after boosting with recombinant MVA expressing a heterologous Env. Preexisting memory CD4+ T cells therefore shape the early immune response to vaccination with a previously unencountered HIV-1 antigen.
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Affiliation(s)
- Suzanne L. Campion
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Elena Brenna
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Elaine Thomson
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Will Fischer
- Los Alamos National Laboratory, Santa Fe, New Mexico, USA
| | | | | | - David A. Price
- Division of Infection and Immunity and
- Systems Immunity Research Institute, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Nicole Frahm
- Bill & Melinda Gates Medical Research Institute, Cambridge, Massachusetts, USA
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Juliana M. McElrath
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Kristen W. Cohen
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Janine R. Maenza
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Stephen R. Walsh
- Department of Medicine, Division of Infectious Diseases, Brigham and Women’s Hospital, Boston, Massachusetts, USA
| | - Lindsey R. Baden
- Department of Medicine, Division of Infectious Diseases, Brigham and Women’s Hospital, Boston, Massachusetts, USA
| | - Barton F. Haynes
- Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Bette Korber
- Los Alamos National Laboratory, Santa Fe, New Mexico, USA
| | - Persephone Borrow
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Andrew J. McMichael
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
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7
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Munusamy Ponnan S, Thiruvengadam K, Kathirvel S, Shankar J, Rajaraman A, Mathaiyan M, Dinesha TR, Poongulali S, Saravanan S, Murugavel KG, Swaminathan S, Tripathy SP, Neogi U, Velu V, Hanna LE. Elevated Numbers of HIV-Specific Poly-Functional CD8 + T Cells With Stem Cell-Like and Follicular Homing Phenotypes in HIV-Exposed Seronegative Individuals. Front Immunol 2021; 12:638144. [PMID: 33889151 PMCID: PMC8056154 DOI: 10.3389/fimmu.2021.638144] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Accepted: 02/12/2021] [Indexed: 01/08/2023] Open
Abstract
HIV-specific CD8+ T cells are known to play a key role in viral control during acute and chronic HIV infection. Although many studies have demonstrated the importance of HIV-specific CD8+ T cells in viral control, its correlation with protection against HIV infection remains incompletely understood. To better understand the nature of the immune response that contributes to the early control of HIV infection, we analyzed the phenotype, distribution and function of anti-viral CD8+ T cells in a cohort of HIV-exposed seronegative (HESN) women, and compared them with healthy controls and HIV-infected individuals. Further, we evaluated the in vitro viral inhibition activity of CD8+ T cells against diverse HIV-1 strains. We found that the HESN group had significantly higher levels of CD8+ T cells that express T-stem cell-like (TSCM) and follicular homing (CXCR5+) phenotype with more effector like characteristics as compared to healthy controls. Further, we observed that the HESN population had a higher frequency of HIV-specific poly-functional CD8+ T cells with robust in vitro virus inhibiting capacity against different clades of HIV. Overall, our results demonstrate that the HESN population has elevated levels of HIV-specific poly-functional CD8+ T cells with robust virus inhibiting ability and express elevated levels of markers pertaining to TSCM and follicular homing phenotype. These results demonstrate that future vaccine and therapeutic strategies should focus on eliciting these critical CD8+ T cell subsets.
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Affiliation(s)
- Sivasankaran Munusamy Ponnan
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India.,Centre for Infectious Disease Research, Indian Institute of Science (IISc), Bangalore, India
| | - Kannan Thiruvengadam
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - Sujitha Kathirvel
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - Janani Shankar
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - Akshaya Rajaraman
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - Manikannan Mathaiyan
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | | | - Selvamuthu Poongulali
- Chennai Antiviral Research and Treatment Centre and Clinical Research Site (CART CRS), Infectious Diseases Medical Center, Voluntary Health Services (VHS), Chennai, India
| | | | | | - Soumya Swaminathan
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - Srikanth Prasad Tripathy
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - Ujjwal Neogi
- Division of Clinical Microbiology, Karolinska Institute, Stockholm, Sweden
| | - Vijayakumar Velu
- Division of Microbiology and Immunology, Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States.,Department of Pathology and Laboratory Medicine, Emory School of Medicine, Emory University, Atlanta, GA, United States
| | - Luke Elizabeth Hanna
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
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Agrawal B. Heterologous Immunity: Role in Natural and Vaccine-Induced Resistance to Infections. Front Immunol 2019; 10:2631. [PMID: 31781118 PMCID: PMC6856678 DOI: 10.3389/fimmu.2019.02631] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 10/23/2019] [Indexed: 12/11/2022] Open
Abstract
The central paradigm of vaccination is to generate resistance to infection by a specific pathogen when the vacinee is re-exposed to that pathogen. This paradigm is based on two fundamental characteristics of the adaptive immune system, specificity and memory. These characteristics come from the clonal specificity of T and B cells and the long-term survival of previously-encountered memory cells which can rapidly and specifically expand upon re-exposure to the same specific antigen. However, there is an increasing awareness of the concept, as well as experimental documentation of, heterologous immunity and cross-reactivity of adaptive immune lymphocytes in protection from infection. This awareness is supported by a number of human epidemiological studies in vaccine recipients and/or individuals naturally-resistant to certain infections, as well as studies in mouse models of infections, and indeed theoretical considerations regarding the disproportional repertoire of available T and B cell clonotypes compared to antigenic epitopes found on pathogens. Heterologous immunity can broaden the protective outcomes of vaccinations, and natural resistance to infections. Besides exogenous microbes/pathogens and/or vaccines, endogenous microbiota can also impact the outcomes of an infection and/or vaccination through heterologous immunity. Moreover, utilization of viral and/or bacterial vaccine vectors, capable of inducing heterologous immunity may also influence the natural course of many infections/diseases. This review article will briefly discuss these implications and redress the central dogma of specificity in the immune system.
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Affiliation(s)
- Babita Agrawal
- Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
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9
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Salwe S, Singh A, Padwal V, Velhal S, Nagar V, Patil P, Deshpande A, Patel V. Immune signatures for HIV-1 and HIV-2 induced CD4 +T cell dysregulation in an Indian cohort. BMC Infect Dis 2019; 19:135. [PMID: 30744575 PMCID: PMC6371624 DOI: 10.1186/s12879-019-3743-7] [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: 07/04/2018] [Accepted: 01/25/2019] [Indexed: 01/19/2023] Open
Abstract
Background HIV-2 infection is characterised by a longer asymptomatic phase and slower AIDS progression than HIV-1 infection. Identifying unique immune signatures associated with HIV-2 pathogenesis may thus provide therapeutically useful insight into the management of HIV infection. This study examined the dynamics of the CD4+T cell compartment, critical in disease progression, focussing on chronic HIV-2 and HIV-1 infected individuals at various stages of disease progression. Methods A total of 111 participants including untreated and treated HIV infected individuals and seronegative individuals were enrolled in this study. The relative proportion of CD4+T cell subsets, expressing CD25 (IL-2Rα) and CD127 (IL-7R), in HIV infected individuals and seronegative controls were assessed by multiparametric flow cytometry. Additionally, levels of immune activation and cytotoxic T lymphocytes in both the CD4+T and CD8+T cell compartments was evaluated. Results Both treated and untreated, HIV-1 and HIV-2 infected individuals showed apparent dysregulation in CD4+ T cell subset frequency that was associated with disease progression. Furthermore, longitudinal sampling from a group of HIV-1 infected individuals on virologically effective ART showed no significant change in dysregulated CD4+T cell subset frequency. For both ART naïve and receiving groups associations with disease progression were strongest and significant with CD4+ T cell subset frequency compared to per cell expression of IL-2Rα and IL-7Rα. In untreated HIV-2 infected individuals, T cell activation was lower compared to ART naïve HIV-1 infected individuals and higher than seronegative individuals. Also, the level of Granzyme-B expressing circulating T cells was higher in both ART-naïve HIV-1 and HIV-2 infected individuals compared to seronegative controls. Conclusion Dysregulation of IL-2 and IL-7 homeostasis persists in CD4+T cell subsets irrespective of presence or absence of viremia or antiretroviral therapy in HIV infection. Furthermore, we report for the first time on levels of circulating Granzyme-B expressing CD4+T and CD8+T cells in chronic HIV-2 infection. Lower immune activation in these individuals indicates that persistent immune activation driven CD4+T cell depletion, as observed in untreated HIV-1 infected individuals, may not be as severe and provides evidence for a disparate pathogenesis mechanism. Our work also supports novel immunomodulatory therapeutic strategies for both HIV-1 and HIV-2 infection. Electronic supplementary material The online version of this article (10.1186/s12879-019-3743-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sukeshani Salwe
- Department of Biochemistry and Virology, National Institute for Research in Reproductive Health, Indian Council of Medical Research, J. M. Street, Parel, Mumbai, 400012, India
| | - Amitkumar Singh
- Department of Biochemistry and Virology, National Institute for Research in Reproductive Health, Indian Council of Medical Research, J. M. Street, Parel, Mumbai, 400012, India
| | - Varsha Padwal
- Department of Biochemistry and Virology, National Institute for Research in Reproductive Health, Indian Council of Medical Research, J. M. Street, Parel, Mumbai, 400012, India
| | - Shilpa Velhal
- Department of Biochemistry and Virology, National Institute for Research in Reproductive Health, Indian Council of Medical Research, J. M. Street, Parel, Mumbai, 400012, India
| | - Vidya Nagar
- Department of Medicine, Grant Medical College & Sir J. J. group of Hospitals, Mumbai, 400008, India
| | - Priya Patil
- Department of Medicine, Grant Medical College & Sir J. J. group of Hospitals, Mumbai, 400008, India
| | - Alaka Deshpande
- Department of Medicine, Grant Medical College & Sir J. J. group of Hospitals, Mumbai, 400008, India
| | - Vainav Patel
- Department of Biochemistry and Virology, National Institute for Research in Reproductive Health, Indian Council of Medical Research, J. M. Street, Parel, Mumbai, 400012, India.
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10
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Parsons MS, Lloyd SB, Lee WS, Kristensen AB, Amarasena T, Center RJ, Keele BF, Lifson JD, LaBranche CC, Montefiori D, Wines BD, Hogarth PM, Swiderek KM, Venturi V, Davenport MP, Kent SJ. Partial efficacy of a broadly neutralizing antibody against cell-associated SHIV infection. Sci Transl Med 2018; 9:9/402/eaaf1483. [PMID: 28794282 DOI: 10.1126/scitranslmed.aaf1483] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 12/08/2016] [Accepted: 05/09/2017] [Indexed: 12/26/2022]
Abstract
Broadly neutralizing antibodies (BnAbs) protect macaques from cell-free simian/human immunodeficiency virus (SHIV) challenge, but their efficacy against cell-associated SHIV is unclear. Virus in cell-associated format is highly infectious, present in transmission-competent bodily fluids, and potentially capable of evading antibody-mediated neutralization. The PGT121 BnAb, which recognizes an epitope consisting of the V3 loop and envelope glycans, mediates antibody-dependent cellular cytotoxicity and neutralization of cell-to-cell HIV-1 transmission. To evaluate whether a BnAb can prevent infection after cell-associated viral challenge, we infused pigtail macaques with PGT121 or an isotype control and challenged animals 1 hour later intravenously with SHIVSF162P3-infected splenocytes. All five controls had high viremia 1 week after challenge. Three of six PGT121-infused animals were completely protected, two of six animals had a 1-week delay in onset of high viremia, and one animal had a 7-week delay in onset of viremia. The infused antibody had decayed on average to 2.0 μg/ml by 1 week after infusion and was well below 1 μg/ml (range, <0.1 to 0.8 μg/ml) by 8 weeks. The animals with a 1-week delay before high viremia had relatively lower plasma concentrations of PGT121. Transfer of 22 million peripheral blood mononuclear cells (PBMCs) stored at weeks 1 to 4 from the animal with the 7-week delayed onset of viremia into uninfected macaques did not initiate infection. Our results show that HIV-1-specific neutralizing antibodies have partial efficacy against cell-associated virus exposure in macaques. We conclude that sustaining high concentrations of bioavailable BnAb is important for protecting against cell-associated virus.
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Affiliation(s)
- Matthew S Parsons
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3000, Australia.
| | - Sarah B Lloyd
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3000, Australia
| | - Wen Shi Lee
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3000, Australia
| | - Anne B Kristensen
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3000, Australia
| | - Thakshila Amarasena
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3000, Australia
| | - Rob J Center
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3000, Australia.,Centre for Biomedical Research, Burnet Institute, Melbourne, Victoria 3004, Australia
| | - Brandon F Keele
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Jeffrey D Lifson
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | | | | | - Bruce D Wines
- Centre for Biomedical Research, Burnet Institute, Melbourne, Victoria 3004, Australia
| | - P Mark Hogarth
- Centre for Biomedical Research, Burnet Institute, Melbourne, Victoria 3004, Australia
| | | | - Vanessa Venturi
- Kirby Institute for Infection and Immunity, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Miles P Davenport
- Kirby Institute for Infection and Immunity, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Stephen J Kent
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3000, Australia. .,Melbourne Sexual Health Centre, Alfred Hospital Department of Infectious Diseases, Central Clinical School, Monash University, Melbourne, Victoria 3053, Australia.,Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, University of Melbourne, Parkville, Victoria 3052, Australia
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11
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Ruiz MJ, Salido J, Abusamra L, Ghiglione Y, Cevallos C, Damilano G, Rodriguez AM, Trifone C, Laufer N, Giavedoni LD, Sued O, Salomón H, Gherardi MM, Turk G. Evaluation of Different Parameters of Humoral and Cellular Immune Responses in HIV Serodiscordant Heterosexual Couples: Humoral Response Potentially Implicated in Modulating Transmission Rates. EBioMedicine 2017; 26:25-37. [PMID: 29129698 PMCID: PMC5832641 DOI: 10.1016/j.ebiom.2017.11.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 10/24/2017] [Accepted: 11/01/2017] [Indexed: 02/05/2023] Open
Abstract
As the HIV/AIDS pandemic still progresses, understanding the mechanisms governing viral transmission as well as protection from HIV acquisition is fundamental. In this context, cohorts of HIV serodiscordant heterosexual couples (SDC) represent a unique tool. The present study was aimed to evaluate specific parameters of innate, cellular and humoral immune responses in SDC. Specifically, plasma levels of cytokines and chemokines, HIV-specific T-cell responses, gp120-specific IgG and IgA antibodies, and HIV-specific antibody-dependent cellular cytotoxicity (ADCC) activity were assessed in nine HIV-exposed seronegative individuals (ESN) and their corresponding HIV seropositive partners (HIV+-P), in eighteen chronically infected HIV subjects (C), nine chronically infected subjects known to be HIV transmitters (CT) and ten healthy HIV− donors (HD). Very low magnitude HIV-specific cellular responses were found in two out of six ESN. Interestingly, HIV+-P had the highest ADCC magnitude, the lowest IgA levels and the highest IgG/IgA ratio, all compared to CT. Positive correlations between CD4+ T-cell counts and both IgG/IgA ratios and %ADCC killing uniquely distinguished HIV+-P. Additionally, evidence of IgA interference with ADCC responses from HIV+-P and CT is provided. These data suggest for the first time a potential role of ADCC and/or gp120-specific IgG/IgA balance in modulating heterosexual transmission. In sum, this study provides key information to understand the host factors that influence viral transmission, which should be considered in both the development of prophylactic vaccines and novel immunotherapies for HIV-1 infection. The evaluation of different immune parameters in HIV serodiscordant couples helped identify factors shaping transmission. Innate and cellular immune responses were apparently not involved in this scenario. HIV-specific ADCC, IgA titer and IgG/IgA balance were identified as factors involved in modulating viral transmission.
The existence of individuals that remain HIV negative despite being repeatedly exposed to the virus has long been described. To date, only homozygosis for a 32-base pair deletion in the ccr5 gene has been consistently shown to be a determinant of HIV resistance. Still, subjects bearing the WT ccr5 gene have also been described as resistant or less susceptible to HIV. Thus, other mechanisms must be involved in this phenomenon. The results presented here postulate ADCC and IgG/IgA ratio as potential mechanisms involved in modulating HIV transmission in the context of serodiscordant couples and inspire further investigations.
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Affiliation(s)
- María Julia Ruiz
- CONICET- Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas en Retrovirus y Sida (INBIRS), Buenos Aires, Argentina
| | - Jimena Salido
- CONICET- Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas en Retrovirus y Sida (INBIRS), Buenos Aires, Argentina
| | | | - Yanina Ghiglione
- CONICET- Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas en Retrovirus y Sida (INBIRS), Buenos Aires, Argentina
| | - Cintia Cevallos
- CONICET- Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas en Retrovirus y Sida (INBIRS), Buenos Aires, Argentina
| | - Gabriel Damilano
- CONICET- Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas en Retrovirus y Sida (INBIRS), Buenos Aires, Argentina
| | - Ana María Rodriguez
- CONICET- Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas en Retrovirus y Sida (INBIRS), Buenos Aires, Argentina
| | - César Trifone
- CONICET- Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas en Retrovirus y Sida (INBIRS), Buenos Aires, Argentina
| | - Natalia Laufer
- CONICET- Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas en Retrovirus y Sida (INBIRS), Buenos Aires, Argentina; Hospital Juan A. Fernández, Unidad Enfermedades Infecciosas, Buenos Aires, Argentina
| | - Luis D Giavedoni
- Department of Virology and Immunology, Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - Omar Sued
- Fundación Huésped, Buenos Aires, Argentina; Hospital Juan A. Fernández, Unidad Enfermedades Infecciosas, Buenos Aires, Argentina
| | - Horacio Salomón
- CONICET- Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas en Retrovirus y Sida (INBIRS), Buenos Aires, Argentina
| | - María Magdalena Gherardi
- CONICET- Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas en Retrovirus y Sida (INBIRS), Buenos Aires, Argentina
| | - Gabriela Turk
- CONICET- Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas en Retrovirus y Sida (INBIRS), Buenos Aires, Argentina.
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12
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Routy JP, Mehraj V. Potential contribution of gut microbiota and systemic inflammation on HIV vaccine effectiveness and vaccine design. AIDS Res Ther 2017; 14:48. [PMID: 28893288 PMCID: PMC5594512 DOI: 10.1186/s12981-017-0164-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 08/11/2017] [Indexed: 02/07/2023] Open
Abstract
The quest for an effective HIV-1 vaccine began as soon as the virus causing AIDS was identified. After several disappointing attempts, results of the Phase-III RV144 trial in Thailand were a beacon of hope for the field demonstrating correlation between protection and immunological markers. In order to optimize vaccine response, we underline results from yellow fever and hepatitis B vaccines, where protective responses were predicted by the pre-vaccination level of immune activation in healthy individuals. Such findings support the assessment and reduction of pre-vaccine immune activation in order to optimize vaccine response. Immune activation in healthy individuals can be influenced by age, presence of CMV infection, gut dysbiosis and microbial translocation. We speculate that the level of immune activation should therefore be assessed to better select participants in vaccine trials, and interventions to reduce inflammation should be used to increase protective HIV vaccine response.
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13
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Brief Report: HIV-1 gp120 T-Cell Responses Correspond to Infection Outcomes in the Global iPrEx Chemoprophylaxis Trial. J Acquir Immune Defic Syndr 2017; 72:184-8. [PMID: 26674373 PMCID: PMC5395050 DOI: 10.1097/qai.0000000000000923] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Association of HIV-1–specific T-cell responses to infection risk in seronegative individuals is controversial. We quantified and phenotypically characterized gp120-specific T-cell responses in HIV-1 exposed, but uninfected subjects enrolled in the global Pre-exposure Prophylaxis Initiative (iPrEx) chemoprophylaxis trial. IFNγ ELISpot responses were detected in 24% of subjects irrespective of infection outcome. HIV-1 gp120 envelope-specific T-cell responses were more uniformly IFN-γ+TNF-α+Mip-1β+ in persistently seronegative subjects relative to subjects who later seroconverted (median frequency of 76.5% and 66.5%, respectively). IFNγ responses targeted the V2 loop for subjects who remained seronegative. HIV-1 gp120 envelope V2 loop-specific CD8+ T-cell responses may help to protect against HIV-1 acquisition.
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14
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Regulatory T-Cell Activity But Not Conventional HIV-Specific T-Cell Responses Are Associated With Protection From HIV-1 Infection. J Acquir Immune Defic Syndr 2017; 72:119-28. [PMID: 26656786 DOI: 10.1097/qai.0000000000000919] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Two distinct hypotheses have been proposed for T-cell involvement in protection from HIV-1 acquisition. First, HIV-1-specific memory T-cell responses generated on HIV-1 exposure could mount an efficient response to HIV-1 and inhibit the establishment of an infection. Second, a lower level of immune activation could reduce the numbers of activated, HIV-1-susceptible CD4 T cells, thereby diminishing the likelihood of infection. METHODS To test these hypotheses, we conducted a prospective study among high-risk heterosexual men and women, and tested peripheral blood samples from individuals who subsequently acquired HIV-1 during follow-up (cases) and from a subset of those who remained HIV-1 uninfected (controls). RESULTS We found no difference in HIV-1-specific immune responses between cases and controls, but Treg frequency was higher in controls as compared with cases and was negatively associated with frequency of effector memory CD4 T cells. CONCLUSIONS Our findings support the hypothesis that low immune activation assists in protection from HIV-1 infection.
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15
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Affiliation(s)
- Akiko Iwasaki
- Howard Hughes Medical Institute, Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut 06520;
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16
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Cellular immune correlates analysis of an HIV-1 preexposure prophylaxis trial. Proc Natl Acad Sci U S A 2015; 112:8379-84. [PMID: 26100867 DOI: 10.1073/pnas.1501443112] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
HIV-1-specific T-cell responses in exposed seronegative subjects suggest that a viral breach of the exposure site is more common than current transmission rates would suggest and that host immunity can extinguish subsequent infection foci. The Preexposure Prophylaxis Initiative (iPrEx) chemoprophylaxis trial provided an opportunity to rigorously investigate these responses in a case-control immunology study; 84 preinfection peripheral blood mononuclear cell samples from individuals enrolled in the iPrEx trial who later seroconverted were matched with 480 samples from enrolled subjects who remained seronegative from both the placebo and active treatment arms. T-cell responses to HIV-1 Gag, Protease, Integrase, Reverse Transcriptase, Vif, and Nef antigens were quantified for all subjects in an IFN-γ enzyme-linked immunospot (ELISpot) assay. IFN-γ responses varied in magnitude and frequency across subjects. A positive response was more prevalent in those who remained persistently HIV-1-negative for Gag (P = 0.007), Integrase (P < 0.001), Vif (P < 0.001), and Nef (P < 0.001). When correlated with outcomes in the iPrEx trial, Vif- and Integrase-specific T-cell responses were associated with reduced HIV-1 infection risk [hazard ratio (HR) = 0.36, 95% confidence interval (95% CI) = 0.19-0.66 and HR = 0.52, 95% CI = 0.28-0.96, respectively]. Antigen-specific responses were independent of emtricitabine/tenofovir disoproxil fumarate use. IFN-γ secretion in the ELISpot was confirmed using multiparametric flow cytometry and largely attributed to effector memory CD4+ or CD8+ T cells. Our results show that HIV-1-specific T-cell immunity can be detected in exposed but uninfected individuals and that these T-cell responses can differentiate individuals according to infection outcomes.
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17
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Ruiz-Riol M, Llano A, Ibarrondo J, Zamarreño J, Yusim K, Bach V, Mothe B, Perez-Alvarez S, Fernandez MA, Requena G, Meulbroek M, Pujol F, Leon A, Cobarsi P, Korber BT, Clotet B, Ganoza C, Sanchez J, Coll J, Brander C. Alternative effector-function profiling identifies broad HIV-specific T-cell responses in highly HIV-exposed individuals who remain uninfected. J Infect Dis 2014; 211:936-46. [PMID: 25249264 DOI: 10.1093/infdis/jiu534] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The characterization of host immune responses to human immunodeficiency virus (HIV) in HIV controllers and individuals with high exposure but seronegativity to HIV (HESN) is needed to guide the development of effective preventive and therapeutic vaccine candidates. However, several technical hurdles severely limit the definition of an effective virus-specific T-cell response. By using a toggle-peptide approach, which takes HIV sequence diversity into account, and a novel, boosted cytokine staining/flow cytometry strategy, we here describe new patterns of T-cell responses to HIV that would be missed by standard assays. Importantly, this approach also allows detection of broad and strong virus-specific T-cell responses in HESN individuals that are characterized by a T-helper type 1 cytokine-like effector profile and produce cytokines that have been associated with potential control of HIV infection, including interleukin 10, interleukin 13, and interleukin 22. These results establish a novel approach to improve the current understanding of HIV-specific T-cell immunity and identify cellular immune responses and individual cytokines as potential markers of relative HIV resistance. As such, the findings also help develop similar strategies for more-comprehensive assessments of host immune responses to other human infections and immune-mediated disorders.
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Affiliation(s)
- Marta Ruiz-Riol
- HIVACAT, Irsicaixa AIDS Research Institute, Autonomous University of Barcelona
| | - Anuska Llano
- HIVACAT, Irsicaixa AIDS Research Institute, Autonomous University of Barcelona
| | - Javier Ibarrondo
- Center for HIV Prevention Research, University of California-Los Angeles
| | - Jennifer Zamarreño
- HIVACAT, Irsicaixa AIDS Research Institute, Autonomous University of Barcelona
| | | | - Vanessa Bach
- HIVACAT, Irsicaixa AIDS Research Institute, Autonomous University of Barcelona
| | - Beatriz Mothe
- HIVACAT, Irsicaixa AIDS Research Institute, Autonomous University of Barcelona Fundació Lluita Contra La Sida, Hospital Universitari Germans Trias i Pujol University of Vic, Spain
| | | | - Marco A Fernandez
- Flow Cytometry Facility, Health Sciences Research Institute Germans Trias i Pujol, Badalona
| | - Gerard Requena
- Flow Cytometry Facility, Health Sciences Research Institute Germans Trias i Pujol, Badalona
| | | | | | | | - Patricia Cobarsi
- Fundació Lluita Contra La Sida, Hospital Universitari Germans Trias i Pujol
| | | | - Bonaventura Clotet
- HIVACAT, Irsicaixa AIDS Research Institute, Autonomous University of Barcelona Fundació Lluita Contra La Sida, Hospital Universitari Germans Trias i Pujol University of Vic, Spain
| | | | - Jorge Sanchez
- Asociacion Civil Impacta Salud y Educacion, Lima, Peru
| | - Josep Coll
- HIVACAT, Irsicaixa AIDS Research Institute, Autonomous University of Barcelona Fundació Lluita Contra La Sida, Hospital Universitari Germans Trias i Pujol
| | - Christian Brander
- HIVACAT, Irsicaixa AIDS Research Institute, Autonomous University of Barcelona Institució Catalana de Recerca i Estudis Avancats (ICREA), Barcelona University of Vic, Spain
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18
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Campion SL, Brodie TM, Fischer W, Korber BT, Rossetti A, Goonetilleke N, McMichael AJ, Sallusto F. Proteome-wide analysis of HIV-specific naive and memory CD4(+) T cells in unexposed blood donors. J Exp Med 2014; 211:1273-80. [PMID: 24958850 PMCID: PMC4076590 DOI: 10.1084/jem.20130555] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2013] [Accepted: 05/29/2014] [Indexed: 12/04/2022] Open
Abstract
The preexisting HIV-1-specific T cell repertoire must influence both the immunodominance of T cells after infection and immunogenicity of vaccines. We directly compared two methods for measuring the preexisting CD4(+) T cell repertoire in healthy HIV-1-negative volunteers, the HLA-peptide tetramer enrichment and T cell library technique, and show high concordance (r = 0.989). Using the library technique, we examined whether naive, central memory, and/or effector memory CD4(+) T cells specific for overlapping peptides spanning the entire HIV-1 proteome were detectable in 10 HLA diverse, HIV-1-unexposed, seronegative donors. HIV-1-specific cells were detected in all donors at a mean of 55 cells/million naive cells and 38.9 and 34.1 cells/million in central and effector memory subsets. Remarkably, peptide mapping showed most epitopes recognized by naive (88%) and memory (56%) CD4(+) T cells had been previously reported in natural HIV-1 infection. Furthermore, 83% of epitopes identified in preexisting memory subsets shared epitope length matches (8-12 amino acids) with human microbiome proteins, suggestive of a possible cross-reactive mechanism. These results underline the power of a proteome-wide analysis of peptide recognition by human T cells for the identification of dominant antigens and provide a baseline for optimizing HIV-1-specific helper cell responses by vaccination.
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Affiliation(s)
- Suzanne L Campion
- Nuffield Department of Medicine Research Building, University of Oxford, Old Road Campus, Headington, Oxford OX3 7FZ, England, UK
| | - Tess M Brodie
- Institute for Research in Biomedicine (IRB), 6-CH-6500 Bellinzona, Switzerland
| | - William Fischer
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM 87545
| | - Bette T Korber
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM 87545
| | - Astrea Rossetti
- Institute for Research in Biomedicine (IRB), 6-CH-6500 Bellinzona, Switzerland
| | - Nilu Goonetilleke
- Department of Microbiology & Immunology and Department of Medicine, University of North Carolina, Chapel Hill, NC 27599 Department of Microbiology & Immunology and Department of Medicine, University of North Carolina, Chapel Hill, NC 27599
| | - Andrew J McMichael
- Nuffield Department of Medicine Research Building, University of Oxford, Old Road Campus, Headington, Oxford OX3 7FZ, England, UK
| | - Federica Sallusto
- Institute for Research in Biomedicine (IRB), 6-CH-6500 Bellinzona, Switzerland
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19
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Chanzu N, Ondondo B. Induction of Potent and Long-Lived Antibody and Cellular Immune Responses in the Genitorectal Mucosa Could be the Critical Determinant of HIV Vaccine Efficacy. Front Immunol 2014; 5:202. [PMID: 24847327 PMCID: PMC4021115 DOI: 10.3389/fimmu.2014.00202] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 04/23/2014] [Indexed: 01/28/2023] Open
Abstract
The field of HIV prevention has indeed progressed in leaps and bounds, but with major limitations of the current prevention and treatment options, the world remains desperate for an HIV vaccine. Sadly, this continues to be elusive, because more than 30 years since its discovery there is no licensed HIV vaccine. Research aiming to define immunological biomarkers to accurately predict vaccine efficacy have focused mainly on systemic immune responses, and as such, studies defining correlates of protection in the genitorectal mucosa, the primary target site for HIV entry and seeding are sparse. Clearly, difficulties in sampling and analysis of mucosal specimens, as well as their limited size have been a major deterrent in characterizing the type (mucosal antibodies, cytokines, chemokines, or CTL), threshold (magnitude, depth, and breadth) and viral inhibitory capacity of HIV-1-specific immune responses in the genitorectal mucosa, where they are needed to immediately block HIV acquisition and arrest subsequent virus dissemination. Nevertheless, a few studies document the existence of HIV-specific immune responses in the genitorectal mucosa of HIV-infected aviremic and viremic controllers, as well as in highly exposed persistently seronegative (HEPS) individuals with natural resistance to HIV-1. Some of these responses strongly correlate with protection from HIV acquisition and/or disease progression, thus providing significant clues of the ideal components of an efficacious HIV vaccine. In this study, we provide an overview of the key features of protective immune responses found in HEPS, elite and viremic controllers, and discuss how these can be achieved through mucosal immunization. Inevitably, HIV vaccine development research will have to consider strategies that elicit potent antibody and cellular immune responses within the genitorectal mucosa or induction of systemic immune cells with an inherent potential to home and persist at mucosal sites of HIV entry.
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Affiliation(s)
- Nadia Chanzu
- Institute of Tropical and Infectious Diseases, College of Health Sciences, University of Nairobi , Nairobi , Kenya
| | - Beatrice Ondondo
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford , Oxford , UK
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20
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Bet A, Sterret S, Sato A, Bansal A, Goepfert PA. Characterization of T-cell responses to cryptic epitopes in recipients of a noncodon-optimized HIV-1 vaccine. J Acquir Immune Defic Syndr 2014; 65:142-50. [PMID: 24442221 PMCID: PMC3896890 DOI: 10.1097/qai.0b013e3182a9917e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Cryptic epitopes (CEs) can be encoded by any of the 5 alternative reading frames (ARFs, 2 sense and 3 antisense) of a known gene. Although CE responses are commonly detected during HIV-1 infection, it is not known whether these responses are induced after vaccination. METHODS Using a bioinformatic approach, we determined that vaccines with codon-optimized HIV inserts significantly skewed CE sequences and are not likely to induce crossreactive responses to natural HIV CE. We then evaluated the CE- and protein-specific T-cell responses using Gag, Pol, and ARF peptide pools among participants immunized with a non-codon optimized vaccine regimen of 2 pGA2/JS7 DNA primes followed by 2 MVA/HIV62 Gag-Pol-Env vector boosts or 4 saline injections. RESULTS Vaccinees had significantly more interferon gamma enzyme-linked immunosorbent spot (IFNγ ELISpot) responses toward Gag (P = 0.003) but not toward Pol protein than did placebo recipients. However, CE-specific T-cell responses were low in magnitude, and their frequencies did not differ significantly between vaccine and placebo recipients. Additionally, most positive CE responses could not be mapped to individual peptides. After expanding responses in a cultured assay, however, the frequency and the median magnitude of responses to ARF peptides were significantly greater in vaccinees (P < 0.0001), indicating that CE-specific T-cell responses are present but below an ex vivo assay's limit of detection. CONCLUSIONS Our data demonstrate that HIV-1 vaccines currently in clinical trials are poorly immunogenic with regard to CE-specific T-cell responses. Therefore, the context of HIV-1 immunogens may need to be modified as a comprehensive strategy to broaden vaccine-induced T-cell responses.
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Affiliation(s)
- Anne Bet
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL USA 35294
| | - Sarah Sterret
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL USA 35294
| | - Alicia Sato
- Statistical Center for HIV/AIDS Research & Prevention (SCHARP), Fred Hutchinson Cancer Research Center, Seattle, WA 98109-1024
| | - Anju Bansal
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL USA 35294
| | - Paul A. Goepfert
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL USA 35294
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL USA 35294
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21
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Quantitative and qualitative differences in the T cell response to HIV in uninfected Ugandans exposed or unexposed to HIV-infected partners. J Virol 2013; 87:9053-63. [PMID: 23760253 DOI: 10.1128/jvi.00721-13] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
HIV-exposed and yet persistently uninfected individuals have been an intriguing, repeated observation in multiple studies, but uncertainty persists on the significance and implications of this in devising protective strategies against HIV. We carried out a cross-sectional analysis of exposed uninfected partners in a Ugandan cohort of heterosexual serodiscordant couples (37.5% antiretroviral therapy naive) comparing their T cell responses to HIV peptides with those of unexposed uninfected individuals. We used an objective definition of exposure and inclusion criteria, blinded ex vivo and cultured gamma interferon (IFN-γ) enzyme-linked immunospot assays, and multiparameter flow cytometry and intracellular cytokine staining to investigate the features of the HIV-specific response in exposed versus unexposed uninfected individuals. A response rate to HIV was detectable in unexposed uninfected (5.7%, 95% confidence interval [CI] = 3.3 to 8.1%) and, at a significantly higher level (12.5%, 95% CI = 9.7 to 15.4%, P = 0.0004), in exposed uninfected individuals. The response rate to Gag was significantly higher in exposed uninfected (10/50 [20.%]) compared to unexposed uninfected (1/35 [2.9%]) individuals (P = 0.0004). The magnitude of responses was also greater in exposed uninfected individuals but not statistically significant. The average number of peptide pools recognized was significantly higher in exposed uninfected subjects than in unexposed uninfected subjects (1.21 versus 0.47; P = 0.0106). The proportion of multifunctional responses was different in the two groups, with a higher proportion of single cytokine responses, mostly IFN-γ, in unexposed uninfected individuals compared to exposed uninfected individuals. Our findings demonstrate both quantitative and qualitative differences in T cell reactivity to HIV between HESN (HIV exposed seronegative) and HUSN (HIV unexposed seronegative) subject groups but do not discriminate as to whether they represent markers of exposure or of protection against HIV infection.
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Munier CML, Kelleher AD, Kent SJ, De Rose R. The role of T cell immunity in HIV-1 infection. Curr Opin Virol 2013; 3:438-46. [PMID: 23747036 DOI: 10.1016/j.coviro.2013.05.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 05/07/2013] [Accepted: 05/07/2013] [Indexed: 12/11/2022]
Abstract
The interplay between the T cell immune response and human immunodeficiency virus (HIV)-1 largely determines the outcome of infection. Typically, the virus overcomes the immune defences leading to a gradual decline in function that permits the development of disease. In recent years, a concerted effort in comparing T cell responses between 'controllers' and 'progressors' is beginning to identify the T cell subsets and factors that affect disease progression related to the effector functions of both CD4 and CD8 T cells. These efforts are providing opportunities for development of novel therapies and vaccines.
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Affiliation(s)
- C Mee Ling Munier
- The Kirby Institute for Infection and Immunity in Society, University of NSW, Sydney, NSW, Australia
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23
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Li WH, Li CY, Yang HB, Zhang HP, Zhang X, Kong LS, Xu XN, Lu SC, Yan HP. Human leucocyte antigen-Bw4 and Gag-specific T cell responses are associated with slow disease progression in HIV-1B-infected anti-retroviral therapy-naive Chinese. Clin Exp Immunol 2013; 171:298-306. [PMID: 23379436 DOI: 10.1111/cei.12025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/24/2012] [Indexed: 11/30/2022] Open
Abstract
In China, the majority of human immunodeficiency virus (HIV) infections are predominately subtype B. It is important to characterize the HIV-1 subtype B-specific and its T cell response within the Chinese population, with the aim of identifying protective correlates of immunity to control HIV-1 infections. In this study, we performed a comprehensive analysis looking into the magnitude/strength of T cell responses directed at the Gag protein of the HIV-1 subtype B, one of the most conserved HIV-1 proteins. The study group consisted of anti-retroviral native and chronic HIV-1 subtype B-infected individuals. We used enzyme-linked immunospot (ELISPOT) assay to quantify the total T cell responses to HIV-1 Gag at the single peptide level. Twenty-eight (38%) peptides were recognized in 24 (82·8%) individuals. The p24 was identified as the most frequently recognized subunit protein with the greatest T cell response in the test, which correlated positively with CD4(+) T cell count and inversely with viral load (VL). At the level of the human leucocyte antigen (HLA) supertypes, we detected the highest levels and a significant correlation with both the CD4(+) T cell count and the VL with Gag T cell responses in Bw4/Bw4. These findings demonstrate that (i) the HIV-1B Gag p24-specific immune responses play an important role in controlling viral replication and slowing clinical progression; and (ii) HLA-Bw4/Bw4 allele has stronger T cell responses, which is associated with slow clinical progression in Chinese HIV patients.
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Affiliation(s)
- W-H Li
- YouAn Hospital, Capital Medical University, Beijing, China
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24
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Murashev BV, Nazarenko OV, Akulova EB, Artemyeva AK, Verevochkin SV, Shaboltas AV, Skochilov RV, Toussova OV, Kozlov AP. The high frequency of HIV type 1-specific cellular immune responses in seronegative individuals with parenteral and/or heterosexual HIV type 1 exposure. AIDS Res Hum Retroviruses 2012; 28:1598-605. [PMID: 22475222 DOI: 10.1089/aid.2011.0335] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Some individuals remain HIV seronegative despite repeated unprotected exposure to the virus. Recent observations led to a concept that acquired immunity plays a role in protection or at least in altered susceptibility to HIV-1 infection in highly exposed seronegative (ESN) individuals. Our aim was to study HIV-specific cellular immune responses induced in parenterally and/or heterosexually ESN individuals. Nine seronegative injection drug users (IDUs), 10 seronegative individuals, and nine of their HIV-positive sexual and/or IDU partners from the cohort of IDUs were included in the study. The discordant couples had unprotected sex, and some of seronegative partners also had parenteral exposure. Cell-mediated responses were measured in peripheral blood mononuclear cells (PBMCs) by ex vivo interferon (IFN)-γ-ELISpot and ICS combining IFN-γ, tumor necrosis factor (TNF)-α, and interleukin (IL)-2 after stimulation with four consensus peptide pools (Nef, Gag, RT, Env, subtype A-EE). Thirteen out of 19 (68%) seronegative study subjects had strong Nef peptide pool-specific ELISpot responses, three (16%) subjects responded against the Gag peptide pool, and one subject had an RT peptide pool response. Nef peptide pool responses in ESN were as high as in seropositive subjects. The multiple HIV-specific cytokine production in both CD4(+) and CD8(+) T cells was shown for several ESN subjects. The functional profiles of the immune responses were different between seronegative and HIV-positive study groups. Whether the observed cellular responses have any protective role against HIV needs to be further investigated.
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Affiliation(s)
- Boris V. Murashev
- Biomedical Center and St. Petersburg State University, St. Petersburg, Russia
| | - Olga V. Nazarenko
- Biomedical Center and St. Petersburg State University, St. Petersburg, Russia
| | | | - Anna K. Artemyeva
- Biomedical Center and St. Petersburg State University, St. Petersburg, Russia
| | | | - Alla V. Shaboltas
- Biomedical Center and St. Petersburg State University, St. Petersburg, Russia
| | - Roman V. Skochilov
- Biomedical Center and St. Petersburg State University, St. Petersburg, Russia
| | - Olga V. Toussova
- Biomedical Center and St. Petersburg State University, St. Petersburg, Russia
| | - Andrei P. Kozlov
- Biomedical Center and St. Petersburg State University, St. Petersburg, Russia
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Abstract
HIV is a disease in which the original clinical observations of severe opportunistic infections gave the first clues regarding the underlying pathology, namely that HIV is essentially an infection of the immune system. HIV infects and deletes CD4(+) T cells that normally coordinate the adaptive T- and B-cell response to defend against intracellular pathogens. The immune defect is immediate and profound: At the time of acute infection with an AIDS virus, typically more than half of the gut-associated CD4(+) T cells are depleted, leaving a damaged immune system to contend with a life-long infection.
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Affiliation(s)
- Bruce Walker
- Ragon Institute of MGH, MIT, and Harvard Mass General Hospital-East, Charlestown, Massachusetts 02129, USA.
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26
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HIV-1-specific enzyme-linked immunosorbent spot assay responses in HIV-1-exposed uninfected partners in discordant relationships compared to those in low-risk controls. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2012; 19:1798-805. [PMID: 22971780 DOI: 10.1128/cvi.00179-12] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A number of studies of highly exposed HIV-1-seronegative individuals (HESN) have found HIV-1-specific cellular responses. However, there is limited evidence that responses prevent infection or are linked to HIV-1 exposure. Peripheral blood mononuclear cells (PBMC) were isolated from HESN in HIV-1-discordant relationships and low-risk controls in Nairobi, Kenya. HIV-1-specific responses were detected using gamma interferon (IFN-γ) enzyme-linked immunosorbent spot (ELISpot) assays stimulated by peptide pools spanning the subtype A HIV-1 genome. The HIV-1 incidence in this HESN cohort was 1.5 per 100 person years. Positive ELISpot responses were found in 34 (10%) of 331 HESN and 14 (13%) of 107 low-risk controls (odds ratio [OR] = 0.76; P = 0.476). The median immunodominant response was 18.9 spot-forming units (SFU)/10(6) peripheral blood mononuclear cells (PBMC). Among HESN, increasing age (OR = 1.24 per 5 years; P = 0.026) and longer cohabitation with the HIV-1-infected partner (OR = 5.88 per 5 years; P = 0.003) were associated with responses. These factors were not associated with responses in controls. Other exposure indicators, including the partner's HIV-1 load (OR = 0.99 per log(10) copy/ml; P = 0.974) and CD4 count (OR = 1.09 per 100 cells/μl; P = 0.238), were not associated with responses in HESN. HIV-1-specific cellular responses may be less relevant to resistance to infection among HESN who are using risk reduction strategies that decrease their direct viral exposure.
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Van Braeckel E, Leroux-Roels G. HIV vaccines: can CD4+ T cells be of help? Hum Vaccin Immunother 2012; 8:1795-8. [PMID: 22906935 DOI: 10.4161/hv.21760] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Defining immune correlates of protection against the human immunodeficiency virus (HIV) remains a major challenge. While the role of neutralizing antibodies and CD8+ T cell responses has been widely acknowledged and applied in vaccine development, little vaccine candidates have focused on CD4+ T cells. As the main target of HIV, CD4+ T cells play a pivotal role in HIV infection. An HIV vaccine that elicits strong, multi-specific, polyfunctional and persisting CD4+ T cell responses would therefore have the potential of lowering viral set point when HIV infection occurs or reducing viral load in already infected patients. In a combined approach with neutralizing antibodies and CD8+ T cells, CD4+ T cells cannot only enhance the magnitude, quality and durability of the desired antibody response, but will also provide the help needed to induce and maintain effective antiviral CD8+ T cell responses. In addition, the disease-modifying potential of the CD4+ T cell response, by lowering viral set point and/or viral load and thus probability of transmission, may be beneficial both at the individual and public health level.
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Abstract
From the publication of the first AIDS issue onwards, major advances have been made in the field of innate immunity during HIV infection. Innate immunity can be defined as the first and unspecific lines of defense constitutively present and ready to be mobilized upon infection. Although a large body of literature adamantly highlights that innate immunity is a critical weapon of defense against HIV and its simian parents (simian immunodeficiency virus, SIV), innate immunity is still underexplored. Focusing on innate immunity may open new paths for the development of innovative therapeutics and vaccine strategies against HIV. Understanding innate immunity may shed light on the natural protection occurring in rare HIV-1-infected individuals who control their infection. This review focuses on innate mechanisms sensing HIV-1 entry and controlling HIV-1 infection, as well as promoting inflammation and shaping adaptive immunity.
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Comparison of sexual behavior and HIV risk between two HIV-1 serodiscordant couple cohorts: the CHAVI 002 study. PLoS One 2012; 7:e37727. [PMID: 22629447 PMCID: PMC3358272 DOI: 10.1371/journal.pone.0037727] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Accepted: 04/23/2012] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND The CHAVI002 study was designed to characterize immune responses, particularly HIV-specific T-cell responses, amongst 2 cohorts of HIV-exposed seronegative (HESN) individuals. The absence of a clear definition of HESNs has impaired comparison of research within and between such cohorts. This report describes two distinct HESN cohorts and attempts to quantify HIV exposure using a 'HIV risk index' (RI) model. METHODS HIV serodiscordant couples (UK; 24, Uganda; 72) and HIV unexposed seronegative (HUSN) controls (UK; 14, Uganda; 26 couples, 3 individuals) completed sexual behavior questionnaires every 3 months over a 9 month period. The two cohorts were heterogeneous, with most HESNs in the UK men who have sex with men (MSM), while all HESNs in Uganda were in heterosexual relationships. Concordance of responses between partners was determined. Each participant's sexual behavior score (SBS) was estimated based on the number and type of unprotected sex acts carried out in defined time periods. Independent HIV acquisition risk factors (partner plasma viral load, STIs, male circumcision, pregnancy) were integrated with the SBS, generating a RI for each HESN. RESULTS 96 HIV serodiscordant couples completed 929 SBQs. SBSs remained relatively stable amongst the UK cohort, whilst decreasing from Visit 1 to 2 in the Ugandan cohort. Compared to the Ugandan cohort, SBSs and RIs in the UK cohort were lower at visit 1, and generally higher at later visits. Differences between the cohorts, with lower rates of ART use in Uganda and higher risk per-act sex in the UK, had major impacts on the SBSs and RIs of each cohort. There was one HIV transmission event in the UK cohort. CONCLUSIONS Employment of a risk quantification model facilitated quantification and comparison of HIV acquisition risk across two disparate HIV serodiscordant couple cohorts.
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30
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HIV-specific CD4 T cell responses to different viral proteins have discordant associations with viral load and clinical outcome. J Virol 2011; 86:277-83. [PMID: 22031937 DOI: 10.1128/jvi.05577-11] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
A successful prophylactic vaccine is characterized by long-lived immunity, which is critically dependent on CD4 T cell-mediated helper signals. Indeed, most licensed vaccines induce antigen-specific CD4 T cell responses, in addition to high-affinity antibodies. However, despite the important role of CD4 T cells in vaccine design and natural infection, few studies have characterized HIV-specific CD4 T cells due to their preferential susceptibility to HIV infection. To establish at the population level the impact of HIV-specific CD4 T cells on viral control and define the specificity of HIV-specific CD4 T cell peptide targeting, we conducted a comprehensive analysis of these responses to the entire HIV proteome in 93 subjects at different stages of HIV infection. We show that HIV-specific CD4 T cell responses were detectable in 92% of individuals and that the breadth of these responses showed a significant inverse correlation with the viral load (P = 0.009, R = -0.31). In particular, CD4 T cell responses targeting Gag were robustly associated with lower levels of viremia (P = 0.0002, R = -0.45). Importantly, differences in the immunodominance profile of HIV-specific CD4 T cell responses distinguished HIV controllers from progressors. Furthermore, Gag/Env ratios were a potent marker of viral control, with a high frequency and magnitude of Gag responses and low proportion of Env responses associated with effective immune control. At the epitope level, targeting of three distinct Gag peptides was linked to spontaneous HIV control (P = 0.60 to 0.85). Inclusion of these immunogenic proteins and peptides in future HIV vaccines may act as a critical cornerstone for enhancing protective T cell responses.
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