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Sponaugle A, Weideman AMK, Ranek J, Atassi G, Kuruc J, Adimora AA, Archin NM, Gay C, Kuritzkes DR, Margolis DM, Vincent BG, Stanley N, Hudgens MG, Eron JJ, Goonetilleke N. Dominant CD4 + T cell receptors remain stable throughout antiretroviral therapy-mediated immune restoration in people with HIV. Cell Rep Med 2023; 4:101268. [PMID: 37949070 PMCID: PMC10694675 DOI: 10.1016/j.xcrm.2023.101268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 06/05/2023] [Accepted: 10/10/2023] [Indexed: 11/12/2023]
Abstract
In people with HIV (PWH), the post-antiretroviral therapy (ART) window is critical for immune restoration and HIV reservoir stabilization. We employ deep immune profiling and T cell receptor (TCR) sequencing and examine proliferation to assess how ART impacts T cell homeostasis. In PWH on long-term ART, lymphocyte frequencies and phenotypes are mostly stable. By contrast, broad phenotypic changes in natural killer (NK) cells, γδ T cells, B cells, and CD4+ and CD8+ T cells are observed in the post-ART window. Whereas CD8+ T cells mostly restore, memory CD4+ T subsets and cytolytic NK cells show incomplete restoration 1.4 years post ART. Surprisingly, the hierarchies and frequencies of dominant CD4 TCR clonotypes (0.1%-11% of all CD4+ T cells) remain stable post ART, suggesting that clonal homeostasis can be independent of homeostatic processes regulating CD4+ T cell absolute number, phenotypes, and function. The slow restoration of host immunity post ART also has implications for the design of ART interruption studies.
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Affiliation(s)
- Alexis Sponaugle
- Department of Microbiology & Immunology, UNC Chapel Hill, Chapel Hill, NC, USA
| | - Ann Marie K Weideman
- Department of Biostatistics, UNC Chapel Hill, Chapel Hill, NC, USA; Center for AIDS Research, School of Medicine, UNC Chapel Hill, Chapel Hill, NC, USA
| | - Jolene Ranek
- Computational Medicine Program, UNC Chapel Hill, Chapel Hill, NC, USA; Curriculum in Bioinformatics and Computational Biology, UNC Chapel Hill, Chapel Hill, NC, USA
| | - Gatphan Atassi
- Lineberger Comprehensive Cancer Center, UNC Chapel Hill, Chapel Hill, NC, USA
| | - JoAnn Kuruc
- Department of Medicine, UNC Chapel Hill, Chapel Hill, NC, USA
| | - Adaora A Adimora
- Center for AIDS Research, School of Medicine, UNC Chapel Hill, Chapel Hill, NC, USA; Department of Medicine, UNC Chapel Hill, Chapel Hill, NC, USA; Department of Epidemiology, Gillings School of Global Public Health, UNC Chapel Hill, Chapel Hill, NC, USA
| | - Nancie M Archin
- Department of Medicine, UNC Chapel Hill, Chapel Hill, NC, USA
| | - Cynthia Gay
- Department of Medicine, UNC Chapel Hill, Chapel Hill, NC, USA
| | - Daniel R Kuritzkes
- Division of Infectious Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - David M Margolis
- Department of Microbiology & Immunology, UNC Chapel Hill, Chapel Hill, NC, USA; Department of Medicine, UNC Chapel Hill, Chapel Hill, NC, USA
| | - Benjamin G Vincent
- Department of Microbiology & Immunology, UNC Chapel Hill, Chapel Hill, NC, USA; Department of Medicine, UNC Chapel Hill, Chapel Hill, NC, USA; Curriculum in Bioinformatics and Computational Biology, UNC Chapel Hill, Chapel Hill, NC, USA
| | - Natalie Stanley
- Computational Medicine Program, UNC Chapel Hill, Chapel Hill, NC, USA; Department of Computer Science, UNC Chapel Hill, Chapel Hill, NC, USA
| | - Michael G Hudgens
- Department of Biostatistics, UNC Chapel Hill, Chapel Hill, NC, USA; Center for AIDS Research, School of Medicine, UNC Chapel Hill, Chapel Hill, NC, USA
| | - Joseph J Eron
- Department of Medicine, UNC Chapel Hill, Chapel Hill, NC, USA
| | - Nilu Goonetilleke
- Department of Microbiology & Immunology, UNC Chapel Hill, Chapel Hill, NC, USA; Department of Medicine, UNC Chapel Hill, Chapel Hill, NC, USA.
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2
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Luo X, Frouard J, Zhang G, Neidleman J, Xie G, Sheedy E, Roan NR, Greene WC. Subsets of Tissue CD4 T Cells Display Different Susceptibilities to HIV Infection and Death: Analysis by CyTOF and Single Cell RNA-seq. Front Immunol 2022; 13:883420. [PMID: 35784348 PMCID: PMC9245423 DOI: 10.3389/fimmu.2022.883420] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 05/11/2022] [Indexed: 01/09/2023] Open
Abstract
CD4 T lymphocytes belong to diverse cellular subsets whose sensitivity or resistance to HIV-associated killing remains to be defined. Working with lymphoid cells from human tonsils, we characterized the HIV-associated depletion of various CD4 T cell subsets using mass cytometry and single-cell RNA-seq. CD4 T cell subsets preferentially killed by HIV are phenotypically distinct from those resistant to HIV-associated cell death, in a manner not fully accounted for by their susceptibility to productive infection. Preferentially-killed subsets express CXCR5 and CXCR4 while preferentially-infected subsets exhibit an activated and exhausted effector memory cell phenotype. Single-cell RNA-seq analysis reveals that the subsets of preferentially-killed cells express genes favoring abortive infection and pyroptosis. These studies emphasize a complex interplay between HIV and distinct tissue-based CD4 T cell subsets, and the important contribution of abortive infection and inflammatory programmed cell death to the overall depletion of CD4 T cells that accompanies untreated HIV infection.
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Affiliation(s)
- Xiaoyu Luo
- Gladstone Institute of Virology, San Francisco, CA, United States
| | - Julie Frouard
- Gladstone Institute of Virology, San Francisco, CA, United States,Department of Urology, University of California, San Francisco, San Francisco, CA, United States
| | - Gang Zhang
- Gladstone Institute of Virology, San Francisco, CA, United States
| | - Jason Neidleman
- Gladstone Institute of Virology, San Francisco, CA, United States,Department of Urology, University of California, San Francisco, San Francisco, CA, United States
| | - Guorui Xie
- Gladstone Institute of Virology, San Francisco, CA, United States,Department of Urology, University of California, San Francisco, San Francisco, CA, United States
| | - Emma Sheedy
- Gladstone Institute of Virology, San Francisco, CA, United States
| | - Nadia R. Roan
- Gladstone Institute of Virology, San Francisco, CA, United States,Department of Urology, University of California, San Francisco, San Francisco, CA, United States
| | - Warner C. Greene
- Gladstone Institute of Virology, San Francisco, CA, United States,Department of Medicine, University of California, San Francisco, San Francisco, CA, United States,Department of Microbiology & Immunology, University of California, San Francisco, San Francisco, CA, United States,*Correspondence: Warner C. Greene,
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3
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Crespo-Bermejo C, de Arellano ER, Lara-Aguilar V, Valle-Millares D, Gómez-Lus ML, Madrid R, Martín-Carbonero L, Briz V. Persistent low-Level viremia in persons living with HIV undertreatment: An unresolved status. Virulence 2021; 12:2919-2931. [PMID: 34874239 PMCID: PMC8654475 DOI: 10.1080/21505594.2021.2004743] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Antiretroviral therapy (ART) allows suppressed viremia to reach less than 50 copies/mL in most treated persons living with HIV (PLWH). However, the existence of PLWH that show events of persistent low-level viremia (pLLV) between 50 and 1000 copies/mL and with different virological consequences have been observed. PLLV has been associated with higher virological failure (VF), viral genotype resistance, adherence difficulties and AIDS events. Moreover, some reports show that pLLV status can lead to residual immune activation and inflammation, with an increased risk of immunovirological failure and a pro-inflammatory cytokine level which can lead to a higher occurrence of non-AIDS defining events (NADEs) and other adverse clinical outcomes. Until now, however, published data have shown controversial results that hinder understanding of the true cause(s) and origin(s) of this phenomenon. Molecular mechanisms related to viral reservoir size and clonal expansion have been suggested as the possible origin of pLLV. This review aims to assess recent findings to provide a global view of the role of pLLV in PLWH and the impact this status may cause on the clinical progression of these patients.
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Affiliation(s)
- Celia Crespo-Bermejo
- Laboratory of Reference and Research on Viral Hepatitis, National Center of Microbiology, Institute of Health Carlos Iii, Majadahonda, Madrid, Spain
| | - Eva Ramírez de Arellano
- Laboratory of Reference and Research on Viral Hepatitis, National Center of Microbiology, Institute of Health Carlos Iii, Majadahonda, Madrid, Spain
| | - Violeta Lara-Aguilar
- Laboratory of Reference and Research on Viral Hepatitis, National Center of Microbiology, Institute of Health Carlos Iii, Majadahonda, Madrid, Spain
| | - Daniel Valle-Millares
- Laboratory of Reference and Research on Viral Hepatitis, National Center of Microbiology, Institute of Health Carlos Iii, Majadahonda, Madrid, Spain
| | - Mª Luisa Gómez-Lus
- Departamento de Medicina- Área de Microbiología. Facultad de Medicina. Universidad Complutense, Madrid, Spain
| | - Ricardo Madrid
- Parque Científico de Madrid, Campus de Cantoblanco, Madrid, Spain.,Department of Genetics, Physiology and Microbiology. Faculty of Biology, Complutense University of Madrid, Madrid, Spain
| | - Luz Martín-Carbonero
- Unidad de Vih. Servicio de Medicina Interna. Hospital Universitario La Paz. Instituto de Investigación Sanitaria Hospital de La Paz (Idipaz), Madrid, Spain
| | - Verónica Briz
- Laboratory of Reference and Research on Viral Hepatitis, National Center of Microbiology, Institute of Health Carlos Iii, Majadahonda, Madrid, Spain
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4
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Bystander CD4 T-cell death is inhibited by broadly neutralizing anti-HIV antibodies only at levels blocking cell-to-cell viral transmission. J Biol Chem 2021; 297:101098. [PMID: 34418431 PMCID: PMC8446805 DOI: 10.1016/j.jbc.2021.101098] [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: 04/04/2021] [Revised: 06/28/2021] [Accepted: 08/17/2021] [Indexed: 11/23/2022] Open
Abstract
The progressive loss of CD4+ T cells during HIV infection of lymphoid tissues involves both the apoptotic death of activated and productively infected CD4 T cells and the pyroptotic death of large numbers of resting and abortively infected bystander CD4 T cells. HIV spreads both through cellular release of virions and cell-to-cell transmission involving the formation of virological synapses. Cell-to-cell transmission results in high-level transfer of large quantities of virions to the target cell exceeding that achieved with cell-free virions. Broadly neutralizing anti-HIV antibodies (bNAbs) binding to HIV envelope protein capably block cell-free virus spread, and when added at higher concentrations can also interdict cell-to-cell transmission. Exploiting these distinct dose–response differences, we now show that four different bNAbs block the pyroptotic death of bystander cells, but only when added at concentrations sufficient to block cell-to-cell transmission. These findings further support the conclusion that HIV killing of abortively infected bystander CD4 T cells requires cell-to-cell transfer of virions. As bNAbs attract more interest as potential therapeutics, it will be important to consider the higher concentrations of these antibodies required to block the inflammatory death of bystander CD4 T cells.
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5
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MAVS Genetic Variation Is Associated with Decreased HIV-1 Replication In Vitro and Reduced CD4 + T Cell Infection in HIV-1-Infected Individuals. Viruses 2020; 12:v12070764. [PMID: 32708557 PMCID: PMC7412276 DOI: 10.3390/v12070764] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 07/10/2020] [Accepted: 07/13/2020] [Indexed: 02/07/2023] Open
Abstract
The mitochondrial antiviral protein MAVS is a key player in the induction of antiviral responses; however, human immunodeficiency virus 1 (HIV-1) is able to suppress these responses. Two linked single nucleotide polymorphisms (SNPs) in the MAVS gene render MAVS insensitive to HIV-1-dependent suppression, and have been shown to be associated with a lower viral load at set point and delayed increase of viral load during disease progression. Here, we studied the underlying mechanisms involved in the control of viral replication in individuals homozygous for this MAVS genotype. We observed that individuals with the MAVS minor genotype had more stable total CD4+ T cell counts during a 7-year follow up and had lower cell-associated proviral DNA loads. Genetic variation in MAVS did not affect immune activation levels; however, a significantly lower percentage of naïve CD4+ but not CD8+ T cells was observed in the MAVS minor genotype. In vitro HIV-1 infection of peripheral blood mononuclear cells (PBMCs) from healthy donors with the MAVS minor genotype resulted in decreased viral replication. Although the precise underlying mechanism remains unclear, our data suggest that the protective effect of the MAVS minor genotype may be exerted by the initiation of local innate responses affecting viral replication and CD4+ T cell susceptibility.
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Leng Q, Tarbe M, Long Q, Wang F. Pre-existing heterologous T-cell immunity and neoantigen immunogenicity. Clin Transl Immunology 2020; 9:e01111. [PMID: 32211191 PMCID: PMC7085466 DOI: 10.1002/cti2.1111] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 01/13/2020] [Accepted: 01/30/2020] [Indexed: 12/22/2022] Open
Abstract
Neoantigens are tumor‐specific mutated proteins that are exempt from central tolerance and are therefore capable of efficiently eliciting effective T‐cell responses. The identification of immunogenic neoantigens in tumor‐specific mutated proteins has promising clinical implications for cancer immunotherapy. However, the factors that may contribute to neoantigen immunogenicity are not yet fully understood. Through molecular mimicry of antigens arising during cancer progression, the gut microbiota and previously encountered pathogens potentially have profound impacts on T‐cell responses to previously unencountered tumor neoantigens. Here, we review the characteristics of immunogenic neoantigens and how host exposure to microbes may affect T‐cell responses to neoantigens. We address the hypothesis that pre‐existing heterologous memory T‐cell immunity is a major factor that influences neoantigen immunogenicity in individual cancer patients. Accumulating data suggest that differences in individual histories of microbial exposure should be taken into account during the optimisation of algorithms that predict neoantigen immunogenicity.
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Affiliation(s)
- Qibin Leng
- Affiliated Cancer Hospital & Institute of Guangzhou Medical University State Key Laboratory of Respiratory Diseases, Guangzhou Medical University Guangzhou China.,The Joint Center for Infection and Immunity Guangzhou Women and Children's Medical Center Guangzhou Institute of Pediatrics Guangzhou Medical University Guangzhou China.,Institute Pasteur of Shanghai Chinese Academy of Science Shanghai China
| | - Marion Tarbe
- The Joint Center for Infection and Immunity Guangzhou Women and Children's Medical Center Guangzhou Institute of Pediatrics Guangzhou Medical University Guangzhou China.,Institute Pasteur of Shanghai Chinese Academy of Science Shanghai China
| | - Qi Long
- Department of Biostatistics, Epidemiology and Informatics Perelman School of Medicine University of Pennsylvania Philadelphia PA USA
| | - Feng Wang
- Department of Immunology and Microbiology Center for Microbiota and Immunological Diseases Shanghai General Hospital Shanghai Institute of Immunology Shanghai Jiao Tong University School of Medicine Shanghai China.,Research Center of Translational Medicine Shanghai Children's Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
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7
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Goonetilleke N, Clutton G, Swanstrom R, Joseph SB. Blocking Formation of the Stable HIV Reservoir: A New Perspective for HIV-1 Cure. Front Immunol 2019; 10:1966. [PMID: 31507594 PMCID: PMC6714000 DOI: 10.3389/fimmu.2019.01966] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 08/05/2019] [Indexed: 12/13/2022] Open
Abstract
Recent studies demonstrate that the stable HIV-1 reservoir in resting CD4+ T cells is mostly formed from viruses circulating when combination antiretroviral therapy (ART) is initiated. Here we explore the immunological basis for these observations. Untreated HIV-1 infection is characterized by a progressive depletion of memory CD4+ T cells which mostly express CD127, the α chain of the IL-7 receptor (IL-7R). Depletion results from both direct infection and bystander loss of memory CD4+ T cells in part attributed to dysregulated IL-7/IL-7R signaling. While IL-7/IL7R signaling is not essential for the generation of effector CD4+ T cells from naïve cells, it is essential for the further transition of effectors to memory CD4+ T cells and their subsequent homeostatic maintenance. HIV-1 infection therefore limits the transition of CD4+ T cells from an effector to long-lived memory state. With the onset of ART, virus load (VL) levels rapidly decrease and the frequency of CD127+ CD4+ memory T cells increases, indicating restoration of effector to memory transition in CD4+ T cells. Collectively these data suggest that following ART initiation, HIV-1 infected effector CD4+ T cells transition to long-lived, CD127+ CD4+ T cells forming the majority of the stable HIV-1 reservoir. We propose that combining ART initiation with inhibition of IL-7/IL-7R signaling to block CD4+ T cell memory formation will limit the generation of long-lived HIV-infected CD4+ T cells and reduce the overall size of the stable HIV-1 reservoir.
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Affiliation(s)
- Nilu Goonetilleke
- Department of Microbiology & Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- UNC HIV-1 Cure Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Genevieve Clutton
- Department of Microbiology & Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- UNC HIV-1 Cure Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Ron Swanstrom
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Lineberger Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Sarah B. Joseph
- Department of Microbiology & Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Lineberger Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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8
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Garg H, Joshi A. Host and Viral Factors in HIV-Mediated Bystander Apoptosis. Viruses 2017; 9:v9080237. [PMID: 28829402 PMCID: PMC5579491 DOI: 10.3390/v9080237] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 08/14/2017] [Accepted: 08/16/2017] [Indexed: 02/07/2023] Open
Abstract
Human immunodeficiency virus (HIV) infections lead to a progressive loss of CD4 T cells primarily via the process of apoptosis. With a limited number of infected cells and vastly disproportionate apoptosis in HIV infected patients, it is believed that apoptosis of uninfected bystander cells plays a significant role in this process. Disease progression in HIV infected individuals is highly variable suggesting that both host and viral factors may influence HIV mediated apoptosis. Amongst the viral factors, the role of Envelope (Env) glycoprotein in bystander apoptosis is well documented. Recent evidence on the variability in apoptosis induction by primary patient derived Envs underscores the role of Env glycoprotein in HIV disease. Amongst the host factors, the role of C-C Chemokine Receptor type 5 (CCR5), a coreceptor for HIV Env, is also becoming increasingly evident. Polymorphisms in the CCR5 gene and promoter affect CCR5 cell surface expression and correlate with both apoptosis and CD4 loss. Finally, chronic immune activation in HIV infections induces multiple defects in the immune system and has recently been shown to accelerate HIV Env mediated CD4 apoptosis. Consequently, those factors that affect CCR5 expression and/or immune activation in turn indirectly regulate HIV mediated apoptosis making this phenomenon both complex and multifactorial. This review explores the complex role of various host and viral factors in determining HIV mediated bystander apoptosis.
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Affiliation(s)
- Himanshu Garg
- Center of Emphasis in Infectious Diseases, Department of Biomedical Sciences, Texas Tech University Health Sciences Center, 5001 El Paso Dr., El Paso, TX 79905, USA.
| | - Anjali Joshi
- Center of Emphasis in Infectious Diseases, Department of Biomedical Sciences, Texas Tech University Health Sciences Center, 5001 El Paso Dr., El Paso, TX 79905, USA.
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9
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Lorio MA, Rosa R, Suarez JF, Ruiz P, Ciancio G, Burke GW, Camargo JF. Influence of immune activation on the risk of allograft rejection in human immunodeficiency virus-infected kidney transplant recipients. Transpl Immunol 2016; 38:40-43. [PMID: 27297667 DOI: 10.1016/j.trim.2016.06.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 06/08/2016] [Accepted: 06/09/2016] [Indexed: 12/20/2022]
Abstract
BACKGROUND HIV infection is associated with high rates of acute rejection following kidney transplantation. The underlying mechanisms for such predisposition are incompletely understood. Pathological immune activation is a hallmark of chronic HIV infection that persists despite effective antiretroviral therapy. We hypothesized that the baseline levels of T cell activation in HIV(+) candidates would correlate with their risk of acute rejection following kidney transplantation. METHODS Single-center retrospective cohort analysis of HIV(+) adult kidney transplants performed between October 2006 and September 2013. The frequency of CD3(+)HLA-DR(+) cells measured by flow cytometry served as a surrogate marker of immune activation. Patients were categorized into tertiles of activation, and the rates of biopsy-proven acute rejection were compared across groups. RESULTS (1) Compared to matched HIV(-) controls, the baseline number of CD3(+)HLA-DR(+) cells was higher in HIV(+) kidney transplant candidates. (2) Abnormally high levels of activation did not decrease with transplant-associated immunosuppression. (3) Patients categorized within the lower and middle CD3(+)HLA-DR(+) tertiles had higher probability of rejection during the first 3years post-transplant compared to those in the higher activation tertile (36.9% vs. 0%; log-rank P=0.04). CONCLUSIONS Pathological immune activation in HIV(+) transplant candidates does not explain their increased susceptibility to allograft rejection. Paradoxically, those with the highest levels of immune activation seem to be less prone to rejection.
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Affiliation(s)
- Marco A Lorio
- Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Rossana Rosa
- Department of Medicine, Division of Infectious Diseases, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Jose F Suarez
- Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Phillip Ruiz
- Department of Surgery, University of Miami Miller School of Medicine and Miami Transplant Institute at the Jackson Memorial Hospital, Miami, FL, USA
| | - Gaetano Ciancio
- Department of Surgery, University of Miami Miller School of Medicine and Miami Transplant Institute at the Jackson Memorial Hospital, Miami, FL, USA
| | - George W Burke
- Department of Surgery, University of Miami Miller School of Medicine and Miami Transplant Institute at the Jackson Memorial Hospital, Miami, FL, USA
| | - Jose F Camargo
- Department of Medicine, Division of Infectious Diseases, University of Miami Miller School of Medicine, Miami, FL, USA
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Kanduc D. Measles virus hemagglutinin epitopes are potential hotspots for crossreactions with immunodeficiency-related proteins. Future Microbiol 2016; 10:503-15. [PMID: 25865190 DOI: 10.2217/fmb.14.137] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
AIMS Measles virus (MV) infection induces a protective immunity that is accompanied by a transient pathologic suppression of the immune system. This immunologic paradox remains unexplained in spite of the numerous hypotheses that have been advanced (i.e., cytokine production, soluble immunosuppressive factor, cell cycle block, signaling lymphocyte activation molecule receptor and MV infection of dendritic cells, among others). METHODS Searching for molecular link(s) between MV infection and host immunodeficiency, this study used the Immune Epitope DataBase to analyze the peptide sharing between the antigenic MV hemagglutinin (H) protein and human proteins associated with immunodeficiency. RESULTS It was found that the majority of MVH derived epitopes share several exact pentapeptide sequences with numerous human proteins involved in immune functions and immunodeficiency, such as B- and T-cell antigens, and complement components. CONCLUSION The data suggest that crossreactivity might contribute to our understanding of the link between MV immunogenicity and MV-induced immunosuppression, and highlight peptides unique to MV as a basis for developing effective and safe anti-MV vaccines.
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11
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Lipopolysaccharide Increases Immune Activation and Alters T Cell Homeostasis in SHIVB'WHU Chronically Infected Chinese Rhesus Macaque. J Immunol Res 2015; 2015:202738. [PMID: 26713320 PMCID: PMC4680103 DOI: 10.1155/2015/202738] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 11/05/2015] [Indexed: 11/18/2022] Open
Abstract
Immune activation plays a significant role in the disease progression of HIV. Microbial products, especially bacterial lipopolysaccharide (LPS), contribute to immune activation. Increasing evidence indicates that T lymphocyte homeostasis disruptions are associated with immune activation. However, the mechanism by which LPS affects disruption of immune response is still not fully understood. Chronically SHIVB'WHU-infected Chinese rhesus macaques received 50 μg/kg body weight LPS in this study. LPS administration affected the virus/host equilibrium by elevating the levels of viral replication and activating T lymphocytes. LPS induced upregulation of CD8+ naïve T cells and downregulated the number of CD4+ and CD8+ T effector memory cells. The downregulated effector memory cells are associated with a lower frequency of monofunctional and polyfunctional cells, and an upregulated programmed cell death-1 (PD-1) expression on CD4+ and CD8+ T cells was observed in monkeys after LPS stimulation. Our data provide new insights into the function of LPS in the immune activation in SHIV/HIV infection.
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12
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Abstract
Objectives: HIV-1 replication depends on the state of cell activation and division. It is established that SAMHD1 restricts HIV-1 infection of resting CD4+ T cells. The modulation of SAMHD1 expression during T-cell activation and proliferation, however, remains unclear, as well as a role for SAMHD1 during HIV-1 pathogenesis. Methods: SAMHD1 expression was assessed in CD4+ T cells after their activation and in-vitro HIV-1 infection. We performed phenotype analyzes using flow cytometry on CD4+ T cells from peripheral blood and lymph nodes from cohorts of HIV-1-infected individuals under antiretroviral treatment or not, and controls. Results: We show that SAMHD1 expression decreased during CD4+ T-cell proliferation in association with an increased susceptibility to in-vitro HIV-1 infection. Additionally, circulating memory CD4+ T cells are enriched in cells with low levels of SAMHD1. These SAMHD1low cells are highly differentiated, exhibit a large proportion of Ki67+ cycling cells and are enriched in T-helper 17 cells. Importantly, memory SAMHD1low cells were depleted from peripheral blood of HIV-infected individuals. We also found that follicular helper T cells present in secondary lymphoid organs lacked the expression of SAMHD1, which was accompanied by a higher susceptibility to HIV-1 infection in vitro. Conclusion: We demonstrate that SAMHD1 expression is decreased during CD4+ T-cell activation and proliferation. Also, CD4+ T-cell subsets known to be more susceptible to HIV-1 infection, for example, T-helper 17 and follicular helper T cells, display lower levels of SAMHD1. These results pin point a role for SAMHD1 expression in HIV-1 infection and the concomitant depletion of CD4+ T cells.
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13
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Asokan M, Sachidanandam V, Satish KS, Ranga U. Attenuation of immune activation in an open-label clinical trial for HIV-AIDS using a polyherbal formulation. Virusdisease 2015; 25:302-13. [PMID: 25674597 DOI: 10.1007/s13337-014-0218-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 05/05/2014] [Indexed: 10/25/2022] Open
Abstract
To explain a stable clinical outcome observed in a previous pilot clinical trial using a polyherbal formulation (PHF) for HIV-AIDS, we, in the present study, evaluated the T cell functions from fresh and stored blood samples. In three clinical groups-the anti-retroviral therapy, PHF and control arms-we compared the circulating levels of lipopolysaccharide, LPS-binding protein, soluble CD14, aspartate transaminase (AST) and alanine transaminase (ALT). Additionally, we evaluated the expression of T cell markers and gag-specific immune responses. The PHF treatment significantly reduced the levels of sCD14, AST and ALT. In a cross-sectional analysis at 30 months post-treatment, in comparison to the control group, the PHF arm showed significantly low per-cell expression of PD1, CD95 and HLA-DR. The PHF treatment appears to have attenuated general immune activation and hepatic inflammation in the study participants. Targeting the mediators of immune activation must be pursued as a useful strategy for HIV-AIDS management.
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Affiliation(s)
- Mangaiarkarasi Asokan
- HIV-AIDS Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore, 560 064 India
| | - Vijaya Sachidanandam
- Microbiology and Cell Biology Department, Indian Institute of Science, Bangalore, 560 012 India
| | | | - Udaykumar Ranga
- HIV-AIDS Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore, 560 064 India
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Mkhize-Kwitshana ZL, Mabaso ML, Walzl G. Proliferative capacity and cytokine production by cells of HIV-infected and uninfected adults with different helminth infection phenotypes in South Africa. BMC Infect Dis 2014; 14:499. [PMID: 25209883 PMCID: PMC4262143 DOI: 10.1186/1471-2334-14-499] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 09/02/2014] [Indexed: 11/17/2022] Open
Abstract
Background It has been suggested that the proliferative capacity of cells from individuals with HIV or both HIV and helminth infections is attenuated and cytokine production is dysregulated. This study describes peripheral blood mononuclear cell proliferation capacity and cytokine profile from individuals with HIV or both HIV and helminth infections in South Africa. Methods Forty HIV-infected and 22 HIV-uninfected participants were randomly selected and stratified into different helminth infection phenotypes by egg excretion and Ascaris lumbricoides specific –immunoglobulin-E (IgE) levels. Five day cell cultures of participants, unstimulated or stimulated with Phytohaemaglutinnin, Streptokinase, HIV-1 p24 and Ascaris lumbricoides worm antigens were stained with monoclonal antibody-fluorochrome conjugates (Ki67-FITC and CTLA-APC-4). Percentage expression of Ki67 and CTLA-4 was measured to determine cell proliferation and regulation, respectively. Culture supernatants were analysed for the expression of 13 cytokines using the Bioplex (BioRad) system. Kruskal Wallis was used to test for differences in variables between helminth infected subgroups who were either having eggs in stool and high IgE (egg+IgEhi); or eggs in stool and low IgE (egg+IgElo); or no eggs in stool and high IgE (egg-IgEhi) and those without helminth infection (egg-IgElo). Results Individuals excreting eggs in stool with high serum IgE (egg+IgEhi phenotype) had potent mitogen responses but consistently produced low, but statistically non-significant antigen–specific (HIV-1 p24 (p = 0.41) and Ascaris (p = 0.19) and recall antigen (Streptokinase; p = 0.31) Ki67 responses. The group also had reduced type 1 cytokines. Individuals excreting eggs in stool with low serum IgE( egg+IgElo phenotype) had a more favourable antiviral profile, characterized by higher IFNγ, IL-2, lower IL-4 and higher IL-10 production. Conclusion The findings suggest that dual HIV/helminth infection with egg excretion and/or high Ascaris IgE phenotye may be linked with poor proliferative capacity and deleterious cytokine profile with regards to HIV control. Electronic supplementary material The online version of this article (doi:10.1186/1471-2334-14-499) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Zilungile L Mkhize-Kwitshana
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, P,O, Box 7, Congella 4001, South Africa.
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Association between latent proviral characteristics and immune activation in antiretrovirus-treated human immunodeficiency virus type 1-infected adults. J Virol 2014; 88:8629-39. [PMID: 24850730 DOI: 10.1128/jvi.01257-14] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
UNLABELLED Generalized immune activation during HIV infection is associated with an increased risk of cardiovascular disease, neurocognitive disease, osteoporosis, metabolic disorders, and physical frailty. The mechanisms driving this immune activation are poorly understood, particularly for individuals effectively treated with antiretroviral medications. We hypothesized that viral characteristics such as sequence diversity may play a role in driving HIV-associated immune activation. We therefore sequenced proviral DNA isolated from peripheral blood mononuclear cells from HIV-infected individuals on fully suppressive antiretroviral therapy. We performed phylogenetic analyses, calculated viral diversity and divergence in the env and pol genes, and determined coreceptor tropism and the frequency of drug resistance mutations. Comprehensive immune profiling included quantification of immune cell subsets, plasma cytokine levels, and intracellular signaling responses in T cells, B cells, and monocytes. These antiretroviral therapy-treated HIV-infected individuals exhibited a wide range of diversity and divergence in both env and pol genes. However, proviral diversity and divergence in env and pol, coreceptor tropism, and the level of drug resistance did not significantly correlate with markers of immune activation. A clinical history of virologic failure was also not significantly associated with levels of immune activation, indicating that a history of virologic failure does not inexorably lead to increased immune activation as long as suppressive antiretroviral medications are provided. Overall, this study demonstrates that latent viral diversity is unlikely to be a major driver of persistent HIV-associated immune activation. IMPORTANCE Chronic immune activation, which is associated with cardiovascular disease, neurologic disease, and early aging, is likely to be a major driver of morbidity and mortality in HIV-infected individuals. Although treatment of HIV with antiretroviral medications decreases the level of immune activation, levels do not return to normal. The factors driving this persistent immune activation, particularly during effective treatment, are poorly understood. In this study, we investigated whether characteristics of the latent, integrated HIV provirus that persists during treatment are associated with immune activation. We found no relationship between latent viral characteristics and immune activation in treated individuals, indicating that qualities of the provirus are unlikely to be a major driver of persistent inflammation. We also found that individuals who had previously failed treatment but were currently effectively treated did not have significantly increased levels of immune activation, providing hope that past treatment failures do not have a lifelong "legacy" impact.
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Increased Escherichia coli-induced interleukin-23 production by CD16+ monocytes correlates with systemic immune activation in untreated HIV-1-infected individuals. J Virol 2013; 87:13252-62. [PMID: 24067979 DOI: 10.1128/jvi.01767-13] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The level of microbial translocation from the intestine is increased in HIV-1 infection. Proinflammatory cytokine production by peripheral antigen-presenting cells in response to translocated microbes or microbial products may contribute to systemic immune activation, a hallmark of HIV-1 infection. We investigated the cytokine responses of peripheral blood myeloid dendritic cells (mDCs) and monocytes to in vitro stimulation with commensal enteric Escherichia coli in peripheral blood mononuclear cells (PBMC) from untreated HIV-1-infected subjects and from uninfected controls. Levels of interleukin 23 (IL-23) produced by PBMC from HIV-1-infected subjects in response to E. coli stimulation were significantly higher than those produced by PBMC from uninfected subjects. IL-23 was produced primarily by CD16(+) monocytes. This subset of monocytes was increased in frequency and expressed higher levels of Toll-like receptor 4 (TLR4) in HIV-1-infected individuals than in controls. Blocking TLR4 on total CD14(+) monocytes reduced IL-23 production in response to E. coli stimulation. Levels of soluble CD27, an indicator of systemic immune activation, were elevated in HIV-1-infected subjects and were associated with the percentage of CD16(+) monocytes and the induction of IL-23 by E. coli, providing a link between these parameters and systemic inflammation. Taken together, these results suggest that IL-23 produced by CD16(+) monocytes in response to microbial stimulation may contribute to systemic immune activation in HIV-1-infected individuals.
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Rainwater-Lovett K, Nkamba HC, Mubiana-Mbewe M, Moore CB, Moss WJ. Immunologic risk factors for early mortality after starting antiretroviral therapy in HIV-infected Zambian children. AIDS Res Hum Retroviruses 2013; 29:479-87. [PMID: 23025633 DOI: 10.1089/aid.2012.0246] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
To explore immunologic risk factors for death within 90 days of highly active antiretroviral therapy (HAART) initiation, CD4(+) and CD8(+) T cell subsets were measured by flow cytometry and characterized by logistic regression in 149 Zambian children between 9 months and 10 years of age enrolled in a prospective, observational study of the impact of HAART on measles immunity. Of 21 children who died during follow-up, 17 (81%) had known dates of death and 16 (76%) died within 90 days of initiating HAART. Young age and low weight-for-age z-scores were associated with increased risks of mortality within 90 days of starting HAART, whereas CD4(+) T cell percentage was not associated with mortality. After adjusting for these factors, each 10% increase in CD8(+) effector T cells increased the odds of overall mortality [OR=1.43 (95% CI: 1.08, 1.90)] and was marginally associated with early mortality [OR=1.29 (95% CI: 0.97, 1.72)]. Conversely, each 10% increase in CD4(+) central memory T cells decreased the odds of overall [OR=0.06 (95% CI: 0.01, 0.59)] and early mortality [OR=0.09 (95% CI: 0.01, 0.97)]. Logistic regression prediction models demonstrated areas under the receiver-operator characteristic curves of ≥85% for early and overall mortality, with bootstrapped sensitivities of 82-85% upon validation, supporting the predictive accuracy of the models. CD4(+) and CD8(+) T cell subsets may be more accurate predictors of early mortality than CD4(+) T cell percentages and could be used to identify children who would benefit from more frequent clinical monitoring after initiating HAART.
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Affiliation(s)
- Kaitlin Rainwater-Lovett
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Hope C. Nkamba
- Virology Laboratory, University Teaching Hospital, Lusaka, Zambia
| | | | - Carolyn Bolton Moore
- Center for Infectious Disease Research-Zambia, Lusaka, Zambia
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - William J. Moss
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
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Abstract
Apoptosis of uninfected bystander cells is a key element of HIV pathogenesis and believed to be the driving force behind the selective depletion of CD4+ T cells leading to immunodeficiency. While several viral proteins have been implicated in this process the complex interaction between Env glycoprotein expressed on the surface of infected cells and the receptor and co-receptor expressing bystander cells has been proposed as a major mechanism. HIV-1 utilizes CD4 as the primary receptor for entry into cells; however, it is the viral co-receptor usage that greatly influences CD4 decline and progression to AIDS. This phenomenon is relatively simple for X4 viruses, which arise later during the course of the disease, are considered to be highly fusogenic, and cause a rapid CD4+ T cell decline. However, in contrast, R5 viruses in general have a greater transmissibility, are encountered early during the disease and have a lesser pathogenic potential than the former. The above generalization gets complicated in numerous situations where R5 viruses persist throughout the disease and are capable of causing a rigorous CD4+ T cell decline. This review will discuss the multiple factors that are reported to influence HIV induced bystander apoptosis and pathogenesis including Env glycoprotein phenotype, virus tropism, disease stage, co-receptor expression on CD4+ T cells, immune activation and therapies targeting the viral envelope.
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Affiliation(s)
- Himanshu Garg
- Center of Excellence for Infectious Disease, Department of Biomedical Science, Texas Tech University Health Sciences Center, 5001 El Paso Dr, MSB-1 Annex, El Paso, TX 79905, USA.
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Ruffin N, Lantto R, Pensieroso S, Sammicheli S, Hejdeman B, Rethi B, Chiodi F. Immune activation and increased IL-21R expression are associated with the loss of memory B cells during HIV-1 infection. J Intern Med 2012; 272:492-503. [PMID: 22530560 DOI: 10.1111/j.1365-2796.2012.02550.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
OBJECTIVES Microbial translocation and chronic immune activation were previously shown to be associated with impairment of T cell functions and disease progression during infection with human immunodeficiency virus type-1 (HIV-1); however, their impact on B cell function and number remains unknown. By measuring markers of immune activation and molecules involved in apoptosis regulation, we have evaluated the association between microbial translocation and loss of memory B cells in HIV-1-infected patients. METHODS Markers of activation [the interleukin-21 receptor (IL-21R) and CD38] and apoptosis (Bim, Bcl-2 and annexin V) were measured in B cell subpopulations by multicolour flow cytometry. Levels of soluble CD14 (sCD14) and lipopolysaccharide (LPS), measures of microbial translocation, were determined in plasma. Purified B cells were also exposed in vitro to Toll-like receptor (TLR) ligands. RESULTS IL-21R expression was higher in cells from HIV-1-infected patients, compared with control subjects, with the highest levels in nontreated patients. An inverse correlation was observed between IL-21R expression and percentages of circulating resting memory (RM) B cells. IL-21R-positive memory B cells were also more susceptible to spontaneous apoptosis and displayed lower levels of Bcl-2. It is interesting that the levels of sCD14, which are increased during HIV-1 infection, were correlated with decreased percentages of RM B cells and high IL-21R expression. In the plasma of HIV-1-infected individuals, a correlation was found between sCD14 and LPS levels. TLR activation of B cells in vitro resulted in IL-21R up-regulation. CONCLUSIONS Microbial translocation and the associated immune activation during HIV-1 infection may lead to high expression levels of the IL-21R activation marker in RM B cells, a feature associated with increased apoptosis and a reduced number of these cells in the circulation.
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Affiliation(s)
- N Ruffin
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet Venhälsan, South Hospital, Stockholm, Sweden
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Abstract
PURPOSE OF REVIEW To understand the cellular and molecular mechanisms of acute HIV pathogenesis. RECENT FINDINGS Recent studies have given us new insights into the mechanisms of acute HIV pathogenesis by demonstrating the 'systemic' destruction of the CD4 memory T cell compartment. This destruction occurs well before the emergence of a strong and broad immune response, highlighting the failure of the immune response to contain early viral infection and destruction. However, recent data also suggest that very few founder populations of cells are infected early, at the portal of entry, making them ideal targets for vaccine-induced immune responses that may aid in the effective control of early infection and transmission. SUMMARY HIV causes a massive destruction of memory CD4 T cells during the early acute phase of infection. This destruction proceeds largely in the absence of emerging antiviral immune responses, and severely disables the ability of the immune system to generate secondary immune responses. Early preservation of the memory CD4 compartment by shifting emphasis of antiretroviral therapeutic strategies to early treatment, and development of vaccines that can induce strong and broad immune responses, will be critical to prevent the destructive effects of early HIV infection.
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Interferon-alpha administration enhances CD8+ T cell activation in HIV infection. PLoS One 2012; 7:e30306. [PMID: 22291932 PMCID: PMC3265460 DOI: 10.1371/journal.pone.0030306] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 12/13/2011] [Indexed: 12/11/2022] Open
Abstract
Background Type I interferons play important roles in innate immune defense. In HIV infection, type I interferons may delay disease progression by inhibiting viral replication while at the same time accelerating disease progression by contributing to chronic immune activation. Methods To investigate the effects of type I interferons in HIV-infection, we obtained cryopreserved peripheral blood mononuclear cell samples from 10 subjects who participated in AIDS Clinical Trials Group Study 5192, a trial investigating the activity of systemic administration of IFNα for twelve weeks to patients with untreated HIV infection. Using flow cytometry, we examined changes in cell cycle status and expression of activation antigens by circulating T cells and their maturation subsets before, during and after IFNα treatment. Results The proportion of CD38+HLA-DR+CD8+ T cells increased from a mean of 11.7% at baseline to 24.1% after twelve weeks of interferon treatment (p = 0.006). These frequencies dropped to an average of 20.1% six weeks after the end of treatment. In contrast to CD8+ T cells, the frequencies of activated CD4+ T cells did not change with administration of type I interferon (mean percentage of CD38+DR+ cells = 2.62% at baseline and 2.17% after 12 weeks of interferon therapy). As plasma HIV levels fell with interferon therapy, this was correlated with a “paradoxical” increase in CD8+ T cell activation (p<0.001). Conclusion Administration of type I interferon increased expression of the activation markers CD38 and HLA DR on CD8+ T cells but not on CD4+ T cells of HIV+ persons. These observations suggest that type I interferons may contribute to the high levels of CD8+ T cell activation that occur during HIV infection.
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Mkhize-Kwitshana ZL, Taylor M, Jooste P, Mabaso ML, Walzl G. The influence of different helminth infection phenotypes on immune responses against HIV in co-infected adults in South Africa. BMC Infect Dis 2011; 11:273. [PMID: 21999928 PMCID: PMC3213674 DOI: 10.1186/1471-2334-11-273] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2011] [Accepted: 10/14/2011] [Indexed: 11/25/2022] Open
Abstract
Background The convergent distribution of the Human Immunodeficiency Virus (HIV) and helminth infections has led to the suggestion that infection with helminths exacerbates the HIV epidemic in developing countries. In South Africa, it is estimated that 57% of the population lives in poverty and carries the highest burden of both HIV and helmith infections, however, the disease interactions are under-researched. Methods We employed both coproscopy and Ascaris lumbricoides-specific serum IgE to increase diagnostic sensitivity and to distinguish between different helminth infection phenotypes and their effects on immune responses in HIV co-infected individuals. Coproscopy was done by formol ether and Kato Katz methods. HIV positive and negative adults were stratified according to the presence or absence of A. lumbricoides and/or Trichuris trichuria eggs with or without elevated Ascaris IgE. Lymphocyte subsets were phenotyped by flow cytometry. Viral loads, serum total IgE and eosinophils were also analysed. Lymphocyte activation markers (CCR5, HLA-DR, CD25, CD38 and CD71) were determined. Non parametric statistics were used to describe differences in the variables between the subgroups. Results Helminth prevalence ranged between 40%-60%. Four distinct subgroups of were identified, and this included egg positive/high Ascaris-specific IgE (egg+IgEhi), egg positive/low IgE (egg+IgElo), egg negative/high IgE (egg-IgEhi) and egg negative/low IgE (egg-IgElo) individuals. The egg+IgEhi subgroup displayed lymphocytopenia, eosinophilia, (low CD4+ counts in HIV- group), high viral load (in HIV+ group), and an activated lymphocyte profile. High Ascaris IgE subgroups (egg+IgEhi and egg-IgEhi) had eosinophilia, highest viral loads, and lower CD4+ counts in the HIV- group). Egg excretion and low IgE (egg+IgElo) status demonstrated a modified Th2 immune profile with a relatively competent response to HIV. Conclusions People with both helminth egg excretion and high Ascaris-IgE levels had dysregulated immune cells, high viral loads with more immune activation. A modified Th2 helminth response in individuals with egg positive stools and low Ascaris IgE showed a better HIV related immune profile. Future research on helminth-HIV co-infection should include parasite-specific IgE measurements in addition to coproscopy to delineate the different response phenotypes. Helminth infection affects the immune response to HIV in some individuals with high IgE and egg excretion in stool.
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Affiliation(s)
- Zilungile L Mkhize-Kwitshana
- Offfice of the Deputy Dean: Postgraduate and Research, NRM School of Medicine, University of KwaZulu-Natal, Congella, South Africa.
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Decline of CD4⁺ T-cell count before start of therapy and immunological response to treatment in antiretroviral-naive individuals. AIDS 2011; 25:1041-9. [PMID: 21412128 DOI: 10.1097/qad.0b013e3283463ec5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Treatment guidelines recommend initiation of therapy for individuals experiencing rapid CD4 cell decline. It is not known, however, whether the rate of CD4 cell decline before combination antiretroviral therapy (cART) is related to immunological response following cART. METHODS We estimated precART and postcART CD4 cell slopes by mixed models and categorized patients into two groups according to whether estimated precART slopes were above or below the 75th percentile. We compared immunological responses of the two groups through both mixed models and survival techniques. Models were stratified by CD4 cell at baseline, adjusted for HIV RNA, age, sex, HIV transmission group, year of seroconversion, initiation during primary infection, hepatitis C virus and hepatitis B virus serostatus, and cART class. RESULTS Of 2038 eligible patients, 1531 and 507 experienced median (interquartile range) precART CD4 cell slope of −105 (−471 to −61) and −42 (−62 to −80) cells/μl, respectively, over 2 years. After adjusting for potential confounders, individuals with shallower decline experienced a slower rate of CD4 cell recovery following cART initiation of +9.5 [95% confidence interval (CI) +6.6 to +12.2] compared to +13.9 (+13.0 to +14.8) cells/μl per month among those with steeper precART decline (P < 0.001). After stratifying by the baseline CD4 cell count, the adjusted relative hazard of an increase from baseline of more than 50 cells/μl was 0.70 (95% CI 0.62−0.79) for those with a shallower vs. steeper precART decline. CONCLUSION Findings highlight the existence of a subgroup of individuals with shallower precART CD4 cell decline who experience poorer CD4 cell increases after cART; new studies in this group may provide information to optimize responses to therapy.
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Single amino acid change in gp41 region of HIV-1 alters bystander apoptosis and CD4 decline in humanized mice. Virol J 2011; 8:34. [PMID: 21255440 PMCID: PMC3034703 DOI: 10.1186/1743-422x-8-34] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Accepted: 01/21/2011] [Indexed: 11/24/2022] Open
Abstract
Background The mechanism by which HIV infection leads to a selective depletion of CD4 cells leading to immunodeficiency remains highly debated. Whether the loss of CD4 cells is a direct consequence of virus infection or bystander apoptosis of uninfected cells is also uncertain. Results We have addressed this issue in the humanized mouse model of HIV infection using a HIV variant with a point mutation in the gp41 region of the Env glycoprotein that alters its fusogenic activity. We demonstrate here that a single amino acid change (V38E) altering the cell-to-cell fusion activity of the Env minimizes CD4 loss in humanized mice without altering viral replication. This differential pathogenesis was associated with a lack of bystander apoptosis induction by V38E virus even in the presence of similar levels of infected cells. Interestingly, immune activation was observed with both WT and V38E infection suggesting that the two phenomena are likely not interdependent in the mouse model. Conclusions We conclude that Env fusion activity is one of the determinants of HIV pathogenesis and it may be possible to attenuate HIV by targeting gp41.
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The Effect of Antiretroviral Combination Treatment on Epstein-Barr Virus (EBV) Genome Load in HIV-Infected Patients. Viruses 2010; 2:867-879. [PMID: 21994658 PMCID: PMC3185664 DOI: 10.3390/v2040867] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Revised: 02/24/2010] [Accepted: 03/02/2010] [Indexed: 11/21/2022] Open
Abstract
We evaluated the effect of combination anti-retroviral treatment (cART) on the host control of EBV infection in moderately immunosuppressed HIV-1 patients. Twenty HIV-1 infected individuals were followed for five years with repeated measurements of EBV DNA load in peripheral blood lymphocytes in relation to HIV-RNA titers and CD4+ cell counts. Individuals with optimal response, i.e. durable non-detectable HIV-RNA, showed a decline of EBV load to the level of healthy controls. Individuals with non-optimal HIV-1 control did not restore their EBV control. Long-lasting suppression of HIV-replication after early initiation of cART is a prerequisite for re-establishing the immune control of EBV.
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Bosinger SE, Li Q, Gordon SN, Klatt NR, Duan L, Xu L, Francella N, Sidahmed A, Smith AJ, Cramer EM, Zeng M, Masopust D, Carlis JV, Ran L, Vanderford TH, Paiardini M, Isett RB, Baldwin DA, Else JG, Staprans SI, Silvestri G, Haase AT, Kelvin DJ. Global genomic analysis reveals rapid control of a robust innate response in SIV-infected sooty mangabeys. J Clin Invest 2010; 119:3556-72. [PMID: 19959874 DOI: 10.1172/jci40115] [Citation(s) in RCA: 259] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2009] [Accepted: 10/19/2009] [Indexed: 01/07/2023] Open
Abstract
Natural SIV infection of sooty mangabeys (SMs) is nonprogressive despite chronic virus replication. Strikingly, it is characterized by low levels of immune activation, while pathogenic SIV infection of rhesus macaques (RMs) is associated with chronic immune activation. To elucidate the mechanisms underlying this intriguing phenotype, we used high-density oligonucleotide microarrays to longitudinally assess host gene expression in SIV-infected SMs and RMs. We found that acute SIV infection of SMs was consistently associated with a robust innate immune response, including widespread upregulation of IFN-stimulated genes (ISGs) in blood and lymph nodes. While SMs exhibited a rapid resolution of ISG expression and immune activation, both responses were observed chronically in RMs. Systems biology analysis indicated that expression of the lymphocyte inhibitory receptor LAG3, a marker of T cell exhaustion, correlated with immune activation in SIV-infected RMs but not SMs. Our findings suggest that active immune regulatory mechanisms, rather than intrinsically attenuated innate immune responses, underlie the low levels of immune activation characteristic of SMs chronically infected with SIV.
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Affiliation(s)
- Steven E Bosinger
- Department of Pathology and Laboratory Medicine, and Microbiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
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Engram JC, Dunham RM, Makedonas G, Vanderford TH, Sumpter B, Klatt NR, Ratcliffe SJ, Garg S, Paiardini M, McQuoid M, Altman JD, Staprans SI, Betts MR, Garber DA, Feinberg MB, Silvestri G. Vaccine-induced, simian immunodeficiency virus-specific CD8+ T cells reduce virus replication but do not protect from simian immunodeficiency virus disease progression. THE JOURNAL OF IMMUNOLOGY 2009; 183:706-17. [PMID: 19542473 DOI: 10.4049/jimmunol.0803746] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Our limited understanding of the interaction between primate lentiviruses and the host immune system complicates the design of an effective HIV/AIDS vaccine. To identify immunological correlates of protection from SIV disease progression, we immunized two groups of five rhesus macaques (RMs) with either modified vaccinia Ankara (MVA) or MVADeltaudg vectors that expressed SIVmac239 Gag and Tat. Both vectors raised a SIV-specific CD8(+) T cell response, with a magnitude that was greater in mucosal tissues than in peripheral blood. After challenge with SIVmac239, all vaccinated RMs showed mucosal and systemic CD8(+) T cell recall responses that appeared faster and were of greater magnitude than those in five unvaccinated control animals. All vaccinated RMs showed a approximately 1-log lower peak and early set-point SIV viral load than the unvaccinated animals, and then, by 8 wk postchallenge, exhibited levels of viremia similar to the controls. We observed a significant direct correlation between the magnitude of postchallenge SIV-specific CD8(+) T cell responses and SIV viral load. However, vaccinated RMs showed no protection from either systemic or mucosal CD4(+) T cell depletion and no improved survival. The observation that vaccine-induced, SIV-specific CD8(+) T cells that partially control SIVmac239 virus replication fail to protect from immunological or clinical progression of SIV infection underscores both the complexity of AIDS pathogenesis and the challenges of properly assessing the efficacy of candidate AIDS vaccines.
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Affiliation(s)
- Jessica C Engram
- Department of Pathology, University of Pennsylvania, Philadelphia, 19104, USA
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African descent is associated with slower CD4 cell count decline in treatment-naive patients of the Swiss HIV Cohort Study. AIDS 2009; 23:1269-76. [PMID: 19461503 DOI: 10.1097/qad.0b013e32832d4096] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE We investigated the effect of descent (African versus European) on the progression of untreated HIV infections in a prospective cohort study of HIV-1-infected individuals. METHODS We estimated the linear rate of decline of the CD4 cell count and the setpoint viral load in patients with sufficient data points. The effect of descent was assessed by microltivariate regression models including descent, sex, viral subtype, the earliest date of confirmed infection, age, and the baseline CD4 cell count; the rate of CD4 cell count decline was also analyzed with mixed-effect models and with matched comparisons between patients of African and European descent based on the baseline CD4 cell count. RESULTS We found that the decline slope of the CD4 cell count was significantly less steep (+26.6 cells/microl per year; 95% confidence interval, 12.3-41.0; P < 0.001) in patients of African descent (n = 123) compared with patients of European descent (n = 463), and this effect was independent of differences in the infecting viral subtypes. Matched comparisons confirmed the effect of African descent (P < 0.001). Remarkably, the rate of CD4 cell count decline depended strongly on the viral setpoint in patients of European descent (-46.3 cells/microl per year/log10 RNA copies/ml; 95% confidence interval, -55.8 to -36.7; P < 0.001) but not in patients of African descent. CONCLUSION Slower disease progression in patients of African descent might be related to host factors allowing better tolerance of high virus levels in patients of African descent compared with patients of European descent.
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Skowron G, Spritzler JG, Weidler J, Robbins GK, Johnson VA, Chan ES, Asmuth DM, Gandhi RT, Lie Y, Bates M, Pollard RB. Replication capacity in relation to immunologic and virologic outcomes in HIV-1-infected treatment-naive subjects. J Acquir Immune Defic Syndr 2009; 50:250-8. [PMID: 19194319 PMCID: PMC3482469 DOI: 10.1097/qai.0b013e3181938faf] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To evaluate the association between baseline (BL) replication capacity (RC) (RCBL) and immunologic/virologic parameters (at BL and after 48 weeks on therapy) in HIV-1-infected subjects initiating antiretroviral therapy. METHODS RCBL was determined using a modified Monogram PhenoSense HIV drug susceptibility assay on plasma HIV-1 from 321 treatment-naive subjects from AIDS Clinical Trials Group 384. Univariate and multivariable analyses were performed to determine the association of RCBL with BL and on-therapy virologic and immunologic outcomes. RESULTS Higher RCBL was associated with lower baseline CD4 (CD4BL) (r = -0.23, P < 0.0001), higher baseline HIV-1 RNA (r = 0.25, P < 0.0001), higher CD4BL activation percent (r = 0.23, P < 0.0001), and lower CD4BL memory count (r = -0.21, P = 0.0002). In a multivariable model, week 48 CD4 increase (DeltaCD448) was associated with lower CD4BL memory count and higher CD4BL-naive percent (P = 0.004, P = 0.015, respectively). The interaction between CD4BL and RCBL was significant (P = 0.018), with a positive association between RCBL and DeltaCD448 in subjects with higher CD4BL and a negative association at lower absCD4BL. CONCLUSIONS At baseline, higher RC was significantly associated with higher HIV-1 RNA, higher CD4 cell activation, lower CD4 cell count, and lower CD4 memory cell count. These factors may interact, directly or indirectly, to modify the extent to which CD4 recovery occurs in patients starting antiretroviral therapy at different CD4BL counts.
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Affiliation(s)
- Gail Skowron
- Division of Infectious Diseases, Roger Williams Medical Center, Providence, RI 02908, USA.
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Abstract
Mechanisms of HIV-mediated CD4+ T cell loss leading to immunodeficiency are amongst the most extensively studied yet unanswered questions in HIV biology. The level of CD4+ T cell depletion in HIV infected patients far exceeds the number of infected T cells, suggesting an indirect mechanism of HIV pathogenesis termed bystander cell death. Evidence is accumulating that the HIV envelope glycoprotein (Env) is a major determinant of HIV pathogenesis and plays a critical role in bystander cell death. The complex structure and function of HIV Env makes the determination of the mechanism of Env mediated apoptosis more complex than previously thought. This review will examine the complex relationship between HIV Env phenotype, coreceptor expression and immune activation in determining HIV pathogenesis. We review data here corresponding to the role of HIV Env hemifusion activity in HIV pathogenesis and how it interplays with other AIDS associated factors such as chemokine receptor expression and immune activation.
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Affiliation(s)
- H. Garg
- Membrane Structure and Function Section, Center for Cancer Research, Nanobiology Program, National Cancer Institute, National Institutes of Health, P.O. Box B, Building 469, Room 152, Miller Drive, Frederick, MD 21702-1201 USA
| | - R. Blumenthal
- Membrane Structure and Function Section, Center for Cancer Research, Nanobiology Program, National Cancer Institute, National Institutes of Health, P.O. Box B, Building 469, Room 152, Miller Drive, Frederick, MD 21702-1201 USA
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Albendazole treatment of HIV-1 and helminth co-infection: a randomized, double-blind, placebo-controlled trial. AIDS 2008; 22:1601-9. [PMID: 18670219 DOI: 10.1097/qad.0b013e32830a502e] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE Several co-infections have been shown to impact the progression of HIV-1 infection. We sought to determine if treatment of helminth co-infection in HIV-1-infected adults impacted markers of HIV-1 disease progression. DESIGN To date, there have been no randomized trials to examine the effects of soil-transmitted helminth eradication on markers of HIV-1 progression. METHODS A randomized, double-blind, placebo-controlled trial of albendazole (400 mg daily for 3 days) in antiretroviral-naive HIV-1-infected adults (CD4 cell count >200 cells/microl) with soil-transmitted helminth infection was conducted at 10 sites in Kenya (ClinicalTrials.gov NCT00130910). CD4 and plasma HIV-1 RNA levels at 12 weeks following randomization were compared in the trial arms using linear regression, adjusting for baseline values. RESULTS Of 1551 HIV-1-infected individuals screened for helminth infection, 299 were helminth infected. Two hundred and thirty-four adults were enrolled and underwent randomization and 208 individuals were included in intent-to-treat analyses. Mean CD4 cell count was 557 cells/microl and mean plasma viral load was 4.75 log10 copies/ml at enrollment. Albendazole therapy resulted in significantly higher CD4 cell counts among individuals with Ascaris lumbricoides infection after 12 weeks of follow-up (+109 cells/microl; 95% confidence interval +38.9 to +179.0, P = 0.003) and a trend for 0.54 log10 lower HIV-1 RNA levels (P = 0.09). These effects were not seen with treatment of other species of soil-transmitted helminths. CONCLUSION Treatment of A. lumbricoides with albendazole in HIV-1-coinfected adults resulted in significantly increased CD4 cell counts during 3-month follow-up. Given the high prevalence of A. lumbricoides infection worldwide, deworming may be an important potential strategy to delay HIV-1 progression.
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Vajpayee M, Kaushik S, Sreenivas V, Mojumdar K, Mendiratta S, Chauhan NK. Role of immune activation in CD4+ T-cell depletion in HIV-1 infected Indian patients. Eur J Clin Microbiol Infect Dis 2008; 28:69-73. [PMID: 18612665 DOI: 10.1007/s10096-008-0582-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Accepted: 06/06/2008] [Indexed: 11/30/2022]
Abstract
OBJECTIVES The correlation of immune activation with CD4(+) depletion and HIV-1 disease progression has been evidenced by several studies involving mainly clade B virus. However, this needs to be investigated in developing countries such as India predominately infected with clade C virus. MATERIALS AND METHODS In a cross-sectional study of 68 antiretroviral treatment naïve, HIV-1 infected Indian patients, we studied the association between CD4(+) T cells, plasma HIV-1 RNA levels, and immune activation markers using unadjusted and adjusted correlative analyses. RESULTS Significant negative correlations of higher magnitude were observed between the CD4(+) T cell percentages and plasma HIV-1 RNA levels in the study population when adjusted for the effects of immune activation markers. However, the negative association of CD4(+) T cells with immune activation markers remained unaffected when controlled for the effects of plasma HIV-1 RNA levels. CONCLUSIONS Our results support the important role of immune activation in CD4(+) T cell depletion and disease progression during untreated HIV-1 infection.
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Affiliation(s)
- M Vajpayee
- Department of Microbiology, HIV & Immunology Division, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India.
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Sedaghat AR, German J, Teslovich TM, Cofrancesco J, Jie CC, Talbot CC, Siliciano RF. Chronic CD4+ T-cell activation and depletion in human immunodeficiency virus type 1 infection: type I interferon-mediated disruption of T-cell dynamics. J Virol 2008; 82:1870-83. [PMID: 18077723 PMCID: PMC2258719 DOI: 10.1128/jvi.02228-07] [Citation(s) in RCA: 139] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2007] [Accepted: 11/27/2007] [Indexed: 11/20/2022] Open
Abstract
The mechanism of CD4(+) T-cell depletion during chronic human immunodeficiency virus type 1 (HIV-1) infection remains unknown. Many studies suggest a significant role for chronic CD4(+) T-cell activation. We assumed that the pathogenic process of excessive CD4(+) T-cell activation would be reflected in the transcriptional profiles of activated CD4(+) T cells. Here we demonstrate that the transcriptional programs of in vivo-activated CD4(+) T cells from untreated HIV-positive (HIV(+)) individuals are clearly different from those of activated CD4(+) T cells from HIV-negative (HIV(-)) individuals. We observed a dramatic up-regulation of cell cycle-associated and interferon-stimulated transcripts in activated CD4(+) T cells of untreated HIV(+) individuals. Furthermore, we find an enrichment of proliferative and type I interferon-responsive transcription factor binding sites in the promoters of genes that are differentially expressed in activated CD4(+) T cells of untreated HIV(+) individuals compared to those of HIV(-) individuals. We confirm these findings by examination of in vivo-activated CD4(+) T cells. Taken together, these results suggest that activated CD4(+) T cells from untreated HIV(+) individuals are in a hyperproliferative state that is modulated by type I interferons. From these results, we propose a new model for CD4(+) T-cell depletion during chronic HIV-1 infection.
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Affiliation(s)
- Ahmad R Sedaghat
- Johns Hopkins University School of Medicine, Department of Medicine, 879 BRB, 733 N. Broadway, Baltimore, Maryland 21205, USA
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Villacres MC, Literat O, DeGiacomo M, Du W, Frederick T, Kovacs A. Defective response to Toll-like receptor 3 and 4 ligands by activated monocytes in chronic hepatitis C virus infection. J Viral Hepat 2008; 15:137-44. [PMID: 18184197 PMCID: PMC3118839 DOI: 10.1111/j.1365-2893.2007.00904.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Toll-like receptors (TLR) have a critical role in innate immunity against pathogens. We investigated the cytokine response to TLR stimulation in peripheral blood cells of subjects infected with hepatitis C virus (HCV) and/or human immunodeficiency virus (HIV) in the Women Interagency HIV Study (WIHS) cohort. Interleukin (IL)-6 in response to TLR3 and TLR4 ligands such as polyinosinic-polycytidylic acid and lipopolysaccharide was significantly compromised in HCV-infected women. High spontaneous secretion of IL-6 suggested pre-existing cell activation as a factor mediating reduced responses to TLR3 and TLR4 stimulation. To a lesser extent, tumour necrosis factor-alpha and IL-1beta responses to TLR stimulation were also compromised. Monocytes, but not B cells or NK cells, were identified as the cell population spontaneously secreting cytokines and also as the cells responding to TLR stimulation. These results highlight a functional defect in antigen-presenting cells of women with HCV infection or co-infection. In women with existing HIV co-infection, decreased cytokine function of antigen-presenting cells suggests another mechanism contributing to immune dysfunction in addition to the HIV-associated CD4 defect.
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Affiliation(s)
- M C Villacres
- Maternal, Child and Adolescent Center for Infectious Diseases and Virology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.
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Anderson AML, Kosinski AS, Bartlett JA. Decreasing CD4 + T-cell Count During Suppressed or Low-Level Viraemia in Patients with HIV Infection. Antivir Ther 2007. [DOI: 10.1177/135965350701200712] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background Suboptimal improvement in CD4+ T-cell count is not uncommon in HIV-infected patients with suppressed plasma HIV RNA levels, and a decrease in CD4+T-cell count in patients with suppressed or low-level viraemia has been observed. Methods Our objectives were to identify the prevalence of decreasing CD4+ T-cell counts during suppressed or low-level viraemia, to determine the frequency of clinical events during and immediately after such decreases, and to examine for associations with individual variables. A matched case-control study was undertaken using the Duke Infectious Diseases Clinic database ( n=3,949). Cases had at least two consecutive significant decreases in either CD4+ absolute count or CD4+ percentage, while also having plasma HIV RNA levels <1,000 copies/ml. Results The prevalence of decreasing CD4+ T-cell counts during suppressed or low-level viraemia was 1.22%. Only three HIV-associated clinical events occurred. The majority of cases had an increase in the CD4+ T-cell count immediately following the study period. The use of either zidovudine or stavudine was weakly associated with decreasing CD4+ T-cell counts in a multivariable analysis, but this association was not present in cases with only a decrease in CD4+ T-cell percentage. Conclusions Decreasing CD4+ T-cell counts during suppressed or low-level viraemia are rare, typically transient, and not associated with an increase in HIV-associated clinical events.
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Affiliation(s)
- Albert ML Anderson
- Department of Medicine, Division of Infectious Diseases, Duke University Medical Centre, Durham, NC, USA
| | - Andrzej S Kosinski
- Department of Biostatistics and Bioinformatics and Duke Clinical Research Institute, Duke University Medical Centre, Durham, NC, USA
| | - John A Bartlett
- Department of Medicine, Division of Infectious Diseases, Duke University Medical Centre, Durham, NC, USA
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Kamal SM, El Sayed Khalifa K. Immune modulation by helminthic infections: worms and viral infections. Parasite Immunol 2006; 28:483-96. [PMID: 16965284 DOI: 10.1111/j.1365-3024.2006.00909.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Helminthic infections occur worldwide, especially in developing countries. About one-quarter of the world's population, 1.5 billion, are infected with one or more of the major soil-transmitted helminths, including hookworms, ascarids, and whipworms. Schistosomes infect more than 200 million people worldwide with 600 million at risk in 74 countries. The interaction between helminths and the host's immune system provokes particular immunomodulatory and immunoregulatory mechanisms that ensure their survival in the host for years. However, these changes might impair the immunological response to bystander bacterial, viral, and protozoal pathogens and to vaccination. Modulation of the immune system by infection with helminthic parasites is proposed to reduce the levels of allergic responses and to protect against inflammatory bowel disease. In this review, we summarize the immunological milieu associated with helminthic infections and its impact on viral infections, mainly hepatitis B virus, hepatitis C virus, and human immunodeficiency virus in humans and experimental animals.
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Affiliation(s)
- S M Kamal
- Department of Tropical Medicine, Ain Shams Faculty of Medicine, Heliopolis, Cairo, Egypt.
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Wang Z, Metcalf B, Ribeiro RM, McClure H, Kaur A. Th-1-type cytotoxic CD8+ T-lymphocyte responses to simian immunodeficiency virus (SIV) are a consistent feature of natural SIV infection in sooty mangabeys. J Virol 2006; 80:2771-83. [PMID: 16501086 PMCID: PMC1395440 DOI: 10.1128/jvi.80.6.2771-2783.2006] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sooty mangabeys are a natural host of simian immunodeficiency virus (SIV) that remain asymptomatic and do not exhibit increased immune activation or increased T-lymphocyte turnover despite sustained high levels of SIV viremia. In this study we asked whether an altered immune response to SIV contributes to the lack of immunopathology in sooty mangabeys as opposed to species with pathogenic lentivirus infection. SIV-specific cellular immune responses were investigated in a cohort of 25 sooty mangabeys with natural SIV infection. Gamma interferon (IFN-gamma) enzyme-linked immunospot (ELISPOT) assay responses targeting a median of four SIV proteins were detected in all 25 mangabeys and were comparable in magnitude to those of 13 rhesus macaques infected with SIVmac251 for more than 6 months. As with rhesus macaques, Th2 ELISPOT responses to SIV were absent or >10-fold lower than the IFN-gamma ELISPOT response to the same SIV protein. The SIV-specific ELISPOT response was predominantly mediated by CD8+ T lymphocytes; the frequency of circulating SIV-specific CD8+ T lymphocytes ranged between 0.11% and 3.26% in 13 mangabeys. Functionally, the SIV-specific CD8+ T lymphocytes were cytotoxic; secreted IFN-gamma, tumor necrosis factor alpha, and macrophage inflammatory protein 1beta; and had an activated effector phenotype. Although there was a trend toward higher frequencies of SIV-specific CD8+ T lymphocytes in mangabeys with lower viral loads, a significant inverse correlation between SIV viremia and SIV-specific cellular immunity was not detected. The consistent detection of Th1-type SIV-specific cellular immune responses in naturally infected sooty mangabeys suggests that immune attenuation is neither a feature of nor a requirement for maintenance of nonpathogenic SIV infection in its natural host.
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Affiliation(s)
- Zichun Wang
- Division of Immunology, New England Primate Research Center, Harvard Medical School, One Pine Hill Dr., Southborough, Massachusetts 01772, USA
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Chao KH, Wu MY, Chen MJ, Hung CC, Ho HN. Impact of the Menstrual Cycle on Immunologic Markers in HIV-Infected Taiwanese Women. Taiwan J Obstet Gynecol 2006; 45:42-7. [PMID: 17272207 DOI: 10.1016/s1028-4559(09)60189-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE This study tested the relationship between cellular immunity and the menstrual cycle in Taiwanese HIV-infected and normal women. METHODS From October 1997 to October 2001, 21 HIV-seropositive women and 30 controls were enrolled in this study. Blood was sampled for hormone profile (estradiol and progesterone) and immunophenotyping with flow cytometry during the follicular and luteal phases. Immunophenotyping included total blood cell count, lymphocyte count, CD4+ cells, CD8+ cells, and their activation markers, including CD25, CD69, HLA-DR, and CD38. RESULTS The proportion of CD8+ T cells increased during the follicular phase and activating antigens (HLADR and CD38) were elevated on CD8+ T cells of HIV-seropositive women. All these alterations seemed unrelated to the menstrual cycle. CONCLUSIONS The CD8+ T cells were increased and activated in women with HIV infection but these alterations were not affected by the menstrual cycle. Therefore, sex hormones seem not to affect the course of HIV infection.
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Affiliation(s)
- Kuang-Han Chao
- Department of Obstetrics and Gynecology, Medical College and Hospital, National Taiwan University, Taipei, Taiwan
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Paiardini M, Cervasi B, Sumpter B, McClure HM, Sodora DL, Magnani M, Staprans SI, Piedimonte G, Silvestri G. Perturbations of cell cycle control in T cells contribute to the different outcomes of simian immunodeficiency virus infection in rhesus macaques and sooty mangabeys. J Virol 2006; 80:634-42. [PMID: 16378966 PMCID: PMC1346860 DOI: 10.1128/jvi.80.2.634-642.2006] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Accepted: 10/25/2005] [Indexed: 12/21/2022] Open
Abstract
In contrast to human immunodeficiency virus (HIV) infection of humans and experimental simian immunodeficiency virus (SIV) infection of rhesus macaques (RMs), SIV infection of sooty mangabeys (SMs), a natural host African monkey species, is typically nonpathogenic and associated with preservation of CD4+ T-cell counts despite chronic high levels of viral replication. In previous studies, we have shown that the lack of SIV disease progression in SMs is related to lower levels of immune activation and bystander T-cell apoptosis compared to those of pathogenic HIV/SIV infection (G. Silvestri, D. Sodora, R. Koup, M. Paiardini, S. O'Neil, H. M. McClure, S. I. Staprans, and M. B. Feinberg, Immunity 18:441-452, 2003; G. Silvestri, A. Fedanov, S. Germon, N. Kozyr, W. J. Kaiser, D. A. Garber, H. M. McClure, M. B. Feinberg, and S. I. Staprans, J. Virol. 79:4043-4054, 2005). In HIV-infected patients, increased T-cell susceptibility to apoptosis is associated with a complex cell cycle dysregulation (CCD) that involves increased activation of the cyclin B/p34-cdc2 complex and abnormal nucleolar structure with dysregulation of nucleolin turnover. Here we report that CCD is also present during pathogenic SIV infection of RMs, and its extent correlates with the level of immune activation and T-cell apoptosis. In marked contrast, naturally SIV-infected SMs show normal regulation of cell cycle control (i.e., normal intracellular levels of cyclin B and preserved nucleolin turnover) and a low propensity to apoptosis in both peripheral blood- and lymph node-derived T cells. The absence of significant CCD in the AIDS-free, non-immune-activated SMs despite high levels of viral replication indicates that CCD is a marker of disease progression during lentiviral infection and supports the hypothesis that the preservation of cell cycle control may help to confer the disease-resistant phenotype of SIV-infected SMs.
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Affiliation(s)
- M Paiardini
- Division of Infectious Diseases and Emory Vaccine Center, Emory University, 954 Gatewood Rd. NE, Atlanta, GA 30329, USA
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Sadiq ST, McSorley J, Copas AJ, Bennett J, Edwards SJ, Kaye S, Kirk S, French P, Weller IVD. The effects of early syphilis on CD4 counts and HIV-1 RNA viral loads in blood and semen. Sex Transm Infect 2005; 81:380-5. [PMID: 16199736 PMCID: PMC1745048 DOI: 10.1136/sti.2004.012914] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
OBJECTIVE To examine the effect of early syphilis on blood and semen plasma HIV-1 viral loads and CD4 counts. METHODS In a retrospective case-control study, blood plasma HIV-1 viral loads and CD4 counts in cases during early syphilis (n = 63, 27 receiving antiretroviral therapy) were compared to those before and after syphilis and with controls with non-systemic acute sexually transmitted infections (STI) (n = 104, 39 receiving antiretroviral therapy). In a prospective substudy in those not receiving antiretroviral therapy, semen plasma viral loads during early syphilis (n = 13) were compared with those 1 month, 3 months, and 6 months after treatment for syphilis and with controls with no STIs (n = 20). RESULTS Retrospective study: CD4 counts were similar in cases (median 410, n = 139 counts) during early syphilis compared to before (485, n = 80) and after (475, n = 88). In a secondary analysis, a drop in CD4 count (21%) among those with early latent syphilis was observed compared with controls. Blood plasma viral loads did not change significantly overall or in those with primary, secondary, or early latent syphilis. Effects were similar on or off antiretroviral therapy. Prospective study: blood and semen viral loads were slightly higher in cases compared with controls but treatment of early syphilis did not reduce either. CONCLUSIONS We detected no association between early syphilis and changes in blood or semen viral load or CD4 count. Increased HIV-1 infectivity associated with early syphilis is unlikely to be associated with increased levels of HIV-1 RNA in blood or semen.
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Affiliation(s)
- S T Sadiq
- Centre for Sexual Health and HIV Research, Department of Primary Care and Population Sciences, Royal Free and University College Medical School, University College, London, UK.
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Paillot R, Richard S, Bloas F, Piras F, Poulet H, Brunet S, Andreoni C, Juillard V. Toward a detailed characterization of feline immunodeficiency virus-specific T cell immune responses and mediated immune disorders. Vet Immunol Immunopathol 2005; 106:1-14. [PMID: 15910988 DOI: 10.1016/j.vetimm.2004.12.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2004] [Revised: 11/29/2004] [Accepted: 12/21/2004] [Indexed: 11/18/2022]
Abstract
Infection of domestic cats with feline immunodeficiency virus (FIV) is associated with the development of an acquired immunodeficiency syndrome (AIDS). The pathogenesis of FIV is not fully understood but it has been reported that the immune system is progressively impaired during disease progression. As a result, anti-FIV specific immune response will usually not clear the virus and the acute stage is followed by a chronic asymptomatic phase. The overall objective of this study was to characterized FIV-induced immune cellular responses and -mediated immune disorder following the first weeks post-infection. Using both cytokine ELISpot and intracellular staining assays, FIV-specific T cells were monitored at 6, 9 and 12 weeks post-infection. We demonstrated that both IFNgamma(+) and, CD4 and CD8 TNFalpha(+) T cells specifically respond to FIV antigens. These responses were found to reach a peak at 9 weeks post-infection. It was further shown that the TNFalpha(+)CD8(+) responding T cells were contained within a CD8beta(low)CD62L(-) T cell subpopulation, expanded in FIV-infected cats. This T cell subpopulation which present features of activated CD8 T cells was further shown to be susceptible to spontaneous apoptosis following a short-term in vitro culture. Moreover, it was observed that cell death by apoptosis of this T cell subset was increased following FIV antigen-recognition. Therefore, FIV might alter immune homeostasis in inducing chronic activation of TNFalpha(+)CD8(+) T cells which eventually will die following antigen contact while deleting CD4(+) T cells. Interestingly, this study confirmed the strong similarity between FIV and HIV pathogenesis.
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Affiliation(s)
- R Paillot
- Discovery Research, Merial S.A.S., 254 rue Marcel Mérieux BP 7009, 69342 Lyon Cedex 07, France
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Peretz Y, Alter G, Boisvert MP, Hatzakis G, Tsoukas CM, Bernard NF. Human immunodeficiency virus (HIV)-specific gamma interferon secretion directed against all expressed HIV genes: relationship to rate of CD4 decline. J Virol 2005; 79:4908-17. [PMID: 15795276 PMCID: PMC1069552 DOI: 10.1128/jvi.79.8.4908-4917.2005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Immune responses to human immunodeficiency virus (HIV) are detected at all stages of infection and are believed to be responsible for controlling viremia. This study seeks to determine whether gamma interferon (IFN-gamma)-secreting HIV-specific T-cell responses influence disease progression as defined by the rate of CD4 decline. The study population consisted of 31 subjects naive to antiretroviral therapy. All were monitored clinically for a median of 24 months after the time they were tested for HIV-specific responses. The rate of CD4+-T-cell loss was calculated for all participants from monthly CD4 counts. Within this population, 17 subjects were classified as typical progressors, 6 subjects were classified as fast progressors, and 8 subjects were classified as slow progressors. Peripheral blood mononuclear cells were screened for HIV-specific IFN-gamma responses to all expressed HIV genes. Among the detected immune responses, 48% of the recognized peptides were encoded by Gag and 19% were encoded by Nef gene products. Neither the breadth nor the magnitude of HIV-specific responses correlated with the viral load or rate of CD4 decline. The breadth and magnitude of HIV-specific responses did not differ significantly among typical, fast, and slow progressors. These results support the conclusion that although diverse HIV-specific IFN-gamma-secreting responses are mounted during the asymptomatic phase, these responses do not seem to modulate disease progression rates.
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Affiliation(s)
- Yoav Peretz
- Research Institute of the McGill University Health Center, Montreal General Hospital, 1650 Cedar Ave., Rm. C10-160, Montreal, Quebec H3G 1A4, Canada
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Ayash-Rashkovsky M, Bentwich Z, Arditti F, Friedman S, Reisner Y, Borkow G. A novel small animal model for HIV-1 infection. FASEB J 2005; 19:1149-51. [PMID: 15833767 DOI: 10.1096/fj.04-3184fje] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Lethally irradiated normal BALB/c mice, reconstituted with murine SCID bone marrow and engrafted with human PBMC (Trimera mice), were used to establish a novel murine model for HIV-1 infection. The Trimera mice were successfully infected with different clades and primary isolates of T- and M-tropic HIV-1, with the infection persisting in the animals for 4-6 wk. Rapid loss of the human CD4+ T cells, decrease in CD4/CD8 ratio, and increased T cell activation accompanied the viral infection. All HIV-1 infected animals were able to generate both primary and secondary immune responses, including HIV specific human humoral and cellular responses. In addition to testing the efficacy of new antiviral compounds, this new murine HIV-1 model may be used for studying host-virus interactions and, most importantly, for screening and developing potential HIV-1 protective vaccines and adjuvants (Ayash-Rashkovsky et al., http://www.fasebj.org/cgi/doi/10.1096/fj.04-3185fje; doi:10.1096/fj.04-3185fje.).
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Moanna A, Dunham R, Paiardini M, Silvestri G. CD4+ t-cell depletion in hiv infection: Killed by friendly fire? Curr HIV/AIDS Rep 2005; 2:16-23. [PMID: 16091244 DOI: 10.1007/s11904-996-0004-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Recent studies have emphasized the role of a chronic, generalized activation of the immune system as a prominent cause of CD4+ T-cell depletion in HIV-infected patients. The HIV-induced immune activation is a strong predictor of disease progression in humans, and lack of immune activation is a key feature of nonpathogenic simian immunodeficiency virus (SIV) infection of natural hosts. The mechanisms by which immune activation induces CD4+ T-cell depletion are still incompletely understood, but likely involve changes in the complex dynamics of the naive, memory, and effector subsets of T cells. A better understanding of how HIV-induced immune activation leads to CD4+ T-cell depletion may provide new targets for immune-based interventions that could be used, in addition to standard antiretroviral therapy, to slow disease progression in HIV-infected individuals.
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Affiliation(s)
- Abeer Moanna
- Emory Vaccine Center, Emory University School of Medicine, 954 Gatewood Road NE, Atlanta, GA 30329, USA
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Paiardini M, Cervasi B, Albrecht H, Muthukumar A, Dunham R, Gordon S, Radziewicz H, Piedimonte G, Magnani M, Montroni M, Kaech SM, Weintrob A, Altman JD, Sodora DL, Feinberg MB, Silvestri G. Loss of CD127 Expression Defines an Expansion of Effector CD8+T Cells in HIV-Infected Individuals. THE JOURNAL OF IMMUNOLOGY 2005; 174:2900-9. [PMID: 15728501 DOI: 10.4049/jimmunol.174.5.2900] [Citation(s) in RCA: 185] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The immunodeficiency that follows HIV infection is related to the virus-mediated killing of infected CD4(+) T cells, the chronic activation of the immune system, and the impairment of T cell production. In this study we show that in HIV-infected individuals the loss of IL-7R (CD127) expression defines the expansion of a subset of CD8(+) T cells, specific for HIV as well as other Ags, that show phenotypic (i.e., loss of CCR7 and CD62 ligand expression with enrichment in activated and/or proliferating cells) as well as functional (i.e., production of IFN-gamma, but not IL-2, decreased ex vivo proliferative potential and increased susceptibility to apoptosis) features of effector T cells. Importantly, in HIV-infected individuals the levels of CD8(+)CD127(-) T cells are directly correlated with the main markers of disease progression (i.e., plasma viremia and CD4(+) T cell depletion) as well as with the indices of overall T cell activation. In all, these results identify the expansion of CD8(+)CD127(-) effector-like T cells as a novel feature of the HIV-associated immune perturbation. Further studies are thus warranted to determine whether measurements of CD127 expression on CD8(+) T cells may be useful in the clinical management of HIV-infected individuals.
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Affiliation(s)
- Mirko Paiardini
- Department of Medicine, and Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA 30322, USA
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48
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Borkow G, Bentwich Z. Chronic immune activation associated with chronic helminthic and human immunodeficiency virus infections: role of hyporesponsiveness and anergy. Clin Microbiol Rev 2005; 17:1012-30, table of contents. [PMID: 15489359 PMCID: PMC523563 DOI: 10.1128/cmr.17.4.1012-1030.2004] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Chronic immune activation is one of the hallmarks of human immunodeficiency virus (HIV) infection. It is present also, with very similar characteristics, in very large human populations infested with helminthic infections. We have tried to review the studies addressing the changes in the immune profiles and responses of hosts infected with either one of these two chronic infections. Not surprisingly, several of the immune derangements and impairments seen in HIV infection, and considered by many to be the "specific" effects of HIV, can be found in helminth-infected but HIV-noninfected individuals and can thus be accounted for by the chronic immune activation itself. A less appreciated element in chronic immune activation is the immune suppression and anergy which it may generate. Both HIV and helminth infections represent this aspect in a very wide and illustrative way. Different degrees of anergy and immune hyporesponsiveness are present in these infections and probably have far-reaching effects on the ability of the host to cope with these and other infections. Furthermore, they may have important practical implications, especially with regard to protective vaccinations against AIDS, for populations chronically infected with helminths and therefore widely anergic. The current knowledge of the mechanisms responsible for the generation of anergy by chronic immune activation is thoroughly reviewed.
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Affiliation(s)
- Gadi Borkow
- Animal Scienes, Faculty of Agriculture, Hebrew University, Rehovot, Israel
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Mucosal Immunity and Vaccines Against Simian Immunodeficiency Virus and Human Immunodeficiency Virus. Mucosal Immunol 2005. [DOI: 10.1016/b978-012491543-5/50056-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Bull ME, Vahlenkamp TW, Dow JL, Collisson EW, Winslow BJ, Phadke AP, Tompkins MB, Tompkins WAF. Spontaneous T cell apoptosis in feline immunodeficiency virus (FIV)-infected cats is inhibited by IL2 and anti-B7.1 antibodies. Vet Immunol Immunopathol 2004; 99:25-37. [PMID: 15113651 DOI: 10.1016/j.vetimm.2004.01.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2003] [Revised: 01/05/2004] [Accepted: 01/05/2004] [Indexed: 10/26/2022]
Abstract
Lymph node (LN) T cells from feline immunodeficiency virus (FIV)-infected cats have an increased expression of B7 co-stimulatory molecules as well as their ligand CTLA4, resembling an activation phenotype shown to induce anergy and apoptosis in activated T cells. In addition, LN T cells from FIV-infected cats also show increased spontaneous apoptosis compared to uninfected animals. The apoptosis observed in these animals occurs primarily in T cells expressing B7 and CTLA4, suggesting a role for B7 and CTLA4 interactions in the induction of anergy/apoptosis. In order to investigate the role of B7 and CTLA4 interactions on T cell apoptosis in LN T cells from FIV-infected cats, we performed blocking experiments by measuring T cell apoptosis in LN T cell cultures treated with anti-feline B7.1, B7.2, and CTLA4 specific antibodies, as well as interleukin (IL)-2. The addition of IL2, the primary cytokine produced by B7/CD28 interactions, resulted in a significant decrease of T cell apoptosis in cultured LN cells as assessed by two-color flow cytometry and TUNEL assay. The addition of anti-B7.1 antibodies significantly inhibited T cell apoptosis in FIV-infected cats with low-level plasma viremia, while addition of anti-B7.2 and anti-CTLA4 antibodies had no affect. These results suggest a role of B7 signaling in the increased spontaneous apoptosis observed in LN T cells from FIV-infected animals.
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Affiliation(s)
- Marta E Bull
- Immunology Program, College of Veterinary Medicine, North Carolina State University, 4700 Hillsborough St., Raleigh, NC 27606, USA
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