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Kim I, Srinivasula S, DeGrange P, Long B, Jang H, Carrasquillo JA, Lane HC, Di Mascio M. Quantitative PET imaging of the CD4 pool in nonhuman primates. Eur J Nucl Med Mol Imaging 2022; 50:14-26. [PMID: 36028577 PMCID: PMC9668939 DOI: 10.1007/s00259-022-05940-4] [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: 03/18/2022] [Accepted: 08/08/2022] [Indexed: 01/19/2023]
Abstract
PURPOSE Previous SPECT and PET semi-quantitative in vivo imaging studies in monkeys have demonstrated specific uptake of radiolabeled rhesus recombinant anti-CD4 monoclonal antibody fragment CD4R1-F(ab΄)2 in the spleen and clusters of lymph nodes (LNs) but yielded conflicting results of imaging the gut CD4 + T-cell pool. Here, using PET dynamic imaging with kinetic analysis, we performed a fully quantitative CD4 imaging in rhesus macaques. METHODS The biodistributions of [89Zr]Zr-CD4R1-F(ab΄)2 and/or of [89Zr]Zr-ibalizumab were performed with static PET scans up to 144 h (6 days) post-injection in 18 rhesus macaques with peripheral blood CD4 + T cells/μl ranging from ~ 20 to 2400. Fully quantitative analysis with a 4-h dynamic scan, arterial sampling, metabolite evaluation, and model fitting was performed in three immunocompetent monkeys to estimate the binding potential of CD4 receptors in the LNs, spleen, and gut. RESULTS The biodistributions of [89Zr]Zr-CD4R1-F(ab΄)2 and [89Zr]Zr-ibalizumab were similar in lymphoid tissues with a clear delineation of the CD4 pool in the LNs and spleen and a significant difference in lymphoid tissue uptake between immunocompetent and immunocompromised macaques. Consistent with our previous SPECT imaging of [99mTc]Tc-CD4R1-F(ab΄)2, the [89Zr]Zr-CD4R1-F(ab΄)2 and [89Zr]Zr-Ibalizumab uptakes in the gut were low and not different between uninfected and SIV-infected CD4-depleted monkeys. Ex vivo studies of large and small intestines confirmed the in vivo images. CONCLUSION The majority of specific binding to CD4 + tissue was localized to LNs and spleen with minimal uptake in the gut. Binding potential derived from fully quantitative studies revealed that the contribution of the gut is lower than the spleen's contribution to the total body CD4 pool.
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Affiliation(s)
- Insook Kim
- grid.418021.e0000 0004 0535 8394AIDS Imaging Research Section, Applied/Developmental Research Directorate, Frederick National Laboratory for Cancer Research, Frederick, MD 21702 USA
| | - Sharat Srinivasula
- grid.418021.e0000 0004 0535 8394AIDS Imaging Research Section, Clinical Monitoring Research Program Directorate, Frederick National Laboratory for Cancer Research, Frederick, MD 21702 USA
| | - Paula DeGrange
- grid.419681.30000 0001 2164 9667AIDS Imaging Research Section, Integrated Research Facility, NIAID, NIH, Frederick, MD 21702 USA
| | - Brad Long
- grid.419681.30000 0001 2164 9667AIDS Imaging Research Section, Integrated Research Facility, NIAID, NIH, Frederick, MD 21702 USA
| | - Hyukjin Jang
- grid.418021.e0000 0004 0535 8394AIDS Imaging Research Section, Clinical Monitoring Research Program Directorate, Frederick National Laboratory for Cancer Research, Frederick, MD 21702 USA
| | - Jorge A. Carrasquillo
- grid.51462.340000 0001 2171 9952Molecular Imaging and Therapy Service, Radiology Department, Memorial Sloan Kettering Cancer Center, New York, NY 10065 USA ,grid.48336.3a0000 0004 1936 8075Molecular Imaging Branch, Center for Cancer Research, NCI, NIH, Bethesda, MD 20892 USA
| | - H. Clifford Lane
- grid.419681.30000 0001 2164 9667Laboratory of Immunoregulation, Division of Intramural Research, NIAID, NIH, Bethesda, MD 20892 USA
| | - Michele Di Mascio
- grid.419681.30000 0001 2164 9667AIDS Imaging Research Section, Division of Clinical Research, NIAID, NIH, Bethesda, MD 20892 USA
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Xun J, Zhang X, Guo S, Lu H, Chen J. Editing out HIV: application of gene editing technology to achieve functional cure. Retrovirology 2021; 18:39. [PMID: 34922576 PMCID: PMC8684261 DOI: 10.1186/s12977-021-00581-1] [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: 02/06/2021] [Accepted: 11/05/2021] [Indexed: 03/01/2023] Open
Abstract
Highly active antiretroviral therapy (HAART) successfully suppresses human immunodeficiency virus (HIV) replication and improves the quality of life of patients living with HIV. However, current HAART does not eradicate HIV infection because an HIV reservoir is established in latently infected cells and is not recognized by the immune system. The successful curative treatment of the Berlin and London patients following bone marrow transplantation inspired researchers to identify an approach for the functional cure of HIV. As a promising technology, gene editing-based strategies have attracted considerable attention and sparked much debate. Herein, we discuss the development of different gene editing strategies in the functional cure of HIV and highlight the potential for clinical applications prospects. ![]()
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Affiliation(s)
- Jingna Xun
- Scientific Research Center, Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Shanghai, 201508, China.,State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Xinyu Zhang
- Scientific Research Center, Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Shanghai, 201508, China
| | - Shuyan Guo
- Shanghai Foreign Language School, Shanghai International Studies University, Shanghai, China
| | - Hongzhou Lu
- Department of Infectious Diseases and Immunology, Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Shanghai, 201508, China
| | - Jun Chen
- Department of Infectious Diseases and Immunology, Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Shanghai, 201508, China.
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3
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Eckard AR, Hughes HY, Hagood NL, O’Riordan MA, Labbato D, Kosco JC, Scott SE, McComsey GA. Fecal Calprotectin Is Elevated in HIV and Related to Systemic Inflammation. J Acquir Immune Defic Syndr 2021; 86:231-239. [PMID: 33065582 PMCID: PMC8285069 DOI: 10.1097/qai.0000000000002538] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 10/05/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND Fecal calprotectin (FC), a biomarker of gastrointestinal (GI) inflammation, is used in the diagnosis and management of inflammatory bowel disease. HIV infection severely damages gut-associated lymphoid and epithelial tissues leading to GI inflammation that drives systemic inflammation and increases subsequent risk of comorbidities. For the first time, we compared FC concentrations by HIV and antiretroviral therapy (ART) status and determined the relationship to systemic inflammation. METHODS People with and without HIV were enrolled and underwent a comprehensive clinical and laboratory assessment. Stool samples were collected, and FC was measured by enzyme-linked immunosorbent assay ELISA. Plasma biomarkers of inflammation were also measured. RESULTS One hundred one participants with HIV (83 ART-treated and 18 ART-naive) and 89 uninfected controls were enrolled. There were no significant differences between ART-naive and ART-treated participants, but both HIV groups had significantly higher FC concentrations than controls when FC was considered as a continuous variable or by cut-offs used in inflammatory bowel disease. The highest median and largest proportion of participants with FC >100 µg/g were seen in ART-naive, followed by ART-treated and then controls. Among HIV participants, FC concentrations were positively associated with high-sensitivity C-reactive protein, soluble tumor necrosis factor receptor II, and soluble vascular cellular adhesion molecule and inversely associated with CD4 counts. CONCLUSIONS FC concentrations are elevated in HIV regardless of ART status. ART and immune reconstitution seem to reduce FC but not to concentrations seen in uninfected controls. Our results suggest a role for FC as a noninvasive surrogate measurement of GI inflammation and associated systemic inflammation in HIV.
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Affiliation(s)
| | - Heather Y. Hughes
- Medical University of South Carolina, Charleston, SC, USA
- Ralph H. Johnson VA Medical Center, Charleston, SC, USA
| | | | | | - Danielle Labbato
- University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | - Julia C. Kosco
- University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | - Sarah E. Scott
- University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | - Grace A. McComsey
- University Hospitals Cleveland Medical Center, Cleveland, OH, USA
- Case Western Reserve University School of Medicine, Cleveland, OH, USA
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4
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Planchais C, Hocqueloux L, Ibanez C, Gallien S, Copie C, Surenaud M, Kök A, Lorin V, Fusaro M, Delfau-Larue MH, Lefrou L, Prazuck T, Lévy M, Seddiki N, Lelièvre JD, Mouquet H, Lévy Y, Hüe S. Early Antiretroviral Therapy Preserves Functional Follicular Helper T and HIV-Specific B Cells in the Gut Mucosa of HIV-1-Infected Individuals. THE JOURNAL OF IMMUNOLOGY 2018; 200:3519-3529. [PMID: 29632141 DOI: 10.4049/jimmunol.1701615] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 03/14/2018] [Indexed: 12/25/2022]
Abstract
HIV-1 infection is associated with B cell dysregulation and dysfunction. In HIV-1-infected patients, we previously reported preservation of intestinal lymphoid structures and dendritic cell maturation pathways after early combination antiretroviral therapy (e-ART), started during the acute phase of the infection, compared with late combination antiretroviral therapy started during the chronic phase. In this study, we investigated whether the timing of combination antiretroviral therapy initiation was associated with the development of the HIV-1-specific humoral response in the gut. The results showed that e-ART was associated with higher frequencies of functional resting memory B cells in the gut. These frequencies correlated strongly with those of follicular Th cells in the gut. Importantly, frequencies of HIV-1 Env gp140-reactive B cells were higher in patients given e-ART, in whom gp140-reactive IgG production by mucosal B cells increased after stimulation. Moreover, IL-21 release by PBMCs stimulated with HIV-1 peptide pools was greater with e-ART than with late combination antiretroviral therapy. Thus, early treatment initiation helps to maintain HIV-1-reactive memory B cells in the gut as well as follicular Th cells, whose role is crucial in the development of potent affinity-matured and broadly neutralizing Abs.
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Affiliation(s)
- Cyril Planchais
- INSERM U955, équipe 16, Faculté de Médecine, Université Paris Est Créteil, Créteil F-94010, France.,Vaccine Research Institute, Faculté de Médecine, Université Paris Est Créteil, Créteil F-94010, France
| | - Laurent Hocqueloux
- Service des Maladies Infectieuses et Tropicales, Centre Hospitalier Régional d'Orléans-La Source, Orléans F-45000, France
| | - Clara Ibanez
- INSERM U955, équipe 16, Faculté de Médecine, Université Paris Est Créteil, Créteil F-94010, France.,Vaccine Research Institute, Faculté de Médecine, Université Paris Est Créteil, Créteil F-94010, France
| | - Sébastien Gallien
- Vaccine Research Institute, Faculté de Médecine, Université Paris Est Créteil, Créteil F-94010, France.,Assistance Publique-Hôpitaux de Paris, Service d'Immunologie Clinique, Groupe Henri-Mondor Albert-Chenevier, Créteil F-94010, France
| | - Christiane Copie
- Assistance Publique-Hôpitaux de Paris, Département de Pathologie, Groupe Henri-Mondor Albert-Chenevier, Créteil F-94010, France.,INSERM U955, équipe 9, Faculté de Médecine, Université Paris Est Créteil, Créteil F-94010, France
| | - Mathieu Surenaud
- INSERM U955, équipe 16, Faculté de Médecine, Université Paris Est Créteil, Créteil F-94010, France.,Vaccine Research Institute, Faculté de Médecine, Université Paris Est Créteil, Créteil F-94010, France
| | - Ayrin Kök
- Laboratory of Humoral Response to Pathogens, Department of Immunology, Pasteur Institute, Paris 75015, France.,INSERM U1222, Paris 75015, France
| | - Valérie Lorin
- Laboratory of Humoral Response to Pathogens, Department of Immunology, Pasteur Institute, Paris 75015, France.,INSERM U1222, Paris 75015, France
| | - Mathieu Fusaro
- Assistance Publique-Hôpitaux de Paris, Service d'Immunologie Biologique, Groupe Henri-Mondor Albert-Chenevier, Créteil F-94010, France
| | - Marie-Hélène Delfau-Larue
- Assistance Publique-Hôpitaux de Paris, Service d'Immunologie Biologique, Groupe Henri-Mondor Albert-Chenevier, Créteil F-94010, France
| | - Laurent Lefrou
- Service d'Hépato-Gastro-Entérologie, Centre Hospitalier Régional d'Orléans-La Source, Orléans F-45000, France; and
| | - Thierry Prazuck
- Service des Maladies Infectieuses et Tropicales, Centre Hospitalier Régional d'Orléans-La Source, Orléans F-45000, France
| | - Michael Lévy
- Assistance Publique-Hôpitaux de Paris, Service d'Hépato-Gastro-Entérologie, Groupe Henri-Mondor Albert-Chenevier, Créteil F-94010, France
| | - Nabila Seddiki
- INSERM U955, équipe 16, Faculté de Médecine, Université Paris Est Créteil, Créteil F-94010, France.,Vaccine Research Institute, Faculté de Médecine, Université Paris Est Créteil, Créteil F-94010, France
| | - Jean-Daniel Lelièvre
- INSERM U955, équipe 16, Faculté de Médecine, Université Paris Est Créteil, Créteil F-94010, France.,Vaccine Research Institute, Faculté de Médecine, Université Paris Est Créteil, Créteil F-94010, France.,Assistance Publique-Hôpitaux de Paris, Service d'Immunologie Clinique, Groupe Henri-Mondor Albert-Chenevier, Créteil F-94010, France
| | - Hugo Mouquet
- Vaccine Research Institute, Faculté de Médecine, Université Paris Est Créteil, Créteil F-94010, France.,Laboratory of Humoral Response to Pathogens, Department of Immunology, Pasteur Institute, Paris 75015, France.,INSERM U1222, Paris 75015, France
| | - Yves Lévy
- INSERM U955, équipe 16, Faculté de Médecine, Université Paris Est Créteil, Créteil F-94010, France; .,Vaccine Research Institute, Faculté de Médecine, Université Paris Est Créteil, Créteil F-94010, France.,Assistance Publique-Hôpitaux de Paris, Service d'Immunologie Clinique, Groupe Henri-Mondor Albert-Chenevier, Créteil F-94010, France
| | - Sophie Hüe
- INSERM U955, équipe 16, Faculté de Médecine, Université Paris Est Créteil, Créteil F-94010, France; .,Vaccine Research Institute, Faculté de Médecine, Université Paris Est Créteil, Créteil F-94010, France.,Assistance Publique-Hôpitaux de Paris, Service d'Immunologie Biologique, Groupe Henri-Mondor Albert-Chenevier, Créteil F-94010, France
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5
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Gootenberg DB, Paer JM, Luevano JM, Kwon DS. HIV-associated changes in the enteric microbial community: potential role in loss of homeostasis and development of systemic inflammation. Curr Opin Infect Dis 2018; 30:31-43. [PMID: 27922852 PMCID: PMC5325247 DOI: 10.1097/qco.0000000000000341] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Supplemental Digital Content is available in the text Purpose of review Despite HIV therapy advances, average life expectancy in HIV-infected individuals on effective treatment is significantly decreased relative to uninfected persons, largely because of increased incidence of inflammation-related diseases, such as cardiovascular disease and renal dysfunction. The enteric microbial community could potentially cause this inflammation, as HIV-driven destruction of gastrointestinal CD4+ T cells may disturb the microbiota–mucosal immune system balance, disrupting the stable gut microbiome and leading to further deleterious host outcomes. Recent findings Varied enteric microbiome changes have been reported during HIV infection, but unifying patterns have emerged. Community diversity is decreased, similar to pathologies such as inflammatory bowel disease, obesity, and Clostridium difficile infection. Many taxa frequently enriched in HIV-infected individuals, such as Enterobacteriaceae and Erysipelotrichaceae, have pathogenic potential, whereas depleted taxa, such as Bacteroidaceae and Ruminococcaceae, are more linked with anti-inflammatory properties and maintenance of gut homeostasis. The gut viral community in HIV has been found to contain a greater abundance of pathogenesis-associated Adenoviridae and Anelloviridae. These bacterial and viral changes correlate with increased systemic inflammatory markers, such as serum sCD14, sCD163, and IL-6. Summary Enteric microbial community changes may contribute to chronic HIV pathogenesis, but more investigation is necessary, especially in the developing world population with the greatest HIV burden (Video, Supplemental Digital Content 1, which includes the authors’ summary of the importance of the work).
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Affiliation(s)
- David B Gootenberg
- aRagon Institute of MGH, MIT, and Harvard, Massachusetts General Hospital, Cambridge bHarvard Medical School, Boston cDivision of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
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6
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Total HIV-1 DNA, a Marker of Viral Reservoir Dynamics with Clinical Implications. Clin Microbiol Rev 2017; 29:859-80. [PMID: 27559075 DOI: 10.1128/cmr.00015-16] [Citation(s) in RCA: 147] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
HIV-1 DNA persists in infected cells despite combined antiretroviral therapy (cART), forming viral reservoirs. Recent trials of strategies targeting latent HIV reservoirs have rekindled hopes of curing HIV infection, and reliable markers are thus needed to evaluate viral reservoirs. Total HIV DNA quantification is simple, standardized, sensitive, and reproducible. Total HIV DNA load influences the course of the infection and is therefore clinically relevant. In particular, it is predictive of progression to AIDS and death, independently of HIV RNA load and the CD4 cell count. Baseline total HIV DNA load is predictive of the response to cART. It declines during cART but remains quantifiable, at a level that reflects both the history of infection (HIV RNA zenith, CD4 cell count nadir) and treatment efficacy (residual viremia, cumulative viremia, immune restoration, immune cell activation). Total HIV DNA load in blood is also predictive of the presence and severity of some HIV-1-associated end-organ disorders. It can be useful to guide individual treatment, notably, therapeutic de-escalation. Although it does not distinguish between replication-competent and -defective latent viruses, the total HIV DNA load in blood, tissues, and cells provides insights into HIV pathogenesis, probably because all viral forms participate in host cell activation and HIV pathogenesis. Total HIV DNA is thus a biomarker of HIV reservoirs, which can be defined as all infected cells and tissues containing all forms of HIV persistence that participate in pathogenesis. This participation may occur through the production of new virions, creating new cycles of infection and disseminating infected cells; maintenance or amplification of reservoirs by homeostatic cell proliferation; and viral transcription and synthesis of viral proteins without new virion production. These proteins can induce immune activation, thus participating in the vicious circle of HIV pathogenesis.
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7
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Korolevskaya LB, Shmagel KV, Shmagel NG, Saidakova EV. Systemic activation of the immune system in HIV infection: The role of the immune complexes (hypothesis). Med Hypotheses 2016; 88:53-6. [PMID: 26880638 DOI: 10.1016/j.mehy.2016.01.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 01/19/2016] [Indexed: 02/05/2023]
Abstract
Currently, immune activation is proven to be the basis for the HIV infection pathogenesis and a strong predictor of the disease progression. Among the causes of systemic immune activation the virus and its products, related infectious agents, pro-inflammatory cytokines, and regulatory CD4+ T cells' decrease are considered. Recently microbial translocation (bacterial products yield into the bloodstream as a result of the gastrointestinal tract mucosal barrier integrity damage) became the most popular hypothesis. Previously, we have found an association between immune complexes present in the bloodstream of HIV infected patients and the T cell activation. On this basis, we propose a significantly modified hypothesis of immune activation in HIV infection. It is based on the immune complexes' participation in the immunocompetent cells' activation. Immune complexes are continuously formed in the chronic phase of the infection. Together with TLR-ligands (viral antigens, bacterial products coming from the damaged gut) present in the bloodstream they interact with macrophages. As a result macrophages are transformed into the type II activated forms. These macrophages block IL-12 production and start synthesizing IL-10. High level of this cytokine slows down the development of the full-scale Th1-response. The anti-viral reactions are shifted towards the serogenesis. Newly synthesized antibodies' binding to viral antigens leads to continuous formation of the immune complexes capable of interacting with antigen-presenting cells.
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Affiliation(s)
- Larisa B Korolevskaya
- Institute of Ecology and Genetics of Microorganisms UB RAS, Perm, Russia; Perm State University, Perm, Russia.
| | - Konstantin V Shmagel
- Institute of Ecology and Genetics of Microorganisms UB RAS, Perm, Russia; Perm State University, Perm, Russia
| | - Nadezhda G Shmagel
- Perm Regional Centre for Protection against AIDS and Infectious Diseases, Perm, Russia; Perm State University, Perm, Russia
| | - Evgeniya V Saidakova
- Institute of Ecology and Genetics of Microorganisms UB RAS, Perm, Russia; Perm State University, Perm, Russia
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8
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Vergnon-Miszczycha D, Lucht F, Roblin X, Pozzetto B, Paul S, Bourlet T. [Key role played by the gut associated lymphoid tissue during human immunodeficiency virus infection]. Med Sci (Paris) 2015; 31:1092-101. [PMID: 26672662 DOI: 10.1051/medsci/20153112012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The gut associated lymphoid tissue (GALT) is the site of numerous immunological disturbances during HIV-1 infection. It constitutes the largest reservoir for HIV, not or very poorly susceptible to antiretroviral therapy (ART), making it a major obstacle to HIV cure. Moreover, the GALT is involved in systemic immune activation in HIV-infected individuals: intestinal damage due to viral replication and severe CD4(+) T cell depletion in the GALT leads to microbial translocation, a key driver of immune activation, and in turn, disease progression. In this review, we describe the role of the GALT in HIV infection and we discuss therapeutic options to decrease the intestinal viral reservoir and to preserve immune function in the gut of HIV-infected people. Achieving these goals is necessary for a long-term infection control after the interruption of ART.
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Affiliation(s)
- Delphine Vergnon-Miszczycha
- GIMAP/EA3064, Inserm CIC 1408 vaccinologie, université de Saint-Étienne, COMUE de Lyon, 42023 Saint-Étienne, France - Service de maladies infectieuses et tropicales, CHU de Saint-Étienne, 42055 Saint-Étienne Cedex 02, France
| | - Frédéric Lucht
- GIMAP/EA3064, Inserm CIC 1408 vaccinologie, université de Saint-Étienne, COMUE de Lyon, 42023 Saint-Étienne, France - Service de maladies infectieuses et tropicales, CHU de Saint-Étienne, 42055 Saint-Étienne Cedex 02, France
| | - Xavier Roblin
- GIMAP/EA3064, Inserm CIC 1408 vaccinologie, université de Saint-Étienne, COMUE de Lyon, 42023 Saint-Étienne, France - Service de gastro-entérologie, CHU de Saint-Étienne, 42055 Saint-Étienne Cedex 02, France
| | - Bruno Pozzetto
- GIMAP/EA3064, Inserm CIC 1408 vaccinologie, université de Saint-Étienne, COMUE de Lyon, 42023 Saint-Étienne, France - Laboratoire des agents infectieux et d'hygiène, CHU de Saint-Étienne, 42055 Saint-Étienne Cedex 02, France
| | - Stéphane Paul
- GIMAP/EA3064, Inserm CIC 1408 vaccinologie, université de Saint-Étienne, COMUE de Lyon, 42023 Saint-Étienne, France - Laboratoire d'immunologie, CHU de Saint-Étienne, 42055 Saint-Étienne Cedex 02, France
| | - Thomas Bourlet
- GIMAP/EA3064, Inserm CIC 1408 vaccinologie, université de Saint-Étienne, COMUE de Lyon, 42023 Saint-Étienne, France - Laboratoire des agents infectieux et d'hygiène, CHU de Saint-Étienne, 42055 Saint-Étienne Cedex 02, France
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9
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Matsuyama-Murata M, Inaba K, Horiuchi R, Fukazawa Y, Ibuki K, Hayami M, Miura T. Genetic similarity of circulating and small intestinal virus at the end stage of acute pathogenic simian-human immunodeficiency virus infection. Front Microbiol 2013; 4:204. [PMID: 23885255 PMCID: PMC3717482 DOI: 10.3389/fmicb.2013.00204] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2013] [Accepted: 07/01/2013] [Indexed: 11/13/2022] Open
Abstract
To understand the pathogenicity of acquired immune deficiency syndrome (AIDS), it is important to clarify where, when and how the virus replicates in the body of infected individuals. To identify the major virus replication site at the end stage of SHIV infection, we investigated the systemic tissues of SHIV-infected monkeys that developed AIDS-like disease. We quantified proviral DNA, and compared the mutation patterns of the viruses in various systemic tissues and in peripheral blood through phylogenetic analysis of the full genome sequence. We found that the amounts of proviral DNA detected in internal tissues were higher than those in peripheral blood mononuclear cells. In the sequence and phylogenetic tree analyses, the mutation patterns of the viruses in each tissue were generally different. However, the mutation pattern of the viruses in the jejunum and mesenteric lymph node were most similar to that of plasma viral RNA among the tissues examined in all three monkeys. In two of the three monkeys, which were euthanized earlier, viruses in the jejunum and mesenteric lymph node occupied the root position of the phylogenetic tree. Furthermore, in these tissues, more than 50% of SHIV-expressing cells were identified as macrophages based on co-expression of CD68. These results suggest that macrophages of the small intestine and/or mesenteric lymph node are the major virus production site at the end stage of SHIV infection of macaques.
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Affiliation(s)
- Megumi Matsuyama-Murata
- Laboratory of Primate Model, Experimental Research Center for Infectious Diseases, Institute for Virus Research, Kyoto University Kyoto, Japan
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10
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Brenchley JM. Mucosal immunity in human and simian immunodeficiency lentivirus infections. Mucosal Immunol 2013; 6:657-65. [PMID: 23549448 PMCID: PMC4154146 DOI: 10.1038/mi.2013.15] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Overwhelming evidence indicates that distinct pathological phenomenon occurs within the gastrointestinal (GI) tract of progressively simian immunodeficiency virus (SIV)-infected Asian macaques and HIV-infected humans compared with other anatomical sites. Massive loss of GI tract lamina propria CD4 T cells, alteration in the profile of lymphocytic cytokine production, changes in the landscape of GI tract antigen-presenting cells, and variations to the structural barrier of the GI tract are hallmarks of progressive HIV/SIV infections. The pathology within the GI tract results in translocation of microbial products from the lumen of the intestine into peripheral circulation. These translocated microbial products directly stimulate the immune system and exacerbate immune activation and, thus, disease progression. Initiation of combination antiretroviral therapy (cART) does not restore completely the immunological abnormalities within the GI tract. This incomplete restoration within the GI tract may contribute to the increased mortality observed within HIV-infected individuals treated for decades with cART. Novel therapeutic interventions aimed at enhancing GI tract anatomy and physiology may improve the prognosis of HIV-infected individuals.
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Affiliation(s)
- JM Brenchley
- Program in Tissue Immunity and Repair and Lab of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
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11
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Impact of highly active antiretroviral therapy initiation on CD4(+) T-cell repopulation in duodenal and rectal mucosa. AIDS 2013; 27:867-877. [PMID: 23262500 DOI: 10.1097/qad.0b013e32835d85b4] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
OBJECTIVE The objective of this study was to assess the effects of HAART initiation on CD4(+) T-cell repopulation and T-cell immune activation in rectal and duodenal mucosa. DESIGN The effects of HAART on the gastrointestinal tract remain controversial, and studies have reached different conclusions regarding its effectiveness at restoring mucosal CD4(+) T cells depending upon time of initiation, duration of treatment and gastrointestinal tract region studied. METHODS We obtained blood, rectal biopsies and duodenal biopsies from 14 chronically infected individuals at baseline and at 4-9 months post-HAART initiation. We examined CD4(+) T-cell frequencies in blood, rectum and duodenum at both time points, and performed a detailed assessment of CD4(+) T-cell phenotype, immune activation marker expression and HIV-specific CD8(+) T-cell responses in blood and rectal mucosa. RESULTS CD4(+) T-cell percentages increased significantly in blood, rectal and duodenal mucosa after 4-9 months of HAART (P = 0.02, 0.0005, 0.0002), but remained lower than in uninfected controls. HIV-specific CD8(+) T-cell responses in blood and rectal mucosa declined following HAART initiation (P = 0.0015, 0.021). CD8(+) T-cell coexpression of CD38 and HLA-DR in blood and mucosa, as well as plasma sCD14, declined significantly. CD28 expression on blood and mucosal CD8(+) T cells increased, whereas programmed death receptor-1 expression on blood HIV-specific CD4(+) and CD8(+) T cells decreased. CONCLUSION Within the first months of HAART, limited CD4(+) T-cell reconstitution occurs in small and large intestinal mucosa. Nevertheless, decreased immune activation and increased CD28 expression suggest rapid immunological benefits of HAART despite incomplete CD4(+) T-cell reconstitution.
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12
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Abstract
HIV-1 is transmitted by sexual contact across mucosal surfaces, by maternal-infant exposure, and by percutaneous inoculation. For reasons that are still incompletely understood, CCR5-tropic viruses (R5 viruses) are preferentially transmitted by all routes. Transmission is followed by an orderly appearance of viral and host markers of infection in the blood plasma. In the acute phase of infection, HIV-1 replicates exponentially and diversifies randomly, allowing for an unambiguous molecular identification of transmitted/founder virus genomes and a precise characterization of the population bottleneck to virus transmission. Sexual transmission of HIV-1 most often results in productive clinical infection arising from a single virus, highlighting the extreme bottleneck and inherent inefficiency in virus transmission. It remains to be determined if HIV-1 transmission is largely a stochastic process whereby any reasonably fit R5 virus can be transmitted or if there are features of transmitted/founder viruses that facilitate their transmission in a biologically meaningful way. Human tissue explant models of HIV-1 infection and animal models of SIV/SHIV/HIV-1 transmission, coupled with new challenge virus strains that more closely reflect transmitted/founder viruses, have the potential to elucidate fundamental mechanisms in HIV-1 transmission relevant to vaccine design and other prevention strategies.
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Affiliation(s)
- George M Shaw
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, 19104, USA
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13
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Sandler NG, Douek DC. Microbial translocation in HIV infection: causes, consequences and treatment opportunities. Nat Rev Microbiol 2012; 10:655-66. [PMID: 22886237 DOI: 10.1038/nrmicro2848] [Citation(s) in RCA: 326] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Systemic immune activation is increased in HIV-infected individuals, even in the setting of virus suppression with antiretroviral therapy. Although numerous factors may contribute, microbial products have recently emerged as potential drivers of this immune activation. In this Review, we describe the intestinal damage that occurs in HIV infection, the evidence for translocation of microbial products into the systemic circulation and the pathways by which these products activate the immune system. We also discuss novel therapies that disrupt the translocation of microbial products and the downstream effects of microbial translocation.
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Affiliation(s)
- Netanya G Sandler
- Human Immunology Section, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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14
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Novel approaches to inhibit HIV entry. Viruses 2012; 4:309-24. [PMID: 22470838 PMCID: PMC3315218 DOI: 10.3390/v4020309] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 01/17/2012] [Accepted: 02/07/2012] [Indexed: 12/22/2022] Open
Abstract
Human Immunodeficiency Virus (HIV) entry into target cells is a multi-step process involving binding of the viral glycoprotein, Env, to its receptor CD4 and a coreceptor-either CCR5 or CXCR4. Understanding the means by which HIV enters cells has led to the identification of genetic polymorphisms, such as the 32 base-pair deletion in the ccr5 gene (ccr5∆32) that confers resistance to infection in homozygous individuals, and has also resulted in the development of entry inhibitors-small molecule antagonists that block infection at the entry step. The recent demonstration of long-term control of HIV infection in a leukemic patient following a hematopoietic stem cell transplant using cells from a ccr5∆32 homozygous donor highlights the important role of the HIV entry in maintaining an established infection and has led to a number of attempts to treat HIV infection by genetically modifying the ccr5 gene. In this review, we describe the HIV entry process and provide an overview of the different classes of approved HIV entry inhibitors while highlighting novel genetic strategies aimed at blocking HIV infection at the level of entry.
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15
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Avettand-Fenoel V, Hocqueloux L, Müller-Trutwin M, Prazuck T, Melard A, Chaix ML, Agoute E, Michau C, Rouzioux C. Greater diversity of HIV DNA variants in the rectum compared to variants in the blood in patients without HAART. J Med Virol 2012; 83:1499-507. [PMID: 21739438 DOI: 10.1002/jmv.22132] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The gut-associated lymphoid tissue represents the largest reservoir of HIV-1. Improving knowledge of this reservoir by studying the diversity of viral population is a key step towards understanding the pathogenesis and dynamics of HIV. Obtaining samples is difficult and little information is available on gut viral quasispecies during the course of infection in humans. The aim of this study was to characterize rectal viral strains and their diversity and to investigate the relationships between the rectal tissue reservoir and viral variants in the blood. Phylogenetic analyses were performed on the env sequences for rectal HIV DNA, blood HIV DNA, and HIV RNA clones, with maximum-likelihood and neighbor-joining methods on seven patients. Genetic diversity was assessed. Higher diversity of HIV DNA clones was noted in the rectum compared to blood in four out of five patients without HAART. Viral diversity was present in the rectum from time of the primary infection. Similar degrees of diversity were observed in the rectum and blood during HAART. Rectal and blood HIV variants were interspersed partially or totally in the seven patients. A certain number of rectal HIV DNA clones were clustered together in six patients. These results suggest that variants in the rectum were more heterogeneous than variants in the blood from patients without HAART, probably because the activated milieu of gut-associated lymphoid tissue may provide an improved environment for viral replication, and indicate exchange of viral populations between blood and rectal tissues, reflecting the dynamics of HIV during course of infection.
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Affiliation(s)
- Véronique Avettand-Fenoel
- Virology Unit, AP-HP, Necker Hospital for Sick Children, Paris, France; Paris Descartes University, EA3620, Paris, France.
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16
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Iglesias E, García D, Márquez G, Prieto YC, Sánchez J, Trimiño L, Soria Y, García D. Two mucosal-parenteral schedules to coadminister a multiantigenic formulation against HIV-1 in Balb/c mice. Int Immunopharmacol 2012; 12:487-93. [PMID: 22240123 DOI: 10.1016/j.intimp.2011.12.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 12/29/2011] [Accepted: 12/30/2011] [Indexed: 11/27/2022]
Abstract
Previous studies showed that simultaneous immunization through the nasal (IN) and subcutaneous (SC) route of a multiantigenic formulation induced a Th1 anti-HIV humoral and cellular immune responses. The formulation was comprised of a recombinant protein of HIV-1 (named CR3; Cellular Response number 3) and the surface and nucleocapsid antigens of hepatitis B virus. This study asks whether four times simultaneous administration through the IN and SC routes (SC+IN) of the multiantigenic formulation induces a similar systemic and mucosal immune responses than two sequential IN priming and two SC boosting (2IN&2SC) inoculations in mice. To answer this question, we tested the same total dose of each antigen per animal in both schedules of inoculation. We found that SC+IN and 2IN&2SC coadministration induced comparable levels of CR3(HIV)-specific IFN-γ-secreting cells and CD8+ cells proliferation in the systemic compartment of animals. Consistent with these findings, a similar Th1 profile considering anti-CR3 IgG1:IGg2a ratio was observed. Additionally, the level of IgG antibodies and the frequency of seroconverting animals in vagina were not different. However, in the case of IgA antibodies the same parameters were significantly higher in the SC+IN group. We also found important level of HBsAg-specific antibodies in serum and vaginal washes.
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Affiliation(s)
- Enrique Iglesias
- Centro de Ingeniería Genética y Biotecnología (CIGB), P.O. Box 6162, Havana 10600, Cuba.
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17
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Sui Y, Gagnon S, Dzutsev A, Zhu Q, Yu H, Hogg A, Wang Y, Xia Z, Belyakov IM, Venzon D, Klinman D, Strober W, Kelsall B, Franchini G, Berzofsky JA. TLR agonists and/or IL-15 adjuvanted mucosal SIV vaccine reduced gut CD4⁺ memory T cell loss in SIVmac251-challenged rhesus macaques. Vaccine 2011; 30:59-68. [PMID: 22041305 DOI: 10.1016/j.vaccine.2011.10.043] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Accepted: 10/18/2011] [Indexed: 01/08/2023]
Abstract
Adjuvant plays an important role in increasing and directing vaccine-induced immune responses. In a previous study, we found that a mucosal SIV vaccine using a combination of IL-15 and TLR agonists as adjuvant mediated partial protection against SIVmac251 rectal challenge, whereas neither IL-15 nor TLR agonists alone as an adjuvant impacted the plasma viral loads. In this study, dissociation of CD4(+) T cell preservation with viral loads was observed in the animals vaccinated with adjuvants. Significantly higher levels of memory CD4(+) T cell numbers were preserved after SIVmac251 infection in the colons of the animals vaccinated with vaccine containing any of these adjuvants compared to no adjuvant. When we measured the viral-specific CD8(+) tetramer responses in the colon lamina propria, we found significantly higher levels of gag, tat, and pol epitope tetramer(+) T cell responses in these animals compared to ones without adjuvant, even if some of the animals had similarly high viral loads. Furthermore, this CD4(+) T preservation was positively correlated with increased levels of gag and Tat, but not pol tetramer(+) T cell responses, and inversely correlated with beta-chemokine expression. The pre-challenged APOBEC3G expression level, which has previously been shown inversely associated with viral loads, was further found positively correlated with CD4(+) T cell number preservation. Overall, these data highlight one unrecognized role of adjuvant in HIV vaccine development, and show that vaccines can produce a surprising discordance between CD4(+) T cell levels and SIV viral load.
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Affiliation(s)
- Yongjun Sui
- Vaccine Branch, National Cancer Institute, National Institutes of Health, 10 Center Drive, Bethesda, MD 20892, United States.
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18
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Singh I, Carville A, Tzipori S. Cryptosporidiosis in rhesus macaques challenged during acute and chronic phases of SIV infection. AIDS Res Hum Retroviruses 2011; 27:989-97. [PMID: 21314434 DOI: 10.1089/aid.2010.0229] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The intestinal immune dysfunction due to loss of mucosal and peripheral CD4(+) T cells in individuals with HIV/AIDS is presumably responsible for the establishment of persistent cryptosporidiosis. Simian immunodeficiency virus (SIV)-infected macaques were used to investigate the phase/timing in SIV infection, which permits a self-limiting Cryptosporidium parvum infection to become persistent in immunodeficient hosts because of significant mucosal immune defects. Two groups of SIV-infected macaques were challenged with C. parvum; one was challenged during the acute SIV infection phase (2 weeks post-SIV infection) and the second was challenged during the chronic SIV phase (CD4 counts 200-500 cells/μl of blood). Samples (fecal, blood, biopsy, and necropsy) were collected at different time points after infection to correlate the progression of disease with the immune status of the animals. All seven SIV-infected macaques challenged during the acute phase of SIV infection became persistently infected and excreted oocysts for 1-4 months. However, four of the six in the chronic SIV phase became infected with cryptosporidiosis, of which one survived 2 weeks and one became naturally infected. Sequential analysis of CD4(+) in blood and intestines of coinfected macaques exhibited pronounced losses of CD4 T cells during the first 2 weeks after SIV infection, followed by transient rebound of CD4 T cells in the gut after C. parvum infection, and then a gradual loss over subsequent months. Persistent cryptosporidiosis was more consistently induced during the acute SIV phase indicating that profound viral damage to gut lymphoid tissue during the acute phase was more conducive, compared with the chronic phase, to establishing persistent cryptosporidiosis than low circulating CD4 T cells.
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Affiliation(s)
- Inderpal Singh
- Division of Infectious Diseases, Tufts University Cummings School of Veterinary Medicine, North Grafton, Massachusetts
| | - Angela Carville
- Department of Comparative Pathology, New England Regional Primate Research Center, Southborough, Massachusetts
| | - Saul Tzipori
- Division of Infectious Diseases, Tufts University Cummings School of Veterinary Medicine, North Grafton, Massachusetts
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19
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Feasey NA, Healey P, Gordon MA. Review article: the aetiology, investigation and management of diarrhoea in the HIV-positive patient. Aliment Pharmacol Ther 2011; 34:587-603. [PMID: 21777262 DOI: 10.1111/j.1365-2036.2011.04781.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Diarrhoea is a common presentation throughout the course of HIV disease. AIM To review the literature relating to aetiology, investigation and management of diarrhoea in the HIV-infected adult. METHODS The PubMed database was searched using major subject headings 'AIDS' or 'HIV' and 'diarrhoea' or 'intestinal parasite'. The search was limited to adults and to studies with >10 patients. RESULTS Diarrhoea affects 40-80% of HIV-infected adults untreated with antiretroviral therapy (ART). First-line investigation is by stool microbiology. Reported yield varies with geography and methodology. Molecular and immunological methods and special stains have improved diagnostic yield. Endoscopy is diagnostic in 30-70% of cases of pathogen-negative diarrhoea and evidence supports flexible sigmoidoscopy as a first line screening procedure (80-95% sensitive for CMV colitis), followed by colonoscopy and terminal ileoscopy. Radiology is useful to assess severity, distribution, complications and to diagnose HIV-related malignancies. Side effects and compliance with ART are important considerations in assessment. There is a good evidence base for many specific therapies, but optimal treatment of cryptosporidiosis is unclear and only limited data support symptomatic treatments. CONCLUSIONS The immunological response to HIV infection and Antiretroviral therapy remains incompletely understood. Antiretroviral therapy regimens need to be optimised to suppress HIV while minimising side effects. Effective agents for management of cryptosporidiosis are lacking. There is an urgent need for enhanced regional diagnostic facilities in countries with a high prevalence of HIV. The ongoing roll-out of Antiretroviral therapy in low-resource settings will continue to change the aetiology and management of this problem, necessitating ongoing surveillance and study.
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Affiliation(s)
- N A Feasey
- Department of Gastroenterology, University of Liverpool, Liverpool, UK
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20
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The HIV-1-specific protein Casp8p41 induces death of infected cells through Bax/Bak. J Virol 2011; 85:7965-75. [PMID: 21653671 DOI: 10.1128/jvi.02515-10] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Casp8p41, a novel protein generated when HIV-1 protease cleaves caspase 8, independently causes NF-κB activation, proinflammatory cytokine production, and cell death. Here we investigate the mechanism by which Casp8p41 induces cell death. Immunogold staining and electron microscopy demonstrate that Casp8p41 localizes to mitochondria of activated primary CD4 T cells, suggesting mitochondrial involvement. Therefore, we assessed the dependency of Casp8p41-induced death on Bax/Bak and caspase 9. In wild-type (WT) mouse embryonic fibroblast (MEF) cells, Casp8p41 causes rapid mitochondrial depolarization (P < 0.001), yet Casp8p41 expression in Bax/Bak double-knockout (DKO) MEF cells does not. Similarly, caspase 9-deficient T cells (JMR cells), which express Casp8p41, undergo minimal cell death, whereas reconstituting these cells with caspase 9 (F9 cells) restores Casp8p41 cytotoxicity (P < 0.01). The infection of caspase 9-deficient cells with a green fluorescent protein (GFP) HIV-1 reporter virus results in cell death in 32% of infected GFP-positive cells, while the restoration of caspase 9 expression in these cells restores infected-cell killing to 68% (P < 0.05), with similar levels of viral replication between infections. Our data demonstrate that Casp8p41 requires Bax/Bak to induce mitochondrial depolarization, which leads to caspase 9 activation following either Casp8p41 expression or HIV-1 infection. This understanding allows the design of strategies to interrupt this form of death of HIV-1-infected cells.
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21
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Abstract
To constrain the growth of the HIV/AIDS pandemic and ultimately end it, effective measures must be developed to prevent sexual mucosal transmission, the major route by which new infections are acquired. I review sexual mucosal transmission of HIV and SIV, with a focus on vaginal transmission in the SIV rhesus macaque animal model, and the evidence for small founder populations of infected cells and the local expansion at the portal of entry necessary to establish systemic infection. These early events represent windows of maximum opportunity for interventions to prevent systemic infection. I highlight the paradoxical role the innate immune response plays in actually facilitating transmission, and a novel microbicide strategy that targets this innate response to prevent systemic infection, and I conclude with an agenda for future research that emphasizes mucosal immunology, virology and pathogenesis studies at each anatomic site of entry.
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Affiliation(s)
- Ashley T Haase
- Department of Microbiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA.
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22
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23
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Saksena NK, Wang B, Zhou L, Soedjono M, Ho YS, Conceicao V. HIV reservoirs in vivo and new strategies for possible eradication of HIV from the reservoir sites. HIV AIDS (Auckl) 2010; 2:103-22. [PMID: 22096389 PMCID: PMC3218690 DOI: 10.2147/hiv.s6882] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Even though the treatment of human immunodeficiency virus (HIV)-infected individuals with highly active antiretroviral therapy (HAART) provides a complete control of plasma viremia to below detectable levels (<40 copies/mL plasma), there is an unequal distribution of all antiretroviral drugs across diverse cellular and anatomic compartments in vivo. The main consequence of this is the acquisition of resistance by HIV to all known classes of currently prescribed antiretroviral drugs and the establishment of HIV reservoirs in vivo. HIV has a distinct advantage of surviving in the host via both pre-and postintegration latency. The postintegration latency is caused by inert and metabolically inactive provirus, which cannot be accessed either by the immune system or the therapeutics. This integrated provirus provides HIV with a safe haven in the host where it is incessantly challenged by its immune selection pressure and also by HAART. Thus, the provirus is one of the strategies for viral concealment in the host and the provirus can be rekindled, through unknown stimuli, to create progeny for productive infection of the host. Thus, the reservoir establishment remains the biggest impediment to HIV eradication from the host. This review provides an overview of HIV reservoir sites and discusses both the virtues and problems associated with therapies/strategies targeting these reservoir sites in vivo.
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Affiliation(s)
- Nitin K Saksena
- Retroviral Genetics Division, Center for Virus Research, Westmead Millennium Institute, The University of Sydney, Westmead, NSW, Sydney, Australia
| | - Bin Wang
- Retroviral Genetics Division, Center for Virus Research, Westmead Millennium Institute, The University of Sydney, Westmead, NSW, Sydney, Australia
| | - Li Zhou
- Retroviral Genetics Division, Center for Virus Research, Westmead Millennium Institute, The University of Sydney, Westmead, NSW, Sydney, Australia
| | - Maly Soedjono
- Retroviral Genetics Division, Center for Virus Research, Westmead Millennium Institute, The University of Sydney, Westmead, NSW, Sydney, Australia
| | - Yung Shwen Ho
- Retroviral Genetics Division, Center for Virus Research, Westmead Millennium Institute, The University of Sydney, Westmead, NSW, Sydney, Australia
| | - Viviane Conceicao
- Retroviral Genetics Division, Center for Virus Research, Westmead Millennium Institute, The University of Sydney, Westmead, NSW, Sydney, Australia
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24
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Sellier P, Mannioui A, Bourry O, Dereuddre-Bosquet N, Delache B, Brochard P, Calvo J, Prévot S, Roques P. Antiretroviral treatment start-time during primary SIV(mac) infection in macaques exerts a different impact on early viral replication and dissemination. PLoS One 2010; 5:e10570. [PMID: 20485497 PMCID: PMC2868019 DOI: 10.1371/journal.pone.0010570] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Accepted: 04/20/2010] [Indexed: 12/25/2022] Open
Abstract
Background The time of infection is rarely known in human cases; thus, the effects of delaying the initiation of antiretroviral therapy (ART) on the peripheral viral load and the establishment of viral reservoirs are poorly understood. Methodology/Principal Findings Six groups of macaques, infected intravenously with SIVmac251, were given placebo or antiretroviral therapy to explore reservoir establishment; macaques were treated for 2 weeks, with treatment starting 4 hours, 7 or 14 days after infection. Viral replication and dissemination were measured in the gut (rectum), in the lung and in blood and lymphoid tissues (peripheral lymph nodes), by quantifying viral RNA, DNA and 2LTR circles. We used immunohistochemistry (CD4 and CD68) to assess the impact of these treatments on the relative amount of virus target cells in tissue. Treatment that was started 4 hours post-infection (pi) decreased viral replication and dissemination in blood and tissue samples, which were assessed on day 14 (RNA/DNA/2LTR circles). The virus remained detectable and lymphoid tissues were activated in LN and the gut in both placebo- and ART-treated animals. Viral RNA in plasma continued to be lower in macaques treated seven days after infection; however, this was not the case for viral DNA in peripheral blood mononuclear cells. There was a small but significant difference in RNA and DNA levels in tissues between placebo- and ART-treated animals on day 21. When started 14 days after infection, treatment resulted in a limited decrease in the plasma viral load. Conclusions Treatment that was started 4 hours after infection significantly reduced viral replication and dissemination. When started 7 days after infection, it was of slight virological benefit in peripheral blood and in tissues, and treatment was even less effective if started 14 days pi. These data favor starting ART no longer than one week after intravenous SIVmac251 exposure.
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Affiliation(s)
- Pierre Sellier
- Division of ImmunoVirology (SIV), Institute of Emerging Diseases and Innovative Therapies (IMETI), CEA, Fontenay-aux-Roses, France
- UMR E1, University Paris Sud XI, Orsay, France
- Hôpital Lariboisière, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Abdelkrim Mannioui
- Division of ImmunoVirology (SIV), Institute of Emerging Diseases and Innovative Therapies (IMETI), CEA, Fontenay-aux-Roses, France
- UMR E1, University Paris Sud XI, Orsay, France
| | - Olivier Bourry
- Division of ImmunoVirology (SIV), Institute of Emerging Diseases and Innovative Therapies (IMETI), CEA, Fontenay-aux-Roses, France
- UMR E1, University Paris Sud XI, Orsay, France
| | - Nathalie Dereuddre-Bosquet
- Division of ImmunoVirology (SIV), Institute of Emerging Diseases and Innovative Therapies (IMETI), CEA, Fontenay-aux-Roses, France
- UMR E1, University Paris Sud XI, Orsay, France
| | - Benoit Delache
- Division of ImmunoVirology (SIV), Institute of Emerging Diseases and Innovative Therapies (IMETI), CEA, Fontenay-aux-Roses, France
- UMR E1, University Paris Sud XI, Orsay, France
| | - Patricia Brochard
- Division of ImmunoVirology (SIV), Institute of Emerging Diseases and Innovative Therapies (IMETI), CEA, Fontenay-aux-Roses, France
- UMR E1, University Paris Sud XI, Orsay, France
| | - Julien Calvo
- Division of ImmunoVirology (SIV), Institute of Emerging Diseases and Innovative Therapies (IMETI), CEA, Fontenay-aux-Roses, France
- UMR E1, University Paris Sud XI, Orsay, France
| | - Sophie Prévot
- Service d'Anatomie et Cytologie Pathologiques, Hôpital Antoine Béclère, Assistance Publique-Hôpitaux de Paris, Clamart, France
| | - Pierre Roques
- Division of ImmunoVirology (SIV), Institute of Emerging Diseases and Innovative Therapies (IMETI), CEA, Fontenay-aux-Roses, France
- UMR E1, University Paris Sud XI, Orsay, France
- * E-mail:
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Abstract
Measures to prevent sexual mucosal transmission of human immunodeficiency virus (HIV)-1 are urgently needed to curb the growth of the acquired immunodeficiency syndrome (AIDS) pandemic and ultimately bring it to an end. Studies in animal models and acute HIV-1 infection reviewed here reveal potential viral vulnerabilities at the mucosal portal of entry in the earliest stages of infection that might be most effectively targeted by vaccines and microbicides, thereby preventing acquisition and averting systemic infection, CD4 T-cell depletion and pathologies that otherwise rapidly ensue.
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Affiliation(s)
- Ashley T Haase
- Department of Microbiology, University of Minnesota, Minnesota 55455, USA.
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26
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Cycling of gut mucosal CD4+ T cells decreases after prolonged anti-retroviral therapy and is associated with plasma LPS levels. Mucosal Immunol 2010; 3:172-81. [PMID: 19956090 PMCID: PMC2830855 DOI: 10.1038/mi.2009.129] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The gut mucosa is an important site of HIV immunopathogenesis with severe depletion of CD4+ T cells occurring during acute infection. The effect of prolonged anti-retroviral therapy (ART) on cycling and restoration of T lymphocytes in the gut remains unclear. Colon and terminal ileal biopsies and peripheral blood samples were collected from viremic, untreated, HIV-infected participants, patients treated with prolonged ART (>5 years), and uninfected controls and analyzed by flow cytometry. In the gut, the proportion of cycling T cells decreased and the number of CD4+ T cells normalized in treated patients in parallel with beta 7 expression on CD4+ T cells in blood. Cycling of gut T cells in viremic patients was associated with increased plasma LPS levels, but not colonic HIV-RNA. These data suggest that gut T-cell activation and microbial translocation may be interconnected whereas prolonged ART may decrease activation and restore gut CD4+ T cells.
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27
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Hel Z, Stringer E, Mestecky J. Sex steroid hormones, hormonal contraception, and the immunobiology of human immunodeficiency virus-1 infection. Endocr Rev 2010; 31:79-97. [PMID: 19903932 PMCID: PMC2852204 DOI: 10.1210/er.2009-0018] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Worldwide, an increasing number of women use oral or injectable hormonal contraceptives. However, inadequate information is available to aid women and health care professionals in weighing the potential risks of hormonal contraceptive use in individuals living with HIV-1 or at high risk of infection. Numerous epidemiological studies and challenge studies in a rhesus macaque model suggest that progesterone-based contraceptives increase the risk of HIV-1 infection in humans and simian immunodeficiency virus (SIV) infection in macaques, accelerate disease progression, and increase viral shedding in the genital tract. However, because several other studies in humans have not observed any effect of exogenously administered progesterone on HIV-1 acquisition and disease progression, the issue continues to be a topic of intense research and ongoing discussion. In contrast to progesterone, systemic or intravaginal treatment with estrogen efficiently protects female rhesus macaques against the transmission of SIV, likely by enhancing the natural protective properties of the lower genital tract mucosal tissue. Although the molecular and cellular mechanisms underlying the effect of sex steroid hormones on HIV-1 and SIV acquisition and disease progression are not well understood, progesterone and estrogen are known to regulate a number of immune mechanisms that may exert an effect on retroviral infection. This review summarizes current knowledge of the effects of various types of sex steroid hormones on immune processes involved in the biology of HIV-1 infection.
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Affiliation(s)
- Zdenek Hel
- Department of Pathology, University of Alabama at Birmingham, 845 19th Street South, Birmingham, Alabama 35294-2170, USA.
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Ali SA, Huang MB, Campbell PE, Roth WW, Campbell T, Khan M, Newman G, Villinger F, Powell MD, Bond VC. Genetic characterization of HIV type 1 Nef-induced vesicle secretion. AIDS Res Hum Retroviruses 2010; 26:173-92. [PMID: 20156100 DOI: 10.1089/aid.2009.0068] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The HIV-1 Nef protein is known to be secreted, and our group has shown that Nef is secreted from nef-transfected and HIV-1-infected cells in small exosome-like vesicles (d. 40-100 nm). The role of secreted Nef remains to be fully characterized. Thus, it is important to characterize the nature of and the mechanisms regulating Nef secretion. We hypothesized that specific structural domains on the Nef protein interact with components of the endosomal trafficking machinery, sorting Nef into multivesicular bodies (MVB) and packaging it in exosome-like vesicles. To identify those domains, a series of mutants spanning the entire nef sequence were made and cloned into the expression vector pQB1, which expresses the mutants as Nef-GFP fusion proteins. These constructs were used in transient transfection assays to identify sequences necessary for secretion of the Nef-GFP fusion protein. N-terminal domains were identified as critical for Nef-induced vesicle secretion: (1) a basic cluster of four arginine residues (aa 17, 19, 21, 22), (2) the phosphofurin acidic cluster sequence (PACS; Glu62-65), and (3) a previously uncharacterized domain spanning amino acid residues 66-70 (VGFPV), which we named the secretion modification region (SMR). Additional amino acids P25, 29GVG31, and T44 were identified in HIV-1 Nef as regulating its secretion. These residues have not been associated with other reported Nef functions. The myristoylation domain, ubiquitination lysine residues, and the C-terminal portion of Nef (aa 71-206) had no effect on secretion. A minimal HIV-1 Nef sequence, comprising the identified motifs, was sufficient for Nef-induced vesicle secretion.
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Affiliation(s)
- Syed A. Ali
- Department of Microbiology, Biochemistry, and Immunology, Morehouse School of Medicine, Atlanta, Georgia 30310
| | - Ming-Bo Huang
- Department of Microbiology, Biochemistry, and Immunology, Morehouse School of Medicine, Atlanta, Georgia 30310
| | - Patrick E. Campbell
- Department of Microbiology, Biochemistry, and Immunology, Morehouse School of Medicine, Atlanta, Georgia 30310
| | - William W. Roth
- Department of Microbiology, Biochemistry, and Immunology, Morehouse School of Medicine, Atlanta, Georgia 30310
| | - Tamika Campbell
- Department of Microbiology, Biochemistry, and Immunology, Morehouse School of Medicine, Atlanta, Georgia 30310
| | - Mahfuz Khan
- Department of Microbiology, Biochemistry, and Immunology, Morehouse School of Medicine, Atlanta, Georgia 30310
| | - Gale Newman
- Department of Microbiology, Biochemistry, and Immunology, Morehouse School of Medicine, Atlanta, Georgia 30310
| | - Francois Villinger
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Michael D. Powell
- Department of Microbiology, Biochemistry, and Immunology, Morehouse School of Medicine, Atlanta, Georgia 30310
| | - Vincent C. Bond
- Department of Microbiology, Biochemistry, and Immunology, Morehouse School of Medicine, Atlanta, Georgia 30310
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Abstract
PURPOSE OF REVIEW Here we present recent studies examining the gastrointestinal tract during primary HIV and simian immunodeficiency virus infections and emphasizing the onset of severe pathologic processes that are not adequately reflected in peripheral blood. We discuss these findings and hypotheses relating to the role of the gastrointestinal tract in HIV-1 pathogenesis. RECENT FINDINGS High levels of viral replication in the gastrointestinal mucosa during primary HIV and simian immunodeficiency virus infections lead to severe depletion of effector memory CD4 T cells coinciding with increased immune activation and mucosal damage. Viral reservoirs established at this stage appear to be persistent over the course of infection and during therapy. In the simian immunodeficiency virus model of AIDS, onset of the impaired intestinal epithelial barrier function and renewal was observed during primary viral infection. Dysfunction of the mucosal immune system and the epithelial barrier may contribute to viral persistence and impaired responses to microbial pathogens in infected individuals. SUMMARY A better understanding of the impact of HIV infection on the mucosal immune system may help in the development of newer preventive and therapeutic strategies directed against the virus.
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Chandran P, Kabir SN. Dual action microbicides: reappraisal of their roles in contraceptive research. Reprod Biomed Online 2009; 20:103-13. [PMID: 20158995 DOI: 10.1016/j.rbmo.2009.10.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2009] [Revised: 05/22/2009] [Accepted: 09/11/2009] [Indexed: 10/20/2022]
Abstract
Of the variety of contraceptive options available for women, very few provide dual protection against sexually transmitted diseases. Due to increased incidence of human immunodeficiency virus type 1 (HIV-1), genital herpes, hepatitis B and human papilloma virus, development of novel contraceptive strategies that incorporate antiviral activity has become the top priority in contraceptive research. Topical microbicides are now considered to be the last ray of hope, as they would ideally provide protection against unwanted pregnancy, proper lubrication during sexual activity, and preclude the vaginal/rectal transmission of sexually transmitted diseases. A large number of vaginal microbicides are in the preclinical or clinical stages of evaluation for their safety, efficacy and acceptability. However, a major bottleneck in the development of novel mechanism-based dual microbicides has been their detergent-like effects, along with debilitating action on the vaginal microflora. Hence the search is still on for the ideal dual microbicide/s that may obliterate these disadvantages and provide an invincible shield to women in their crusade against unintended pregnancy as well as sexually transmitted diseases. The present review highlights the current scenario towards the development of novel contraceptive strategies to counteract the rampant spread of sexually transmitted diseases, with special reference to HIV/AIDS.
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Affiliation(s)
- Poornima Chandran
- Department of Reproductive Biology Research, Indian Institute of Chemical Biology, Jadavpur, Kolkata 700032, India
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31
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Role of collagen deposition in lymphatic tissues and immune reconstruction during HIV-1 and SIV infections. Curr HIV/AIDS Rep 2009; 6:29-35. [DOI: 10.1007/s11904-009-0005-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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32
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Masopust D. Developing an HIV cytotoxic T-lymphocyte vaccine: issues of CD8 T-cell quantity, quality and location. J Intern Med 2009; 265:125-37. [PMID: 19093965 DOI: 10.1111/j.1365-2796.2008.02054.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Issues of quantity, quality and location impact the ability of CD8 T cells to mediate protection from infection. These issues are considered in light of human immunodeficiency virus (HIV)/simian immunodeficiency virus (SIV) vaccination. Methods are reviewed that result in 100- to 1000-fold higher frequencies of vaccine-specific memory CD8 T cells than that achieved by current HIV/SIV vaccine approaches. Data demonstrating that location within mucosal tissues has a direct impact on memory CD8 T-cell function are discussed. Arguments are made that establishing memory CD8 T cells within mucosal sites of transmission, a priori to natural infection, may be essential for conferring optimal and rapid protection. Lastly, it is proposed that heterologous prime-boost vaccination with recombinant live replicating vectors, which has the potential to induce tremendous numbers of cytolytic memory CD8 T cells within mucosal tissues, would provide a far more stringent test of the hypothesis that memory CD8 T cells could, in principal, form the basis for a preventative HIV vaccine.
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Affiliation(s)
- D Masopust
- Department of Microbiology, Center for Immunology, University of Minnesota, Minneapolis, MN 55455, USA.
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33
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Estes JD, Haase AT, Schacker TW. The role of collagen deposition in depleting CD4+ T cells and limiting reconstitution in HIV-1 and SIV infections through damage to the secondary lymphoid organ niche. Semin Immunol 2008; 20:181-6. [PMID: 18595731 DOI: 10.1016/j.smim.2008.04.002] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Accepted: 04/16/2008] [Indexed: 10/21/2022]
Abstract
The hallmark of HIV/SIV infections is the progressive depletion of CD4+ T cells that ultimately renders the host incapable of defending against AIDS defining opportunistic infections and malignancies. Although many potential mechanisms have been proposed to explain CD4+ T cell loss, we review here the growing evidence that fibrotic 'scarring' and consequent damage to the lymphatic tissue niche contributes to CD4+ T cell decline and limits CD4+ T cell re-population with retroviral therapy.
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Affiliation(s)
- Jacob D Estes
- AIDS and Cancer Virus Program, Science Applications International Corporation-Frederick, Inc., National Cancer Institute, Frederick, MD, USA
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34
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Cytokine expression in the colonic mucosa of human immunodeficiency virus-infected individuals before and during 9 months of antiretroviral therapy. Antimicrob Agents Chemother 2008; 52:3377-84. [PMID: 18573939 DOI: 10.1128/aac.00250-08] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
High-level human immunodeficiency virus (HIV) replication and the rapid breakdown of the mucosal immune system are the hallmarks of HIV infection in the gut. Cytokine dysregulation may be related to both phenomena. Using real-time PCR we quantified the colonic mucosal mRNA expression of selected proinflammatory and regulatory (gamma interferon [IFN-gamma], tumor necrosis factor alpha [TNF-alpha], and interleukin-2 [IL-2], IL-4, IL-6, and IL-10) and HIV-inhibitory (IL-16, CCL3, and CCL5) cytokines for 10 HIV-infected patients before and during 9 months of highly active antiretroviral therapy (HAART). HIV RNA and T-cell dynamics were measured in the colonic mucosa and the blood. Seven HIV-negative individuals served as controls. The mucosal mRNA expression of TNF-alpha, IFN-gamma, IL-4, IL-6, and IL-10 was significantly higher in HIV-infected patients than in control patients and remained elevated during 9 months of HAART despite the decline in blood and mucosal HIV RNA levels and an increase in the level of CD4(+) T lymphocytes. The mRNA levels of CCL3 and CCL5, both of which were elevated before treatment, returned to nearly normal during therapy. Despite reductions in levels of mucosal HIV RNA and the restoration of mucosal CD4(+) T lymphocytes, antiretroviral therapy failed to restore the normal colonic immunologic environment.
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35
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Abstract
There has recently been a resurgence of interest in the gastrointestinal pathology observed in patients infected with HIV. The gastrointestinal tract is a major site of HIV replication, which results in massive depletion of lamina propria CD4 T cells during acute infection. Highly active antiretroviral therapy leads to incomplete suppression of viral replication and substantially delayed and only partial restoration of gastrointestinal CD4 T cells. The gastrointestinal pathology associated with HIV infection comprises significant enteropathy with increased levels of inflammation and decreased levels of mucosal repair and regeneration. Assessment of gut mucosal immune system has provided novel directions for therapeutic interventions that modify the consequences of acute HIV infection.
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Affiliation(s)
- JM Brenchley
- Human Immunology Section, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - DC Douek
- Human Immunology Section, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
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36
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Ganusov VV, De Boer RJ. Do most lymphocytes in humans really reside in the gut? Trends Immunol 2007; 28:514-8. [PMID: 17964854 DOI: 10.1016/j.it.2007.08.009] [Citation(s) in RCA: 139] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2007] [Revised: 08/14/2007] [Accepted: 08/14/2007] [Indexed: 10/22/2022]
Abstract
It is widely believed that the gut, and particularly the lamina propria (LP) of the gut, contains most of the lymphocytes in humans. The strong depletion of CD4(+) T cells from the gut LP of HIV-infected patients was, therefore, suggested to be such a large, irreversible insult that it could explain HIV disease progression. However, reviewing data from different mammalian species, we found that only 5%-20% of all lymphocytes reside in the gut, and that only 1%-9% of the total lymphocyte number is located in the gut LP. Our findings suggest that spleen and lymph nodes, rather than the gut, are the largest immune compartments in mammals.
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Affiliation(s)
- Vitaly V Ganusov
- Theoretical Biology, Utrecht University, Utrecht, The Netherlands.
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37
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Okoye A, Meier-Schellersheim M, Brenchley JM, Hagen SI, Walker JM, Rohankhedkar M, Lum R, Edgar JB, Planer SL, Legasse A, Sylwester AW, Piatak M, Lifson JD, Maino VC, Sodora DL, Douek DC, Axthelm MK, Grossman Z, Picker LJ. Progressive CD4+ central memory T cell decline results in CD4+ effector memory insufficiency and overt disease in chronic SIV infection. ACTA ACUST UNITED AC 2007; 204:2171-85. [PMID: 17724130 PMCID: PMC2118701 DOI: 10.1084/jem.20070567] [Citation(s) in RCA: 242] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Primary simian immunodeficiency virus (SIV) infections of rhesus macaques result in the dramatic depletion of CD4+ CCR5+ effector–memory T (TEM) cells from extra-lymphoid effector sites, but in most infections, an increased rate of CD4+ memory T cell proliferation appears to prevent collapse of effector site CD4+ TEM cell populations and acute-phase AIDS. Eventually, persistent SIV replication results in chronic-phase AIDS, but the responsible mechanisms remain controversial. Here, we demonstrate that in the chronic phase of progressive SIV infection, effector site CD4+ TEM cell populations manifest a slow, continuous decline, and that the degree of this depletion remains a highly significant correlate of late-onset AIDS. We further show that due to persistent immune activation, effector site CD4+ TEM cells are predominantly short-lived, and that their homeostasis is strikingly dependent on the production of new CD4+ TEM cells from central–memory T (TCM) cell precursors. The instability of effector site CD4+ TEM cell populations over time was not explained by increasing destruction of these cells, but rather was attributable to progressive reduction in their production, secondary to decreasing numbers of CCR5− CD4+ TCM cells. These data suggest that although CD4+ TEM cell depletion is a proximate mechanism of immunodeficiency, the tempo of this depletion and the timing of disease onset are largely determined by destruction, failing production, and gradual decline of CD4+ TCM cells.
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Affiliation(s)
- Afam Okoye
- Vaccine and Gene Therapy Institute, Department of Pathology, and the Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006., USA
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38
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Critchfield JW, Lemongello D, Walker DH, Garcia JC, Asmuth DM, Pollard RB, Shacklett BL. Multifunctional human immunodeficiency virus (HIV) gag-specific CD8+ T-cell responses in rectal mucosa and peripheral blood mononuclear cells during chronic HIV type 1 infection. J Virol 2007; 81:5460-71. [PMID: 17344302 PMCID: PMC1900284 DOI: 10.1128/jvi.02535-06] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The intestinal tract is a lymphocyte-rich site that undergoes severe depletion of memory CD4(+) T cells within days of simian immunodeficiency virus or human immunodeficiency virus type 1 (HIV-1) infection. An ensuing influx of virus-specific CD8(+) T cells, which persist throughout the chronic phase of infection, has also been documented in the gastrointestinal tract. However, little is known of the functionality of these effector cells or their relationship to the disease course. In this study, we measured CD8(+) T-cell responses to HIV-1 peptides in paired rectal and blood samples from chronically infected patients. In both blood and rectum, there was an immunodominant CD8(+) T-cell response to HIV Gag compared to Pol and Env (P < 0.01). In contrast, cytomegalovirus pp65 peptides elicited gamma interferon (IFN-gamma) secretion strongly in peripheral blood mononuclear cells (PBMC) but weakly in rectal CD8(+) T cells (P = 0.015). Upon stimulation with HIV peptides, CD8(+) T cells from both sites were capable of mounting complex responses including degranulation (CD107 expression) and IFN-gamma and tumor necrosis factor alpha (TNF-alpha) production. In rectal tissue, CD107 release was frequently coupled with production of IFN-gamma or TNF-alpha. In patients not on antiretroviral therapy, the magnitude of Gag-specific responses, as a percentage of CD8(+) T cells, was greater in the rectal mucosa than in PBMC (P = 0.054); however, the breakdown of responding cells into specific functional categories was similar in both sites. These findings demonstrate that rectal CD8(+) T cells are capable of robust and varied HIV-1-specific responses and therefore likely play an active role in eliminating infected cells during chronic infection.
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Affiliation(s)
- J William Critchfield
- Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis, CA 95616, USA
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39
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Mestecky J. Humoral immune responses to the human immunodeficiency virus type-1 (HIV-1) in the genital tract compared to other mucosal sites. J Reprod Immunol 2007; 73:86-97. [PMID: 17354294 DOI: 10.1016/j.jri.2007.01.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Infection with the human immunodeficiency virus-1 (HIV-1) must be considered as a primarily mucosal disease. On a worldwide basis, the absolute majority of HIV infections occur through mucosal surfaces of the genital and intestinal tracts, and the earliest and most dramatic immunologic alterations are induced by the virus in mucosal tissues. However, individual compartments of mucosal components of the immune system display remarkable differences with respect to dominant antibody isotypes, virus phenotypes, densities and origins of cells involved in innate and specific immunity, presence or absence of inductive sites, and routes of immunizations that induce humoral and cellular responses. In this regard, the mucosal immune system of the female and male genital tracts exhibit several features which are distinct from other mucosal tissues, including dominance of the IgG isotype, local as well as pronounced systemic origin of antibodies, the absence of organized lymphoepithelial inductive sites and limited humoral responses stimulated by local antigen administration. Furthermore, it is evident that, irrespective of the route of infection, HIV-1 induces easily detectable IgG but not IgA specific antibody responses. These differences must be considered in the design of protective vaccines against infection with HIV and other agents of sexually transmitted diseases.
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Affiliation(s)
- Jiri Mestecky
- Department of Microbiology, University of Alabama at Birmingham, Box 1, 845 19th Street South, Birmingham, AL 35294, USA.
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40
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Mestecky J. Humoral immune responses to the human immunodeficiency virus type-1 (HIV-1) in the genital tract compared to other mucosal sites. J Reprod Immunol 2007; 72:1-17. [PMID: 17095369 DOI: 10.1016/j.jri.2006.05.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2006] [Revised: 05/21/2006] [Accepted: 05/22/2006] [Indexed: 12/12/2022]
Abstract
Infection with the human immunodeficiency virus-1 (HIV-1) must be considered as a primarily mucosal disease. On a worldwide basis, the absolute majority of HIV infections occur through mucosal surfaces of the genital and intestinal tracts, and the earliest and most dramatic immunologic alterations are induced by the virus in mucosal tissues. However, individual compartments of mucosal components of the immune system display remarkable differences with respect to dominant antibody isotypes, virus phenotypes, densities and origins of cells involved in innate and specific immunity, presence or absence of inductive sites, and routes of immunizations that induce humoral and cellular responses. In this regard, the mucosal immune system of the female and male genital tracts exhibit several features which are distinct from other mucosal tissues, including dominance of the IgG isotype, local as well as pronounced systemic origin of antibodies, the absence of organized lymphoepithelial inductive sites and limited humoral responses stimulated by local antigen administration. Furthermore, it is evident that, irrespective of the route of infection, HIV-1 induces easily detectable IgG but not IgA specific antibody responses. These differences must be considered in the design of protective vaccines against infection with HIV and other agents of sexually transmitted diseases.
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Affiliation(s)
- Jiri Mestecky
- Department of Microbiology, University of Alabama at Birmingham, Box 1, 845 19th Street South, Birmingham, AL 35294, USA.
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41
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Centlivre M, Sala M, Wain-Hobson S, Berkhout B. In HIV-1 pathogenesis the die is cast during primary infection. AIDS 2007; 21:1-11. [PMID: 17148962 DOI: 10.1097/qad.0b013e3280117f7f] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The chronic stage of HIV-1 infection has been extensively described as a slowly evolving phase, in which the virus induces T-cell death slightly faster than the human body is able to recover. In contrast, T-cell and viral replication dynamics during primary infection have been less well studied. Recent studies in the SIV-macaque model and in HIV-positive patients during the acute infection period have highlighted the massive and irreversible depletion of CD4 memory T cells in the mucosa, particularly in the gut. Hence, gut-associated lymphoid tissue (GALT) plays a central role in the early stages of HIV-1 pathogenesis. Due to its particular cytokine expression pattern, GALT may favour the differential replication of certain HIV-1 subtypes during primary infection, particularly of subtype C. This could enhance the chance of a successful transmission. Moreover, these early events taking place in GALT during primary infection have major implications for therapy and vaccine design.
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42
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Hel Z, McGhee JR, Mestecky J. HIV infection: first battle decides the war. Trends Immunol 2006; 27:274-81. [PMID: 16679064 DOI: 10.1016/j.it.2006.04.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2006] [Revised: 03/28/2006] [Accepted: 04/21/2006] [Indexed: 10/24/2022]
Abstract
The traditional view of HIV-1 infection characterized by the slow decline of CD4+ T cells has radically changed in light of recent observations in rhesus macaques and humans of rapid and extensive infection and removal of memory CD4+ T cells in mucosal tissues within the first three weeks of infection. This initial strike to the immune system seems to be the distinguishing feature of HIV-1 pathogenesis and its extent sets the overall course of the ensuing infection. Qualitatively different mechanisms of CD4+ T-cell depletion prevail during the acute, chronic and advanced phases of infection depending on the availability of the target-cell population and competence of the immune system. The elimination of CD4+ T cells in mucosal lymphoid tissues results in the absence of important regulatory and effector functions that these cells normally perform in controlling immune responses to environmental antigens and pathogens. Ablation of acute HIV-1 viremia limits the initial damage to the CD4+ T-cell compartment and helps to establish a state of equilibrium between the replicating virus, the availability of the target-cell population and the immune control characteristic of long-term non-progression.
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Affiliation(s)
- Zdenek Hel
- Department of Pathology, University of Alabama at Birmingham, 619 19th Street South, Room SW-W286, Birmingham, AL 35249-7331, USA.
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43
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Abstract
The pathogenesis of human immunodeficiency virus has long been thought to center on a gradual depletion of CD4(+) T cells, with an average of 100 cells lost per microliter of blood per year. However, studies of macaques infected with simian immunodeficiency virus and humans infected with human immunodeficiency virus have shown that the infection rapidly kills most CD4(+) T cells at mucosal surfaces. Although most CD4(+) T cells reside at these sites, the magnitude of this assault on the immune system is not reflected in the peripheral blood. Here we consider models of human immunodeficiency virus disease pathogenesis given those findings and propose a hypothesis to account for particular aspects of the disease during the chronic phase of infection that can be directly attributed to early depletion of mucosal CD4(+) T cells.
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Affiliation(s)
- Jason M Brenchley
- Human Immunology Section, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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44
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Sanchez TH, Brooks JT, Sullivan PS, Juhasz M, Mintz E, Dworkin MS, Jones JL. Bacterial diarrhea in persons with HIV infection, United States, 1992-2002. Clin Infect Dis 2005; 41:1621-7. [PMID: 16267735 DOI: 10.1086/498027] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2005] [Accepted: 07/14/2005] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND To describe trends in bacterial diarrhea among human immunodeficiency virus (HIV)-infected persons during 1992-2002, we examined data from a longitudinal record review study of persons with HIV infection who were receiving medical care in >100 medical facilities in 9 major United States cities. METHODS An analysis was performed using data from 44,778 persons who were followed up for a mean of 2.6 years. We calculated incidence rates and rate ratios for bacterial diarrhea, by stage of HIV disease, and determined odds ratios (ORs) to compare bacterial diarrhea diagnosis in 2002 versus 1992. RESULTS The mean annual incidence of bacterial diarrhea was 7.2 cases per 1000 person-years. The incidence of Clostridium difficile-associated diarrhea, the most common bacterial cause of diarrhea, was 4.1 cases per 1000 person-years. Compared with persons without AIDS, persons with AIDS were more likely to have bacterial diarrhea (incidence rate ratio, 1.3-9.9, varying by clinical versus immunologic AIDS and type of bacterial diarrhea). Between 1992 and 2002, the overall rate of bacterial diarrhea in persons with clinical AIDS decreased (OR, 0.4; 95% confidence interval, 0.2-0.6). During the same period, bacterial diarrhea rates among other persons in the analysis did not significantly change. CONCLUSIONS C. difficile is the most common recognized cause of bacterial diarrhea among persons infected with HIV. The risk for bacterial diarrhea increases with increased severity of HIV disease. Health care professionals should be aware that patients with AIDS are at increased risk for bacterial diarrhea, and they should reinforce recommendations for decreasing the chances of acquiring bacterial diarrhea.
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Affiliation(s)
- Travis H Sanchez
- Division of HIV/AIDS Prevention--Surveillance and Epidemiology, National Center for HIV, STD, and TB Prevention, National Center for Infectious Disease, Centers for Disease Control and Prevention, Atlanta, GA, USA.
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45
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46
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Li Q, Duan L, Estes JD, Ma ZM, Rourke T, Wang Y, Reilly C, Carlis J, Miller CJ, Haase AT. Peak SIV replication in resting memory CD4+ T cells depletes gut lamina propria CD4+ T cells. Nature 2005; 434:1148-52. [PMID: 15793562 DOI: 10.1038/nature03513] [Citation(s) in RCA: 781] [Impact Index Per Article: 41.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2004] [Accepted: 03/07/2005] [Indexed: 11/09/2022]
Abstract
In early simian immunodeficiency virus (SIV) and human immunodeficiency virus-1 (HIV-1) infections, gut-associated lymphatic tissue (GALT), the largest component of the lymphoid organ system, is a principal site of both virus production and depletion of primarily lamina propria memory CD4+ T cells; that is, CD4-expressing T cells that previously encountered antigens and microbes and homed to the lamina propria of GALT. Here, we show that peak virus production in gut tissues of SIV-infected rhesus macaques coincides with peak numbers of infected memory CD4+ T cells. Surprisingly, most of the initially infected memory cells were not, as expected, activated but were instead immunophenotypically 'resting' cells that, unlike truly resting cells, but like the first cells mainly infected at other mucosal sites and peripheral lymph nodes, are capable of supporting virus production. In addition to inducing immune activation and thereby providing activated CD4+ T-cell targets to sustain infection, virus production also triggered an immunopathologically limiting Fas-Fas-ligand-mediated apoptotic pathway in lamina propria CD4+ T cells, resulting in their preferential ablation. Thus, SIV exploits a large, resident population of resting memory CD4+ T cells in GALT to produce peak levels of virus that directly (through lytic infection) and indirectly (through apoptosis of infected and uninfected cells) deplete CD4+ T cells in the effector arm of GALT. The scale of this CD4+ T-cell depletion has adverse effects on the immune system of the host, underscoring the importance of developing countermeasures to SIV that are effective before infection of GALT.
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Affiliation(s)
- Qingsheng Li
- Department of Microbiology, Medical School, University of Minnesota, MMC 196, 420 Delaware Street S.E, Minneapolis 55455, USA
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47
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Picker LJ, Hagen SI, Lum R, Reed-Inderbitzin EF, Daly LM, Sylwester AW, Walker JM, Siess DC, Piatak M, Wang C, Allison DB, Maino VC, Lifson JD, Kodama T, Axthelm MK. Insufficient production and tissue delivery of CD4+ memory T cells in rapidly progressive simian immunodeficiency virus infection. ACTA ACUST UNITED AC 2005; 200:1299-314. [PMID: 15545355 PMCID: PMC2211921 DOI: 10.1084/jem.20041049] [Citation(s) in RCA: 263] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
The mechanisms linking human immunodeficiency virus replication to the progressive immunodeficiency of acquired immune deficiency syndrome are controversial, particularly the relative contribution of CD4+ T cell destruction. Here, we used the simian immunodeficiency virus (SIV) model to investigate the relationship between systemic CD4+ T cell dynamics and rapid disease progression. Of 18 rhesus macaques (RMs) infected with CCR5-tropic SIVmac239 (n = 14) or CXCR4-tropic SIVmac155T3 (n = 4), 4 of the former group manifested end-stage SIV disease by 200 d after infection. In SIVmac155T3 infections, naive CD4+ T cells were dramatically depleted, but this population was spared by SIVmac239, even in rapid progressors. In contrast, all SIVmac239-infected RMs demonstrated substantial systemic depletion of CD4+ memory T cells by day 28 after infection. Surprisingly, the extent of CD4+ memory T cell depletion was not, by itself, a strong predictor of rapid progression. However, in all RMs destined for stable infection, this depletion was countered by a striking increase in production of short-lived CD4+ memory T cells, many of which rapidly migrated to tissue. In all rapid progressors (P < 0.0001), production of these cells initiated but failed by day 42 of infection, and tissue delivery of new CD4+ memory T cells ceased. Thus, although profound depletion of tissue CD4+ memory T cells appeared to be a prerequisite for early pathogenesis, it was the inability to respond to this depletion with sustained production of tissue-homing CD4+ memory T cells that best distinguished rapid progressors, suggesting that mechanisms of the CD4+ memory T cell generation play a crucial role in maintaining immune homeostasis in stable SIV infection.
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Affiliation(s)
- Louis J Picker
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, West Campus, 505 NW 185th Ave., Beaverton, OR 97006, USA.
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Smith PD, Wahl SW. Immunobiology of Mucosal HIV-1 Infection * *This work was supported by National Institutes of Health grants DK-47322, HD-41361, and DK-64400 and the Research Service of the Department of Veterans Affairs. Mucosal Immunol 2005. [DOI: 10.1016/b978-012491543-5/50071-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Mehandru S, Poles MA, Tenner-Racz K, Horowitz A, Hurley A, Hogan C, Boden D, Racz P, Markowitz M. Primary HIV-1 infection is associated with preferential depletion of CD4+ T lymphocytes from effector sites in the gastrointestinal tract. ACTA ACUST UNITED AC 2004; 200:761-70. [PMID: 15365095 PMCID: PMC2211967 DOI: 10.1084/jem.20041196] [Citation(s) in RCA: 872] [Impact Index Per Article: 43.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Given its population of CCR5-expressing, immunologically activated CD4(+) T cells, the gastrointestinal (GI) mucosa is uniquely susceptible to human immunodeficiency virus (HIV)-1 infection. We undertook this study to assess whether a preferential depletion of mucosal CD4(+) T cells would be observed in HIV-1-infected subjects during the primary infection period, to examine the anatomic subcompartment from which these cells are depleted, and to examine whether suppressive highly active antiretroviral therapy could result in complete immune reconstitution in the mucosal compartment. Our results demonstrate that a significant and preferential depletion of mucosal CD4(+) T cells compared with peripheral blood CD4(+) T cells is seen during primary HIV-1 infection. CD4(+) T cell loss predominated in the effector subcompartment of the GI mucosa, in distinction to the inductive compartment, where HIV-1 RNA was present. Cross-sectional analysis of a cohort of primary HIV-1 infection subjects showed that although chronic suppression of HIV-1 permits near-complete immune recovery of the peripheral blood CD4(+) T cell population, a significantly greater CD4(+) T cell loss remains in the GI mucosa, despite up to 5 yr of fully suppressive therapy. Given the importance of the mucosal compartment in HIV-1 pathogenesis, further study to elucidate the significance of the changes observed here is critical.
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Affiliation(s)
- Saurabh Mehandru
- Aaron Diamond AIDS Research Center, The Rockefeller University, 455 First Ave., 7th Fl., New York, NY 10016, USA
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