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Stapleton JT. Human Pegivirus Type 1: A Common Human Virus That Is Beneficial in Immune-Mediated Disease? Front Immunol 2022; 13:887760. [PMID: 35707535 PMCID: PMC9190258 DOI: 10.3389/fimmu.2022.887760] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 05/03/2022] [Indexed: 12/25/2022] Open
Abstract
Two groups identified a novel human flavivirus in the mid-1990s. One group named the virus hepatitis G virus (HGV) and the other named it GB Virus type C (GBV-C). Sequence analyses found these two isolates to be the same virus, and subsequent studies found that the virus does not cause hepatitis despite sharing genome organization with hepatitis C virus. Although HGV/GBV-C infection is common and may cause persistent infection in humans, the virus does not appear to directly cause any other known disease state. Thus, the virus was renamed “human pegivirus 1” (HPgV-1) for “persistent G” virus. HPgV-1 is found primarily in lymphocytes and not hepatocytes, and several studies found HPgV-1 infection associated with prolonged survival in people living with HIV. Co-infection of human lymphocytes with HPgV-1 and HIV inhibits HIV replication. Although three viral proteins directly inhibit HIV replication in vitro, the major effects of HPgV-1 leading to reduced HIV-related mortality appear to result from a global reduction in immune activation. HPgV-1 specifically interferes with T cell receptor signaling (TCR) by reducing proximal activation of the lymphocyte specific Src kinase LCK. Although TCR signaling is reduced, T cell activation is not abolished and with sufficient stimulus, T cell functions are enabled. Consequently, HPgV-1 is not associated with immune suppression. The HPgV-1 immunomodulatory effects are associated with beneficial outcomes in other diseases including Ebola virus infection and possibly graft-versus-host-disease following stem cell transplantation. Better understanding of HPgV-1 immune escape and mechanisms of inflammation may identify novel therapies for immune-based diseases.
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Affiliation(s)
- Jack T. Stapleton
- Medicine Service, Iowa City Veterans Administration Healthcare, Iowa City, IA, United States
- Departments of Internal Medicine, Microbiology & Immunology, University of Iowa, Iowa City, IA, United States
- *Correspondence: Jack T. Stapleton,
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2
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Tissue presentation of human pegivirus infection in liver transplanted recipients. Microb Pathog 2022; 167:105571. [PMID: 35550845 DOI: 10.1016/j.micpath.2022.105571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 04/16/2022] [Accepted: 05/05/2022] [Indexed: 02/08/2023]
Abstract
Human pegivirus-1 (HPgV-1) is known for its protective role in HIV co-infected individuals. This immunomodulatory effect raised questions concerning the possible role of HPgV-1 infection and the risk of rejection in liver transplanted patients. We aimed to evaluate the possible protective effect of HPgV-1 on graft outcome of liver transplanted patients. A total of 283 patients were recruited. Formalin-fixed paraffin-embedded tissue samples were collected from the explanted liver. HBV-DNA, HCV-RNA, and HPgV-1-RNA were determined using PCR and multiplex RT-PCR assays. The clinical course of patients including the occurrence of acute cellular rejection was compared between HPgV-1-infected vs. uninfected patients. HBV-DNA, HCV-RNA and HPgV-1-RNA were detected in 42.6%, 4.9%, and 7.8% of samples, respectively. None of the HPgV-1-infected patients experienced graft rejection. Group LASSO logistic regression revealed that HPgV-1 infection was the only factor which significantly reduced the odds of graft rejection (OR = 0.5, 95% CI = 0.29-0.89). No significant association was found between the presence of HPgV-1 with HBV and HCV infections. The lack of graft rejection in HPgV-1-infected liver transplanted patients might indicate a possible role of this virus for graft surveillance. Since these are still preliminary findings, prospective studies should further elucidate the role of HPgV-1 in liver transplantation outcomes.
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Heffron AS, Lauck M, Somsen ED, Townsend EC, Bailey AL, Sosa M, Eickhoff J, Capuano III S, Newman CM, Kuhn JH, Mejia A, Simmons HA, O’Connor DH. Discovery of a Novel Simian Pegivirus in Common Marmosets ( Callithrix jacchus) with Lymphocytic Enterocolitis. Microorganisms 2020; 8:microorganisms8101509. [PMID: 33007921 PMCID: PMC7599636 DOI: 10.3390/microorganisms8101509] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/26/2020] [Accepted: 09/28/2020] [Indexed: 11/30/2022] Open
Abstract
From 2010 to 2015, 73 common marmosets (Callithrix jacchus) housed at the Wisconsin National Primate Research Center (WNPRC) were diagnosed postmortem with lymphocytic enterocolitis. We used unbiased deep-sequencing to screen the blood of deceased enterocolitis-positive marmosets for viruses. In five out of eight common marmosets with lymphocytic enterocolitis, we discovered a novel pegivirus not present in ten matched, clinically normal controls. The novel virus, which we named Southwest bike trail virus (SOBV), is most closely related (68% nucleotide identity) to a strain of simian pegivirus A isolated from a three-striped night monkey (Aotus trivirgatus). We screened 146 living WNPRC common marmosets for SOBV, finding an overall prevalence of 34% (50/146). Over four years, 85 of these 146 animals died or were euthanized. Histological examination revealed 27 SOBV-positive marmosets from this cohort had lymphocytic enterocolitis, compared to 42 SOBV-negative marmosets, indicating no association between SOBV and disease in this cohort (p = 0.0798). We also detected SOBV in two of 33 (6%) clinically normal marmosets screened during transfer from the New England Primate Research Center, suggesting SOBV could be exerting confounding influences on comparisons of common marmoset studies from multiple colonies.
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Affiliation(s)
- Anna S. Heffron
- Department of Pathology and Laboratory Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53711, USA; (A.S.H.); (M.L.); (E.D.S.); (E.C.T.); (C.M.N.)
| | - Michael Lauck
- Department of Pathology and Laboratory Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53711, USA; (A.S.H.); (M.L.); (E.D.S.); (E.C.T.); (C.M.N.)
| | - Elizabeth D. Somsen
- Department of Pathology and Laboratory Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53711, USA; (A.S.H.); (M.L.); (E.D.S.); (E.C.T.); (C.M.N.)
| | - Elizabeth C. Townsend
- Department of Pathology and Laboratory Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53711, USA; (A.S.H.); (M.L.); (E.D.S.); (E.C.T.); (C.M.N.)
| | - Adam L. Bailey
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA;
| | - Megan Sosa
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA; (M.S.); (S.C.III); (A.M.); (H.A.S.)
| | - Jens Eickhoff
- Department of Biostatistics & Medical Informatics, University of Wisconsin-Madison, Madison, WI 53705, USA;
| | - Saverio Capuano III
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA; (M.S.); (S.C.III); (A.M.); (H.A.S.)
| | - Christina M. Newman
- Department of Pathology and Laboratory Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53711, USA; (A.S.H.); (M.L.); (E.D.S.); (E.C.T.); (C.M.N.)
| | - Jens H. Kuhn
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, MD 21702, USA;
| | - Andres Mejia
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA; (M.S.); (S.C.III); (A.M.); (H.A.S.)
| | - Heather A. Simmons
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA; (M.S.); (S.C.III); (A.M.); (H.A.S.)
| | - David H. O’Connor
- Department of Pathology and Laboratory Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53711, USA; (A.S.H.); (M.L.); (E.D.S.); (E.C.T.); (C.M.N.)
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715, USA; (M.S.); (S.C.III); (A.M.); (H.A.S.)
- Correspondence: ; Tel.: +1-608-890-0845
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Fama A, Xiang J, Link BK, Allmer C, Klinzman D, Feldman AL, Nowakowski GS, Liebow M, Larson MC, Maurer MJ, Ansell SM, Novak AJ, Asmann YW, Slager SL, Call TG, Habermann TM, Cerhan JR, Stapleton JT. Human Pegivirus infection and lymphoma risk and prognosis: a North American study. Br J Haematol 2018; 182:644-653. [PMID: 29808922 DOI: 10.1111/bjh.15416] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 03/26/2018] [Indexed: 12/12/2022]
Abstract
We evaluated the association of Human Pegivirus (HPgV) viraemia with risk of developing lymphoma, overall and by major subtypes. Because this virus has also been associated with better prognosis in the setting of co-infection with human immunodeficiency virus, we further assessed the association of HPgV with prognosis. We used risk factor data and banked plasma samples from 2094 lymphoma cases newly diagnosed between 2002 and 2009 and 1572 frequency-matched controls. Plasma samples were tested for HPgV RNA by reverse transcription polymerase chain reaction (RT-PCR), and those with RNA concentrations <5000 genome equivalents/ml were confirmed using nested RT-PCR methods. To assess the role of HPgV in lymphoma prognosis, we used 2948 cases from a cohort study of newly diagnosed lymphoma patients (included all cases from the case-control study). There was a positive association of HPgV viraemia with risk of lymphoma overall (Odds ratio = 2·14; 95% confidence interval [CI] 1·63-2·80; P < 0·0001), and for all major subtypes except Hodgkin lymphoma and chronic lymphocytic leukaemia/small lymphocytic lymphoma, and this was not confounded by other lymphoma risk factors. In contrast, there was no association of HPgV viraemia with event-free survival (Hazard ratio [HR] = 1·00; 95% CI 0·85-1·18) or overall survival (HR = 0·97; 95% CI 0·79-1·20) for lymphoma overall, or any of the subtypes. These data support the hypothesis for a role of HPgV in the aetiology of multiple lymphoma subtypes.
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Affiliation(s)
- Angelo Fama
- Division of Hematology, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.,Ematologia, Azienda Unità Sanitaria Locale-IRCCS di Reggio Emilia, Reggio Emilia, Italy
| | - Jinhua Xiang
- Department of Internal Medicine, University of Iowa and Iowa City Veterans Affairs Medical Center, Iowa City, IA, USA
| | - Brian K Link
- Department of Internal Medicine, University of Iowa, Iowa City, IA, USA
| | - Cristine Allmer
- Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA
| | - Donna Klinzman
- Department of Internal Medicine, University of Iowa and Iowa City Veterans Affairs Medical Center, Iowa City, IA, USA
| | - Andrew L Feldman
- Department of Laboratory Medicine & Pathology, Mayo Clinic, Rochester, MN, USA
| | - Grzegorz S Nowakowski
- Division of Hematology, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA
| | - Mark Liebow
- Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA
| | - Melissa C Larson
- Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA
| | - Matthew J Maurer
- Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA
| | - Stephen M Ansell
- Division of Hematology, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA
| | - Anne J Novak
- Division of Hematology, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA
| | - Yan W Asmann
- Department of Health Sciences Research, Mayo Clinic, Jacksonville, FL, USA
| | - Susan L Slager
- Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA
| | - Timothy G Call
- Division of Hematology, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA
| | - Thomas M Habermann
- Division of Hematology, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA
| | - James R Cerhan
- Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA
| | - Jack T Stapleton
- Department of Internal Medicine, University of Iowa and Iowa City Veterans Affairs Medical Center, Iowa City, IA, USA
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McLinden JH, Bhattarai N, Stapleton JT, Chang Q, Kaufman TM, Cassel SL, Sutterwala FS, Haim H, Houtman JC, Xiang J. Yellow Fever Virus, but Not Zika Virus or Dengue Virus, Inhibits T-Cell Receptor-Mediated T-Cell Function by an RNA-Based Mechanism. J Infect Dis 2017; 216:1164-1175. [PMID: 28968905 PMCID: PMC5853456 DOI: 10.1093/infdis/jix462] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 08/13/2017] [Indexed: 01/03/2023] Open
Abstract
The Flavivirus genus within the Flaviviridae family is comprised of many important human pathogens including yellow fever virus (YFV), dengue virus (DENV), and Zika virus (ZKV), all of which are global public health concerns. Although the related flaviviruses hepatitis C virus and human pegivirus (formerly named GBV-C) interfere with T-cell receptor (TCR) signaling by novel RNA and protein-based mechanisms, the effect of other flaviviruses on TCR signaling is unknown. Here, we studied the effect of YFV, DENV, and ZKV on TCR signaling. Both YFV and ZKV replicated in human T cells in vitro; however, only YFV inhibited TCR signaling. This effect was mediated at least in part by the YFV envelope (env) protein coding RNA. Deletion mutagenesis studies demonstrated that expression of a short, YFV env RNA motif (vsRNA) was required and sufficient to inhibit TCR signaling. Expression of this vsRNA and YFV infection of T cells reduced the expression of a Src-kinase regulatory phosphatase (PTPRE), while ZKV infection did not. YFV infection in mice resulted in impaired TCR signaling and PTPRE expression, with associated reduction in murine response to experimental ovalbumin vaccination. Together, these data suggest that viruses within the flavivirus genus inhibit TCR signaling in a species-dependent manner.
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Affiliation(s)
- James H McLinden
- Research Service, Iowa City Veterans Affairs Medical Center
- Department of Internal Medicine, University of Iowa, Iowa City
| | - Nirjal Bhattarai
- Research Service, Iowa City Veterans Affairs Medical Center
- Department of Internal Medicine, University of Iowa, Iowa City
| | - Jack T Stapleton
- Research Service, Iowa City Veterans Affairs Medical Center
- Department of Internal Medicine, University of Iowa, Iowa City
- Department of Microbiology, University of Iowa, Iowa City
| | - Qing Chang
- Research Service, Iowa City Veterans Affairs Medical Center
- Department of Internal Medicine, University of Iowa, Iowa City
| | - Thomas M Kaufman
- Research Service, Iowa City Veterans Affairs Medical Center
- Department of Internal Medicine, University of Iowa, Iowa City
| | - Suzanne L Cassel
- Research Service, Iowa City Veterans Affairs Medical Center
- Department of Internal Medicine, University of Iowa, Iowa City
| | - Fayyaz S Sutterwala
- Research Service, Iowa City Veterans Affairs Medical Center
- Department of Internal Medicine, University of Iowa, Iowa City
| | - Hillel Haim
- Research Service, Iowa City Veterans Affairs Medical Center
- Department of Internal Medicine, University of Iowa, Iowa City
| | - Jon C Houtman
- Research Service, Iowa City Veterans Affairs Medical Center
- Department of Internal Medicine, University of Iowa, Iowa City
- Department of Microbiology, University of Iowa, Iowa City
| | - Jinhua Xiang
- Research Service, Iowa City Veterans Affairs Medical Center
- Department of Internal Medicine, University of Iowa, Iowa City
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Singh S, Blackard JT. Human pegivirus (HPgV) infection in sub-Saharan Africa-A call for a renewed research agenda. Rev Med Virol 2017; 27. [PMID: 29148108 DOI: 10.1002/rmv.1951] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2017] [Revised: 08/26/2017] [Accepted: 08/28/2017] [Indexed: 12/14/2022]
Abstract
The human pegivirus (HPgV)-formerly GB virus C-has a beneficial impact on HIV disease progression that has been described in multiple studies. Given the high prevalence of HIV in sub-Saharan Africa and the continuing need to suppress HIV replication, this review provides a comprehensive overview of the existing data on HPgV infection in sub-Saharan Africa, with a particular focus on studies of prevalence and the circulating HPgV genotypes. This review also highlights the need for additional studies of HPgV conducted on the African continent and proposes a research agenda for evaluation of HPgV.
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Affiliation(s)
- Shivank Singh
- Division of Digestive Diseases, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Jason T Blackard
- Division of Digestive Diseases, University of Cincinnati College of Medicine, Cincinnati, OH, USA
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Horemheb-Rubio G, Ramos-Cervantes P, Arroyo-Figueroa H, Ávila-Ríos S, García-Morales C, Reyes-Terán G, Escobedo G, Estrada G, García-Iglesias T, Muñoz-Saucedo N, Kershenobich D, Ostrosky-Wegman P, Ruiz-Palacios GM. High HPgV replication is associated with improved surrogate markers of HIV progression. PLoS One 2017; 12:e0184494. [PMID: 28910347 PMCID: PMC5598987 DOI: 10.1371/journal.pone.0184494] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 08/24/2017] [Indexed: 02/06/2023] Open
Abstract
Background Human Pegivirus (HPgV) may have a beneficial effect on HIV disease progression in co-infected patients; however, the virologic characteristics of this infection are not well defined. In this study, we determined HPgV viremia prevalence in Mexico and provide new insights to understand HPgV infection and HPgV/HIV co-infection. Methods We analyzed and quantified 7,890 serum samples for HPgV viremia by One-Step RT-Real-Time PCR, 6,484 from healthy blood donors and 1,406 from HIV-infected patients. Data on HIV progression were obtained from patients’ records. HPgV genotyping was performed in 445 samples by nested PCR of the 5’URT region. Finite Mixture Models were used to identify clustering patterns of HPgV viremia in blood donors and co-infected antiretroviral (ART)-naïve patients. Results HPgV was detected in 2.98% of blood donors and 33% of HIV patients, with a wide range of viral loads. The most prevalent genotypes were 3 (58.6%)and 2 (33.7%). HPgV viral loads from healthy blood donors and HPgV/HIV+ ART-naïve co-infected patients were clustered into two component distributions, low and high, with a cut-off point of 5.07log10 and 5.06log10, respectively. High HPgV viremia was associated with improved surrogate markers of HIV infection, independent of the estimated duration of HIV infection or HIV treatment. Conclusions HPgV prevalence in Mexico was similar to that reported for other countries. The prevalent genotypes could be related to Mexico’s geographic location and ethnicity, since genotype 2 is frequent in the United States and Europe and genotype 3 in Asia and Amerindian populations. HPgV viral load demonstrated two patterns of replication, low and high. The more pronounced beneficial response observed in co-infected patients with high HPgV viremia may explain discrepancies found between other studies. Mechanisms explaining high and low HPgV replication should be explored to determine whether the persistently elevated replication depends on host or viral factors.
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Affiliation(s)
- Gibran Horemheb-Rubio
- Department of Infectious Diseases, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Pilar Ramos-Cervantes
- Department of Infectious Diseases, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Hugo Arroyo-Figueroa
- Department of Infectious Diseases, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Santiago Ávila-Ríos
- Infectious Diseases Research Center, Instituto Nacional de Enfermedades Respiratorias, Mexico City, Mexico
| | - Claudia García-Morales
- Infectious Diseases Research Center, Instituto Nacional de Enfermedades Respiratorias, Mexico City, Mexico
| | - Gustavo Reyes-Terán
- Infectious Diseases Research Center, Instituto Nacional de Enfermedades Respiratorias, Mexico City, Mexico
| | - Galileo Escobedo
- Liver Pancreas and Intestinal Motility Laboratory, Hospital General de México, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Gloria Estrada
- Blood Bank, Hospital General de México, Mexico City, Mexico
| | - Trinidad García-Iglesias
- Immnuology Laboratory, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico
| | - Nayeli Muñoz-Saucedo
- Immnuology Laboratory, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico
| | - David Kershenobich
- Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | | | - Guillermo M. Ruiz-Palacios
- Department of Infectious Diseases, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
- * E-mail:
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Zhang J, Zhang Y, Chaloner K, Stapleton JT. A sequential classification rule based on multiple quantitative tests in the absence of a gold standard. Stat Med 2015; 35:1359-72. [PMID: 26522690 DOI: 10.1002/sim.6780] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 09/20/2015] [Accepted: 10/06/2015] [Indexed: 12/19/2022]
Abstract
In many medical applications, combining information from multiple biomarkers could yield a better diagnosis than any single one on its own. When there is a lack of a gold standard, an algorithm of classifying subjects into the case and non-case status is necessary for combining multiple markers. The aim of this paper is to develop a method to construct a composite test from multiple applicable tests and derive an optimal classification rule under the absence of a gold standard. Rather than combining the tests, we treat the tests as a sequence. This sequential composite test is based on a mixture of two multivariate normal latent models for the distribution of the test results in case and non-case groups, and the optimal classification rule is derived returning the greatest sensitivity at a given specificity. This method is applied to a real-data example and simulation studies have been carried out to assess the statistical properties and predictive accuracy of the proposed composite test. This method is also attainable to implement nonparametrically.
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Affiliation(s)
- Jingyang Zhang
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, U.S.A
| | - Ying Zhang
- Department of Biostatistics, Indiana University Fairbanks School of Public Health and School of Medicine, Indianapolis, IN 46202, U.S.A.,Department of Mathematics, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Kathryn Chaloner
- Department of Biostatistics, University of Iowa, Iowa City, IA 52242, U.S.A.,Department of Statistics and Actuarial Sciences, University of Iowa, Iowa City, IA 52242, U.S.A
| | - Jack T Stapleton
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, U.S.A
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Chivero ET, Bhattarai N, McLinden JH, Xiang J, Stapleton JT. Human Pegivirus (HPgV; formerly known as GBV-C) inhibits IL-12 dependent natural killer cell function. Virology 2015; 485:116-27. [PMID: 26245365 DOI: 10.1016/j.virol.2015.07.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Revised: 07/02/2015] [Accepted: 07/13/2015] [Indexed: 02/06/2023]
Abstract
Human Pegivirus (HPgV, formally GB virus C) infects lymphocytes and NK cells in vivo, and infection is associated with reduced T cell and NK cell activation in HIV-infected individuals. The mechanism by which HPgV inhibits NK cell activation has not been assessed. Following IL-12 stimulation, IFNγ expression was lower in HIV-HPgV co-infected subjects compared to HIV mono-infected subjects (p=0.02). In addition, HPgV positive human sera, extracellular vesicles containing E2 protein, recombinant E2 protein and synthetic E2 peptides containing a predicted Tyk2 interacting motif inhibited NK cell IL-12-mediated IFNγ release. E2 protein also inhibited Tyk2 activation following IL-12 stimulation. In contrast, cytolytic NK cell function was not altered by HPgV. Inhibition of NK cell-induced proinflammatory/antiviral cytokines may contribute to both HPgV persistence and reduced immune activation during HIV-coinfection. Understanding mechanisms by which HPgV alters immune activation may contribute towards novel immunomodulatory therapies to treat HIV and inflammatory diseases.
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Affiliation(s)
- Ernest T Chivero
- The Iowa City Veterans Affairs Medical Center The University of Iowa, Iowa City, IA 52242, USA; Interdisciplinary program in Molecular and Cellular Biology, The University of Iowa, Iowa City, IA 52242, USA
| | - Nirjal Bhattarai
- The Iowa City Veterans Affairs Medical Center The University of Iowa, Iowa City, IA 52242, USA; Department of Internal Medicine, The University of Iowa, Iowa City, IA 52242, USA
| | - James H McLinden
- The Iowa City Veterans Affairs Medical Center The University of Iowa, Iowa City, IA 52242, USA; Department of Internal Medicine, The University of Iowa, Iowa City, IA 52242, USA
| | - Jinhua Xiang
- The Iowa City Veterans Affairs Medical Center The University of Iowa, Iowa City, IA 52242, USA; Department of Internal Medicine, The University of Iowa, Iowa City, IA 52242, USA
| | - Jack T Stapleton
- The Iowa City Veterans Affairs Medical Center The University of Iowa, Iowa City, IA 52242, USA; Interdisciplinary program in Molecular and Cellular Biology, The University of Iowa, Iowa City, IA 52242, USA; Department of Internal Medicine, The University of Iowa, Iowa City, IA 52242, USA; Department of Microbiology, The University of Iowa, Iowa City, IA 52242, USA.
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10
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Detection of GB virus C genomic sequence in the cerebrospinal fluid of a HIV-infected patient in China: a case report and literature review. Epidemiol Infect 2015; 144:106-12. [PMID: 26081197 DOI: 10.1017/s0950268815001326] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Hepatitis G virus or GB virus C (GBV-C) is a human virus of the Flaviviridae family that is structurally and epidemiologically closest to hepatitis C virus, but replicates primarily in lymphocytes. Co-infection with GBV-C has been reported to confer beneficial outcomes in some HIV-positive patients. Up to now, however, studies on GBV-C infection in the central nervous system (CNS) of HIV-infected patient have rarely been reported. Herein, we report on a 32-year-old HIV-1-infected patient with cerebral toxoplasmosis and fungal encephalitis. GBV-C viral loads were detected in CSF by quantitative real-time reverse transcription polymerase chain reaction (RT-PCR), and the results showed that GBV-C viral load was 6·5 log copies/ml. We amplified and sequenced the E2 and 5'-untranslated regions from the purified viral RNA from CSF by RT-PCR. Both sequences belong to genotype 3 and there were some minor nucleotide divergence among the E2 sequences from the CSF of the patient. These data suggest that GBV-C may be able to penetrate the blood-brain barrier and colonize the CNS of HIV-infected patients. However, the exact mechanisms and potential effect of the infected GBV-C in CNS on HIV-associated neuropathy needs to be further explored.
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11
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Chivero ET, Stapleton JT. Tropism of human pegivirus (formerly known as GB virus C/hepatitis G virus) and host immunomodulation: insights into a highly successful viral infection. J Gen Virol 2015; 96:1521-32. [PMID: 25667328 DOI: 10.1099/vir.0.000086] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Human pegivirus (HPgV; originally called GB virus C/hepatitis G virus) is an RNA virus within the genus Pegivirus of the family Flaviviridae that commonly causes persistent infection. Worldwide, ~750 million people are actively infected (viraemic) and an estimated 0.75-1.5 billion people have evidence of prior HPgV infection. No causal association between HPgV and disease has been identified; however, several studies described a beneficial relationship between persistent HPgV infection and survival in individuals infected with human immunodeficiency virus. The beneficial effect appeared to be related to a reduction in host immune activation. HPgV replicates well in vivo (mean plasma viral loads typically >1×107 genome copies ml-1); however, the virus grows poorly in vitro and systems to study this virus are limited. Consequently, mechanisms of viral persistence and host immune modulation remain poorly characterized, and the primary permissive cell type(s) has not yet been identified. HPgV RNA is found in liver, spleen, bone marrow and PBMCs, including T- and B-lymphocytes, NK-cells, and monocytes, although the mechanism of cell-to-cell transmission is unclear. HPgV RNA is also present in serum microvesicles with properties of exosomes. These microvesicles are able to transmit viral RNA to PBMCs in vitro, resulting in productive infection. This review summarizes existing data on HPgV cellular tropism and the effect of HPgV on immune activation in various PBMCs, and discusses how this may influence viral persistence. We conclude that an increased understanding of HPgV replication and immune modulation may provide insights into persistent RNA viral infection of humans.
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Affiliation(s)
- Ernest T Chivero
- Medicine Service, Iowa City Veterans Affairs Medical Center, Interdisciplinary Program in Molecular and Cellular Biology, Departments of Internal Medicine and Microbiology, University of Iowa, Iowa City, IA 52242, USA
| | - Jack T Stapleton
- Medicine Service, Iowa City Veterans Affairs Medical Center, Interdisciplinary Program in Molecular and Cellular Biology, Departments of Internal Medicine and Microbiology, University of Iowa, Iowa City, IA 52242, USA
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Lanteri MC, Vahidnia F, Tan S, Stapleton JT, Norris PJ, Heitman J, Deng X, Keating SM, Brambilla D, Busch MP, Custer B. Downregulation of Cytokines and Chemokines by GB Virus C After Transmission Via Blood Transfusion in HIV-Positive Blood Recipients. J Infect Dis 2014; 211:1585-96. [PMID: 25425697 DOI: 10.1093/infdis/jiu660] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 11/19/2014] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND An association between GB virus C (GBV-C) and improved outcomes of human immunodeficiency virus (HIV) infection has been reported in HIV-positive individuals with active GBV-C coinfection. This study provides insights into the immune mechanisms underlying the protective role of GBV-C in HIV-infected patients. METHODS The concentrations of 64 cytokines and chemokines were measured in plasma samples obtained from the Viral Activation Transfusion Study cohort before transfusion and longitudinally from 30 patients positive for both HIV and GBV-C (hereafter, "cases") and 30 patients positive for HIV and negative for GBV-C (hereafter, "controls"). RESULTS Cases had lower HIV viral loads and higher CD4 T-cell counts than controls after acquisition of GBV-C infection. Most of the modulated cytokines and chemokines were reduced after GBV-C detection, including many proinflammatory cytokines, suggesting an overall antiinflammatory effect of GBV-C in HIV-positive subjects. Most pathways and functions of the measured cytokines were downregulated in cases, except cell death pathways, which were upregulated in various cell subsets in the 3 months after GBV-C detection. CONCLUSIONS GBV-C has a protective effect, in part through a competition mechanism leading to decreased inflammation and improved HIV disease outcome in cases. Further studies are necessary to establish whether GBV-C may have deleterious effects on the host at the cellular level, including depleting the cells that are the targets of HIV.
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Affiliation(s)
| | | | | | - Jack T Stapleton
- Iowa City Veterans Affairs Hospital University of Iowa Carver College of Medicine, Iowa City
| | - Philip J Norris
- Blood Systems Research Institute Department of Laboratory Medicine Department of Medicine, University of California-San Francisco, California
| | | | | | | | | | - Michael P Busch
- Blood Systems Research Institute Department of Laboratory Medicine
| | - Brian Custer
- Blood Systems Research Institute Department of Laboratory Medicine
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13
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Chang CM, Stapleton JT, Klinzman D, McLinden JH, Purdue MP, Katki HA, Engels EA. GBV-C infection and risk of NHL among U.S. adults. Cancer Res 2014; 74:5553-60. [PMID: 25115299 DOI: 10.1158/0008-5472.can-14-0209] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Some retrospective studies suggest an association between infection with GB virus-C (GBV-C) and non-Hodgkin lymphoma (NHL). We evaluated this association prospectively in a nested case-control study within the U.S. Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. Cases (N = 658) and controls (N = 1,316) were individually matched by age, sex, race/ethnicity, timing of study entry, and sample selection. Prediagnostic PLCO serum samples were tested for GBV-C RNA (as a measure of active infection) and E2 antibody (active or resolved infection). Logistic regression was used to estimate odds ratios (OR) for the association between GBV-C and NHL overall and NHL subtypes. Twelve cases (1.8%) and seven controls (0.5%) were GBV-C RNA-positive. GBV-C RNA positivity was associated with NHL overall [OR, 3.43; 95% confidence interval (CI), 1.35-8.71] and, based on small numbers, diffuse large B-cell lymphoma (OR, 5.31; 95% CI, 1.54-18.36). The association with NHL persisted when the interval between testing and selection was greater than 4 years (OR, 6.00; 95% CI, 1.21-29.73). In contrast, E2 antibody positivity was not associated with NHL risk (OR, 1.08; 95% CI, 0.74-1.58). Our study demonstrates that GBV-C infection precedes development of NHL. GBV-C infection may play an etiologic role in a small proportion of NHL cases, perhaps by causing chronic immune stimulation or impaired immunosurveillance.
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Affiliation(s)
- Cindy M Chang
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland.
| | - Jack T Stapleton
- Department of Internal Medicine, Iowa City Veterans Affairs Medical Center, University of Iowa, Iowa City, Iowa
| | - Donna Klinzman
- Department of Internal Medicine, Iowa City Veterans Affairs Medical Center, University of Iowa, Iowa City, Iowa
| | - James H McLinden
- Department of Internal Medicine, Iowa City Veterans Affairs Medical Center, University of Iowa, Iowa City, Iowa
| | - Mark P Purdue
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland
| | - Hormuzd A Katki
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland
| | - Eric A Engels
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland
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14
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Chivero ET, Bhattarai N, Rydze RT, Winters MA, Holodniy M, Stapleton JT. Human pegivirus RNA is found in multiple blood mononuclear cells in vivo and serum-derived viral RNA-containing particles are infectious in vitro. J Gen Virol 2014; 95:1307-1319. [PMID: 24668525 DOI: 10.1099/vir.0.063016-0] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Human pegivirus (HPgV; previously called GB virus C/hepatitis G virus) has limited pathogenicity, despite causing persistent infection, and is associated with prolonged survival in human immunodeficiency virus-infected individuals. Although HPgV RNA is found in and produced by T- and B-lymphocytes, the primary permissive cell type(s) are unknown. We quantified HPgV RNA in highly purified CD4(+) and CD8(+) T-cells, including naïve, central memory and effector memory populations, and in B-cells (CD19(+)), NK cells (CD56(+)) and monocytes (CD14(+)) using real-time reverse transcription-PCR. Single-genome sequencing was performed on viruses within individual cell types to estimate genetic diversity among cell populations. HPgV RNA was present in CD4(+) and CD8(+) T-lymphocytes (nine of nine subjects), B-lymphocytes (seven of ten subjects), NK cells and monocytes (both four of five). HPgV RNA levels were higher in naïve (CD45RA(+)) CD4(+) cells than in central memory and effector memory cells (P<0.01). HPgV sequences were highly conserved among subjects (0.117±0.02 substitutions per site; range 0.58-0.14) and within subjects (0.006±0.003 substitutions per site; range 0.006-0.010). The non-synonymous/synonymous substitution ratio was 0.07, suggesting a low selective pressure. Carboxyfluorescein succinimidyl ester (CFSE)-labelled HPgV RNA-containing particles precipitated by a commercial exosome isolation reagent delivered CSFE to uninfected monocytes, NK cells and T- and B-lymphocytes, and HPgV RNA was transferred to PBMCs with evidence of subsequent virus replication. Thus, HPgV RNA-containing serum particles including microvesicles may contribute to delivery of HPgV to PBMCs in vivo, explaining the apparent broad tropism of this persistent human RNA virus.
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Affiliation(s)
- Ernest T Chivero
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA.,Medicine Service, Iowa City Veterans Affairs Medical Center, Iowa City, IA 52246, USA
| | - Nirjal Bhattarai
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA.,Medicine Service, Iowa City Veterans Affairs Medical Center, Iowa City, IA 52246, USA
| | - Robert T Rydze
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Mark A Winters
- Division of Infectious Diseases, Stanford University School of Medicine, Stanford, CA 94305, USA.,AIDS Research Center, VA Palo Alto Health Care System, Palo Alto, CA 94304, USA
| | - Mark Holodniy
- Division of Infectious Diseases, Stanford University School of Medicine, Stanford, CA 94305, USA.,AIDS Research Center, VA Palo Alto Health Care System, Palo Alto, CA 94304, USA
| | - Jack T Stapleton
- Department of Microbiology, University of Iowa, Iowa City, IA 52242, USA.,Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA.,Medicine Service, Iowa City Veterans Affairs Medical Center, Iowa City, IA 52246, USA
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15
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Stapleton JT, Xiang J, McLinden JH, Bhattarai N, Chivero ET, Klinzman D, Kaufman TM, Chang Q. A novel T cell evasion mechanism in persistent RNA virus infection. TRANSACTIONS OF THE AMERICAN CLINICAL AND CLIMATOLOGICAL ASSOCIATION 2014; 125:14-26. [PMID: 25125715 PMCID: PMC4112695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Hepatitis C virus (HCV) and GB virus type C (GBV-C) are associated with impaired T cell function despite the fact that HCV replicates in hepatocytes and GBV-C in a small proportion of lymphocytes. Recently, we showed that HCV and GBV-C E2-envelope proteins reduce T cell activation via the T cell receptor (TCR) by competing for phosphorylation with a critical kinase in the TCR signaling cascade (Lck). E2 interfered with TCR signaling in E2 expressing cells and in bystander cells. The bystander effect was mediated by virus particles and extracellular microvesicular particles (exosomes). Multiple kinase substrate sites are predicted to reside on viral structural proteins and based on bioinformatic predictions, many RNA virus pathogens may interfere with TCR signaling via a similar mechanism. Identification of T cell inhibitory effects of virus structural proteins may provide novel approaches to enhance the immunogenicity and memory of viral vaccines.
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Affiliation(s)
- Jack T. Stapleton
- Correspondence and reprint requests: Jack T. Stapleton,
Department of Internal Medicine, SW54, GH, University of Iowa, 200 Hawkins Drive, Iowa City, IA 52242319-356-3168319-356-4600
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16
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Ernst D, Greer M, Akmatova R, Pischke S, Wedemeyer H, Heiken H, Tillmann HL, Schmidt RE, Stoll M. Impact of GB virus C viraemia on clinical outcome in HIV-1-infected patients: a 20-year follow-up study. HIV Med 2013; 15:245-50. [DOI: 10.1111/hiv.12094] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/26/2013] [Indexed: 11/27/2022]
Affiliation(s)
- D Ernst
- Department of Immunology and Rheumatology; Hannover Medical School; Hannover Germany
| | - M Greer
- Department of Pulmonology; Hannover Medical School; Hannover Germany
| | - R Akmatova
- Republican ‘AIDS’ Center of Health Ministry of Kyrgyz Republic; Bishkek Kyrgyzstan
| | - S Pischke
- Department of Gastroenterology, Hepatology and Endocrinology; Hannover Medical School; Hannover Germany
| | - H Wedemeyer
- Department of Gastroenterology, Hepatology and Endocrinology; Hannover Medical School; Hannover Germany
| | - H Heiken
- Department of Immunology and Rheumatology; Hannover Medical School; Hannover Germany
| | - HL Tillmann
- Clinical Research Institute; Duke University; Durham NC USA
| | - RE Schmidt
- Department of Immunology and Rheumatology; Hannover Medical School; Hannover Germany
| | - M Stoll
- Department of Immunology and Rheumatology; Hannover Medical School; Hannover Germany
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Bhattarai N, McLinden JH, Xiang J, Landay AL, Chivero ET, Stapleton JT. GB virus C particles inhibit T cell activation via envelope E2 protein-mediated inhibition of TCR signaling. THE JOURNAL OF IMMUNOLOGY 2013; 190:6351-9. [PMID: 23686495 DOI: 10.4049/jimmunol.1300589] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Viruses enter into complex interactions within human hosts, leading to facilitation or suppression of each other's replication. Upon coinfection, GB virus C (GBV-C) suppresses HIV-1 replication in vivo and in vitro, and GBV-C coinfection is associated with prolonged survival in HIV-infected people. GBV-C is a lymphotropic virus capable of persistent infection. GBV-C infection is associated with reduced T cell activation in HIV-infected humans, and immune activation is a critical component of HIV disease pathogenesis. We demonstrate that serum GBV-C particles inhibited activation of primary human T cells. T cell activation inhibition was mediated by the envelope glycoprotein E2, because expression of E2 inhibited TCR-mediated activation of Lck. The region on the E2 protein was characterized and revealed a highly conserved peptide motif sufficient to inhibit TCR-mediated signaling. The E2 region contained a predicted Lck substrate site, and substitution of an alanine or histidine for the tyrosine reversed TCR-signaling inhibition. GBV-C E2 protein and a synthetic peptide representing the inhibitory amino acid sequence were phosphorylated by Lck in vitro. The synthetic peptide also inhibited TCR-mediated activation of primary human CD4(+) and CD8(+) T cells. Extracellular microvesicles from GBV-C E2-expressing cells contained E2 protein and inhibited TCR signaling in bystander T cells not expressing E2. Thus, GBV-C reduced global T cell activation via competition between its envelope protein E2 and Lck following TCR engagement. This novel inhibitory mechanism of T cell activation may provide new approaches for HIV and immunoactivation therapy.
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Affiliation(s)
- Nirjal Bhattarai
- Iowa City Veterans Affairs Medical Center, Iowa City, IA 52242, USA
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18
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Bhattarai N, Stapleton JT. Study design may explain discrepancies in GB virus C effects on interferon-γ and interleukin-2 production and CD38 expression in T lymphocytes. Mem Inst Oswaldo Cruz 2013; 107:568-9; author reply 569. [PMID: 22666874 DOI: 10.1590/s0074-02762012000400023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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Zhang J, Chaloner K, McLinden JH, Stapleton JT. Bayesian analysis and classification of two enzyme-linked immunosorbent assay tests without a gold standard. Stat Med 2013; 32:4102-17. [DOI: 10.1002/sim.5816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2011] [Accepted: 03/18/2013] [Indexed: 11/09/2022]
Affiliation(s)
| | | | - James H. McLinden
- Department of Internal Medicine; University of Iowa; Iowa City; IA; U.S.A
| | - Jack T. Stapleton
- Department of Internal Medicine; University of Iowa; Iowa City; IA; U.S.A
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20
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Stapleton JT, Chaloner K, Martenson JA, Zhang J, Klinzman D, Xiang J, Sauter W, Desai SN, Landay A. GB virus C infection is associated with altered lymphocyte subset distribution and reduced T cell activation and proliferation in HIV-infected individuals. PLoS One 2012; 7:e50563. [PMID: 23209780 PMCID: PMC3510065 DOI: 10.1371/journal.pone.0050563] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Accepted: 10/23/2012] [Indexed: 01/27/2023] Open
Abstract
GBV-C infection is associated with prolonged survival and with reduced T cell activation in HIV-infected subjects not receiving combination antiretroviral therapy (cART). The relationship between GBV-C and T cell activation in HIV-infected subjects was examined. HIV-infected subjects on cART with non-detectable HIV viral load (VL) or cART naïve subjects were studied. GBV-C VL and HIV VL were determined. Cell surface markers of activation (CD38(+)/HLA-DR(+)), proliferation (Ki-67+), and HIV entry co-receptor expression (CCR5+ and CXCR4+) on total CD4+ and CD8+ T cells, and on naïve, central memory (CM), effector memory (EM), and effector CD4+ and CD8+ subpopulations were measured by flow cytometry. In subjects with suppressed HIV VL, GBV-C was consistently associated with reduced activation in naïve, CM, EM, and effector CD4+ cells. GBV-C was associated with reduced CD4+ and CD8+ T cell surface expression of activation and proliferation markers, independent of HIV VL classification. GBV-C was also associated with higher proportions of naïve CD4+ and CD8+ T cells, and with lower proportions of EM CD4+ and CD8+ T cells. In conclusion, GBV-C infection was associated with reduced activation of CD4+ and CD8+ T cells in both HIV viremic and HIV RNA suppressed patients. Those with GBV-C infection demonstrated an increased proportion of naive T cells and a reduction in T cell activation and proliferation independent of HIV VL classification, including those with suppressed HIV VL on cART. Since HIV pathogenesis is thought to be accelerated by T cell activation, these results may contribute to prolonged survival among HIV infected individuals co-infected with GBV-C. Furthermore, since cART therapy does not reduce T cell activation to levels seen in HIV-uninfected people, GBV-C infection may be beneficial for HIV-related diseases in those effectively treated with anti-HIV therapy.
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Affiliation(s)
- Jack T Stapleton
- Research and Medical Services, Iowa City VA Medical Center, Iowa City, Iowa, United States of America.
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Bhattarai N, Rydze RT, Chivero ET, Stapleton JT. GB virus C viremia is associated with higher levels of double-negative T cells and lower T-cell activation in HIV-infected individuals receiving antiretroviral therapy. J Infect Dis 2012; 206:1469-72. [PMID: 22927453 PMCID: PMC3466998 DOI: 10.1093/infdis/jis515] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 06/06/2012] [Indexed: 11/12/2022] Open
Abstract
Double-negative T cells (DNTCs; ie, CD3(+)CD4(-)CD8(-) T cells) play a role in limiting chronic immune activation. GB virus C (GBV-C) infection is associated with reduced T-cell activation in human immunodeficiency virus (HIV)-infected individuals. T-cell activation and DNTCs were measured in HIV-infected subjects with a nondetectable HIV load. GBV-C-viremic subjects had significantly reduced CD4(+) and CD8(+) T-cell activation (P = .003 and .034, respectively) and significantly increased DNTCs (P = .038), compared with nonviremic subjects. GBV-C load correlated with DNTC percentage (P = .004). Thus, GBV-C infection is associated with an increase in DNTCs, which may contribute to reduced immune activation during HIV infection.
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Affiliation(s)
- Nirjal Bhattarai
- Interdisciplinary Program in Molecular and Cellular Biology
- Iowa City Veterans Affairs Medical Center, Iowa City
| | - Robert T. Rydze
- Doris Duke Scholars Program
- Department of Internal Medicine
- Iowa City Veterans Affairs Medical Center, Iowa City
| | - Ernest T. Chivero
- Interdisciplinary Program in Molecular and Cellular Biology
- Iowa City Veterans Affairs Medical Center, Iowa City
| | - Jack T. Stapleton
- Interdisciplinary Program in Molecular and Cellular Biology
- Doris Duke Scholars Program
- Department of Internal Medicine
- Department of Microbiology, Carver College of Medicine, University of Iowa,
- Iowa City Veterans Affairs Medical Center, Iowa City
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Rydze RT, Bhattarai N, Stapleton JT. GB virus C infection is associated with a reduced rate of reactivation of latent HIV and protection against activation-induced T-cell death. Antivir Ther 2012; 17:1271-9. [PMID: 22951385 DOI: 10.3851/imp2309] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/04/2012] [Indexed: 01/10/2023]
Abstract
BACKGROUND GB virus C (GBV-C) coinfection is associated with reduced immune activation and a block in CD4(+) T-cell proliferation following interleukin-2 (IL-2) therapy in HIV-infected individuals. We examined peripheral blood mononuclear cells (PBMCs) from HIV-infected subjects with and without GBV-C viraemia to determine if GBV-C correlated with reactivation of latent HIV, T-cell proliferation or T-cell survival following in vitro activation with phytohaemagglutinin A and IL-2 (PHA/IL-2). METHODS HIV-infected subjects whose HIV viral load was suppressed on combination antiretroviral therapy (cART) for >6 months were studied. PBMCs were cultured with and without PHA/IL-2 and monitored for HIV reactivation, proliferation and survival. GBV-C viraemia and in vitro replication were detected by real-time RT-PCR. HIV reactivation was determined by measuring HIV p24 antigen in culture supernatants. Proliferation was measured by counting viable cells and survival measured by flow cytometry. RESULTS Of 49 HIV-infected individuals, 26 had GBV-C viraemia. Significantly less HIV reactivation and PBMC proliferation following in vitro activation with PHA/IL-2 was observed in samples from GBV-C viraemic subjects compared with non-viraemic controls. Following 5 weeks in culture, GBV-C replication was associated with preservation of CD4(+) and CD8(+) T-cells compared with non-viraemic controls. CONCLUSIONS GBV-C appears to inhibit immune activation and IL-2 signalling pathways, which might contribute to a reduction in reactivation of latent HIV from cellular reservoirs. In addition, GBV-C viraemia was associated with a reduction in activation-induced T-cell death. GBV-C-associated T-cell effects could contribute to the observed protective effect of GBV-C coinfection in HIV-infected individuals.
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Affiliation(s)
- Robert T Rydze
- The Iowa City Veterans Affairs Medical Center, Iowa City, IA, USA
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Bhattarai N, McLinden JH, Xiang J, Kaufman TM, Stapleton JT. GB virus C envelope protein E2 inhibits TCR-induced IL-2 production and alters IL-2-signaling pathways. THE JOURNAL OF IMMUNOLOGY 2012; 189:2211-6. [PMID: 22844114 DOI: 10.4049/jimmunol.1201324] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
GB virus type C (GBV-C) viremia is associated with reduced CD4+ T cell expansion following IL-2 therapy and with a reduction in T cell activation in HIV-infected individuals. The mechanism(s) by which GBV-C might alter T cell activation or IL-2 signaling have not been studied. In this study, we assess IL-2 release, IL-2R expression, IL-2 signaling, and cell proliferation in tet-off Jurkat cells expressing the GBV-C envelope glycoprotein (E2) following activation through the TCR. TCR activation was induced by incubation in anti-CD3/CD28 Abs. IL-2 release was measured by ELISA, STAT5 phosphorylation was assessed by immunoblot, and IL-2Rα (CD25) expression and cell proliferation were determined by flow cytometry. IL-2 and IL-2Rα steady-state mRNA levels were measured by real-time PCR. GBV-C E2 expression significantly inhibited IL-2 release, CD25 expression, STAT5 phosphorylation, and cellular proliferation in Jurkat cells following activation through the TCR compared with control cell lines. Reducing E2 expression by doxycycline reversed the inhibitory effects observed in the E2-expressing cells. The N-terminal 219 aa of E2 was sufficient to inhibit IL-2 signaling. Addition of purified recombinant GBV-C E2 protein to primary human CD4+ and CD8+ T cells inhibited TCR activation-induced IL-2 release and upregulation of IL-2Rα expression. These data provide evidence that the GBV-C E2 protein may contribute to the block in CD4+ T cell expansion following IL-2 therapy in HIV-infected individuals. Furthermore, the effects of GBV-C on IL-2 and IL-2-signaling pathways may contribute to the reduction in chronic immune activation observed in GBV-C/HIV-coinfected individuals.
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Affiliation(s)
- Nirjal Bhattarai
- Iowa City Veterans Affairs Medical Center, Iowa City, IA 52242, USA
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Vahidnia F, Petersen M, Rutherford G, Busch M, Assmann S, Stapleton JT, Custer B. Transmission of GB virus type C via transfusion in a cohort of HIV-infected patients. J Infect Dis 2012; 205:1436-42. [PMID: 22438325 DOI: 10.1093/infdis/jis209] [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
BACKGROUND GB virus C (GBV-C) infection is transmitted by blood exposure and associated with lower human immunodeficiency virus (HIV) load and slower HIV disease progression. Few studies describe predictors of acute GBV-C infection following transfusion in HIV-infected patients. METHODS We used a limited-access database from the National Heart Lung and Blood Institute's Viral Activation Transfusion Study, a randomized controlled trial of leukoreduced versus nonleukoreduced transfusions received by HIV-infected, transfusion-naive patients. Blood samples from 489 subjects were tested for GBV-C markers in pretransfusion and posttransfusion samples. We estimated the risk of acquiring GBV-C RNA and predictors of GBV-C acquisition, using pooled logistic regression. RESULTS GBV-C RNA was detected ≤120 days following the first transfusion in 22 (7.5%) of 294 subjects who were GBV-C negative before transfusion. The risk of GBV-C RNA acquisition increased with each unit transfused (odds ratio, 1.09; 95% confidence interval, 1.06-1.11). Lower baseline HIV load and use of antiretroviral therapy were associated with subsequent GBV-C RNA acquisition, after control for units of blood transfused. Leukoreduced status of transfused units was not associated with GBV-C transmission. CONCLUSIONS Blood transfusion is associated with a significant risk of GBV-C acquisition among HIV-infected patients. Transmission of GBV-C by blood transfusion was inversely related to HIV load.
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Affiliation(s)
- Farnaz Vahidnia
- Department of Epidemiology, Blood Systems Research Institute, San Francisco, CA, USA.
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Bhattarai N, Stapleton JT. GB virus C: the good boy virus? Trends Microbiol 2012; 20:124-30. [PMID: 22325031 DOI: 10.1016/j.tim.2012.01.004] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 01/04/2012] [Accepted: 01/06/2012] [Indexed: 12/16/2022]
Abstract
GB virus C (GBV-C) is a lymphotropic human virus discovered in 1995 that is related to hepatitis C virus (HCV). GBV-C infection has not been convincingly associated with any disease; however, several studies found an association between persistent GBV-C infection and improved survival in HIV-positive individuals. GBV-C infection modestly alters T cell homeostasis in vivo through various mechanisms, including modulation of chemokine and cytokine release and receptor expression, and by diminution of T cell activation, proliferation and apoptosis, all of which may contribute to improved HIV clinical outcomes. In vitro studies confirm these clinical observations and demonstrate an anti-HIV replication effect of GBV-C. This review summarizes existing data on potential mechanisms by which GBV-C interferes with HIV, and the research needed to capitalize on this epidemiological observation.
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Affiliation(s)
- Nirjal Bhattarai
- Interdisciplinary Program in Molecular and Cellular Biology, University of Iowa, Iowa City, IA 52242, USA
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Study of the inhibition capacity of an 18-mer peptide domain of GBV-C virus on gp41-FP HIV-1 activity. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1808:1567-73. [DOI: 10.1016/j.bbamem.2011.02.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Revised: 02/23/2011] [Accepted: 02/25/2011] [Indexed: 11/20/2022]
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Campos RK, Brum MCS, Nogueira CEW, Drumond BP, Alves PA, Siqueira-Lima L, Assis FL, Trindade GS, Bonjardim CA, Ferreira PC, Weiblen R, Flores EF, Kroon EG, Abrahão JS. Assessing the variability of Brazilian Vaccinia virus isolates from a horse exanthematic lesion: coinfection with distinct viruses. Arch Virol 2010; 156:275-83. [DOI: 10.1007/s00705-010-0857-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Accepted: 10/29/2010] [Indexed: 11/29/2022]
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Shankar EM, Balakrishnan P, Vignesh R, Velu V, Jayakumar P, Solomon S. Current Views on the Pathophysiology of GB Virus C Coinfection with HIV-1 Infection. Curr Infect Dis Rep 2010; 13:47-52. [DOI: 10.1007/s11908-010-0142-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Xiang J, McLinden JH, Rydze RA, Chang Q, Kaufman TM, Klinzman D, Stapleton JT. Viruses within the Flaviviridae decrease CD4 expression and inhibit HIV replication in human CD4+ cells. THE JOURNAL OF IMMUNOLOGY 2010; 183:7860-9. [PMID: 19923460 DOI: 10.4049/jimmunol.0902276] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Viral infections alter host cell homeostasis and this may lead to immune evasion and/or interfere with the replication of other microbes in coinfected hosts. Two flaviviruses are associated with a reduction in HIV replication or improved survival in HIV-infected people (dengue virus (DV) and GB virus type C (GBV-C)). GBV-C infection and expression of the GBV-C nonstructural protein 5A (NS5A) and the DV NS5 protein in CD4(+) T cells inhibit HIV replication in vitro. To determine whether the inhibitory effect on HIV replication is conserved among other flaviviruses and to characterize mechanism(s) of HIV inhibition, the NS5 proteins of GBV-C, DV, hepatitis C virus, West Nile virus, and yellow fever virus (YFV; vaccine strain 17D) were expressed in CD4(+) T cells. All NS5 proteins inhibited HIV replication. This correlated with decreased steady-state CD4 mRNA levels and reduced cell surface CD4 protein expression. Infection of CD4(+) T cells and macrophages with YFV (17D vaccine strain) also inhibited HIV replication and decreased CD4 gene expression. In contrast, mumps virus was not inhibited by the expression of flavivirus NS5 protein or by YFV infection, and mumps infection did not alter CD4 mRNA or protein levels. In summary, CD4 gene expression is decreased by all human flavivirus NS5 proteins studied. CD4 regulation by flaviviruses may interfere with innate and adaptive immunity and contribute to in vitro HIV replication inhibition. Characterization of the mechanisms by which flaviviruses regulate CD4 expression may lead to novel therapeutic strategies for HIV and immunological diseases.
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Affiliation(s)
- Jinhua Xiang
- Department of Internal Medicine, Iowa City Veterans Affairs Medical Center and University of Iowa, Iowa City, IA 52242, USA
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Abstract
GB virus C/hepatitis G virus (GBV-C/HGV) is the most closely related human virus to hepatitis C virus (HCV). GBV-C is lymphotropic and not associated with any known disease, although it is associated with improved survival in HIV-infected individuals. In peripheral blood mononuclear cells, GBV-C induces the release of soluble ligands for HIV entry receptors (RANTES, MIP-1a, MIP-1b and SDF-1), suggesting that GBV-C may interact with lymphocytes to induce a chemokine and/or cytokine milieu that is inhibitory to HIV infection. Expression of GBV-C envelope glycoprotein E2 in CD4+ T cells or addition of recombinant E2 to CD4 cells recapitulates the HIV inhibition seen with GBV-C infection. Like HCV E2, GBV-C E2 is predicted to be post-translationally processed in the endoplasmic reticulum and is involved with cell binding. The C-termini of GBV-C E1 and E2 proteins contain predicted transmembrane domains sharing features with HCV TM domains. To date, cellular receptor(s) for GBV-C E2 have not been identified. GBV-C E2-mediated HIV inhibition is dose-dependent and HIV replication is blocked at the binding and/or entry step. In addition, a putative GBV-C E2 fusion peptide interferes with HIV gp41 peptide oligomerization required for HIV-1 fusion, further suggesting that GBV-C E2 may inhibit HIV entry. Additional work is needed to identify the GBV-C E2 cellular receptor, characterize GBV-C E2 domains responsible for HIV inhibition, and to examine GBV-C E2-mediated fusion in the context of the entire envelope protein or viral-particles. Understanding the mechanisms of action may identify novel approaches to HIV therapy.
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Affiliation(s)
- Emma L. Mohr
- Department of Internal Medicine and the Interdisciplinary Program on Molecular and Cellular Biology, The University of Iowa
| | - Jack T. Stapleton
- Department of Internal Medicine and the Interdisciplinary Program on Molecular and Cellular Biology, The University of Iowa,The Iowa City VA Medical Center, Iowa City, IA, USA
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