1
|
Materniak-Kornas M, Kubiś P, Sell B, Pougialis G, Löchelt M, Kuźmak J. An Outbred Calf Model for Determining Innate Immune Sensing and Evolutionary Trajectories of a Cell Culture-Adapted Bovine Foamy Virus Variant. Viruses 2023; 15:1772. [PMID: 37632114 PMCID: PMC10458543 DOI: 10.3390/v15081772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/10/2023] [Accepted: 08/17/2023] [Indexed: 08/27/2023] Open
Abstract
Bovine foamy virus (BFVbta) displays a very high degree of cell-associated replication which is unprecedented even among the other known foamy viruses. Interestingly, recent studies have shown that it can in fact adapt in vitro to high-titer (HT) cell-free transmission due to genetic changes acquired during repeated rounds of cell-free BFVbta passages in immortalized bovine MDBK cells. Molecular clones obtained from the HT BFVbta Riems cell-free variant (HT BFVbta Riems) have been thoroughly characterized in MDBK cell cultures However, during recent years, it has become increasingly clear that the source of the host cells used for virus growth and functional studies of virus replication and virus-cell interactions plays a paramount role. Established cell lines, mostly derived from tumors, but occasionally experimentally immortalized and transformed, frequently display aberrant features relating, for example. to growth, metabolism, and genetics. Even state-of-the-art organoid cultures of primary cells cannot replicate the conditions in an authentic host, especially those concerning cell diversity and the role of innate and adaptive immunity. Therefore, to determine the overall replication characteristics of the cloned wt and HT BFVbta Riems variant, we conducted a small-scale animal pilot study. The replication of the original wt BFVbta Riems isolate, as well as that of its HT variant, were analyzed. Both BFVbta variants established infection in calves, with proviruses in peripheral blood mononuclear cells and induced Gag-specific antibodies. In addition, a related pattern in the host innate immune reaction was detected in the peripheral blood leukocytes of the BFV-infected calves. Surprisingly, an analysis of the Gag sequence two weeks post-inoculation revealed that the HT BFVbta variant showed a very high level of genetic reversion to the wild type (parental BFVbta genotype).
Collapse
Affiliation(s)
- Magdalena Materniak-Kornas
- Department of Biochemistry, National Veterinary Research Institute, 24-100 Pulawy, Poland; (P.K.); (J.K.)
| | - Piotr Kubiś
- Department of Biochemistry, National Veterinary Research Institute, 24-100 Pulawy, Poland; (P.K.); (J.K.)
| | - Bartosz Sell
- Department of Pharmacology and Toxicology, National Veterinary Research Institute, 24-100 Pulawy, Poland;
| | - Georgios Pougialis
- Division of Viral Transformation Mechanisms, Research Program Infection, Inflammation and Cancer, German Cancer Research Center, 69120 Heidelberg, Germany; (G.P.); (M.L.)
| | - Martin Löchelt
- Division of Viral Transformation Mechanisms, Research Program Infection, Inflammation and Cancer, German Cancer Research Center, 69120 Heidelberg, Germany; (G.P.); (M.L.)
- Division of Virus-Associated Carcinogenesis, Research Program Infection, Inflammation and Cancer, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Jacek Kuźmak
- Department of Biochemistry, National Veterinary Research Institute, 24-100 Pulawy, Poland; (P.K.); (J.K.)
| |
Collapse
|
2
|
Couteaudier M, Montange T, Njouom R, Bilounga-Ndongo C, Gessain A, Buseyne F. Plasma antibodies from humans infected with zoonotic simian foamy virus do not inhibit cell-to-cell transmission of the virus despite binding to the surface of infected cells. PLoS Pathog 2022; 18:e1010470. [PMID: 35605011 PMCID: PMC9166401 DOI: 10.1371/journal.ppat.1010470] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 06/03/2022] [Accepted: 03/25/2022] [Indexed: 01/23/2023] Open
Abstract
Zoonotic simian foamy viruses (SFV) establish lifelong infection in their human hosts. Despite repeated transmission of SFV from nonhuman primates to humans, neither transmission between human hosts nor severe clinical manifestations have been reported. We aim to study the immune responses elicited by chronic infection with this retrovirus and previously reported that SFV-infected individuals generate potent neutralizing antibodies that block cell infection by viral particles. Here, we assessed whether human plasma antibodies block SFV cell-to-cell transmission and present the first description of cell-to-cell spreading of zoonotic gorilla SFV. We set-up a microtitration assay to quantify the ability of plasma samples from 20 Central African individuals infected with gorilla SFV and 9 uninfected controls to block cell-associated transmission of zoonotic gorilla SFV strains. We used flow-based cell cytometry and fluorescence microscopy to study envelope protein (Env) localization and the capacity of plasma antibodies to bind to infected cells. We visualized the cell-to-cell spread of SFV by real-time live imaging of a GFP-expressing prototype foamy virus (CI-PFV) strain. None of the samples neutralized cell-associated SFV infection, despite the inhibition of cell-free virus. We detected gorilla SFV Env in the perinuclear region, cytoplasmic vesicles and at the cell surface. We found that plasma antibodies bind to Env located at the surface of cells infected with primary gorilla SFV strains. Extracellular labeling of SFV proteins by human plasma samples showed patchy staining at the base of the cell and dense continuous staining at the cell apex, as well as staining in the intercellular connections that formed when previously connected cells separated from each other. In conclusion, SFV-specific antibodies from infected humans do not block cell-to-cell transmission, at least in vitro, despite their capacity to bind to the surface of infected cells. Trial registration: Clinical trial registration: www.clinicaltrials.gov, https://clinicaltrials.gov/ct2/show/NCT03225794/. Foamy viruses are the oldest known retroviruses and have been mostly described to be nonpathogenic in their natural animal hosts. Simian foamy viruses (SFVs) can be transmitted to humans, in whom they establish persistent infection, as have the simian viruses that led to the emergence of two major human pathogens, human immunodeficiency virus type 1 (HIV-1) and human T lymphotropic virus type 1 (HTLV-1). Such cross-species transmission of SFV is ongoing in many parts of the world where humans have contact with nonhuman primates. We previously showed high titers of neutralizing antibodies in the plasma of most SFV-infected individuals. These antiviral antibodies can inhibit cell-free virus entry. However, SFV efficiently spread from one cell to another. Here, we demonstrate that plasma antibodies do not block such cell-to-cell transmission, despite their capacity to bind to the surface of infected cells. In addition, we document for the first time the cell-to-cell spread of primary zoonotic gorilla SFV.
Collapse
Affiliation(s)
- Mathilde Couteaudier
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Unité d’Epidémiologie et Physiopathologie des Virus Oncogènes, Paris, France
| | - Thomas Montange
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Unité d’Epidémiologie et Physiopathologie des Virus Oncogènes, Paris, France
| | | | | | - Antoine Gessain
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Unité d’Epidémiologie et Physiopathologie des Virus Oncogènes, Paris, France
| | - Florence Buseyne
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Unité d’Epidémiologie et Physiopathologie des Virus Oncogènes, Paris, France
- * E-mail:
| |
Collapse
|
3
|
Evaluation of the stability and intratumoral delivery of foreign transgenes encoded by an oncolytic Foamy Virus vector. Cancer Gene Ther 2022; 29:1240-1251. [PMID: 35145270 PMCID: PMC9363555 DOI: 10.1038/s41417-022-00431-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 12/21/2021] [Accepted: 01/25/2022] [Indexed: 11/12/2022]
Abstract
Foamy Viruses are cell cycle-dependent retroviruses capable of persisting unintegrated in quiescent cells until cell division occurs. This unique ability allows them to target slowly dividing human tumor cells which remains an unmet need in oncolytic virotherapy. We have previously reported the generation of oncolytic Foamy Virus (oFV) vector system and demonstrated its superiority over oncolytic Murine Leukemia Virus vectors in infecting slowly dividing cancer cells. In the present study we evaluated (i) the ability of oFV to carry foreign transgenes and (ii) the genetic stability of these vectors upon serial passage. The thymidine kinase (TK) and inducible caspase 9 (iCasp9) cDNAs could be detected in the oFV backbone for up to 3 in vitro passages. In vivo, GFP-, TK- and iCasp9- carrying oFV vectors propagated efficiently in subcutaneous xenograft glioblastoma tumors and drove transgene expression for up to 66 days. However, in vivo oFV vector spread eventually resulted in complete loss of the iCasp9 cDNA, minor loss of the TK cDNA and negligible loss of the GFP. Our results suggest that oFV is a promising gene delivery platform and that transgenes smaller than 1 kb might be most suitable for oFV arming.
Collapse
|
4
|
Oncolytic Foamy Virus - generation and properties of a nonpathogenic replicating retroviral vector system that targets chronically proliferating cancer cells. J Virol 2021; 95:JVI.00015-21. [PMID: 33692205 PMCID: PMC8139661 DOI: 10.1128/jvi.00015-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Nonpathogenic retroviruses of the Spumaretrovirinae subfamily can persist long-term in the cytoplasm of infected cells, completing their lifecycle only after the nuclear membrane dissolves at the time of cell division. Since the targeting of slowly dividing cancer cells remains an unmet need in oncolytic virotherapy we constructed a replication competent Foamy Virus vector (oFV) from the genomes of two chimpanzee Simian Foamy Viruses (PAN1 and PAN2) and inserted a GFP transgene in place of the bel-2 open reading frame. oFV-GFP infected and propagated with slow kinetics in multiple human tumor cell lines, inducing a syncytial cytopathic effect. Infection of growth arrested MRC5 cells was not productive, but oFV genomes persisted in the cytoplasm and the productive viral lifecycle resumed when cell division was later restored. In vivo, the virus propagated extensively in intraperitoneal ovarian cancer xenografts, slowing tumor growth, significantly prolonging survival of the treated mice and sustaining GFP transgene expression for at least 45 days. Our data indicate that oFV is a promising new replication-competent viral and gene delivery platform for efficient targeting of the most fundamental trait of cancer cells, their ability to sustain chronic proliferation.Significance:The infectivity of certain retroviruses is limited to dividing cells, which makes them attractive tools for targeting cancer cell proliferation. Previously developed replication-competent gammaretroviral vectors spread efficiently in rapidly dividing cancer cells, but not in cancer cells that divide more slowly. In contrast to rapidly proliferating transplantable mouse tumors, slow proliferation is a hallmark of human cancers and may have contributed to the clinical failure of the preclinically promising Murine Leukemia Virus vector Toca511 which failed to show efficacy in a phase 3 clinical trial in patients with glioblastoma. The studies presented in our manuscript show that oncolytic Foamy Virus (oFV) vectors are capable of persisting unintegrated in quiescent cells and resuming their life cycle once the cells start dividing again. This property of oFVs, together with their lack of pathogenicity and their ability to catalyze the fusion of infected cancer cells, makes them an attractive platform for further investigation.
Collapse
|
5
|
Guo G, Wang Y, Hu XM, Li ZR, Tan J, Qiao WT. Human Schlafen 11 exploits codon preference discrimination to attenuate viral protein synthesis of prototype foamy virus (PFV). Virology 2020; 555:78-88. [PMID: 33465725 DOI: 10.1016/j.virol.2020.12.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 12/23/2020] [Accepted: 12/23/2020] [Indexed: 12/27/2022]
Abstract
Recently, the Schlafen (SLFN) proteins have been identified as a novel interferon-stimulated family with antiviral properties. In this study, we reported that SLFN11 inhibited prototype foamy virus (PFV) replication. Over-expression of human SLFN11 reduced viral production, while knockdown of SLFN11 enhanced viral infectivity. In addition, SLFN11 from cattle and African green monkey also suppressed PFV production. Both the ATPase activity and helicase activity of SLFN11 were required for its inhibitory function. Dephosphorylation activated the antiviral activity of SLFN11. More importantly, SLFN11 inhibited the expression of viral protein, which was rescued by viral gene codon optimization. Together, our results demonstrated that SLFN11 impaired PFV viral protein synthesis by exploiting the distinct codon usage between the virus and the host. These findings further broaden our understanding of the antiviral properties of the SLFN family and the molecular mechanism of PFV latent infection.
Collapse
Affiliation(s)
- Ge Guo
- Key Laboratory of Molecular Microbiology and Biotechnology (Ministry of Education) and Key Laboratory of Microbial Functional Genomics (Tianjin), College of Life Sciences, Nankai University, Tianjin, China
| | - Yang Wang
- Key Laboratory of Molecular Microbiology and Biotechnology (Ministry of Education) and Key Laboratory of Microbial Functional Genomics (Tianjin), College of Life Sciences, Nankai University, Tianjin, China
| | - Xiao-Mei Hu
- Key Laboratory of Molecular Microbiology and Biotechnology (Ministry of Education) and Key Laboratory of Microbial Functional Genomics (Tianjin), College of Life Sciences, Nankai University, Tianjin, China
| | - Zhuo-Ran Li
- Key Laboratory of Molecular Microbiology and Biotechnology (Ministry of Education) and Key Laboratory of Microbial Functional Genomics (Tianjin), College of Life Sciences, Nankai University, Tianjin, China
| | - Juan Tan
- Key Laboratory of Molecular Microbiology and Biotechnology (Ministry of Education) and Key Laboratory of Microbial Functional Genomics (Tianjin), College of Life Sciences, Nankai University, Tianjin, China
| | - Wen-Tao Qiao
- Key Laboratory of Molecular Microbiology and Biotechnology (Ministry of Education) and Key Laboratory of Microbial Functional Genomics (Tianjin), College of Life Sciences, Nankai University, Tianjin, China.
| |
Collapse
|
6
|
Complete Genome Sequence of a Baboon Simian Foamy Virus Isolated from an Infected Human. Microbiol Resour Announc 2020; 9:9/27/e00522-20. [PMID: 32616640 PMCID: PMC7330242 DOI: 10.1128/mra.00522-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
We obtained the full-length genome of a simian foamy virus (SFV) from an infected human. This virus originated from a baboon (Papio species, strain SFVpxx_hu9406). The genome is 13,113 nucleotides long with the canonical SFV genome structure. Phylogenetically, SFVpxx_hu9406 clustered closely with SFVpan_V909/03F from a captive baboon and other Cercopithecidae SFVs. We obtained the full-length genome of a simian foamy virus (SFV) from an infected human. This virus originated from a baboon (Papio species, strain SFVpxx_hu9406). The genome is 13,113 nucleotides long with the canonical SFV genome structure. Phylogenetically, SFVpxx_hu9406 clustered closely with SFVpan_V909/03F from a captive baboon and other Cercopithecidae SFVs.
Collapse
|
7
|
Inhibitors of the interferon response increase the replication of gorilla simian foamy viruses. Virology 2019; 541:25-31. [PMID: 31826843 DOI: 10.1016/j.virol.2019.11.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 11/28/2019] [Accepted: 11/29/2019] [Indexed: 12/17/2022]
Abstract
Simian foamy viruses (SFVs) are complex retroviruses that are widespread throughout nonhuman primates. SFVs can also be transmitted to humans, mostly through bites. We previously observed that primary zoonotic gorilla SFV strains grow much more slowly than laboratory-adapted chimpanzee strains. Here, we tested the hypothesis that the growth of SFV is limited by interferon (IFN) using inhibitors of cellular pathways involved in the induction or action of type I IFN. Inhibitors of JAK1/2 (Ruxolitinib) and TBK-1 (BX795) led to a 2- to 4-fold higher percentage of cells infected with zoonotic gorilla SFVs but did not affect the replication of laboratory-adapted chimpanzee SFVs. IKK2 inhibitors (TPCA-1 and BMS345541) had no effect on any of the SFV strains. In conclusion, the addition of molecules that inhibit the type I IFN response to the culture medium can be used as a simple and efficient method to enhance the replication of zoonotic gorilla SFVs.
Collapse
|
8
|
Bergez M, Weber J, Riess M, Erdbeer A, Seifried J, Stanke N, Munz C, Hornung V, König R, Lindemann D. Insights into Innate Sensing of Prototype Foamy Viruses in Myeloid Cells. Viruses 2019; 11:v11121095. [PMID: 31779173 PMCID: PMC6950106 DOI: 10.3390/v11121095] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/21/2019] [Accepted: 11/22/2019] [Indexed: 01/18/2023] Open
Abstract
Foamy viruses (FVs) belong to the Spumaretrovirinae subfamily of retroviruses and are characterized by unique features in their replication strategy. This includes a reverse transcription (RTr) step of the packaged RNA genome late in replication, resulting in the release of particles with a fraction of them already containing an infectious viral DNA (vDNA) genome. Little is known about the immune responses against FVs in their hosts, which control infection and may be responsible for their apparent apathogenic nature. We studied the interaction of FVs with the innate immune system in myeloid cells, and characterized the viral pathogen-associated molecular patterns (PAMPs) and the cellular pattern recognition receptors and sensing pathways involved. Upon cytoplasmic access, full-length but not minimal vector genome containing FVs with active reverse transcriptase, induced an efficient innate immune response in various myeloid cells. It was dependent on cellular cGAS and STING and largely unaffected by RTr inhibition during viral entry. This suggests that RTr products, which are generated during FV morphogenesis in infected cells, and are therefore already present in FV particles taken up by immune cells, are the main PAMPs of FVs with full-length genomes sensed in a cGAS and STING-dependent manner by the innate immune system in host cells of the myeloid lineage.
Collapse
Affiliation(s)
- Maïwenn Bergez
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, 63225 Langen, Germany; (M.B.); (M.R.); (J.S.)
| | - Jakob Weber
- Institute of Virology, Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, 01307 Dresden, Germany; (J.W.); (A.E.); (N.S.); (C.M.)
- CRTD/DFG-Center for Regenerative Therapies, Technische Universität Dresden, 01307 Dresden, Germany
| | - Maximilian Riess
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, 63225 Langen, Germany; (M.B.); (M.R.); (J.S.)
| | - Alexander Erdbeer
- Institute of Virology, Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, 01307 Dresden, Germany; (J.W.); (A.E.); (N.S.); (C.M.)
- CRTD/DFG-Center for Regenerative Therapies, Technische Universität Dresden, 01307 Dresden, Germany
| | - Janna Seifried
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, 63225 Langen, Germany; (M.B.); (M.R.); (J.S.)
| | - Nicole Stanke
- Institute of Virology, Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, 01307 Dresden, Germany; (J.W.); (A.E.); (N.S.); (C.M.)
- CRTD/DFG-Center for Regenerative Therapies, Technische Universität Dresden, 01307 Dresden, Germany
| | - Clara Munz
- Institute of Virology, Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, 01307 Dresden, Germany; (J.W.); (A.E.); (N.S.); (C.M.)
- CRTD/DFG-Center for Regenerative Therapies, Technische Universität Dresden, 01307 Dresden, Germany
| | - Veit Hornung
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 München, Germany;
| | - Renate König
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, 63225 Langen, Germany; (M.B.); (M.R.); (J.S.)
- German Center for Infection Research (DZIF), 63225 Langen, Germany
- Immunity and Pathogenesis Program, SBP Medical Discovery Institute, La Jolla, CA 92037, USA
- Correspondence: (R.K.); (D.L.); Tel.: +49-6103-77-4019 (R.K.); +49-351-458-6210 (D.L.)
| | - Dirk Lindemann
- Institute of Virology, Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, 01307 Dresden, Germany; (J.W.); (A.E.); (N.S.); (C.M.)
- CRTD/DFG-Center for Regenerative Therapies, Technische Universität Dresden, 01307 Dresden, Germany
- Correspondence: (R.K.); (D.L.); Tel.: +49-6103-77-4019 (R.K.); +49-351-458-6210 (D.L.)
| |
Collapse
|
9
|
Kaul A, Schönmann U, Pöhlmann S. Seroprevalence of viral infections in captive rhesus and cynomolgus macaques. Primate Biol 2019; 6:1-6. [PMID: 32110713 PMCID: PMC7041514 DOI: 10.5194/pb-6-1-2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 02/16/2019] [Indexed: 11/11/2022] Open
Abstract
Macaques serve as important animal models for biomedical research. Viral infection of macaques can compromise animal health as well as the results of biomedical research, and infected animals constitute an occupational health risk. Therefore, monitoring macaque colonies for viral infection is an important task. We used a commercial chip-based assay to analyze sera of 231 macaques for the presence of antibody responses against nine animal and human viruses. We report high seroprevalence of cytomegalovirus (CMV), lymphocryptovirus (LCV), rhesus rhadinovirus (RRV) and simian foamy virus (SFV) antibodies in all age groups. In contrast, antibodies against simian retrovirus type D (SRV/D) and simian T cell leukemia virus (STLV) were detected only in 5 % and 10 % of animals, respectively, and were only found in adult or aged animals. Moreover, none of the animals had antibodies against herpes B virus (BV), in keeping with the results of in-house tests previously used for screening. Finally, an increased seroprevalence of measles virus antibodies in animals with extensive exposure to multiple humans for extended periods of time was observed. However, most of these animals were obtained from external sources, and a lack of information on the measles antibody status of the animals at the time of arrival precluded drawing reliable conclusions from the data. In sum, we show, that in the colony studied, CMV, LCV, RRV and SFV infection was ubiquitous and likely acquired early in life while SRV/D and STLV infection was rare and likely acquired during adulthood.
Collapse
Affiliation(s)
- Artur Kaul
- Infection Biology Unit, German Primate Center – Leibniz Institute for
Primate Research, 37077 Göttingen, Germany
| | - Uwe Schönmann
- Laboratory Animal Sciences Unit, German Primate Center, 37077 Göttingen, Germany
| | - Stefan Pöhlmann
- Infection Biology Unit, German Primate Center – Leibniz Institute for
Primate Research, 37077 Göttingen, Germany
- Faculty of Biology and Psychology, University of Göttingen, 37073 Göttingen, Germany
| |
Collapse
|
10
|
Twelfth International Foamy Virus Conference-Meeting Report. Viruses 2019; 11:v11020134. [PMID: 30717288 PMCID: PMC6409691 DOI: 10.3390/v11020134] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 01/29/2019] [Indexed: 01/06/2023] Open
Abstract
The 12th International Foamy Virus Conference took place on 30–31 August 2018 at the Technische Universität Dresden, Dresden, Germany. The meeting included presentations on current research on non-human primate and non-primate foamy viruses (FVs; also called spumaretroviruses) as well as keynote talks on related research areas in retroviruses. The taxonomy of foamy viruses was updated earlier this year to create five new genera in the subfamily, Spumaretrovirinae, based on their animal hosts. Research on viruses from different genera was presented on topics of potential relevance to human health, such as natural infections and cross-species transmission, replication, and viral-host interactions in particular with the immune system, dual retrovirus infections, virus structure and biology, and viral vectors for gene therapy. This article provides an overview of the current state-of-the-field, summarizes the meeting highlights, and presents some important questions that need to be addressed in the future.
Collapse
|
11
|
Clinical and Molecular Features of Feline Foamy Virus and Feline Leukemia Virus Co-Infection in Naturally-Infected Cats. Viruses 2018; 10:v10120702. [PMID: 30544924 PMCID: PMC6315984 DOI: 10.3390/v10120702] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Revised: 12/06/2018] [Accepted: 12/07/2018] [Indexed: 11/17/2022] Open
Abstract
Feline foamy virus (FFV) and feline leukemia virus (FeLV) belong to the Retroviridae family. While disease has not been reported for FFV infection, FeLV infection can cause anemia and immunosuppression (progressive infection). Co-infection with FFV/FeLV allows evaluation of the pathogenic potential and epidemiology of FFV infection in cats with FeLV pathology. Blood and buccal swab samples from 81 cats were collected in Rio de Janeiro. Plasma was serologically tested for FeLV. DNA extracted from peripheral blood mononuclear cells and buccal swabs was used to PCR detect FFV and FeLV. A qPCR was developed to detect and measure FFV proviral loads (pVLs) in cats. FeLV qPCR was performed using previous methods. The median log10 pVL of FFV mono-infected individuals was lower than found in FFV/FeLV co-infected cats in buccal swabs (p = 0.003). We found 78% of cats had detectable buccal FFV DNA in FFV mono-infected and FFV co-infected FeLV-progressive cats, while in FeLV-regressive cats (those without signs of disease) 22% of cats had detectable buccal FFV DNA (p = 0.004). Our results suggest that regressive FeLV infection may reduce FFV saliva transmission, the main mode of FV transmission. We did not find evidence of differences in pathogenicity in FFV mono- and -dually infected cats. In summary, we show that FVs may interact with FeLV within the same host. Our study supports the utility of cats naturally co-infected with retroviruses as a model to investigate the impact of FV on immunocompromised mammalian hosts.
Collapse
|
12
|
Lambert C, Couteaudier M, Gouzil J, Richard L, Montange T, Betsem E, Rua R, Tobaly-Tapiero J, Lindemann D, Njouom R, Mouinga-Ondémé A, Gessain A, Buseyne F. Potent neutralizing antibodies in humans infected with zoonotic simian foamy viruses target conserved epitopes located in the dimorphic domain of the surface envelope protein. PLoS Pathog 2018; 14:e1007293. [PMID: 30296302 PMCID: PMC6193739 DOI: 10.1371/journal.ppat.1007293] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 10/18/2018] [Accepted: 08/23/2018] [Indexed: 12/31/2022] Open
Abstract
Human diseases of zoonotic origin are a major public health problem. Simian foamy viruses (SFVs) are complex retroviruses which are currently spilling over to humans. Replication-competent SFVs persist over the lifetime of their human hosts, without spreading to secondary hosts, suggesting the presence of efficient immune control. Accordingly, we aimed to perform an in-depth characterization of neutralizing antibodies raised by humans infected with a zoonotic SFV. We quantified the neutralizing capacity of plasma samples from 58 SFV-infected hunters against primary zoonotic gorilla and chimpanzee SFV strains, and laboratory-adapted chimpanzee SFV. The genotype of the strain infecting each hunter was identified by direct sequencing of the env gene amplified from the buffy coat with genotype-specific primers. Foamy virus vector particles (FVV) enveloped by wild-type and chimeric gorilla SFV were used to map the envelope region targeted by antibodies. Here, we showed high titers of neutralizing antibodies in the plasma of most SFV-infected individuals. Neutralizing antibodies target the dimorphic portion of the envelope protein surface domain. Epitopes recognized by neutralizing antibodies have been conserved during the cospeciation of SFV with their nonhuman primate host. Greater neutralization breadth in plasma samples of SFV-infected humans was statistically associated with smaller SFV-related hematological changes. The neutralization patterns provide evidence for persistent expression of viral proteins and a high prevalence of coinfection. In conclusion, neutralizing antibodies raised against zoonotic SFV target immunodominant and conserved epitopes located in the receptor binding domain. These properties support their potential role in restricting the spread of SFV in the human population.
Collapse
Affiliation(s)
- Caroline Lambert
- Unité d’Épidémiologie et Physiopathologie des Virus Oncogènes, Institut Pasteur, Paris, France
- UMR CNRS 3569, Institut Pasteur, Paris, France
- Sorbonne Paris Cité, Cellule Pasteur, Université Paris Diderot, Institut Pasteur, Paris, France
| | - Mathilde Couteaudier
- Unité d’Épidémiologie et Physiopathologie des Virus Oncogènes, Institut Pasteur, Paris, France
- UMR CNRS 3569, Institut Pasteur, Paris, France
| | - Julie Gouzil
- Unité d’Épidémiologie et Physiopathologie des Virus Oncogènes, Institut Pasteur, Paris, France
- UMR CNRS 3569, Institut Pasteur, Paris, France
| | - Léa Richard
- Unité d’Épidémiologie et Physiopathologie des Virus Oncogènes, Institut Pasteur, Paris, France
- UMR CNRS 3569, Institut Pasteur, Paris, France
- Sorbonne Paris Cité, Cellule Pasteur, Université Paris Diderot, Institut Pasteur, Paris, France
| | - Thomas Montange
- Unité d’Épidémiologie et Physiopathologie des Virus Oncogènes, Institut Pasteur, Paris, France
- UMR CNRS 3569, Institut Pasteur, Paris, France
| | - Edouard Betsem
- Unité d’Épidémiologie et Physiopathologie des Virus Oncogènes, Institut Pasteur, Paris, France
- UMR CNRS 3569, Institut Pasteur, Paris, France
- University of Yaounde I, Yaounde, Cameroon
| | - Réjane Rua
- Unité d’Épidémiologie et Physiopathologie des Virus Oncogènes, Institut Pasteur, Paris, France
- UMR CNRS 3569, Institut Pasteur, Paris, France
| | - Joelle Tobaly-Tapiero
- CNRS UMR 7212, INSERM U944, Institut Universitaire d’Hématologie, Hôpital Saint-Louis, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Dirk Lindemann
- Institute of Virology, Medical Faculty “Carl Gustav Carus”, Technische Universität Dresden, Dresden, Germany
- Center for Regenerative Therapies Dresden, Technische Universität Dresden, Dresden, Germany
| | - Richard Njouom
- Laboratoire de Virologie, Centre Pasteur du Cameroun, Yaoundé, Cameroon
| | - Augustin Mouinga-Ondémé
- Unité de Rétrovirologie, Centre International de Recherche Médicale de Franceville, Franceville, Gabon
| | - Antoine Gessain
- Unité d’Épidémiologie et Physiopathologie des Virus Oncogènes, Institut Pasteur, Paris, France
- UMR CNRS 3569, Institut Pasteur, Paris, France
| | - Florence Buseyne
- Unité d’Épidémiologie et Physiopathologie des Virus Oncogènes, Institut Pasteur, Paris, France
- UMR CNRS 3569, Institut Pasteur, Paris, France
- * E-mail:
| |
Collapse
|
13
|
Pinto-Santini DM, Stenbak CR, Linial ML. Foamy virus zoonotic infections. Retrovirology 2017; 14:55. [PMID: 29197389 PMCID: PMC5712078 DOI: 10.1186/s12977-017-0379-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 11/22/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Foamy viruses (FV) are ancient complex retroviruses that differ from orthoretroviruses such as human immunodeficiency virus (HIV) and murine leukemia virus (MLV) and comprise a distinct subfamily of retroviruses, the Spumaretrovirinae. FV are ubiquitous in their natural hosts, which include cows, cats, and nonhuman primates (NHP). FV are transmitted mainly through saliva and appear nonpathogenic by themselves, but they may increase morbidity of other pathogens in coinfections. CONCLUSIONS This review summarizes and discusses what is known about FV infection of natural hosts. It also emphasizes what is known about FV zoonotic infections A large number of studies have revealed that the FV of NHP, simian foamy viruses (SFV), are transmitted to humans who interact with infected NHP. SFV from a variety of NHP establish persistent infection in humans, while bovine foamy virus and feline foamy virus rarely or never do. The possibility of FV recombination and mutation leading to pathogenesis is considered. Since humans can be infected by SFV, a seemingly nonpathogenic virus, there is interest in using SFV vectors for human gene therapy. In this regard, detailed understanding of zoonotic SFV infection is highly relevant.
Collapse
Affiliation(s)
| | | | - Maxine L. Linial
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N., A3-205, Seattle, WA 98109 USA
| |
Collapse
|
14
|
Muniz CP, Cavalcante LTF, Jia H, Zheng H, Tang S, Augusto AM, Pissinatti A, Fedullo LP, Santos AF, Soares MA, Switzer WM. Zoonotic infection of Brazilian primate workers with New World simian foamy virus. PLoS One 2017; 12:e0184502. [PMID: 28931021 PMCID: PMC5606925 DOI: 10.1371/journal.pone.0184502] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 08/24/2017] [Indexed: 11/19/2022] Open
Abstract
Simian foamy viruses (SFVs) are retroviruses present in nearly all nonhuman primates (NHPs), including Old World primates (OWP) and New World primates (NWP). While all confirmed human infections with SFV are from zoonotic transmissions originating from OWP, little is known about the zoonotic transmission potential of NWP SFV. We conducted a longitudinal, prospective study of 56 workers occupationally exposed to NWP in Brazil. Plasma from these workers was tested using Western blot (WB) assays containing NWP SFV antigens. Genomic DNA from blood and buccal swabs was analyzed for the presence of proviral SFV sequences by three nested PCR tests and a new quantitative PCR assay. Exposure histories were obtained and analyzed for associations with possible SFV infection. Ten persons (18%) tested seropositive and two persons were seroindeterminate (3.6%) for NWP SFV. Six persons had seroreactivity over 2–3 years suggestive of persistent infection. All SFV NWP WB-positive workers reported at least one incident involving NWP, including six reporting NWP bites. NWP SFV viral DNA was not detected in the blood or buccal swabs from all 12 NWP SFV seroreactive workers. We also found evidence of SFV seroreversion in three workers suggestive of possible clearance of infection. Our findings suggest that NWP SFV can be transmitted to occupationally-exposed humans and can elicit specific humoral immune responses but infection remains well-controlled resulting in latent infection and may occasionally clear.
Collapse
Affiliation(s)
- Cláudia P. Muniz
- Departamento de Genética, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Laboratory Branch, Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | | | - Hongwei Jia
- Laboratory Branch, Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - HaoQiang Zheng
- Laboratory Branch, Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Shaohua Tang
- Laboratory Branch, Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Anderson M. Augusto
- Fundação Jardim Zoológico da Cidade do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Luiz P. Fedullo
- Fundação Jardim Zoológico da Cidade do Rio de Janeiro, Rio de Janeiro, Brazil
| | - André F. Santos
- Departamento de Genética, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marcelo A. Soares
- Departamento de Genética, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Programa de Oncovirologia, Instituto Nacional de Câncer, Rio de Janeiro, Brazil
| | - William M. Switzer
- Laboratory Branch, Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
- * E-mail:
| |
Collapse
|
15
|
Buseyne F, Gessain A, Soares MA, Santos AF, Materniak-Kornas M, Lesage P, Zamborlini A, Löchelt M, Qiao W, Lindemann D, Wöhrl BM, Stoye JP, Taylor IA, Khan AS. Eleventh International Foamy Virus Conference-Meeting Report. Viruses 2016; 8:v8110318. [PMID: 27886074 PMCID: PMC5127032 DOI: 10.3390/v8110318] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 11/08/2016] [Accepted: 11/10/2016] [Indexed: 12/11/2022] Open
Abstract
The Eleventh International Foamy Virus Conference took place on 9–10 June 2016 at the Institut Pasteur, Paris, France. The meeting reviewed progress on foamy virus (FV) research, as well as related current topics in retrovirology. FVs are complex retroviruses that are widespread in several animal species. Several research topics on these viruses are relevant to human health: cross-species transmission and viral emergence, vectors for gene therapy, development of antiretroviral drugs, retroviral evolution and its influence on the human genome. In this article, we review the conference presentations on these viruses and highlight the major questions to be answered.
Collapse
Affiliation(s)
- Florence Buseyne
- Unité d'Épidémiologie et Physiopathologie des Virus Oncogènes, Institut Pasteur, 75015 Paris, France.
- Centre National de la Recherche Scientifique (CNRS), UMR3569, 75015 Paris, France.
| | - Antoine Gessain
- Unité d'Épidémiologie et Physiopathologie des Virus Oncogènes, Institut Pasteur, 75015 Paris, France.
- Centre National de la Recherche Scientifique (CNRS), UMR3569, 75015 Paris, France.
| | - Marcelo A Soares
- Department of Genetics, Universidade Federal do Rio de Janeiro, 21949-570 Rio de Janeiro, Brazil.
- Oncovirology Program, Instituto Nacional de Câncer, 20231-050 Rio de Janeiro, Brazil.
| | - André F Santos
- Department of Genetics, Universidade Federal do Rio de Janeiro, 21949-570 Rio de Janeiro, Brazil.
| | | | - Pascale Lesage
- Institut Universitaire d'Hématologie, Hôpital Saint-Louis, Université Paris Diderot, Sorbonne Paris Cité, INSERM U944, CNRS UMR 7212, 75010 Paris, France.
| | - Alessia Zamborlini
- Institut Universitaire d'Hématologie, Hôpital Saint-Louis, Université Paris Diderot, Sorbonne Paris Cité, INSERM U944, CNRS UMR 7212, 75010 Paris, France.
- Conservatoire National des Arts et Métiers, Laboratoire de Pathologie et Virologie Moléculaire, 75003 Paris, France.
| | - Martin Löchelt
- Department of Molecular Diagnostics of Oncogenic Infections, Research Program Infection, Inflammation and Cancer, 69120 Heidelberg, Germany.
| | - Wentao Qiao
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071, China.
| | - Dirk Lindemann
- Institute of Virology, Medical Faculty "Carl Gustav Carus", Technische Universität Dresden, 01307 Dresden, Germany.
| | - Birgitta M Wöhrl
- University of Bayreuth, Department of Biopolymers, 95447 Bayreuth, Germany.
| | | | | | - Arifa S Khan
- Laboratory of Retroviruses, Division of Viral Products, OVRR, CBER, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA.
| |
Collapse
|
16
|
Lambert C, Rua R, Gessain A, Buseyne F. A new sensitive indicator cell line reveals cross-transactivation of the viral LTR by gorilla and chimpanzee simian foamy viruses. Virology 2016; 496:219-226. [PMID: 27348053 DOI: 10.1016/j.virol.2016.06.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 06/13/2016] [Accepted: 06/14/2016] [Indexed: 12/25/2022]
Abstract
The majority of currently identified simian foamy virus (SFV)-infected Cameroonian and Gabonese individuals harbor SFV from the gorilla lineage. We constructed an indicator cell line for the quantification of gorilla SFVs, in which the U3 sequence of a gorilla SFV directs the expression of the β-galactosidase protein. The gorilla foamy virus activated β-galactosidase (GFAB) cells efficiently quantified two zoonotic primary gorilla isolates and SFVs from three chimpanzee subspecies. Primary gorilla SFVs replicated more slowly and at lower levels than primary chimpanzee SFVs. Analysis of previously described motifs of Tas proteins and U3 LTRs involved in viral gene synthesis revealed conservation of such motifs in Tas proteins from gorilla and chimpanzee SFVs, but little sequence homology in the LTR regions previously shown to interact with viral and cellular factors.
Collapse
Affiliation(s)
- Caroline Lambert
- Unité d'épidémiologie et physiopathologie des virus oncogènes, Institut Pasteur, 28 rue du Dr Roux, 75015 Paris, France; UMR CNRS 3569, Institut Pasteur, Paris 75015, France; Sorbonne Paris Cité, Cellule Pasteur, Université Paris Diderot, Institut Pasteur, 75015 Paris, France
| | - Réjane Rua
- Unité d'épidémiologie et physiopathologie des virus oncogènes, Institut Pasteur, 28 rue du Dr Roux, 75015 Paris, France
| | - Antoine Gessain
- Unité d'épidémiologie et physiopathologie des virus oncogènes, Institut Pasteur, 28 rue du Dr Roux, 75015 Paris, France; UMR CNRS 3569, Institut Pasteur, Paris 75015, France
| | - Florence Buseyne
- Unité d'épidémiologie et physiopathologie des virus oncogènes, Institut Pasteur, 28 rue du Dr Roux, 75015 Paris, France; UMR CNRS 3569, Institut Pasteur, Paris 75015, France.
| |
Collapse
|
17
|
Bähr A, Singer A, Hain A, Vasudevan AAJ, Schilling M, Reh J, Riess M, Panitz S, Serrano V, Schweizer M, König R, Chanda S, Häussinger D, Kochs G, Lindemann D, Münk C. Interferon but not MxB inhibits foamy retroviruses. Virology 2016; 488:51-60. [DOI: 10.1016/j.virol.2015.10.034] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 09/11/2015] [Accepted: 10/31/2015] [Indexed: 11/26/2022]
|
18
|
Willems L, Gillet NA. APOBEC3 Interference during Replication of Viral Genomes. Viruses 2015; 7:2999-3018. [PMID: 26110583 PMCID: PMC4488724 DOI: 10.3390/v7062757] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 05/26/2015] [Accepted: 06/04/2015] [Indexed: 01/05/2023] Open
Abstract
Co-evolution of viruses and their hosts has reached a fragile and dynamic equilibrium that allows viral persistence, replication and transmission. In response, infected hosts have developed strategies of defense that counteract the deleterious effects of viral infections. In particular, single-strand DNA editing by Apolipoprotein B Editing Catalytic subunits proteins 3 (APOBEC3s) is a well-conserved mechanism of mammalian innate immunity that mutates and inactivates viral genomes. In this review, we describe the mechanisms of APOBEC3 editing during viral replication, the viral strategies that prevent APOBEC3 activity and the consequences of APOBEC3 modulation on viral fitness and host genome integrity. Understanding the mechanisms involved reveals new prospects for therapeutic intervention.
Collapse
Affiliation(s)
- Luc Willems
- Molecular and Cellular Epigenetics, Interdisciplinary Cluster for Applied Genoproteomics (GIGA) of University of Liège (ULg), B34, 1 avenue de L'Hôpital, Sart-Tilman Liège 4000, Belgium.
- Molecular and Cellular Biology, Gembloux Agro-Bio Tech, University of Liège (ULg), 13 avenue Maréchal Juin, Gembloux 5030, Belgium.
| | - Nicolas Albert Gillet
- Molecular and Cellular Epigenetics, Interdisciplinary Cluster for Applied Genoproteomics (GIGA) of University of Liège (ULg), B34, 1 avenue de L'Hôpital, Sart-Tilman Liège 4000, Belgium.
- Molecular and Cellular Biology, Gembloux Agro-Bio Tech, University of Liège (ULg), 13 avenue Maréchal Juin, Gembloux 5030, Belgium.
| |
Collapse
|
19
|
A Seminomadic Population in Bangladesh with Extensive Exposure to Macaques Does Not Exhibit High Levels of Zoonotic Simian Foamy Virus Infection. J Virol 2015; 89:7414-6. [PMID: 25926651 DOI: 10.1128/jvi.01065-15] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 04/24/2015] [Indexed: 01/15/2023] Open
Abstract
Simian foamy viruses (SVF) are ubiquitous in nonhuman primates (NHP). SFV can be zoonotically transmitted to humans who either work with or live commensally with NHP. We analyzed the blood of 45 Bangladeshi performing monkey owners (an ethnic group called the Bedey) for SFV infection. Surprisingly, a PCR assay failed to detect SFV infection in any of these participants. This is in contrast to our previously reported infection rate of about 5% among Bangladeshi villagers.
Collapse
|