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Persaud AT, Khela J, Fernandes C, Chaphekar D, Burnie J, Tang VA, Colpitts CC, Guzzo C. Virion-incorporated CD14 enables HIV-1 to bind LPS and initiate TLR4 signaling in immune cells. J Virol 2024; 98:e0036324. [PMID: 38661384 DOI: 10.1128/jvi.00363-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Accepted: 04/01/2024] [Indexed: 04/26/2024] Open
Abstract
HIV-1 has a broad range of nuanced interactions with the immune system, and the incorporation of cellular proteins by nascent virions continues to redefine our understanding of the virus-host relationship. Proteins located at the sites of viral egress can be selectively incorporated into the HIV-1 envelope, imparting new functions and phenotypes onto virions, and impacting viral spread and disease. Using virion capture assays and western blot, we show that HIV-1 can incorporate the myeloid antigen CD14 into its viral envelope. Virion-incorporated CD14 remained biologically active and able to bind its natural ligand, bacterial lipopolysaccharide (LPS), as demonstrated by flow virometry and immunoprecipitation assays. Using a Toll-like receptor 4 (TLR4) reporter cell line, we also demonstrated that virions with bound LPS can trigger TLR4 signaling to activate transcription factors that regulate inflammatory gene expression. Complementary assays with THP-1 monocytes demonstrated enhanced secretion of inflammatory cytokines like tumor necrosis factor alpha (TNF-α) and the C-C chemokine ligand 5 (CCL5), when exposed to LPS-loaded virus. These data highlight a new type of interplay between HIV-1 and the myeloid cell compartment, a previously well-established cellular contributor to HIV-1 pathogenesis and inflammation. Persistent gut inflammation is a hallmark of chronic HIV-1 infection, and contributing to this effect is the translocation of microbes across the gut epithelium. Our data herein provide proof of principle that virion-incorporated CD14 could be a novel mechanism through which HIV-1 can drive chronic inflammation, facilitated by HIV-1 particles binding bacterial LPS and initiating inflammatory signaling in TLR4-expressing cells.IMPORTANCEHIV-1 establishes a lifelong infection accompanied by numerous immunological changes. Inflammation of the gut epithelia, exacerbated by the loss of mucosal T cells and cytokine dysregulation, persists during HIV-1 infection. Feeding back into this loop of inflammation is the translocation of intestinal microbes across the gut epithelia, resulting in the systemic dissemination of bacterial antigens, like lipopolysaccharide (LPS). Our group previously demonstrated that the LPS receptor, CD14, can be readily incorporated by HIV-1 particles, supporting previous clinical observations of viruses derived from patient plasma. We now show that CD14 can be incorporated by several primary HIV-1 isolates and that this virion-incorporated CD14 can remain functional, enabling HIV-1 to bind to LPS. This subsequently allowed CD14+ virions to transfer LPS to monocytic cells, eliciting pro-inflammatory signaling and cytokine secretion. We posit here that virion-incorporated CD14 is a potential contributor to the dysregulated immune responses present in the setting of HIV-1 infection.
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Affiliation(s)
- Arvin T Persaud
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Jasmin Khela
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Claire Fernandes
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Deepa Chaphekar
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Jonathan Burnie
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Vera A Tang
- Flow Cytometry and Virometry Core Facility, Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Che C Colpitts
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Christina Guzzo
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Department of Immunology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
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2
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Burnie J, Fernandes C, Chaphekar D, Wei D, Ahmed S, Persaud AT, Khader N, Cicala C, Arthos J, Tang VA, Guzzo C. Identification of CD38, CD97, and CD278 on the HIV surface using a novel flow virometry screening assay. Sci Rep 2023; 13:23025. [PMID: 38155248 PMCID: PMC10754950 DOI: 10.1038/s41598-023-50365-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 12/19/2023] [Indexed: 12/30/2023] Open
Abstract
While numerous cellular proteins in the HIV envelope are known to alter virus infection, methodology to rapidly phenotype the virion surface in a high throughput, single virion manner is lacking. Thus, many human proteins may exist on the virion surface that remain undescribed. Herein, we developed a novel flow virometry screening assay to discover new proteins on the surface of HIV particles. By screening a CD4+ T cell line and its progeny virions, along with four HIV isolates produced in primary cells, we discovered 59 new candidate proteins in the HIV envelope that were consistently detected across diverse HIV isolates. Among these discoveries, CD38, CD97, and CD278 were consistently present at high levels on virions when using orthogonal techniques to corroborate flow virometry results. This study yields new discoveries about virus biology and demonstrates the utility and feasibility of a novel flow virometry assay to phenotype individual virions.
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Affiliation(s)
- Jonathan Burnie
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, Canada
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON, Canada
| | - Claire Fernandes
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, Canada
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON, Canada
| | - Deepa Chaphekar
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, Canada
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON, Canada
| | - Danlan Wei
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Shubeen Ahmed
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, Canada
| | - Arvin Tejnarine Persaud
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, Canada
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON, Canada
| | - Nawrah Khader
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON, Canada
| | - Claudia Cicala
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - James Arthos
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Vera A Tang
- Flow Cytometry and Virometry Core Facility, Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, 451 Smyth Road, Ottawa, ON, Canada
| | - Christina Guzzo
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, Canada.
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON, Canada.
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3
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Burnie J, Persaud AT, Thaya L, Liu Q, Miao H, Grabinsky S, Norouzi V, Lusso P, Tang VA, Guzzo C. P-selectin glycoprotein ligand-1 (PSGL-1/CD162) is incorporated into clinical HIV-1 isolates and can mediate virus capture and subsequent transfer to permissive cells. Retrovirology 2022; 19:9. [PMID: 35597982 PMCID: PMC9123692 DOI: 10.1186/s12977-022-00593-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 04/21/2022] [Indexed: 11/16/2022] Open
Abstract
Background P-selectin glycoprotein ligand-1 (PSGL-1/CD162) has been studied extensively for its role in mediating leukocyte rolling through interactions with its cognate receptor, P-selectin. Recently, PSGL-1 was identified as a novel HIV-1 host restriction factor, particularly when expressed at high levels in the HIV envelope. Importantly, while the potent antiviral activity of PSGL-1 has been clearly demonstrated in various complementary model systems, the breadth of PSGL-1 incorporation across genetically diverse viral isolates and clinical isolates has yet to be described. Additionally, the biological activity of virion-incorporated PSGL-1 has also yet to be shown. Results Herein we assessed the levels of PSGL-1 on viruses produced through transfection with various amounts of PSGL-1 plasmid DNA (0–250 ng), compared to levels of PSGL-1 on viruses produced through infection of T cell lines and primary PBMC. We found that very low levels of PSGL-1 plasmid DNA (< 2.5 ng/well) were necessary to generate virus models that could closely mirror the phenotype of viruses produced via infection of T cells and PBMC. Unique to this study, we show that PSGL-1 is incorporated in a broad range of HIV-1 and SIV isolates and that virions with incorporated PSGL-1 are detectable in plasma from viremic HIV-1-infected individuals, corroborating the relevance of PSGL-1 in natural infection. Additionally, we show that PSGL-1 on viruses can bind its cognate selectin receptors, P-, E-, and L-selectins. Finally, we show viruses with endogenous levels of PSGL-1 can be captured by P-selectin and transferred to HIV-permissive bystander cells, highlighting a novel role for PSGL-1 in HIV-1 infection. Notably, viruses which contained high levels of PSGL-1 were noninfectious in our hands, in line with previous findings reporting the potent antiviral activity of PSGL-1. Conclusions Our results indicate that levels of PSGL-1 incorporation into virions can vary widely among model systems tested, and that careful tailoring of plasmid levels is required to recapitulate physiological systems when using pseudovirus models. Taken together, our data suggest that PSGL-1 may play diverse roles in the physiology of HIV-1 infection, particularly due to the functionally active state of PSGL-1 on virion surfaces and the breadth of PSGL-1 incorporation among a wide range of viral isolates. Supplementary Information The online version contains supplementary material available at 10.1186/s12977-022-00593-5.
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Affiliation(s)
- Jonathan Burnie
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, Canada.,Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON, Canada
| | - Arvin Tejnarine Persaud
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, Canada.,Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON, Canada
| | - Laxshaginee Thaya
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, Canada.,Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON, Canada
| | - Qingbo Liu
- Viral Pathogenesis Section, Laboratory of Immunoregulation (LIR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Huiyi Miao
- Viral Pathogenesis Section, Laboratory of Immunoregulation (LIR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Stephen Grabinsky
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, Canada
| | - Vanessa Norouzi
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, Canada
| | - Paolo Lusso
- Viral Pathogenesis Section, Laboratory of Immunoregulation (LIR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Vera A Tang
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, Flow Cytometry and Virometry Core Facility, University of Ottawa, Ottawa, ON, Canada
| | - Christina Guzzo
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, Canada. .,Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON, Canada.
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Persaud AT, Burnie J, Thaya L, DSouza L, Martin S, Guzzo C. A UV-LED module that is highly effective at inactivating human coronaviruses and HIV-1. Virol J 2022; 19:29. [PMID: 35144624 PMCID: PMC8829982 DOI: 10.1186/s12985-022-01754-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 01/24/2022] [Indexed: 11/10/2022] Open
Abstract
Ultraviolet (UV) light has previously been established as useful method of disinfection, with demonstrated efficacy to inactivate a broad range of microorganisms. The advent of ultraviolet light-emitting diodes provides advantages in ease of disinfection, in that there can be delivery of germicidal UV with the same light unit that delivers standard white light to illuminate a room. Herein we demonstrate the efficacy and feasibility of ultraviolet light-emitting diodes as a means of decontamination by inactivating two distinct virus models, human coronavirus 229E and human immunodeficiency virus. Importantly, the same dose of ultraviolet light that inactivated human viruses also elicited complete inactivation of ultraviolet-resistant bacterial spores (Bacillus pumilus), a gold standard for demonstrating ultraviolet-mediated disinfection. This work demonstrates that seconds of ultraviolet light-emitting diodes (UV-LED) exposure can inactivate viruses and bacteria, highlighting that UV-LED could be a useful and practical tool for broad sanitization of public spaces.
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Affiliation(s)
- Arvin T Persaud
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Room SW560, Toronto, ON, M1C 1A4, Canada.,Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON, M5S 3G5, Canada
| | - Jonathan Burnie
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Room SW560, Toronto, ON, M1C 1A4, Canada.,Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON, M5S 3G5, Canada
| | - Laxshaginee Thaya
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Room SW560, Toronto, ON, M1C 1A4, Canada.,Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON, M5S 3G5, Canada
| | - Liann DSouza
- Safe Antiviral Technologies Inc, 822 Manning Ave, Toronto, ON, M6G 2W8, Canada
| | - Steven Martin
- Safe Antiviral Technologies Inc, 822 Manning Ave, Toronto, ON, M6G 2W8, Canada
| | - Christina Guzzo
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Room SW560, Toronto, ON, M1C 1A4, Canada. .,Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON, M5S 3G5, Canada.
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5
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Persaud AT, Bennett SA, Thaya L, Burnie J, Guzzo C. Human monocytes store and secrete preformed CCL5, independent of de novo protein synthesis. J Leukoc Biol 2021; 111:573-583. [PMID: 34114669 DOI: 10.1002/jlb.3a0820-522rr] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 04/29/2021] [Accepted: 05/05/2021] [Indexed: 12/24/2022] Open
Abstract
Monocytes are a subset of circulating peripheral blood mononuclear cells with diverse roles in immunity, including sentinel roles in cytokine secretion. Conventionally, cytokines require an inductive stimulus for their expression and secretion, resulting in a time lag from the time of stimulation to when the proteins are packaged and secreted. Because cytokines are the main communicators in the immune system, their temporal expression is a key factor in coordinating responses to efficiently resolve infection. Herein, we identify that circulating human monocytes contain preformed cytokines that are stored intracellularly, in both resting and activated states. Having preformed cytokines bypasses the time lag associated with de novo synthesis, allowing monocytes to secrete immune mediators immediately upon activation or sensing of microbe-associated molecular patterns. We demonstrate here that, out of several cytokines evaluated, human monocytes contain a previously undescribed reservoir of the preformed chemokine CCL5. Furthermore, we showed that CCL5 could be secreted from monocytes treated with the protein synthesis inhibitor (cycloheximide) and Golgi blocker (brefeldin A). We examined the possibility for uptake of extracellular CCL5 from platelet aggregates and observed no significant levels of platelet binding to our enriched monocyte preparations, indicating that the source of preformed CCL5 was not from platelets. Preformed CCL5 was observed to be distributed throughout the cytoplasm and partially colocalized with CD63+ and Rab11A+ membranes, implicating endosomal compartments in the intracellular storage and trafficking of CCL5.
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Affiliation(s)
- Arvin Tejnarine Persaud
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Stephen Andrew Bennett
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Laxshaginee Thaya
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Jonathan Burnie
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Christina Guzzo
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
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6
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Burnie J, Tang VA, Welsh JA, Persaud AT, Thaya L, Jones JC, Guzzo C. Flow Virometry Quantification of Host Proteins on the Surface of HIV-1 Pseudovirus Particles. Viruses 2020; 12:v12111296. [PMID: 33198254 PMCID: PMC7697180 DOI: 10.3390/v12111296] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/04/2020] [Accepted: 11/09/2020] [Indexed: 12/20/2022] Open
Abstract
The HIV-1 glycoprotein spike (gp120) is typically the first viral antigen that cells encounter before initiating immune responses, and is often the sole target in vaccine designs. Thus, characterizing the presence of cellular antigens on the surfaces of HIV particles may help identify new antiviral targets or impact targeting of gp120. Despite the importance of characterizing proteins on the virion surface, current techniques available for this purpose do not support high-throughput analysis of viruses, and typically only offer a semi-quantitative assessment of virus-associated proteins. Traditional bulk techniques often assess averages of viral preparations, which may mask subtle but important differences in viral subsets. On the other hand, microscopy techniques, which provide detail on individual virions, are difficult to use in a high-throughput manner and have low levels of sensitivity for antigen detection. Flow cytometry is a technique that traditionally has been used for rapid, high-sensitivity characterization of single cells, with limited use in detecting viruses, since the small size of viral particles hinders their detection. Herein, we report the detection and surface antigen characterization of HIV-1 pseudovirus particles by light scattering and fluorescence with flow cytometry, termed flow virometry for its specific application to viruses. We quantified three cellular proteins (integrin α4β7, CD14, and CD162/PSGL-1) in the viral envelope by directly staining virion-containing cell supernatants without the requirement of additional processing steps to distinguish virus particles or specific virus purification techniques. We also show that two antigens can be simultaneously detected on the surface of individual HIV virions, probing for the tetraspanin marker, CD81, in addition to α4β7, CD14, and CD162/PSGL-1. This study demonstrates new advances in calibrated flow virometry as a tool to provide sensitive, high-throughput characterization of the viral envelope in a more efficient, quantitative manner than previously reported techniques.
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Affiliation(s)
- Jonathan Burnie
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4, Canada; (J.B.); (A.T.P.); (L.T.)
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON M5S 3G5, Canada
| | - Vera A. Tang
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Flow Cytometry and Virometry Core Facility, Ottawa, ON K1H 8M5, Canada;
| | - Joshua A. Welsh
- Translational Nanobiology Section, Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (J.A.W.); (J.C.J.)
| | - Arvin T. Persaud
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4, Canada; (J.B.); (A.T.P.); (L.T.)
| | - Laxshaginee Thaya
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4, Canada; (J.B.); (A.T.P.); (L.T.)
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON M5S 3G5, Canada
| | - Jennifer C. Jones
- Translational Nanobiology Section, Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (J.A.W.); (J.C.J.)
| | - Christina Guzzo
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4, Canada; (J.B.); (A.T.P.); (L.T.)
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON M5S 3G5, Canada
- Correspondence: ; Tel.: +1-(416)-287-7436
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7
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Abstract
The incorporation of biologically active host proteins into HIV-1 is a well-established phenomenon, particularly due to the budding mechanism of viral egress in which viruses acquire their external lipid membrane directly from the host cell. While this mechanism might seemingly imply that host protein incorporation is a passive uptake of all cellular antigens associated with the plasma membrane at the site of budding, this is not the case. Herein, we review the evidence indicating that host protein incorporation can be a selective and conserved process. We discuss how HIV-1 virions displaying host proteins on their surface can exhibit a myriad of altered phenotypes, with notable impacts on infectivity, homing, neutralization, and pathogenesis. This review describes the canonical and emerging methods to detect host protein incorporation, highlights the well-established host proteins that have been identified on HIV-1 virions, and reflects on the role of these incorporated proteins in viral pathogenesis and therapeutic targeting. Despite many advances in HIV treatment and prevention, there remains a global effort to develop increasingly effective anti-HIV therapies. Given the broad range of biologically active host proteins acquired on the surface of HIV-1, additional studies on the mechanisms and impacts of these incorporated host proteins may inform the development of novel treatments and vaccine designs.
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Affiliation(s)
- Jonathan Burnie
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON M5S 3G5, Canada.
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4, Canada.
| | - Christina Guzzo
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON M5S 3G5, Canada.
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4, Canada.
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Hodgetts S, Nooney L, Al-Akeel R, Curry A, Awad S, Matthews R, Burnie J. Efungumab and caspofungin: pre-clinical data supporting synergy. J Antimicrob Chemother 2008; 61:1132-9. [DOI: 10.1093/jac/dkn075] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Nooney L, Al-Akeel R, Awad S, AlShami I, Matthews R, Burnie J. P1967 Mycograb increases Candida sensitivity tofiuconazole in vitro. Int J Antimicrob Agents 2007. [DOI: 10.1016/s0924-8579(07)71806-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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10
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Abstract
Hepatosplenic candidiasis is traditionally diagnosed by blood culture, magnetic resonance imaging (MRI), and histological analysis. The limitations of these methods include: low sensitivity (blood culture) and failure to isolate the organism (MRI/histology). This report describes a case of hepatosplenic candidiasis diagnosed by simultaneous polymerase chain reaction (PCR) analysis of liver biopsy and serum. PCR of biopsy and/or serum may offer a sensitive and specific diagnostic test for hepatosplenic candidiasis. Candida species can be identified, which helps guide antifungal chemotherapy, an important aspect in this difficult to treat infection.
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Affiliation(s)
- A Kirby
- Department of Medical Microbiology, Clinical Sciences Building, Manchester Royal Infirmary, UK.
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11
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Rao J, Qamruddin A, Martinez A, Hassan I, Burnie J. Sternal wound infection due to pneumococcus. J Infect 2002. [DOI: 10.1016/s0163-4453(02)90354-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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12
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Matthews R, Burnie J. Antifungal antibodies: a new approach to the treatment of systemic candidiasis. Curr Opin Investig Drugs 2001; 2:472-6. [PMID: 11566001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Antibody-based therapeutics have come of age, with advances in the genetic engineering of recombinant antibodies allowing application of a growing knowledge of the immunopathology of diseases to the development of novel drugs. For infections such as systemic candidiasis, which still have a mortality of 40 to 50%, antifungal antibodies could provide long-awaited novel therapies for use in combination with antifungal agents. They may also evolve into safe, broad-spectrum agents for prophylaxis in high-risk immunocompromised patients. Mycograb, a human genetically recombinant antibody against heat shock protein 90 (hsp90), has just started trials in patients with systemic candidiasis.
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Affiliation(s)
- R Matthews
- NeuTec Pharma plc & The Infectious Disease Research Group, Manchester University, Central Manchester Healthcare Trust, UK
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Burnie J, Matthews R, Jiman-Fatami A, Gottardello P, Hodgetts S, D'arcy S. Analysis of 42 cases of septicemia caused by an epidemic strain of methicillin-resistant Staphylococcus aureus: evidence of resistance to vancomycin. Clin Infect Dis 2000; 31:684-9. [PMID: 11017816 DOI: 10.1086/314035] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/1999] [Revised: 02/07/2000] [Indexed: 11/03/2022] Open
Abstract
Recent case reports of vancomycin treatment failures in the United States, Japan, and France have prompted a retrospective analysis of 42 cases of septicemia caused by epidemic methicillin-resistant Staphylococcus aureus strain 15 (EMRSA-15), which is the most prevalent epidemic strain of methicillin-resistant S. aureus in the United Kingdom; all cases occurred in a teaching hospital in Manchester, United Kingdom, between 1994 and 1998. Mortality was lowest (4%) in patients with rifampin-susceptible isolates treated with vancomycin and rifampin. It rose to 38% in patients who were treated with both antibiotics but in whom the organism became resistant to rifampin during therapy, and it reached 78% in patients who had rifampin-resistant isolates or in whom rifampin was contraindicated (P<.0001; Fisher exact test, 2-tailed). All isolates were susceptible to vancomycin by conventional laboratory testing, but susceptibility was lost by growth in vancomycin in vitro, becoming resistant at a minimum inhibitory concentration of 8 mg/L. This was associated with accumulation of cell-wall material. The deoxyribonucleic acid fingerprint remained unchanged. This study suggests that rifampin played a key role in the prevention of deaths caused by an epidemic strain of methicillin-resistant S. aureus that readily gave rise to a subpopulation with reduced susceptibility to vancomycin.
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Affiliation(s)
- J Burnie
- Infectious Diseases Research Unit, University of Manchester, Central Manchester Healthcare Trust, Manchester, United Kingdom.
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14
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Affiliation(s)
- R A Barnes
- UWCM, Cardiff, Imperial College School of Medicine, London
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15
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16
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Affiliation(s)
- R Matthews
- University Department of Medical Microbiology, Manchester Royal Infirmary, UK
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Hodgetts S, Matthews R, Morrissey G, Mitsutake K, Piper P, Burnie J. Over-expression of Saccharomyces cerevisiae hsp90 enhances the virulence of this yeast in mice. FEMS Immunol Med Microbiol 1996; 16:229-34. [PMID: 9116640 DOI: 10.1111/j.1574-695x.1996.tb00140.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Saccharomyces cerevisiae, a yeast of low pathogenic potential, is a rare but well-documented cause of invasive infections in humans. The yeast Candida albicans is a much commoner cause of significant and life-threatening infections. In such infections the heat shock protein hsp90 is an immunodominant antigen associated with protective humoral immunity. In this study it was shown that over-expression of S. cerevisiae hsp90, the amino acid sequence of which shows 84% identity to C. albicans hsp90, significantly increased the virulence of a laboratory strain of S. cerevisiae in mice, both in terms of colony counts in the kidney, liver, and spleen, and in terms of mortality. This is the first direct evidence that hsp90 is a virulence factor.
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Affiliation(s)
- S Hodgetts
- Department of Medical Microbiology, Manchester Royal Infirmary, UK
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Abstract
For many years, there has been controversy over the role of antibodies in immunity to Candida, but recently specific antibodies to mannoproteins and hsp90 have been shown to be protective against murine candidiasis. Combined with technical advances in antibody engineering, this raises the possibility of harnessing such antibodies into a new range of therapeutics.
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Affiliation(s)
- R Matthews
- University Dept of Medical Microbiology, Manchester Royal Infirmary, UK
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Abstract
Seroconversion to hsp90 is associated with recovery from systemic candidiasis in humans, and a murine monoclonal antibody to this hsp90 antigen (LKVIRK epitope) was protective in mice. A human recombinant antibody to the same epitope was assessed in acute and chronic models of murine invasive candidiasis. Lethal intravenous challenge with fluconazole-susceptible (strain 4) or fluconazole-resistant (strain 019) Candida albicans, followed 2 h later by a single dose of recombinant antibody, was associated with a statistically significant drop in mortality of > or = 40% (two experiments in BALB/c mice given strain 4; one experiment in CD-1 mice given strain 019) or 23% (BALB/c mice, strain 019). In mice sublethally infected with strain 4, treatment with recombinant antibody was associated with improved renal clearance of infection. Antibody-mediated protection may involve neutralization of the protein-binding properties of circulating candidal hsp90, since LKVIRK strongly bound dexamethasone in vitro.
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Affiliation(s)
- R Matthews
- Department of Medical Microbiology, University of Manchester Medical School, United Kingdom
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Ellis ME, Clink H, Ernst P, Halim MA, Padmos A, Spence D, Kalin M, Hussain Qadri SM, Burnie J, Greer W. Controlled study of fluconazole in the prevention of fungal infections in neutropenic patients with haematological malignancies and bone marrow transplant recipients. Eur J Clin Microbiol Infect Dis 1994; 13:3-11. [PMID: 8168557 DOI: 10.1007/bf02026116] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The efficacy and safety of oral fluconazole versus a polyene regimen in preventing mycoses in neutropenic patients was compared. Patients with haematological malignancy or bone marrow transplantation received as antifungal prophylaxis either fluconazole 200 mg daily or a regimen consisting of clotrimazole trouches 10 mg twice daily with mycostatin, 500,000 I.U. four times daily, benadryl and cepacol mouthwash. Ninety patients at risk for fungus infection were evaluable. Four of 42 patients (9.5%; confidence interval 2%-23%) on fluconazole and 17 of 48 patients (35.4%; confidence interval 22%-52%) (p < 0.01) on the clotrimazole regimen developed a clinically significant fungal infection, including 3 (7.1%) and 11 (22.9%) patients respectively who had severe fungal infection, mainly pulmonary aspergillosis. Death directly due to a fungal infection within 100 days of the start of prophylaxis occurred in 2 of 42 patients (4.8%) and 9 of 48 patients (18.8%) respectively (p < 0.06). Kaplan-Meier analysis showed that the chance of survival on fluconazole was statistically greater than for the clotrimazole regimen (p < 0.04). A decrease of candidal colonisation of the gastrointestinal and genitourinary tracts occurred only in patients receiving fluconazole. No significant toxicity occurred. A 200 mg daily dose of fluconazole given to these patients thus appears to be well tolerated and to provide a protective effect against the development of fungal infection and death from severe fungal disease.
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Affiliation(s)
- M E Ellis
- Department of Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
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Bostock A, Khattak MN, Matthews R, Burnie J. Comparison of PCR fingerprinting, by random amplification of polymorphic DNA, with other molecular typing methods for Candida albicans. J Gen Microbiol 1993; 139:2179-84. [PMID: 7902410 DOI: 10.1099/00221287-139-9-2179] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Fingerprinting by random amplification of polymorphic DNA (RAPD) was compared with existing molecular typing systems for Candida albicans. Fifteen isolates were chosen, including three from the same patient; these gave 14 distinct karyotypes by pulsed-field gel electrophoresis (PFGE) and 7 different DNA types by EcoRI-generated restriction fragment length polymorphisms (RFLPs). RAPD with primer I (5'GCTGGTGG3') gave 5 types, whereas primer II (5'GCGCACGG3') yielded 11 types. Combining the results from both primers, all isolates were unique by RAPD with the exception of the three from the same patient. RAPD provided a fast, economical and reproducible means of typing C. albicans with a level of discrimination approaching that of PFGE.
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Affiliation(s)
- A Bostock
- Department of Medical Microbiology, Manchester University, UK
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Ellis ME, Dossing M, al-Hokail A, Qadri SH, Hainau B, Burnie J. Progressive Chronic Pulmonary Aspergillosis: A Diagnostic and Therapeutic Challenge. Med Chir Trans 1992; 85:763-4. [PMID: 1494172 PMCID: PMC1293772 DOI: 10.1177/014107689208501220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- M E Ellis
- Department of Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
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Matthews R, Burnie J. Acquired immunity to systemic candidiasis in immunodeficient mice: role of antibody to heat-shock protein 90. J Infect Dis 1992; 166:1193-5. [PMID: 1402035 DOI: 10.1093/infdis/166.5.1193] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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Abstract
The immunodominant antigens of many microbial pathogens are heat shock proteins (hsps). In systemic candidal infections, a major target of protective antibody is an epitope shared with human hsp90. Here, Ruth Matthews and James Burnie suggest that fungal hsp90 plays a key pathogenic role in systemic infection by either binding to certain serum proteins, causing them to malfunction, or by mimicking the functional activity of other proteins.
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Affiliation(s)
- R Matthews
- Department of Medical Microbiology, Manchester University Medical School, UK
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Abstract
The gene encoding a histidine-containing protein (HPr)-like protein was identified in a cDNA library of Aspergillus fumigatus. The predicted amino acid sequence of the fungal HPr showed greater homology with HPr from Gram-positive bacteria than from Gram-negative bacteria. Since other components of the phosphoenolpyruvate: carbohydrate phosphotransferase system have not been identified in eukaryotes, this raises the question of what regulatory function the HPr-like protein might have evolved in this fungus.
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Affiliation(s)
- S Barker
- Department of Medical Microbiology, Manchester University, UK
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Abstract
Part of the gene coding for the immunodominant 47 kDa antigen of the human fungal pathogen Candida albicans was cloned and sequenced. The predicted amino acid sequence was homologous to stress proteins, the most extensive similarity being with the heat shock protein hsp 90 of Saccharomyces cerevisiae. The 47 kDa antigen has diagnostic and therapeutic potential and is the first candidal antigen to be cloned and sequenced.
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Affiliation(s)
- R Matthews
- Department of Medical Microbiology, St. Bartholomew's Hospital, West Smithfield, London, U.K
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Burnie J. Atlas of Human Parasitology. Clin Mol Pathol 1989. [DOI: 10.1136/jcp.42.3.335-d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Abstract
DNA fingerprinting was assessed as an improved typing system for Candida albicans aimed at speeding the implementation of cross infection control measures in outbreaks of systemic candidiasis. The study was carried out with 45 previously characterised isolates from five different outbreaks and with 96 unrelated isolates from a mixed control population. Sixteen different genotypes were produced. Results were obtainable within days, reproducibility was high, and there was good discrimination among different outbreaks. Compared with existing typing systems DNA fingerprinting provides a robust system that may be used rapidly to identify outbreaks of nosocomial candidiasis in laboratories with no specialist skill in typing C albicans.
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Affiliation(s)
- R Matthews
- Department of Medical Microbiology, St Bartholomew's Hospital, London
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Burnie J. Bacterial cell surface techniques. J Immunol Methods 1988. [DOI: 10.1016/0022-1759(88)90187-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Abstract
Clinical observation and animal models of candidosis suggest that, although T lymphocytes are important in preventing superficial candidosis, defence against systemic candidosis depends upon humoral immunity. An antibody response to the immunodominant 47 kD antigen of Candida albicans is invariably associated with recovery. The presence of this antibody in patients with chronic mucocutaneous candidosis and the acquired immunodeficiency syndrome (AIDS) could account for the rarity of disseminated candidal infection in these conditions. Polyclonal B cell activation may be responsible for the frequency with which this antibody is produced in AIDS. Antibody to the 47 kD antigen could be useful in the treatment and prevention of systemic candidosis, though not in the superficial candidosis of AIDS.
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Affiliation(s)
- R Matthews
- Department of Medical Microbiology, St Bartholomew's Hospital, London
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Matthews R, Burnie J. Diagnosis of systemic candidiasis by an enzyme-linked dot immunobinding assay for a circulating immunodominant 47-kilodalton antigen. J Clin Microbiol 1988; 26:459-63. [PMID: 3281974 PMCID: PMC266313 DOI: 10.1128/jcm.26.3.459-463.1988] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
A dot immunobinding assay based on the detection of the immunodominant 47-kilodalton (kDa) antigen of Candida albicans is described for the serological diagnosis of systemic candidiasis. It was compared with a reverse passive latex agglutination test and a dot immunobinding assay with total unfractionated hyperimmune serum to C. albicans. Use of the 47-kDa antigen-specific probe increased both the sensitivity and specificity of the assay system. Patients with systemic candidiasis were detected earlier in the course of the infection. The rate of detection of systemic C. albicans infections in neutropenic patients was 77% compared with 55% with total antibody in the dot immunobinding assay and 29% with the latex test. All three assay systems were positive in over 73% of infected patients who were not neutropenic. The 47-kDa antigen-specific probe was relatively specific to C. albicans. Antibody probes to the immunodominant antigens of other yeasts might be incorporated in the same dot immunobinding assay to detect systemic candidiasis caused by other species of yeasts.
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Affiliation(s)
- R Matthews
- Department of Medical Microbiology, St. Bartholomew's Hospital, London, United Kingdom
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Burnie J. Clinical Microbiology. Clin Mol Pathol 1988. [DOI: 10.1136/jcp.41.2.239-e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Pamphilon D, Prentice A, Wedzicha J, Woods M, Matthews R, Burnie J. A clinical and serological study of the effect of itraconazole in the management of invasive aspergillosis. ACTA ACUST UNITED AC 1987. [DOI: 10.1016/0888-0786(87)90009-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Abstract
Immunoblotting has recently become popular as a way of fingerprinting those hospital pathogens where other more conventional typing systems are deficient. Extracts of microorganisms are prepared by chemical or enzymic means, run on a standard SDS-PAGE gel and transferred onto nitrocellulose membrane. They are then probed either by a hyperimmune antiserum raised in a rabbit or by serum from a patient who has been previously infected by the organism. The pattern of antigenic bands which stain forms the basis of the method. This article discusses the limitations of the system, makes recommendations for further systems and outlines a typical fingerprinting protocol.
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Abstract
This study examines the influence of limb velocity and lateral dominance on the relationship between the knee flexors and extensors. Thirty preadolescents, 18 male and 12 female, performed a series of reciprocal knee flexion-extension movements on the Cybex II isokinetic system. The tests were performed at a range of selected velocities and on both dominant and nondominant limbs. The agonist-antagonist ratios considered were the peak torque ratios, the torque ratio produced at specific angles, and the ratio comparing the total work performed by the hamstrings with that of the quadriceps. The results showed that an increased limb velocity produces a significant increase in the peak torque and work ratios (P less than 0.05), limb velocity has no significant effect on the torque ratio produced at 30 degrees and 60 degrees in the preadolescents, and lower limb lateral dominance has no significant effect on the three ratios examined.
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Abstract
A new method of typing Candida albicans based on immunoblotting is described. Isolates were disrupted by a mixture of enzymic pretreatment with alpha-mannosidase followed by sonication. They were then stained using a modified ELISA system by a rabbit hyperimmune serum raised against a single isolate, C. albicans NCTC 3153. The 190 isolates examined from the London Hospital produced 16 different types. Type 1 accounted for 43% of the isolates and was the commonest type outside the intensive care unit. Type 2 caused an outbreak of systemic candidosis on the intensive care unit. The technique was much more sensitive than the serotyping and morphotyping methods and lacked the phenotypic variability of the biotyping procedure previously used to define the outbreak. The gel-to-gel variation precludes its use in large scale epidemiological work. Its value lies in identification of outbreaks so that they can be controlled by the introduction of measures to prevent cross-infection.
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Burnie J, Brodie DA. Velocity characteristics of an hydraulic weight training system. Br J Sports Med 1986; 20:132-4. [PMID: 3779342 PMCID: PMC1478350 DOI: 10.1136/bjsm.20.3.132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Abstract
Eighteen preadolescent males (mean age 11.4 +/- 0.59 years) performed 15 knee flexion-extension repetitions on both legs. Peak torque (T peak) and torque acceleration energy (TAE) were measured using the Cybex II Isokinetic system, which permitted a study of the effect of limb velocity on T peak, TAE, and reciprocal muscle group ratios. The effect of limb dominance was also assessed. The results indicated (Student's t test) that an increase in limb velocity from 1.05 rad/s to 4.2 rad/s produced a significant decrease in the T peak generated (P less than 0.001). A similar increase in limb velocity resulted in a significant increase in the TAE recorded (P less than 0.001). The limb velocity was also shown to influence the T peak and TAE ratios in reciprocal muscle groups. At a limb velocity 1.05 rad/s mean T peak ratios of 0.64 and 0.66 were recorded for the dominant and nondominant limbs, respectively. At 4.2 rad/s, ratios recorded for dominant and non-dominant limbs were 0.79 and 0.80, respectively. The limb velocity of 1.05 rad/s produced TAE ratios of 0.21 (dominant) and 0.14 (nondominant), and at 4.2 rad/s, ratios of 0.28 and 0.24 were recorded for dominant and non-dominant limbs, respectively. No significant difference (P less than 0.001) was observed between T peak and TAE values recorded for the dominant and non-dominant limbs under the same conditions. These results indicate that young boys show velocity-related isokinetic strength characteristics similar to adults. Although they have lower absolute levels, the children showed typical adult reciprocal muscle group ratios. Limb dominance at this age is not reflected in strength differences.
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Abstract
A new reverse passive latex agglutination test for the detection of serum antigen in systemic Candida albicans infection is reported. 1700 sera were examined from 91 patients who had either proven or suspected systemic candidosis, 183 patients who were colonized and 636 patients with no evidence of candidal infection. Thirty of the systemically infected patients had lymphoproliferative disorders and the rest a variety of surgical or medical diseases with no underlying neutropenia. The latex particles were sensitised with an antiserum raised in rabbits against a pressate of Candida albicans. The degree of antigenaemia was proportional to the likelihood of invasive disease such that a diagnostic cut-off point of 1 in 8 produced a test for systemic candidosis with a sensitivity of 90% and specificity of 80.4% in patients with lymphoproliferative disorders. In the remaining medical and surgical patients a diagnostic cut-off point of 1 in 10 produced a test with a sensitivity of 96.7% and specificity of 98.8%. The patients with lymphoproliferative disorders tended to produce lower serum antigen levels. The sera were also assayed for antibody using latex particles sensitised with pressate.
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Noble BJ, Brodie DA, Burnie J. PERCEPTION OF ISOKINETIC MUSCLE TENSION. Med Sci Sports Exerc 1985. [DOI: 10.1249/00005768-198504000-00074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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