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Abstract
Acquired immunodeficiency syndrome (AIDS) was first reported more than 30 years ago among homosexuals in the United States. The epidemiology of this disease indicates that there are three modes of transmission: Blood, mother-to-child, and sexual contact transmission. The pathogen of AIDS is human immunodeficiency virus (HIV), primarily HIV-1. HIV-1 could not break through the structurally and functionally integral skin, and primarily invades the human body through the mucosa irrespective of their integrity. Therefore, the mucosae are the natural transmission routes for HIV-1. The mucosae involved in HIV-1 transmission include the mucosae of the gastrointestinal tract and the urogenital tract. The risks of HIV-1 transmission vary significantly between mucosal sites and individuals, and are associated with mucosal integrity, abundance of target cells, immune status of the host, commensal microbes, and host genetic background. Many factors are closely related to the barrier function of the mucosa, and studies on their roles in HIV-1 invasion could promote the prevention and control of mucosal transmission of HIV-1.
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Affiliation(s)
- Gui-Bo Yang
- National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
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2
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Johnson J, Flores MG, Rosa J, Han C, Salvi AM, DeMali KA, Jagnow JR, Sparks A, Haim H. The High Content of Fructose in Human Semen Competitively Inhibits Broad and Potent Antivirals That Target High-Mannose Glycans. J Virol 2020; 94:e01749-19. [PMID: 32102878 PMCID: PMC7163146 DOI: 10.1128/jvi.01749-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 02/17/2020] [Indexed: 11/20/2022] Open
Abstract
Semen is the primary transmission vehicle for various pathogenic viruses. Initial steps of transmission, including cell attachment and entry, likely occur in the presence of semen. However, the unstable nature of human seminal plasma and its toxic effects on cells in culture limit the ability to study in vitro virus infection and inhibition in this medium. We found that whole semen significantly reduces the potency of antibodies and microbicides that target glycans on the envelope glycoproteins (Envs) of HIV-1. The extraordinarily high concentration of the monosaccharide fructose in semen contributes significantly to the effect by competitively inhibiting the binding of ligands to α1,2-linked mannose residues on Env. Infection and inhibition in whole human seminal plasma are accurately mimicked by a stable synthetic simulant of seminal fluid that we formulated. Our findings indicate that, in addition to the protein content of biological secretions, their small-solute composition impacts the potency of antiviral microbicides and mucosal antibodies.IMPORTANCE Biological secretions allow viruses to spread between individuals. Each type of secretion has a unique composition of proteins, salts, and sugars, which can affect the infectivity potential of the virus and inhibition of this process. Here, we describe HIV-1 infection and inhibition in whole human seminal plasma and a synthetic simulant that we formulated. We discovered that the sugar fructose in semen decreases the activity of a broad and potent class of antiviral agents that target mannose sugars on the envelope protein of HIV-1. This effect of semen fructose likely reduces the efficacy of such inhibitors to prevent the sexual transmission of HIV-1. Our findings suggest that the preclinical evaluation of microbicides and vaccine-elicited antibodies will be improved by their in vitro assessment in synthetic formulations that simulate the effects of semen on HIV-1 infection and inhibition.
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Affiliation(s)
- Jacklyn Johnson
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Manuel G Flores
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - John Rosa
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Changze Han
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Alicia M Salvi
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Kris A DeMali
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Jennifer R Jagnow
- In Vitro Fertilization and Reproductive Testing Laboratory, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Amy Sparks
- In Vitro Fertilization and Reproductive Testing Laboratory, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Hillel Haim
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
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3
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Le Tortorec A, Matusali G, Mahé D, Aubry F, Mazaud-Guittot S, Houzet L, Dejucq-Rainsford N. From Ancient to Emerging Infections: The Odyssey of Viruses in the Male Genital Tract. Physiol Rev 2020; 100:1349-1414. [PMID: 32031468 DOI: 10.1152/physrev.00021.2019] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The male genital tract (MGT) is the target of a number of viral infections that can have deleterious consequences at the individual, offspring, and population levels. These consequences include infertility, cancers of male organs, transmission to the embryo/fetal development abnormalities, and sexual dissemination of major viral pathogens such as human immunodeficiency virus (HIV) and hepatitis B virus. Lately, two emerging viruses, Zika and Ebola, have additionally revealed that the human MGT can constitute a reservoir for viruses cleared from peripheral circulation by the immune system, leading to their sexual transmission by cured men. This represents a concern for future epidemics and further underlines the need for a better understanding of the interplay between viruses and the MGT. We review here how viruses, from ancient viruses that integrated the germline during evolution through old viruses (e.g., papillomaviruses originating from Neanderthals) and more modern sexually transmitted infections (e.g., simian zoonotic HIV) to emerging viruses (e.g., Ebola and Zika) take advantage of genital tract colonization for horizontal dissemination, viral persistence, vertical transmission, and endogenization. The MGT immune responses to viruses and the impact of these infections are discussed. We summarize the latest data regarding the sources of viruses in semen and the complex role of this body fluid in sexual transmission. Finally, we introduce key animal findings that are relevant for our understanding of viral infection and persistence in the human MGT and suggest future research directions.
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Affiliation(s)
- Anna Le Tortorec
- University of Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail)-UMR_S1085, Rennes, France
| | - Giulia Matusali
- University of Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail)-UMR_S1085, Rennes, France
| | - Dominique Mahé
- University of Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail)-UMR_S1085, Rennes, France
| | - Florence Aubry
- University of Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail)-UMR_S1085, Rennes, France
| | - Séverine Mazaud-Guittot
- University of Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail)-UMR_S1085, Rennes, France
| | - Laurent Houzet
- University of Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail)-UMR_S1085, Rennes, France
| | - Nathalie Dejucq-Rainsford
- University of Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail)-UMR_S1085, Rennes, France
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4
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Abdulhaqq SA, Martinez M, Kang G, Rodriguez IV, Nichols SM, Beaumont D, Joseph J, Azzoni L, Yin X, Wise M, Weiner D, Liu Q, Foulkes A, Münch J, Kirchhoff F, Coutifaris C, Tomaras GD, Sariol C, Marx PA, Li Q, Kraiselburd EN, Montaner LJ. Repeated semen exposure decreases cervicovaginal SIVmac251 infection in rhesus macaques. Nat Commun 2019; 10:3753. [PMID: 31434895 PMCID: PMC6704120 DOI: 10.1038/s41467-019-11814-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Accepted: 08/02/2019] [Indexed: 01/23/2023] Open
Abstract
Semen is the vehicle for virion dissemination in the female reproductive tract (FRT) in male-to-female HIV transmission. Recent data suggests that higher frequency semen exposure is associated with activation of anti-HIV mechanisms in HIV negative sex workers. Here, we use a non-human primate (NHP) model to show that repeated vaginal exposure to semen significantly reduces subsequent infection by repeated low-dose vaginal SIVmac251 challenge. Repeated semen exposures result in lower CCR5 expression in circulating CD4+ T-cells, as well as higher expression of Mx1 (in correlation with IFNε expression) and FoxP3 in the cervicovaginal mucosa, and increased infiltration of CD4+ T-cells. Establishing in vivo evidence of competing effects of semen on transmission impacts our basic understanding of what factors may determine HIV infectivity in humans. Our results clearly indicate that repeated semen exposure can profoundly modulate the FRT microenvironment, paradoxically promoting host resistance against HIV acquisition.
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Affiliation(s)
| | - Melween Martinez
- Caribbean Primate Research Center and Animal Resources Center, University of Puerto Rico (UPR), San Juan, United States
| | - Guobin Kang
- School of Biological Sciences University of Nebraska, Lincoln, NE, USA
| | - Idia V Rodriguez
- Caribbean Primate Research Center and Animal Resources Center, University of Puerto Rico (UPR), San Juan, United States
| | - Stephanie M Nichols
- Caribbean Primate Research Center and Animal Resources Center, University of Puerto Rico (UPR), San Juan, United States
| | - David Beaumont
- Duke Human Vaccine Institute and Department of Surgery, Immunology and Molecular Genetics and Microbiology, Duke University, Durham, NC, USA
| | | | | | | | - Megan Wise
- The Wistar Institute, Philadelphia, PA, USA
| | | | - Qin Liu
- The Wistar Institute, Philadelphia, PA, USA
| | | | - Jan Münch
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | | | - Georgia D Tomaras
- Duke Human Vaccine Institute and Department of Surgery, Immunology and Molecular Genetics and Microbiology, Duke University, Durham, NC, USA
| | - Carlos Sariol
- Caribbean Primate Research Center and Animal Resources Center, University of Puerto Rico (UPR), San Juan, United States
| | - Preston A Marx
- Tulane National Primate Research Center, and Department of Tropical Medicine, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, USA
| | - Qingsheng Li
- School of Biological Sciences University of Nebraska, Lincoln, NE, USA
| | - Edmundo N Kraiselburd
- Caribbean Primate Research Center and Animal Resources Center, University of Puerto Rico (UPR), San Juan, United States
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5
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Kordy K, Tobin NH, Aldrovandi GM. HIV and SIV in Body Fluids: From Breast Milk to the Genitourinary Tract. ACTA ACUST UNITED AC 2019; 15:139-152. [PMID: 33312088 DOI: 10.2174/1573395514666180605085313] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
HIV-1 is present in many secretions including oral, intestinal, genital, and breast milk. However, most people exposed to HIV-1 within these mucosal compartments do not become infected despite often frequent and repetitive exposure over prolonged periods of time. In this review, we discuss what is known about the levels of cell-free HIV RNA, cell-associated HIV DNA and cell-associated HIV RNA in external secretions. Levels of virus are usually lower than contemporaneously obtained blood, increased in settings of inflammation and infection, and decreased in response to antiretroviral therapy. Additionally, each mucosal compartment has unique innate and adaptive immune responses that affect the composition and presence of HIV-1 within each external secretion. We discuss the current state of knowledge about the types and amounts of virus present in the various excretions, touch on innate and adaptive immune responses as they affect viral levels, and highlight important areas for further study.
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Affiliation(s)
- Kattayoun Kordy
- Department of Pediatrics, Keck School of Medicine at the University of Southern California, Los Angeles, CA, USA
| | - Nicole H Tobin
- Department of Pediatrics, David Geffen School of Medicine at the University of California, Los Angeles, CA, USA
| | - Grace M Aldrovandi
- Department of Pediatrics, David Geffen School of Medicine at the University of California, Los Angeles, CA, USA
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6
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Röcker A, Roan NR, Yadav JK, Fändrich M, Münch J. Structure, function and antagonism of semen amyloids. Chem Commun (Camb) 2018; 54:7557-7569. [PMID: 29873340 DOI: 10.1039/c8cc01491d] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Amyloid fibrils are linear polypeptide aggregates with a cross-β structure. These fibrils are best known for their association with neurodegenerative diseases, such as Alzheimer's or Parkinson's, but they may also be used by living organisms as functional units, e.g. in the synthesis of melanin or in the formation of bacterial biofilms. About a decade ago, in a search for semen factors that modulate infection by HIV-1 (a sexually transmitted virus and the causative agent of the acquired immune deficiency syndrome (AIDS)), it was demonstrated that semen harbors amyloid fibrils capable of markedly increasing HIV infection rates. This discovery not only created novel opportunities to prevent sexual HIV-1 transmission but also stimulated research to unravel the natural role of these factors. We discuss here the identification of these intriguing structures, their molecular properties, and their effects on both sexually transmitted diseases and reproductive health. Moreover, we review strategies to antagonize semen amyloid to prevent sexual transmission of viruses.
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Affiliation(s)
- Annika Röcker
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany.
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7
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Abstract
The 2014 western Africa Ebola virus (EBOV) epidemic was unprecedented in magnitude, infecting over 28,000 and causing over 11,000 deaths. During this outbreak, multiple instances of EBOV sexual transmission were reported, including cases where the infectious individual had recovered from EBOV disease months before transmission. Potential human host factors in EBOV sexual transmission remain unstudied. Several basic seminal amyloids, most notably semen-derived enhancer of viral infection (SEVI), enhance in vitro infection by HIV and several other viruses. To test the ability of these peptides to enhance EBOV infection, viruses bearing the EBOV glycoprotein (EboGP) were preincubated with physiological concentrations of SEVI before infection of physiologically relevant cell lines and primary cells. Preincubation with SEVI significantly increased EboGP-mediated infectivity and replication in epithelium- and monocyte-derived cell lines. This enhancement was dependent upon amyloidogenesis and positive charge, and infection results were observed with both viruses carrying EboGP and authentic EBOV as well as with semen. SEVI enhanced binding of virus to cells and markedly increased its subsequent internalization. SEVI also stimulated uptake of a fluid phase marker by macropinocytosis, a critical mechanism by which cells internalize EBOV. We report a previously unrecognized ability of SEVI and semen to significantly alter viral physical properties critical for transmissibility by increasing the stability of EboGP-bearing recombinant viruses during incubation at elevated temperature and providing resistance to desiccation. Given the potential for EBOV sexual transmission to spark new transmission chains, these findings represent an important interrogation of factors potentially important for this EBOV transmission route.
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8
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Kordy K, Elliott J, Tanner K, Johnson EJ, McGowan IM, Anton PA. Human Semen or Seminal Plasma Does Not Enhance HIV-1 BaL Ex Vivo Infection of Human Colonic Explants. AIDS Res Hum Retroviruses 2018; 34:459-466. [PMID: 29343073 PMCID: PMC5934974 DOI: 10.1089/aid.2017.0118] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
To determine whether human whole semen (WS) and seminal plasma (SP) either previously frozen or freshly acquired altered ex vivo infectibility of human colonic explants or was associated with histology or toxicity changes, which may influence mucosal HIV-1 transmission in vivo. Pooled human semen samples were freshly obtained from study volunteers (never frozen) and from commercial sources (frozen/thawed). Endoscopically acquired rectal biopsies were evaluated for toxicity following titered ex vivo WS/SP exposure by histological grading and by MTT assay. The ex vivo HIV-1 biopsy challenge model was used to evaluate effects of exposure to either previously frozen or freshly acquired WS/SP on HIVBaL infectibility at a range of viral inocula (104-100 TCID50). To evaluate the effects at lower viral inocula of HIV-1 (10-2-102), experiments in the presence or absence of WS/SP were also performed utilizing TZM-bl cells. MTT assays and histological scoring demonstrated no tissue degradation of biopsies when exposed for 2 h to concentrations of 10% or 100% of either fresh or previously frozen WS/SP. Ex vivo biopsy HIV-1 challenge experiments showed no differences in the presence of freshly acquired or previously frozen/thawed WS/SP compared with control; no differences were seen with lower infectious titers on TZM-bl cells. Within the limits of assay sensitivity and variability, these data show no toxicity or significant enhancement of HIV-1 infectibility of human rectal mucosa using the colorectal explant model with either pooled fresh or frozen/thawed nonautologous human semen.
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Affiliation(s)
| | - Julie Elliott
- Department of Medicine, Center for HIV Prevention Research, UCLA AIDS Institute, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Karen Tanner
- Department of Medicine, Center for HIV Prevention Research, UCLA AIDS Institute, David Geffen School of Medicine at UCLA, Los Angeles, California
| | | | - Ian M. McGowan
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Peter A. Anton
- Department of Medicine, Center for HIV Prevention Research, UCLA AIDS Institute, David Geffen School of Medicine at UCLA, Los Angeles, California
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9
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Chen J, Ren R, Yu F, Wang C, Zhang X, Li W, Tan S, Jiang S, Liu S, Li L. A Degraded Fragment of HIV-1 Gp120 in Rat Hepatocytes Forms Fibrils and Enhances HIV-1 Infection. Biophys J 2017; 113:1425-1439. [PMID: 28978437 DOI: 10.1016/j.bpj.2017.08.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 07/03/2017] [Accepted: 08/04/2017] [Indexed: 12/26/2022] Open
Abstract
Identification of the host or viral factors that enhance HIV infection is critical for preventing sexual transmission of HIV. Amyloid fibrils derived from human semen, including semen-derived enhancer of virus infection and semenogelins, enhance HIV-1 infection dramatically in vitro. In this study, we reported that a short-degraded peptide fragment 1 (DPF1) derived from native HIV-1 envelope protein gp120-loaded rat hepatocytes, formed fibrils by self-assembly and thus enhanced HIV-1 infection by promoting the binding of HIV-1 to target cells. Furthermore, DPF1-formed fibrils might be used as a crossing seed to accelerate the formation of semen-derived enhancer of virus infection and semenogelin fibrils. It will be helpful to clarify the viral factors that affect HIV-1 infection. DPF1 as an analog of gp120 containing the critical residues for CD4 binding might be useful for designing of HIV vaccines and developing HIV entry inhibitors.
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Affiliation(s)
- Jinquan Chen
- Guangdong Provincial Key Laboratory of New Drug Screening, Guangzhou Key Laboratory of Drug Research for Emerging Virus Prevention and Treatment, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China; Jiangsu Protein Drug Engineering Laboratory, Jiangsu Food and Pharmaceutical Science College, Huai'an, China
| | - Ruxia Ren
- Guangdong Provincial Key Laboratory of New Drug Screening, Guangzhou Key Laboratory of Drug Research for Emerging Virus Prevention and Treatment, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Fei Yu
- College of Life Sciences, Agricultural University of Hebei, Baoding, China; Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Chunyan Wang
- Center for Clinical Laboratory, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xuanxuan Zhang
- Guangdong Provincial Key Laboratory of New Drug Screening, Guangzhou Key Laboratory of Drug Research for Emerging Virus Prevention and Treatment, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Wenjuan Li
- Guangdong Provincial Key Laboratory of New Drug Screening, Guangzhou Key Laboratory of Drug Research for Emerging Virus Prevention and Treatment, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Suiyi Tan
- Guangdong Provincial Key Laboratory of New Drug Screening, Guangzhou Key Laboratory of Drug Research for Emerging Virus Prevention and Treatment, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Shibo Jiang
- Key Laboratory of Medical Molecular Virology of MOE/MOH, School of Basic Medical Sciences, Fudan University, Shanghai, China; Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York
| | - Shuwen Liu
- Guangdong Provincial Key Laboratory of New Drug Screening, Guangzhou Key Laboratory of Drug Research for Emerging Virus Prevention and Treatment, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China.
| | - Lin Li
- Guangdong Provincial Key Laboratory of New Drug Screening, Guangzhou Key Laboratory of Drug Research for Emerging Virus Prevention and Treatment, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China.
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10
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Sheik DA, Dewhurst S, Yang J. Natural Seminal Amyloids as Targets for Development of Synthetic Inhibitors of HIV Transmission. Acc Chem Res 2017; 50:2159-2166. [PMID: 28809479 DOI: 10.1021/acs.accounts.7b00154] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Amyloids refer to a class of protein or peptide aggregates that are heterogeneous in size, morphology, and composition, and are implicated to play a central role in many neurodegenerative and systemic diseases. The strong correlation between biological activity and extent of aggregation of amyloidogenic proteins and peptides has led to an explosion of research efforts to target these materials with synthetic molecules or engineered antibodies to try to attenuate their function in disease pathology. Although many of these efforts to attenuate amyloid function have shown great promise in laboratory settings, the vast majority of work has been focused on targeting amyloids associated with neurologic diseases, which has been met with significant additional challenges that preclude clinical evaluation. Only recently have researchers started applying their efforts toward neutralizing the activity of amyloids associated with non-neurologic diseases. For instance, small peptides present in high abundance in human semen have been found to aggregate into amyloid-like fibrils, with in vitro experiments indicating that these amyloid fibrils could potentially increase the rate of infection of pathogens such as HIV by over 400 000-fold during sexual contact. Mechanistic investigations of naturally occurring seminal amyloid species such as Semen-derived Enhancer of Virus Infection (SEVI) and related natural peptide aggregates suggest that these materials interact strongly with virus particles and cell surfaces, facilitating viral attachment and internalization into cells and, thus, possibly promoting sexual transmission of disease. Such amyloid mediators in HIV transmission represent an attractive target for development of chemical approaches to attenuate their biological activity. For instance, the activity of seminal amyloids in genital fluids potentially allows for topical delivery of amyloid-targeting molecules, which could minimize common problems with systemic toxicity or permeability across biological barriers. In addition, molecules that target these amyloid mediators in viral attachment could potentially work synergistically with current antiviral agents to reduce the rate of HIV transmission. This Account will briefly summarize some of the key evidence in support of the capability of SEVI to enhance viral infection, and will highlight examples, many from our group, of recent efforts aimed at inhibiting its activity using synthetic small molecules, oligomeric peptides, and polymeric materials. We present various chemical strategies that have shown promise for neutralizing the role of SEVI in HIV transmission including the development of aggregation inhibitors of SEVI fibril formation, small molecule amyloid binders that modulate the charge or structure of SEVI, and synthetic molecules that form bioresistive coatings on SEVI and inhibit its interaction with the virus or cell surface. We discuss some unique challenges that hamper translation of these molecular strategies toward clinical evaluation, and propose several opportunities for researchers to address these challenges.
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Affiliation(s)
- Daniel A. Sheik
- Department
of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0358, United States
| | - Stephen Dewhurst
- Department
of Microbiology and Immunology, University of Rochester, Rochester, New York 14642, United States
| | - Jerry Yang
- Department
of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0358, United States
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11
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Zika virus preferentially replicates in the female reproductive tract after vaginal inoculation of rhesus macaques. PLoS Pathog 2017; 13:e1006537. [PMID: 28746373 PMCID: PMC5546709 DOI: 10.1371/journal.ppat.1006537] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 08/07/2017] [Accepted: 07/17/2017] [Indexed: 01/18/2023] Open
Abstract
Zika virus (ZIKV) is a mosquito-transmitted virus that can cause severe defects in an infected fetus. ZIKV is also transmitted by sexual contact, although the relative importance of sexual transmission is unclear. To better understand the role of sexual transmission in ZIKV pathogenesis, a nonhuman primate (NHP) model of vaginal transmission was developed. ZIKV was readily transmitted to mature cycling female rhesus macaque (RM) by vaginal inoculation with 104–106 plaque-forming units (PFU). However, there was variability in susceptibility between the individual RM with 1–>8 vaginal inoculations required to establish infection. After treatment with Depoprovera, a widely used contraceptive progestin, two RM that initially resisted 8 vaginal ZIKV inoculations became infected after one ZIKV inoculation. Thus, Depoprovera seemed to enhance susceptibility to vaginal ZIKV transmission. Unexpectedly, the kinetics of virus replication and dissemination after intravaginal ZIKV inoculation were markedly different from RM infected with ZIKV by subcutaneous (SQ) virus inoculation. Several groups have reported that after SQ ZIKV inoculation vRNA is rapidly detected in blood plasma with vRNA less common in urine and saliva and only rarely detected in female reproductive tract (FRT) secretions. In contrast, in vaginally inoculated RM, plasma vRNA is delayed for several days and ZIKV replication in, and vRNA shedding from, the FRT was found in all 6 animals. Further, after intravaginal transmission ZIKV RNA shedding from FRT secretions was detected before or simultaneously with plasma vRNA, and persisted for at least as long. Thus, ZIKV replication in the FRT was independent of, and often preceded virus replication in the tissues contributing to plasma vRNA. These results support the conclusion that ZIKV preferentially replicates in the FRT after vaginal transmission, but not after SQ transmission, and raise the possibility that there is enhanced fetal infection and pathology after vaginal ZIKV transmission compared to a mosquito transmitted ZIKV. Zika virus was introduced to Brazil in 2015 and it rapidly spread to all of tropical America. Although Zika virus infection is usually mild in adults, it can cause severe birth defects in the developing fetus that makes it critical to prevent ZIKV infection in women who are pregnant or who could become pregnant. Although Zika virus is transmitted primarily by mosquito bite, it can also be transmitted by sex. To understand the role of sexual transmission in Zika virus disease, we inoculated rhesus monkeys intravaginally with the virus and monitored virus in blood and reproductive tract secretions. ZIKV was detected in the female reproductive tract before it was detected in plasma and replication levels in the female reproductive tract did not reflect ZIKV levels in other parts of the body. Thus ZIKV prefers the reproductive tract after vaginal transmission suggesting that fetal disease could be more common or severe after vaginal ZIKV transmission compared to a mosquito transmitted ZIKV infection.
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12
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Epigallocatechin Gallate Inhibits Macaque SEVI-Mediated Enhancement of SIV or SHIV Infection. J Acquir Immune Defic Syndr 2017; 75:232-240. [PMID: 28328549 DOI: 10.1097/qai.0000000000001361] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Human semen contains a factor that can enhance HIV infection up to 10-fold in cultures. This factor is termed semen-derived enhancer of virus infection (SEVI) and is composed of proteolytic fragments (PAP248-286) from prostatic acid phosphatase in semen. In this study, we examined whether macaque SEVI can facilitate simian immunodeficiency virus (SIV) or chimeric simian/human immunodeficiency virus (SHIV) infection. We also studied the effect of epigallocatechin gallate (EGCG) on macaque SEVI-mediated SIV or SHIV enhancement. METHODS SIV or SHIV was mixed with different concentrations of macaque SEVI in the presence or absence of EGCG. The mixture was added to cultures of TZM-bl cells or macaque PBMCs. The effect of EGCG on macaque SEVI was measured by Congo-red staining assay and thioflavin T (ThT) fluorescence assay and was visualized by a transmission electron microscope. RESULTS We identified that there is one amino acid difference at the site of 277 between human PAP248-286 and macaque PAP248-286. Macaque SEVI significantly enhanced SIV or SHIV infection of TZM-bl cells and macaque PBMCs. EGCG could block macaque SEVI-mediated enhancement of SIV or SHIV infection. Mechanistically, EGCG could degrade the formation of macaque SEVI amyloid fibrils that facilitates HIV attachment to the target cells. CONCLUSIONS The finding that macaque SEVI could enhance SIV or SHIV infection indicates the possibility to use the macaque SEVI in vivo studies with the macaque models. In addition, future studies are necessary to examine whether EGCG can be used as an effective microbicide for preventing SIV or SHIV mucosal transmission.
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13
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HIV-Enhancing and HIV-Inhibiting Properties of Cationic Peptides and Proteins. Viruses 2017; 9:v9050108. [PMID: 28505117 PMCID: PMC5454421 DOI: 10.3390/v9050108] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 05/05/2017] [Accepted: 05/10/2017] [Indexed: 12/26/2022] Open
Abstract
Cationic antimicrobial peptides and proteins have historically been ascribed roles in innate immunity that infer killing of microbial and viral pathogens and protection of the host. In the context of sexually transmitted HIV-1, we take an unconventional approach that questions this paradigm. It is becoming increasingly apparent that many of the cationic polypeptides present in the human genital or anorectal mucosa, or human semen, are capable of enhancing HIV-1 infection, often in addition to other reported roles as viral inhibitors. We explore how the in vivo environment may select for or against the HIV-enhancing aspects of these cationic polypeptides by focusing on biological relevance. We stress that the distinction between enhancing and inhibiting HIV-1 infection is not mutually exclusive to specific classes of cationic polypeptides. Understanding how virally enhancing peptides and proteins act to promote sexual transmission of HIV-1 would be important for the design of topical microbicides, mucosal vaccines, and other preventative measures.
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14
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Introini A, Boström S, Bradley F, Gibbs A, Glaessgen A, Tjernlund A, Broliden K. Seminal plasma induces inflammation and enhances HIV-1 replication in human cervical tissue explants. PLoS Pathog 2017; 13:e1006402. [PMID: 28542587 PMCID: PMC5453613 DOI: 10.1371/journal.ppat.1006402] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 06/01/2017] [Accepted: 05/06/2017] [Indexed: 12/16/2022] Open
Abstract
The most immediate and evident effect of mucosal exposure to semen in vivo is a local release of proinflammatory mediators accompanied by an influx of leukocytes into the female genital mucosa (FGM). The implication of such response in HIV-1 transmission has never been addressed due to limitations of currently available experimental models. Using human tissue explants from the uterine cervix, we developed a system of mucosal exposure to seminal plasma (SP) that supports HIV-1 replication. Treatment of ectocervical explants with SP resulted in the upregulation of inflammatory and growth factors, including IL-6, TNF, CCL5, CCL20, CXCL1, and CXCL8, and IL1A, CSF2, IL7, PTGS2, as evaluated by measuring protein levels in explant conditioned medium (ECM) and gene expression in tissue. SP treatment was also associated with increased recruitment of monocytes and neutrophils, as observed upon incubation of peripheral blood leukocytes with ECM in a transwell system. To evaluate the impact of the SP-mediated response on local susceptibility to HIV-1, we infected ectocervical explants with the CCR5-tropic variant HIV-1BaL either in the presence of SP, or after explant pre-incubation with SP. In both experimental settings SP enhanced virus replication as evaluated by HIV-1 p24gag released in explant culture medium over time, as well as by HIV-1 DNA quantification in explants infected in the presence of SP. These results suggest that a sustained inflammatory response elicited by SP soon after coitus may promote HIV-1 transmission to the FGM. Nevertheless, ectocervical tissue explants did not support the replication of transmitted/founder HIV-1 molecular clones, regardless of SP treatment. Our system offers experimental and analytical advantages over traditional models of HIV-1 transmission for the study of SP immunoregulatory effect on the FGM, and may provide a useful platform to ultimately identify new determinants of HIV-1 infection at this site.
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Affiliation(s)
- Andrea Introini
- Unit of Infectious Diseases, Center for Molecular Medicine, Department of Medicine Solna, Karolinska University Hospital Solna, Karolinska Institutet, Stockholm, Sweden
| | - Stéphanie Boström
- Unit of Infectious Diseases, Center for Molecular Medicine, Department of Medicine Solna, Karolinska University Hospital Solna, Karolinska Institutet, Stockholm, Sweden
| | - Frideborg Bradley
- Unit of Infectious Diseases, Center for Molecular Medicine, Department of Medicine Solna, Karolinska University Hospital Solna, Karolinska Institutet, Stockholm, Sweden
| | - Anna Gibbs
- Unit of Infectious Diseases, Center for Molecular Medicine, Department of Medicine Solna, Karolinska University Hospital Solna, Karolinska Institutet, Stockholm, Sweden
| | - Axel Glaessgen
- Department of Clinical Pathology and Cytology, Unilabs AB, Capio St Göran Hospital, Stockholm, Sweden
| | - Annelie Tjernlund
- Unit of Infectious Diseases, Center for Molecular Medicine, Department of Medicine Solna, Karolinska University Hospital Solna, Karolinska Institutet, Stockholm, Sweden
| | - Kristina Broliden
- Unit of Infectious Diseases, Center for Molecular Medicine, Department of Medicine Solna, Karolinska University Hospital Solna, Karolinska Institutet, Stockholm, Sweden
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15
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16
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Abstract
Amyloid formation has been most studied in the context of neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease, as well as in amyloidosis. However, it is becoming increasingly clear that amyloid is also present in the healthy setting; for example nontoxic amyloid formation is important for melanin synthesis and in innate immunity. Furthermore, bacteria have mechanisms to produce functional amyloid structures with important roles in bacterial physiology and interaction with host cells. Here, we will discuss some novel aspects of fibril-forming proteins in humans and bacteria. First, the amyloid-forming properties of the antimicrobial peptide human defensin 6 (HD6) will be considered. Intriguingly, unlike other antimicrobial peptides, HD6 does not kill bacteria. However, recent data show that HD6 can form amyloid structures at the gut mucosa with strong affinity for bacterial surfaces. These so-called nanonets block bacterial invasion by entangling the bacteria in net-like structures. Next, the role of functional amyloid fibrils in human semen will be discussed. These fibrils were discovered through their property to enhance HIV infection but they may also have other yet unknown functions. Finally, the role of amyloid formation in bacteria will be reviewed. The recent finding that bacteria can make amyloid in a controlled fashion without toxic effects is of particular interest and may have implications for human disease. The role of amyloid in health and disease is beginning to be unravelled, and here, we will review some of the most recent findings in this exciting area.
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Affiliation(s)
- P Bergman
- Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - N R Roan
- Department of Urology, University of California, San Francisco, CA, USA.,The J. David Gladstone Institutes, San Francisco, CA, USA
| | - U Römling
- Department of Microbiology, Tumor and Cellbiology, Karolinska Institutet, Stockholm, Sweden
| | - C L Bevins
- Department of Microbiology and Immunology, School of Medicine, University of California, Davis, CA, USA
| | - J Münch
- Institute of Molecular Virology, Ulm University Medical Centre, Ulm, Germany.,Ulm Peptide Pharmaceuticals, Ulm University, Ulm, Germany
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17
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Abdulhaqq SA, Zorrilla C, Kang G, Yin X, Tamayo V, Seaton KE, Joseph J, Garced S, Tomaras GD, Linn KA, Foulkes AS, Azzoni L, VerMilyea M, Coutifaris C, Kossenkov AV, Showe L, Kraiselburd EN, Li Q, Montaner LJ. HIV-1-negative female sex workers sustain high cervical IFNɛ, low immune activation, and low expression of HIV-1-required host genes. Mucosal Immunol 2016; 9:1027-38. [PMID: 26555708 PMCID: PMC4864149 DOI: 10.1038/mi.2015.116] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Accepted: 09/30/2015] [Indexed: 02/04/2023]
Abstract
Sex workers practicing in high HIV endemic areas have been extensively targeted to test anti-HIV prophylactic strategies. We hypothesize that in women with high levels of genital exposure to semen changes in cervico-vaginal mucosal and/or systemic immune activation will contribute to a decreased susceptibility to HIV-1 infection. To address this question, we assessed sexual activity and immune activation status (in peripheral blood), as well as cellular infiltrates and gene expression in ectocervical mucosa biopsies in female sex workers (FSWs; n=50), as compared with control women (CG; n=32). FSWs had low-to-absent HIV-1-specific immune responses with significantly lower CD38 expression on circulating CD4(+) or CD8(+) T-cells (both: P<0.001) together with lower cervical gene expression of genes associated with leukocyte homing and chemotaxis. FSWs also had increased levels of interferon-ɛ (IFNɛ) gene and protein expression in the cervical epithelium together with reduced expression of genes associated with HIV-1 integration and replication. A correlative relationship between semen exposure and elevated type-1 IFN expression in FSWs was also established. Overall, our data suggest that long-term condomless sex work can result in multiple changes within the cervico-vaginal compartment that would contribute to sustaining a lower susceptibility for HIV-1 infection in the absence of HIV-specific responses.
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Affiliation(s)
| | - Carmen Zorrilla
- Maternal-Infant Study Center (CEMI), University of Puerto Rico, Medical Sciences Campus, San Juan, PR 00963
| | - Guobin Kang
- University of Nebraska, School of Biological Sciences and Nebraska Center for Virology, Lincoln, NE 68583
| | | | - Vivian Tamayo
- Maternal-Infant Study Center (CEMI), University of Puerto Rico, Medical Sciences Campus, San Juan, PR 00963
| | - Kelly E. Seaton
- Duke Human Vaccine Institute, Duke University, Durham, NC 27710
| | | | - Sheyla Garced
- Maternal-Infant Study Center (CEMI), University of Puerto Rico, Medical Sciences Campus, San Juan, PR 00963
| | | | - Kristin A. Linn
- Department of Biostatistics and Epidemiology University of Pennsylvania Philadelphia, PA 19104
| | - Andrea S. Foulkes
- University of Massachusetts, Division of Biostatistics and Epidemiology, Amherst, MA 01003
| | | | | | | | | | | | | | - Qingsheng Li
- University of Nebraska, School of Biological Sciences and Nebraska Center for Virology, Lincoln, NE 68583
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18
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Abstract
Objectives: Semen composition is influenced by HIV-1 infection, yet the impact of semen components on HIV infection of primary target cells has only been studied in samples from HIV-uninfected donors. Design: We compared the effect of seminal plasma (SP) from chronically HIV-infected (SP+) versus uninfected donors (SP–) on HIV-1 infection of peripheral blood mononuclear cells (PBMCs) and CD4+ T cells. Methods: Primary cells were infected with HIV-1 in the presence of SP+ or SP– and analyzed for infection level, metabolic activity, HIV receptor expression, proliferation and activation. SP+ and SP– were compared for infection-enhancing peptides, cytokines and prostaglandin E2 levels. Results: SP– efficiently enhanced HIV-1 R5 infection of CD4+ T cells, whereas SP+ enhancing activity was significantly reduced. RANTES (CCL5) concentrations were elevated in SP+ relative to SP–, whereas the concentrations of infectivity-enhancing peptides [semen-derived enhancer of viral infection (SEVI), SEM1, SEM2] were similar. CCR5 membrane expression levels were reduced on CD4+ T cells shortly postexposure to SP+ compared with SP– and correlated to R5-tropic HIV-1 infection levels, and CCR5 ligands’ concentrations in semen. SP+ and SP– displayed similar enhancing activity on PBMC infection by X4-tropic HIV-1. Addition/depletion of RANTES (regulated on activation, normal T-cell expressed and secreted) from SPs modulated their effect on PBMC infection by R5-tropic HIV-1. Conclusion: Semen from HIV-infected donors exhibits a significantly reduced enhancing potential on CD4+ T-cell infection by R5-tropic HIV-1 when compared with semen from uninfected donors. Our data indicate that elevated seminal concentrations of RANTES in HIV-infected men can influence the ability of semen to enhance infection.
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19
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Roan NR, Münch J. Improving preclinical models of HIV microbicide efficacy. Trends Microbiol 2016; 23:445-7. [PMID: 26250616 DOI: 10.1016/j.tim.2015.05.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 04/18/2015] [Accepted: 05/01/2015] [Indexed: 01/05/2023]
Abstract
Despite potent in vitro efficacy, most topical microbicides fail to effectively prevent HIV transmission. One reason for clinical failure may be that current microbicide testing does not reflect the environment encountered during sexual virus transmission. We discuss how preclinical microbicide development could be improved by more closely mimicking real-life conditions.
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Affiliation(s)
- Nadia R Roan
- Department of Urology, University of California, San Francisco, San Francisco, CA 94158, USA; Gladstone Institute of Virology and Immunology, San Francisco, CA 94158, USA
| | - Jan Münch
- Institute of Molecular Virology, UPEP, Ulm University Medical Centre, Meyerhofstrasse 1, 89081 Ulm, Germany; Ulm Peptide Pharmaceuticals, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
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20
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Van Dis ES, Moore TC, Lavender KJ, Messer RJ, Keppler OT, Verheyen J, Dittmer U, Hasenkrug KJ. No SEVI-mediated enhancement of rectal HIV-1 transmission of HIV-1 in two humanized mouse cohorts. Virology 2015; 488:88-95. [PMID: 26609939 DOI: 10.1016/j.virol.2015.11.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 10/14/2015] [Accepted: 11/06/2015] [Indexed: 11/28/2022]
Abstract
Amyloid fibrils from semen-derived peptide (SEVI) enhance HIV-1 infectivity in vitro but the ability of SEVI to mediate enhancement of HIV infection in vivo has not been tested. In this study we used immunodeficient mice reconstituted with human immune systems to test for in vivo enhancement of HIV-1 transmission. This mouse model supports mucosal transmission of HIV-1 via the intrarectal route leading to productive infection. In separate experiments with humanized mouse cohorts reconstituted with two different donor immune systems, high dose HIV-1JR-CSF that had been incubated with SEVI amyloid fibrils at physiologically relevant concentrations did not show an increased incidence of infection compared to controls. In addition, SEVI failed to enhance rectal transmission with a reduced concentration of HIV-1. Although we confirmed potent SEVI-mediated enhancement of HIV infectivity in vitro, this model showed no evidence that it plays a role in the much more complex situation of in vivo transmission.
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Affiliation(s)
- Erik S Van Dis
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, MT 59840, USA
| | - Tyler C Moore
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, MT 59840, USA
| | - Kerry J Lavender
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, MT 59840, USA
| | - Ronald J Messer
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, MT 59840, USA
| | - Oliver T Keppler
- Institute of Medical Virology, National Reference Center for Retroviruses, University of Frankfurt, Frankfurt, Germany
| | - Jens Verheyen
- Institute for Virology, University Hospital Essen, University of Duisburg-Essen, 45122 Essen, Germany
| | - Ulf Dittmer
- Institute for Virology, University Hospital Essen, University of Duisburg-Essen, 45122 Essen, Germany
| | - Kim J Hasenkrug
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, MT 59840, USA.
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21
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Lump E, Castellano LM, Meier C, Seeliger J, Erwin N, Sperlich B, Stürzel CM, Usmani S, Hammond RM, von Einem J, Gerold G, Kreppel F, Bravo-Rodriguez K, Pietschmann T, Holmes VM, Palesch D, Zirafi O, Weissman D, Sowislok A, Wettig B, Heid C, Kirchhoff F, Weil T, Klärner FG, Schrader T, Bitan G, Sanchez-Garcia E, Winter R, Shorter J, Münch J. A molecular tweezer antagonizes seminal amyloids and HIV infection. eLife 2015; 4. [PMID: 26284498 PMCID: PMC4536748 DOI: 10.7554/elife.05397] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 07/20/2015] [Indexed: 12/26/2022] Open
Abstract
Semen is the main vector for HIV transmission and contains amyloid fibrils that enhance viral infection. Available microbicides that target viral components have proven largely ineffective in preventing sexual virus transmission. In this study, we establish that CLR01, a ‘molecular tweezer’ specific for lysine and arginine residues, inhibits the formation of infectivity-enhancing seminal amyloids and remodels preformed fibrils. Moreover, CLR01 abrogates semen-mediated enhancement of viral infection by preventing the formation of virion–amyloid complexes and by directly disrupting the membrane integrity of HIV and other enveloped viruses. We establish that CLR01 acts by binding to the target lysine and arginine residues rather than by a non-specific, colloidal mechanism. CLR01 counteracts both host factors that may be important for HIV transmission and the pathogen itself. These combined anti-amyloid and antiviral activities make CLR01 a promising topical microbicide for blocking infection by HIV and other sexually transmitted viruses. DOI:http://dx.doi.org/10.7554/eLife.05397.001 Human Immunodeficiency Virus (HIV) is a sexually transmitted virus that can cause a serious disease that weakens the immune system. The virus is most commonly transmitted between individuals in semen, the male reproductive fluid. Semen contains deposits of protein fragments called amyloid fibrils, which can increase the transmission of HIV by trapping viral particles. This helps the virus to attach to the membranes surrounding human cells, which increases the risk of infection. Therefore, therapies that reduce the levels of amyloid fibrils in semen might be able to reduce the transmission of HIV. Drugs that prevent amyloid formation are already being developed because structurally similar fibrils can also form in the brains of individuals with neurodegenerative diseases. One such molecule—called CLR01—works by binding to particular sites on the proteins that form fibrils in the brain. This inhibits fibril formation and slowly disassembles the fibrils that have already formed. CLR01 physically interacts with these residues in a way that resembles a tweezer. The peptides in the amyloid fibrils in semen also have these sites, which suggests that CLR01 might also disrupt amyloid fibrils from forming in semen. Here Lump and Castellano et al. show that CLR01 can both disrupt fibril formation and remodel fibrils that have already formed. In addition, CLR01 prevents HIV particles from interacting with these fibrils and can displace the virus particles that have already bound to the fibrils. In the presence of CLR01, human cells exposed to semen that contained HIV were less likely to become infected with the virus. Unexpectedly, CLR01 also directly destroys HIV and other enveloped viruses such as HCV or HSV particles by disrupting the membranes that surround the virus. Therefore, Lump and Castellano et al.'s findings reveal that CLR01 has considerable potential to be used as an agent for reducing the transmission of HIV and other sexually transmitted viral diseases. DOI:http://dx.doi.org/10.7554/eLife.05397.002
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Affiliation(s)
- Edina Lump
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Laura M Castellano
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, United States.,Pharmacology Graduate Group, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, United States
| | - Christoph Meier
- Institute of Organic Chemistry III/Macromolecular Chemistry, Ulm University, Ulm, Germany
| | - Janine Seeliger
- Physical Chemistry I-Biophysical Chemistry, Department of Chemistry and Chemical Biology, Technical University of Dortmund, Dortmund, Germany
| | - Nelli Erwin
- Physical Chemistry I-Biophysical Chemistry, Department of Chemistry and Chemical Biology, Technical University of Dortmund, Dortmund, Germany
| | - Benjamin Sperlich
- Physical Chemistry I-Biophysical Chemistry, Department of Chemistry and Chemical Biology, Technical University of Dortmund, Dortmund, Germany
| | - Christina M Stürzel
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Shariq Usmani
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Rebecca M Hammond
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, United States.,Biology Department, Swarthmore College, Swarthmore, United States
| | - Jens von Einem
- Institute of Virology, Ulm University Medical Center, Ulm, Germany
| | - Gisa Gerold
- Institute of Experimental Virology, Twincore, Centre for Experimental and Clinical Infection Research, Hannover, Germany
| | - Florian Kreppel
- Institute of Gene Therapy, Ulm University Medical Center, Ulm, Germany
| | | | - Thomas Pietschmann
- Institute of Experimental Virology, Twincore, Centre for Experimental and Clinical Infection Research, Hannover, Germany
| | - Veronica M Holmes
- Division of Infectious Diseases, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, United States
| | - David Palesch
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Onofrio Zirafi
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Drew Weissman
- Division of Infectious Diseases, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, United States
| | - Andrea Sowislok
- Department of Chemistry, University of Duisburg-Essen, Essen, Germany
| | - Burkhard Wettig
- Department of Chemistry, University of Duisburg-Essen, Essen, Germany
| | - Christian Heid
- Department of Chemistry, University of Duisburg-Essen, Essen, Germany
| | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany.,Ulm-Peptide Pharmaceuticals, Ulm University, Ulm, Germany
| | - Tanja Weil
- Institute of Organic Chemistry III/Macromolecular Chemistry, Ulm University, Ulm, Germany.,Ulm-Peptide Pharmaceuticals, Ulm University, Ulm, Germany
| | | | - Thomas Schrader
- Department of Chemistry, University of Duisburg-Essen, Essen, Germany
| | - Gal Bitan
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, United States.,Brain Research Institute, University of California at Los Angeles, Los Angeles, Los Angeles, United States.,Molecular Biology Institute, University of California, Los Angeles, United States
| | | | - Roland Winter
- Physical Chemistry I-Biophysical Chemistry, Department of Chemistry and Chemical Biology, Technical University of Dortmund, Dortmund, Germany
| | - James Shorter
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, United States.,Pharmacology Graduate Group, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, United States
| | - Jan Münch
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany.,Ulm-Peptide Pharmaceuticals, Ulm University, Ulm, Germany
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22
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Critical Review: Immunomodulation by Seminal Factors and Implications for Male-to-Female HIV-1 Transmission. J Acquir Immune Defic Syndr 2015; 69:131-7. [PMID: 25642971 DOI: 10.1097/qai.0000000000000561] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The role of semen in heterosexual transmission of the HIV-1 has been marginally viewed as an inert vehicle for the delivery of virus. However, studies from the field of reproductive biology have made it clear that seminal fluid is a complex and dynamic medium containing high concentrations of factors that play key roles in modulating the local immune response in the female reproductive tract during fertilization and embryogenesis. It is therefore strongly implied that the same seminal factors responsible for guiding the immune response in reproduction also play a role in male-to-female transmission of HIV-1. To begin to understand how these factors affect male-to-female HIV-1 transmission, multiple studies have comparatively profiled the contents of seminal fluid collected from uninfected and HIV-1-infected men. This review provides an overview of these studies, as well as a discussion of the potential impact of semen on HIV-1 transmission.
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23
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Zirafi O, Kim KA, Roan NR, Kluge SF, Müller JA, Jiang S, Mayer B, Greene WC, Kirchhoff F, Münch J. Semen enhances HIV infectivity and impairs the antiviral efficacy of microbicides. Sci Transl Med 2015; 6:262ra157. [PMID: 25391483 DOI: 10.1126/scitranslmed.3009634] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Topically applied microbicides potently inhibit HIV in vitro but have largely failed to exert protective effects in clinical trials. One possible reason for this discrepancy is that the preclinical testing of microbicides does not faithfully reflect the conditions of HIV sexual transmission. We report that candidate microbicides that target HIV components show greatly reduced antiviral efficacy in the presence of semen, the main vector for HIV transmission. This diminished antiviral activity was dependent on the ability of amyloid fibrils in semen to enhance the infectivity of HIV. Thus, the anti-HIV efficacy of microbicides determined in the absence of semen greatly underestimated the drug concentrations needed to block semen-exposed virus. One notable exception was maraviroc. This HIV entry inhibitor targets the host cell CCR5 co-receptor and was highly active against both untreated and semen-exposed HIV. These data help to explain why microbicides have failed to protect against HIV in clinical trials and suggest that antiviral compounds targeting host factors hold promise for further development. These findings also suggest that the in vitro efficacy of candidate microbicides should be determined in the presence of semen to identify the best candidates for the prevention of HIV sexual transmission.
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Affiliation(s)
- Onofrio Zirafi
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany
| | - Kyeong-Ae Kim
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany
| | - Nadia R Roan
- Gladstone Institute of Virology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA. Department of Urology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Silvia F Kluge
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany
| | - Janis A Müller
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany
| | - Shibo Jiang
- Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY 10065, USA
| | - Benjamin Mayer
- Institute of Epidemiology and Medical Biometry, Ulm University, 89081 Ulm, Germany
| | - Warner C Greene
- Gladstone Institute of Virology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA. Departments of Medicine and Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany
| | - Jan Münch
- Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany.
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24
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Abstract
HIV-1 infection typically results from the transmission of a single viral variant, the transmitted/founder (T/F) virus. Studies of these HIV-1 variants provide critical information about the transmission bottlenecks and the selective pressures acting on the virus in the transmission fluid and in the recipient tissues. These studies reveal that T/F virus phenotypes are shaped by stochastic and selective forces that restrict transmission and may be targets for prevention strategies. In this Review, we highlight how studies of T/F viruses contribute to a better understanding of the biology of HIV-1 transmission and discuss how these findings affect HIV-1 prevention strategies.
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25
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Characterization of the Influence of Semen-Derived Enhancer of Virus Infection on the Interaction of HIV-1 with Female Reproductive Tract Tissues. J Virol 2015; 89:5569-80. [PMID: 25740984 DOI: 10.1128/jvi.00309-15] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 02/27/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The majority of human immunodeficiency virus type 1 (HIV-1) transmission events occur in women when semen harboring infectious virus is deposited onto the mucosal barriers of the vaginal, ectocervical, and endocervical epithelia. Seminal factors such as semen-derived enhancer of virus infection (SEVI) fibrils were previously shown to greatly enhance the infectivity of HIV-1 in cell culture systems. However, when SEVI is intravaginally applied to living animals, there is no effect on vaginal transmission. To define how SEVI might function in the context of sexual transmission, we applied HIV-1 and SEVI to intact human and rhesus macaque reproductive tract tissues to determine how it influences virus interactions with these barriers. We show that SEVI binds HIV-1 and sequesters most virions to the luminal surface of the stratified squamous epithelium, significantly reducing the number of virions that penetrated the tissue. In the simple columnar epithelium, SEVI was no longer fibrillar in structure and was detached from virions but allowed significantly deeper epithelial virus penetration. These observations reveal that the action of SEVI in intact tissues is very different in the anatomical context of sexual transmission and begin to explain the lack of stimulation of infection observed in the highly relevant mucosal transmission model. IMPORTANCE The most common mode of HIV-1 transmission in women occurs via genital exposure to the semen of HIV-infected men. A productive infection requires the virus to penetrate female reproductive tract epithelial barriers to infect underlying target cells. Certain factors identified within semen, termed semen-derived enhancers of virus infection (SEVI), have been shown to significantly enhance HIV-1 infectivity in cell culture. However, when applied to the genital tracts of living female macaques, SEVI did not enhance virus transmission. Here we show that SEVI functions very differently in the context of intact mucosal tissues. SEVI decreases HIV-1 penetration of squamous epithelial barriers in humans and macaques. At the mucus-coated columnar epithelial barrier, the HIV-1/SEVI interaction is disrupted. These observations suggest that SEVI may not play a significant stimulatory role in the efficiency of male-to-female sexual transmission of HIV.
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Sheik DA, Brooks L, Frantzen K, Dewhurst S, Yang J. Inhibition of the enhancement of infection of human immunodeficiency virus by semen-derived enhancer of virus infection using amyloid-targeting polymeric nanoparticles. ACS NANO 2015; 9:1829-1836. [PMID: 25619867 PMCID: PMC4426188 DOI: 10.1021/nn5067254] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The semen-derived enhancer of virus infection (SEVI) is a natural amyloid material that has been shown to substantially increase viral attachment and infectivity of HIV in cells. We previously reported that synthetic monomeric and oligomeric amyloid-targeting molecules could form protein-resistive coatings on SEVI and inhibit SEVI- and semen-mediated enhancement of HIV infectivity. While oligomeric amyloid-binding compounds showed substantial improvement in apparent binding to SEVI compared to monomeric compounds, we observed only a modest correlation between apparent binding to SEVI and activity for reducing SEVI-mediated HIV infection. Here, we synthesized amyloid-binding polyacrylate-based polymers and polymeric nanoparticles of comparable size to HIV virus particles (∼150 nm) to assess the effect of sterics on the inhibition of SEVI-mediated enhancement of HIV infectivity. We show that these polymeric materials exhibit excellent capability to reduce SEVI-mediated enhancement of HIV infection, with the nanoparticles exhibiting the greatest activity (IC50 value of ∼4 μg/mL, or 59 nM based on polymer) of any SEVI-neutralizing agent reported to date. The results support that the improved activity of these nanomaterials is likely due to their increased size (diameters = 80-200 nm) compared to amyloid-targeting small molecules and that steric interactions may play as important a role as binding affinity in inhibiting viral infection mediated by SEVI amyloids. In contrast to the previously reported SEVI-neutralizing, amyloid-targeting molecules (which required concentrations at least 100-fold above the Kd to observe activity), the approximate 1:1 ratio of apparent Kd to IC50 for activity of these polymeric materials suggests the majority of polymer molecules that are bound to SEVI contribute to the inhibition of HIV infectivity enhanced by SEVI. Such size-related effects on physical inhibition of protein-protein interactions may open further opportunities for the use of targeted nanomaterials in disease intervention.
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Affiliation(s)
- Daniel A. Sheik
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla CA 92093-0358, United States
| | - Lauren Brooks
- Department of Microbiology and Immunology, University of Rochester, Rochester, New York 14642, United States
| | - Kristen Frantzen
- Department of Microbiology and Immunology, University of Rochester, Rochester, New York 14642, United States
| | - Stephen Dewhurst
- Department of Microbiology and Immunology, University of Rochester, Rochester, New York 14642, United States
| | - Jerry Yang
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla CA 92093-0358, United States
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Dobard C, Sharma S, Parikh UM, West R, Taylor A, Martin A, Pau CP, Hanson DL, Lipscomb J, Smith J, Novembre F, Hazuda D, Garcia-Lerma JG, Heneine W. Postexposure protection of macaques from vaginal SHIV infection by topical integrase inhibitors. Sci Transl Med 2014; 6:227ra35. [PMID: 24622515 DOI: 10.1126/scitranslmed.3007701] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Coitally delivered microbicide gels containing antiretroviral drugs are important for HIV prevention. However, to date, microbicides have contained entry or reverse transcriptase inhibitors that block early steps in virus infection and thus need to be given as a preexposure dose that interferes with sexual practices and may limit compliance. Integrase inhibitors block late steps after virus infection and therefore are more suitable for post-coital dosing. We first determined the kinetics of strand transfer in vitro and confirmed that integration begins about 6 hours after infection. We then used a repeat-challenge macaque model to assess efficacy of vaginal gels containing integrase strand transfer inhibitors when applied before or after simian/human immunodeficiency virus (SHIV) challenge. We showed that gel containing the strand transfer inhibitor L-870812 protected two of three macaques when applied 30 min before SHIV challenge. We next evaluated the efficacy of 1% raltegravir gel and demonstrated its ability to protect macaques when applied 3 hours after SHIV exposure (five of six protected; P < 0.05, Fisher's exact test). Breakthrough infections showed no evidence of drug resistance in plasma or vaginal secretions despite continued gel dosing after infection. We documented rapid vaginal absorption reflecting a short pharmacological lag time and noted that vaginal, but not plasma, virus load was substantially reduced in the breakthrough infection after raltegravir gel treatment. We provide a proof of concept that topically applied integrase inhibitors protect against vaginal SHIV infection when administered shortly before or 3 hours after virus exposure.
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Affiliation(s)
- Charles Dobard
- Laboratory Branch, Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA
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Münch J, Ständker L, Forssmann WG, Kirchhoff F. Discovery of modulators of HIV-1 infection from the human peptidome. Nat Rev Microbiol 2014; 12:715-22. [PMID: 25110191 PMCID: PMC7097597 DOI: 10.1038/nrmicro3312] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Kirchhoff and colleagues discuss the discovery of novel antimicrobial peptides by systematic screening of complex peptide and protein libraries that have been derived from human bodily fluids and tissues, with a focus on the isolation of endogenous agents that affect HIV-1 infection. Almost all human proteins are subject to proteolytic degradation, which produces a broad range of peptides that have highly specific and sometimes unexpected functions. Peptide libraries that have been generated from human bodily fluids or tissues are a rich but mostly unexplored source of bioactive compounds that could be used to develop antimicrobial and immunomodulatory therapeutic agents. In this Innovation article, we describe the discovery, optimization and application of endogenous bioactive peptides from human-derived peptide libraries, with a particular focus on the isolation of endogenous inhibitors and promoters of HIV-1 infection.
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Affiliation(s)
- Jan Münch
- 1] Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany. [2] Ulm Peptide Pharmaceuticals, Ulm University, 89081 Ulm, Germany
| | - Ludger Ständker
- 1] Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany. [2] Ulm Peptide Pharmaceuticals, Ulm University, 89081 Ulm, Germany
| | - Wolf-Georg Forssmann
- 1] Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany. [2] Pharis Biotec GmbH, 30625 Hannover, Germany
| | - Frank Kirchhoff
- 1] Institute of Molecular Virology, Ulm University Medical Center, 89081 Ulm, Germany. [2] Ulm Peptide Pharmaceuticals, Ulm University, 89081 Ulm, Germany
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Nguyen PV, Kafka JK, Ferreira VH, Roth K, Kaushic C. Innate and adaptive immune responses in male and female reproductive tracts in homeostasis and following HIV infection. Cell Mol Immunol 2014; 11:410-27. [PMID: 24976268 DOI: 10.1038/cmi.2014.41] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 05/08/2014] [Indexed: 12/13/2022] Open
Abstract
The male and female reproductive tracts are complex microenvironments that have diverse functional demands. The immune system in the reproductive tract has the demanding task of providing a protective environment for a fetal allograft while simultaneously conferring protection against potential pathogens. As such, it has evolved a unique set of adaptations, primarily under the influence of sex hormones, which make it distinct from other mucosal sites. Here, we discuss the various components of the immune system that are present in both the male and female reproductive tracts, including innate soluble factors and cells and humoral and cell-mediated adaptive immunity under homeostatic conditions. We review the evidence showing unique phenotypic and functional characteristics of immune cells and responses in the male and female reproductive tracts that exhibit compartmentalization from systemic immunity and discuss how these features are influenced by sex hormones. We also examine the interactions among the reproductive tract, sex hormones and immune responses following HIV-1 infection. An improved understanding of the unique characteristics of the male and female reproductive tracts will provide insights into improving clinical treatments of the immunological causes of infertility and the design of prophylactic interventions for the prevention of sexually transmitted infections.
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Meier C, Weil T, Kirchhoff F, Münch J. Peptide nanofibrils as enhancers of retroviral gene transfer. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2014; 6:438-51. [PMID: 24865496 DOI: 10.1002/wnan.1275] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 04/10/2014] [Accepted: 04/18/2014] [Indexed: 01/13/2023]
Abstract
Amyloid fibrils are polypeptide-based polymers that are typically associated with neurodegenerative disorders such as Alzheimer's disease. More recently, it has become clear that amyloid fibrils also fulfill functional roles in hormone storage and biosynthesis. Furthermore, it has been demonstrated that semen contains abundant levels of polycationic amyloid fibrils. The natural role of these seminal amyloids remains elusive. Strikingly, however, they drastically enhance HIV-1 infection and may be exploited by the virus to increase its sexual transmission rate. Their strong activity in enhancing HIV-1 infection suggests that seminal amyloid might also promote transduction by retroviral vectors. Indeed, SEVI (semen-derived enhancer of virus infection), the best characterized seminal amyloid, boosts retroviral gene transfer more efficiently than conventional additives. However, the use of SEVI as laboratory tool for efficient retroviral gene transfer is limited because the polypeptide monomers are relatively expensive to produce. Furthermore, standardized production of SEVI fibrils with similar high activities is difficult to achieve because of the stochastic nature of the amyloid assembly process. These obstacles can be overcome by recently identified smaller peptides that spontaneously self-assemble into nanofibrils. These nanofibrils increase retroviral gene transfer even more efficiently than SEVI, are easy to produce and to handle, and seem to be safe as assessed in an ex vivo gene transfer study. Furthermore, peptide-based nanofibrils allow to concentrate viral particles by low-speed centrifugation. Specific adaption and customization of self-assembling peptides might lead to novel nanofibrils with versatile biological functions, e.g., targeted retroviral gene transfer or drug delivery.
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Affiliation(s)
- Christoph Meier
- Department of Organic Chemistry III, Ulm University, Ulm, Germany
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Ferreira VH, Kafka JK, Kaushic C. Influence of common mucosal co-factors on HIV infection in the female genital tract. Am J Reprod Immunol 2014; 71:543-54. [PMID: 24617528 DOI: 10.1111/aji.12221] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Accepted: 01/28/2014] [Indexed: 12/14/2022] Open
Abstract
Women constitute almost half of HIV-infected population globally, and the female genital tract (FGT) accounts for approximately 40% of all new HIV infections worldwide. The FGT is composed of upper and lower parts, distinct in their morphological and functional characteristics. Co-factors in the genital microenvironment, such as presence of hormones, semen, and other sexually transmitted infections, can facilitate or deter HIV infection and play a critical role in determining susceptibility to HIV. In this review, we examine some of these co-factors and their potential influence. Presence of physical and chemical barriers such as epithelial tight junctions, mucus, and anti-microbial peptides can actively block and inhibit viral replication, presenting a significant deterrent to HIV. Upon exposure, HIV and other pathogens first encounter the genital epithelium: cells that express a wide repertoire of pattern recognition receptors that can recognize and directly initiate innate immune responses. These and other interactions in the genital tract can lead to direct and indirect inflammation and enhance the number of local target cells, immune activation, and microbial translocation, all of which promote HIV infection and replication. Better understanding of the dynamics of HIV transmission in the female genital tract would be invaluable for improving the design of prophylactic strategies against HIV.
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Affiliation(s)
- Victor H Ferreira
- Department of Pathology and Molecular Medicine, McMaster Immunology Research Centre, Michael G. DeGroote Institute of Infectious Diseases Research, McMaster University, Hamilton, ON, Canada
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