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Buckner LR, Amedee AM, Albritton HL, Kozlowski PA, Lacour N, McGowin CL, Schust DJ, Quayle AJ. Chlamydia trachomatis Infection of Endocervical Epithelial Cells Enhances Early HIV Transmission Events. PLoS One 2016; 11:e0146663. [PMID: 26730599 PMCID: PMC4701475 DOI: 10.1371/journal.pone.0146663] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 12/21/2015] [Indexed: 01/20/2023] Open
Abstract
Chlamydia trachomatis causes a predominantly asymptomatic, but generally inflammatory, genital infection that is associated with an increased risk for HIV acquisition. Endocervical epithelial cells provide the major niche for this obligate intracellular bacterium in women, and the endocervix is also a tissue in which HIV transmission can occur. The mechanism by which CT infection enhances HIV susceptibility at this site, however, is not well understood. Utilizing the A2EN immortalized endocervical epithelial cell line grown on cell culture inserts, we evaluated the direct role that CT-infected epithelial cells play in facilitating HIV transmission events. We determined that CT infection significantly enhanced the apical-to-basolateral migration of cell-associated, but not cell-free, HIVBaL, a CCR5-tropic strain of virus, across the endocervical epithelial barrier. We also established that basolateral supernatants from CT-infected A2EN cells significantly enhanced HIV replication in peripheral mononuclear cells and a CCR5+ T cell line. These results suggest that CT infection of endocervical epithelial cells could facilitate both HIV crossing the mucosal barrier and subsequent infection or replication in underlying target cells. Our studies provide a mechanism by which this common STI could potentially promote the establishment of founder virus populations and the maintenance of local HIV reservoirs in the endocervix. Development of an HIV/STI co-infection model also provides a tool to further explore the role of other sexually transmitted infections in enhancing HIV acquisition.
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Affiliation(s)
- Lyndsey R. Buckner
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, United States of America
| | - Angela M. Amedee
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, United States of America
| | - Hannah L. Albritton
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, United States of America
| | - Pamela A. Kozlowski
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, United States of America
| | - Nedra Lacour
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, United States of America
| | - Chris L. McGowin
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, United States of America
- Department of Medicine, Section of Infectious Diseases, Louisiana State University Health Sciences Center, New Orleans, Louisiana, 70112, United States of America
| | - Danny J. Schust
- Department of Obstetrics, Gynecology and Women’s Health, University of Missouri, Columbia, MO 65201, United States of America
| | - Alison J. Quayle
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, United States of America
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Merino AM, Sabbaj S, Easlick J, Goepfert P, Kaslow RA, Tang J. Dimorphic HLA-B signal peptides differentially influence HLA-E- and natural killer cell-mediated cytolysis of HIV-1-infected target cells. Clin Exp Immunol 2013; 174:414-23. [PMID: 23952339 PMCID: PMC3826307 DOI: 10.1111/cei.12187] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/11/2013] [Indexed: 12/18/2022] Open
Abstract
As a mechanism of self-protection, signal peptides cleaved from human leukocyte antigen (HLA) class I products bind to HLA-E before the complex interacts with the natural killer (NK) cell receptor CD94/NKG2A to inhibit NK-mediated cell lysis. Two types of the signal peptides differ in their position 2 (P2) anchor residue, with P2-methionine (P2-M) having higher HLA-E binding affinity than P2-threonine (P2-T). All HLA-A and HLA-C molecules carry P2-M, whereas HLA-B products have either P2-M or P2-T. Epidemiological evidence suggests that P2-M is unfavourable in the context of HIV-1 infection, being associated with accelerated acquisition of HIV-1 infection in two African cohorts. To begin elucidating the functional mechanism, we studied NK-mediated killing of CD4(+) T cells and monocyte-derived macrophages infected with two laboratory-adapted HIV-1 strains and two transmitted/founder (T/F) viruses. In the presence of target cells derived from individuals with the three HLA-B P2 genotypes (M/M, M/T and T/T), NK-mediated cytolysis was elevated consistently for P2-T in a dose-dependent manner for all cell and virus combinations tested (P = 0·008-0·03). Treatment of target cells with an anti-HLA-E monoclonal antibody restored NK-mediated cytolysis of cells expressing P2-M. Observations on cell lysis were also substantiated by measurements of HIV-1 p24 antigen in the culture supernatants. Overall, our experiments indicate that the anti-HIV-1 function mediated by NK cells is compromised by P2-M, corroborating the association of HLA-B genotype encoding P2-M with accelerated HIV-1 acquisition.
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Affiliation(s)
- A M Merino
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA; Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
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Gupta S, Gach JS, Becerra JC, Phan TB, Pudney J, Moldoveanu Z, Joseph SB, Landucci G, Supnet MJ, Ping LH, Corti D, Moldt B, Hel Z, Lanzavecchia A, Ruprecht RM, Burton DR, Mestecky J, Anderson DJ, Forthal DN. The Neonatal Fc receptor (FcRn) enhances human immunodeficiency virus type 1 (HIV-1) transcytosis across epithelial cells. PLoS Pathog 2013; 9:e1003776. [PMID: 24278022 PMCID: PMC3836734 DOI: 10.1371/journal.ppat.1003776] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 10/04/2013] [Indexed: 11/30/2022] Open
Abstract
The mechanisms by which human immunodeficiency virus type 1 (HIV-1) crosses mucosal surfaces to establish infection are unknown. Acidic genital secretions of HIV-1-infected women contain HIV-1 likely coated by antibody. We found that the combination of acidic pH and Env-specific IgG, including that from cervicovaginal and seminal fluids of HIV-1-infected individuals, augmented transcytosis across epithelial cells as much as 20-fold compared with Env-specific IgG at neutral pH or non-specific IgG at either pH. Enhanced transcytosis was observed with clinical HIV-1 isolates, including transmitted/founder strains, and was eliminated in Fc neonatal receptor (FcRn)-knockdown epithelial cells. Non-neutralizing antibodies allowed similar or less transcytosis than neutralizing antibodies. However, the ratio of total:infectious virus was higher for neutralizing antibodies, indicating that they allowed transcytosis while blocking infectivity of transcytosed virus. Immunocytochemistry revealed abundant FcRn expression in columnar epithelia lining the human endocervix and penile urethra. Acidity and Env-specific IgG enhance transcytosis of virus across epithelial cells via FcRn and could facilitate translocation of virus to susceptible target cells following sexual exposure. HIV-1 causes a sexually transmitted disease. However, the mechanisms employed by the virus to cross genital tract tissue and establish infection are uncertain. Since cervicovaginal fluid is acidic and HIV-1 in cervicovaginal fluid is likely coated with antibodies, we explored the effect of low pH and HIV-1-specific antibodies on transcytosis, the movement of HIV-1 across tight-junctioned epithelial cells. We found that the combination of HIV-1-specific antibodies and low pH enhanced transcytosis as much as 20-fold. Virus that underwent transcytosis under these conditions was infectious, and infectivity was highly influenced by whether or not the antibody neutralized the virus. We observed enhanced transcytosis using antibody from cervicovaginal and seminal fluids and using transmitted/founder strains of HIV-1. We also found that the enhanced transcytosis was due to the Fc neonatal receptor (FcRn), which binds immune complexes at acidic pH and releases them at neutral pH. Finally, staining of human tissue revealed abundant FcRn expression on columnar epithelial cells of penile urethra and endocervix. Our findings reveal a novel mechanism wherein HIV-1 may facilitate its own transmission by usurping the antibody response directed against itself. These results have important implications for HIV vaccine development and for understanding the earliest events in HIV transmission.
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Affiliation(s)
- Sandeep Gupta
- Division of Infectious Diseases, Department of Medicine, University of California, Irvine School of Medicine, Irvine, California, United States of America
| | - Johannes S. Gach
- Division of Infectious Diseases, Department of Medicine, University of California, Irvine School of Medicine, Irvine, California, United States of America
| | - Juan C. Becerra
- Division of Infectious Diseases, Department of Medicine, University of California, Irvine School of Medicine, Irvine, California, United States of America
| | - Tran B. Phan
- Division of Infectious Diseases, Department of Medicine, University of California, Irvine School of Medicine, Irvine, California, United States of America
| | - Jeffrey Pudney
- Department of Obstetrics and Gynecology, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Zina Moldoveanu
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Sarah B. Joseph
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Gary Landucci
- Division of Infectious Diseases, Department of Medicine, University of California, Irvine School of Medicine, Irvine, California, United States of America
| | - Medalyn Jude Supnet
- Division of Infectious Diseases, Department of Medicine, University of California, Irvine School of Medicine, Irvine, California, United States of America
| | - Li-Hua Ping
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Davide Corti
- Institute for Research in Biomedicine, Bellinzona, Switzerland
- Humabs BioMed SA, Bellinzona, Switzerland
| | - Brian Moldt
- Department of Immunology and Microbial Science, International AIDS Vaccine Initiative Neutralizing Antibody Center and Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, California, United States of America
| | - Zdenek Hel
- Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Antonio Lanzavecchia
- Institute for Research in Biomedicine, Bellinzona, Switzerland
- Institute of Microbiology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - Ruth M. Ruprecht
- Texas Biomedical Research Institute, San Antonio, Texas, United States of America
| | - Dennis R. Burton
- Department of Immunology and Microbial Science, International AIDS Vaccine Initiative Neutralizing Antibody Center and Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, California, United States of America
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology, and Harvard University, Boston, Massachusetts, United States of America
| | - Jiri Mestecky
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Institute of Immunology and Microbiology, First School of Medicine, Charles University, Prague, Czech Republic
| | - Deborah J. Anderson
- Department of Obstetrics and Gynecology, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Donald N. Forthal
- Division of Infectious Diseases, Department of Medicine, University of California, Irvine School of Medicine, Irvine, California, United States of America
- * E-mail:
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Connell BJ, Lortat-Jacob H. Human immunodeficiency virus and heparan sulfate: from attachment to entry inhibition. Front Immunol 2013; 4:385. [PMID: 24312095 PMCID: PMC3834540 DOI: 10.3389/fimmu.2013.00385] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 11/05/2013] [Indexed: 11/13/2022] Open
Abstract
By targeting cells that provide protection against infection, HIV-1 causes acquired immunodeficiency syndrome. Infection starts when gp120, the viral envelope glycoprotein, binds to CD4 and to a chemokine receptor usually CCR5 or CXCR4. As many microorganisms, HIV-1 also interacts with heparan sulfate (HS), a complex group of cell surface associated anionic polysaccharides. It has been thought that this binding, occurring at a step prior to CD4 recognition, increases infectivity by pre-concentrating the virion particles at the cell surface. Early work, dating from before the identification of CCR5 and CXCR4, showed that a variety of HS mimetics bind to the gp120 V3 loop through electrostatic interactions, compete with cell surface associated HS to bind the virus and consequently, neutralize the infectivity of a number of T-cell line-adapted HIV-1 strains. However, progress made to better understand HIV-1 attachment and entry, coupled with the recent identification of additional gp120 regions mediating HS recognition, have considerably modified this view. Firstly, the V3 loop from CXCR4-using viruses is much more positively charged compared to those using CCR5. HS inhibition of cell attachment is thus restricted to CXCR4-using viruses (such as T-cell line-adapted HIV-1). Secondly, studies aiming at characterizing the gp120/HS complex revealed that HS binding was far more complex than previously thought: in addition to the V3 loop of CXCR4 tropic gp120, HS interacts with several other cryptic areas of the protein, which can be induced upon CD4 binding, and are conserved amongst CCR5 and CXCR4 viruses. In view of these data, this review will detail the present knowledge on HS binding to HIV-1, with regards to attachment and entry processes. It will discuss the perspective of targeting the gp120 co-receptor binding site with HS mimetic compounds, a strategy that recently gave rise to entry inhibitors that work in the low nanomolar range, independently of co-receptor usage.
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Affiliation(s)
- Bridgette J Connell
- University of Grenoble Alpes, Institut de Biologie Structurale , Grenoble , France ; Centre National de la Recherche Scientifique, Institut de Biologie Structurale , Grenoble , France ; Commissariat à l'Énergie Atomique, Direction des Sciences du Vivant, Institut de Biologie Structurale , Grenoble , France
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Rodriguez-Garcia M, Patel MV, Wira CR. Innate and adaptive anti-HIV immune responses in the female reproductive tract. J Reprod Immunol 2013; 97:74-84. [PMID: 23432874 PMCID: PMC3581821 DOI: 10.1016/j.jri.2012.10.010] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Revised: 10/08/2012] [Accepted: 10/15/2012] [Indexed: 01/17/2023]
Abstract
The mucosal surface of the female reproductive tract (FRT) is the primary site of transmission for a plethora of sexually transmitted infections, including human immunodeficiency virus (HIV), that represent a significant burden upon womens' health worldwide. However, fundamental aspects of innate and adaptive immune protection against HIV infection in the FRT are poorly understood. The FRT immune system is regulated by the cyclical changes of the sex hormones estradiol and progesterone across the menstrual cycle, which as we have hypothesized, leads to the creation of a window of vulnerability during the secretory stage of the menstrual cycle, when the risk of HIV transmission is increased. The goal of this review is to summarize the multiple levels of protection against HIV infection in the FRT, the contribution of different cell types including epithelial cells, macrophages, T cells, and dendritic cells to this, and their regulation by estradiol and progesterone. Understanding the unique immune environment in the FRT will allow for the potential development of novel therapeutic interventions such as vaccines and microbicides that may reduce or prevent HIV transmission in women.
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Affiliation(s)
- Marta Rodriguez-Garcia
- Department of Physiology and Neurobiology, Geisel School of Medicine at Dartmouth, Lebanon, NH 03756, USA
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Evaluation of cervical mucosa in transmission bottleneck during acute HIV-1 infection using a cervical tissue-based organ culture. PLoS One 2012; 7:e32539. [PMID: 22412886 PMCID: PMC3296723 DOI: 10.1371/journal.pone.0032539] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Accepted: 02/01/2012] [Indexed: 11/24/2022] Open
Abstract
Background Although there are different strains of HIV-1 in a chronically infected individual, only one or limited virus strains are successfully transmitted to a new individual. The reason for this “transmission bottleneck” is as yet unknown. Methodology/Principal Findings A human cervical explant model was used to measure HIV-1 transmission efficiency of viral strains from chronic infections, and transmitter/founder variants. We also evaluated the genetic characteristics of HIV-1 variants in the inoculums compared to those transmitted across the cervical mucosa. Eight different HIV-1 isolates were used in this study, six chronic isolates and two transmitter/founder viruses. The transmission efficiency of the chronic and transmitter/founder virus isolates and the viral diversity of chronic isolates before and after viral transmission were assessed. The results indicate that transmitter/founder viruses did not display higher transmission efficiency than chronic HIV-1 isolates. Furthermore, no evidence for a difference in diversity was found between the inoculums and transmitted virus strains. Phylogenetic analysis indicated that the sequences of variants in the inoculums and those present in transmitted virus intermingled irrespective of co-receptor usage. In addition, the inoculum and transmitted variants had a similar pairwise distance distribution. Conclusion There was no selection of a single or limited number of viral variants during HIV-1 transmission across the cervical mucosa in the organ culture model, indicating that the cervical mucosa alone may not produce the transmission bottleneck of HIV-1 infection observed in vivo.
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Shacklett BL, Greenblatt RM. Immune responses to HIV in the female reproductive tract, immunologic parallels with the gastrointestinal tract, and research implications. Am J Reprod Immunol 2011; 65:230-41. [PMID: 21223420 DOI: 10.1111/j.1600-0897.2010.00948.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The female reproductive tract is a major site of mucosa-associated lymphoid tissue and susceptibility to HIV infection, yet the tissue site(s) of infection and the impact of HIV infection on this important mucosal tissue remain poorly understood. CD4(+) T cells and other cell types expressing the major coreceptors for HIV, CCR5, and CXCR4 are abundant in both the lower reproductive tract (endocervix and vagina) and the upper tract (endocervix and uterus) and are highly susceptible to infection. Antiviral defenses in the female reproductive tract are mediated by a variety of soluble factors and by mucosal effector cells that differ phenotypically from their counterparts in blood. The immunologic characteristics of the female reproductive tract parallel those of the gut, where major HIV-related immunologic injury occurs. The susceptibility of the female reproductive tract to HIV infection and immunopathogenesis suggests important new avenues for further research.
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Affiliation(s)
- Barbara L Shacklett
- Department of Medical Microbiology and Immunology, and Division of Infectious Diseases, Department of Internal Medicine, School of Medicine, University of California-Davis, 1 Shields Avenue, Davis, CA 95616, USA.
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