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Russi RC, del Balzo D, Reidel IG, Alonso Bivou M, Flor N, Lujan A, Sanchez D, Damiani MT, Veaute C. Evaluation of three formulations based on Polymorphic membrane protein D in mice infected with Chlamydia trachomatis. Front Immunol 2023; 14:1267684. [PMID: 38045697 PMCID: PMC10690417 DOI: 10.3389/fimmu.2023.1267684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 10/23/2023] [Indexed: 12/05/2023] Open
Abstract
The significant impact of Chlamydia trachomatis(Ct) infections worldwide highlights the need to develop a prophylactic vaccine that elicits effective immunity and protects the host from the immunopathological effects of Ct infection. The aim of this study was to evaluate a vaccine based on a fragment of the Polymorphic membrane protein D (FPmpD) of C. trachomatis as an immunogen using a heterologous DNA prime-protein boost strategy in female mice Three different formulations were evaluated as protein boost: free recombinant FPmpD (rFPmpD) or rFPmpD formulated with a liposomal adjuvant alternatively supplemented with CpG or a cationic gemini lipopeptide as immunostimulants. The three candidates induced an increase in the cervicovaginal and systemic titers of anti-rFPmpD antibodies in two strains of mice (BALB/c and C57BL/6), with no evidence of fertility alterations. The three formulations induced a rapid and robust humoral immune response upon the Ct challenge. However, the booster with free rFPmpD more efficiently reduced the shedding of infective Ct and prevented the development of immunopathology. The formulations containing adjuvant induced a strong inflammatory reaction in the uterine tissue. Hence, the prime-boost strategy with the adjuvant-free FPmpD vaccine formulation might constitute a promissory candidate to prevent C. trachomatis intravaginal infection.
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Affiliation(s)
- Romina Cecilia Russi
- Laboratorio de Bioquímica e Inmunidad, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Instituto de Medicina y Biología Experimental de Cuyo, Consejo Nacional de Investigaciones Científicas y Técnicas (IMBECUCONICET), Universidad Nacional de Cuyo, Mendoza, Argentina
- Experimental Immunology Laboratory, School of Biochemistry and Biological Sciences, National University of Litoral, Ciudad Universitaria, Santa Fe, Argentina
| | - Diego del Balzo
- Laboratorio de Bioquímica e Inmunidad, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Instituto de Medicina y Biología Experimental de Cuyo, Consejo Nacional de Investigaciones Científicas y Técnicas (IMBECUCONICET), Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Ivana Gabriela Reidel
- Experimental Immunology Laboratory, School of Biochemistry and Biological Sciences, National University of Litoral, Ciudad Universitaria, Santa Fe, Argentina
- Department of Immuno-Oncology, Beckman Research Institute of City of Hope, Duarte, CA, United States
| | - Mariano Alonso Bivou
- Laboratorio de Bioquímica e Inmunidad, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Instituto de Medicina y Biología Experimental de Cuyo, Consejo Nacional de Investigaciones Científicas y Técnicas (IMBECUCONICET), Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Noelia Flor
- Experimental Immunology Laboratory, School of Biochemistry and Biological Sciences, National University of Litoral, Ciudad Universitaria, Santa Fe, Argentina
| | - Agustín Lujan
- Laboratorio de Bioquímica e Inmunidad, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Instituto de Medicina y Biología Experimental de Cuyo, Consejo Nacional de Investigaciones Científicas y Técnicas (IMBECUCONICET), Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Diego Sanchez
- Laboratorio de Bioquímica e Inmunidad, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Instituto de Medicina y Biología Experimental de Cuyo, Consejo Nacional de Investigaciones Científicas y Técnicas (IMBECUCONICET), Universidad Nacional de Cuyo, Mendoza, Argentina
| | - María Teresa Damiani
- Laboratorio de Bioquímica e Inmunidad, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Instituto de Medicina y Biología Experimental de Cuyo, Consejo Nacional de Investigaciones Científicas y Técnicas (IMBECUCONICET), Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Carolina Veaute
- Experimental Immunology Laboratory, School of Biochemistry and Biological Sciences, National University of Litoral, Ciudad Universitaria, Santa Fe, Argentina
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2
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Yu X, Xu Q, Chen W, Mai Z, Mo L, Su X, Ou J, Lan Y, Zheng H, Xue Y. Rhein inhibits Chlamydia trachomatis infection by regulating pathogen-host cell. Front Public Health 2022; 10:1002029. [PMID: 36238249 PMCID: PMC9552556 DOI: 10.3389/fpubh.2022.1002029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 09/07/2022] [Indexed: 01/27/2023] Open
Abstract
The global incidence of genital Chlamydia trachomatis infection increased rapidly as the primary available treatment of C. trachomatis infection being the use of antibiotics. However, the development of antibiotics resistant stain and other treatment failures are often observed in patients. Consequently, novel therapeutics are urgently required. Rhein is a monomer derivative of anthraquinone compounds with an anti-infection activity. This study investigated the effects of rhein on treating C. trachomatis infection. Rhein showed significant inhibitory effects on the growth of C. trachomatis in multiple serovars of C. trachomatis, including D, E, F and L1, and in various host cells, including HeLa, McCoy and Vero. Rhein could not directly inactivate C. trachomatis but could inhibit the growth of C. trachomatis by regulating pathogen-host cell interactions. Combined with azithromycin, the inhibitory effect of rehin was synergistic both in vitro and in vivo. Together these findings suggest that rhein could be developed for the treatment of C. trachomatis infections.
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Affiliation(s)
- Xueying Yu
- Department of Clinical Laboratory, Dermatology Hospital, Southern Medical University, Guangzhou, China,Department of Clinical Laboratory, Shanghai Fourth People's Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
| | - Qingqing Xu
- Department of Clinical Laboratory, Dermatology Hospital, Southern Medical University, Guangzhou, China
| | - Wentao Chen
- Department of Clinical Laboratory, Dermatology Hospital, Southern Medical University, Guangzhou, China,Guangzhou Key Laboratory for Sexually Transmitted Diseases Control, Guangzhou, China
| | - Zhida Mai
- Department of Clinical Laboratory, Dermatology Hospital, Southern Medical University, Guangzhou, China
| | - Lijun Mo
- Department of Clinical Laboratory, Dermatology Hospital, Southern Medical University, Guangzhou, China
| | - Xin Su
- Department of Clinical Laboratory, Dermatology Hospital, Southern Medical University, Guangzhou, China
| | - Jiangli Ou
- Department of Clinical Laboratory, Dermatology Hospital, Southern Medical University, Guangzhou, China
| | - Yinyuan Lan
- Department of Clinical Laboratory, Dermatology Hospital, Southern Medical University, Guangzhou, China
| | - Heping Zheng
- Department of Clinical Laboratory, Dermatology Hospital, Southern Medical University, Guangzhou, China,Guangzhou Key Laboratory for Sexually Transmitted Diseases Control, Guangzhou, China,*Correspondence: Heping Zheng
| | - Yaohua Xue
- Department of Clinical Laboratory, Dermatology Hospital, Southern Medical University, Guangzhou, China,Guangzhou Key Laboratory for Sexually Transmitted Diseases Control, Guangzhou, China,Yaohua Xue
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3
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Edwards VL, McComb E, Gleghorn JP, Forney L, Bavoil PM, Ravel J. Three-dimensional models of the cervicovaginal epithelia to study host-microbiome interactions and sexually transmitted infections. Pathog Dis 2022; 80:6655985. [PMID: 35927516 PMCID: PMC9419571 DOI: 10.1093/femspd/ftac026] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 06/14/2022] [Accepted: 08/02/2022] [Indexed: 02/03/2023] Open
Abstract
2D cell culture systems have historically provided controlled, reproducible means to analyze host-pathogen interactions observed in the human reproductive tract. Although inexpensive, straightforward, and requiring a very short time commitment, these models recapitulate neither the functionality of multilayered cell types nor the associated microbiome that occurs in a human. Animal models have commonly been used to recreate the complexity of human infections. However, extensive modifications of animal models are required to recreate interactions that resemble those in the human reproductive tract. 3D cell culture models have emerged as alternative means of reproducing vital elements of human infections at a fraction of the cost of animal models and on a scale that allows for replicative experiments. Here, we describe a new 3D model that utilizes transwells with epithelial cells seeded apically and a basolateral extracellular matrix (ECM)-like layer. The model produced tissues with morphologic and physiological resemblance to human cervical and vaginal epithelia, including mucus levels produced by cervical cells. Infection by Chlamydia trachomatis and Neisseria gonorrhoeae was demonstrated, as well as the growth of bacterial species observed in the human vaginal microbiota. This enabled controlled mechanistic analyses of the interactions between host cells, the vaginal microbiota, and STI pathogens. Affordable and semi high-throughput 3D models of the cervicovaginal epithelia that are physiologically relevant by sustaining vaginal bacterial colonization, and facilitate studies of chlamydial and gonococcal infections.
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Affiliation(s)
- Vonetta L Edwards
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, United States,Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, United States
| | | | - Jason P Gleghorn
- Department of Biomedical Engineering, University of Delaware, Newark, DE, United States
| | - Larry Forney
- Department of Biological Sciences, University of Idaho, Moscow, ID, United States
| | - Patrik M Bavoil
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, United States,Department of Microbial Pathogenesis, University of Maryland, Baltimore, MD, United States
| | - Jacques Ravel
- Corresponding author: Institute for Genome Sciences and Department of Microbiology and Immunology, University of Maryland School of Medicine, Health Science Research Facility (HSRDF), 670 W. Baltimore Street, Baltimore, MD 21201, United States. Tel: +1 410-706-5674; E-mail:
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4
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Heterologous prime-boost vaccination based on Polymorphic protein D protects against intravaginal Chlamydia trachomatis infection in mice. Sci Rep 2022; 12:6664. [PMID: 35459778 PMCID: PMC9030682 DOI: 10.1038/s41598-022-10633-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 04/04/2022] [Indexed: 11/08/2022] Open
Abstract
The control of the worldwide spread of sexually transmitted Chlamydia trachomatis (Ct) infection urgently demands the development of a preventive vaccine. In this work, we designed a vaccine based on a fragment of polymorphic protein D (FPmpD) that proved to be immunogenic enough to generate a robust systemic and mucosal IgG humoral immune response in two strains of mice. We used a heterologous prime-boost strategy, including simultaneous systemic and mucosal administration routes. The high titers of anti-PmpD antibodies elicited by this immunization scheme did not affect murine fertility. We tested the vaccine in a mouse model of Ct intravaginal infection. Anti-PmpD antibodies displayed potent neutralizing activity in vitro and protective effects in uterine tissues in vivo. Notably, the humoral immune response of PmpD-vaccinated mice was faster and stronger than the primary immune response of non-vaccinated mice when exposed to Ct. FPmpD-based vaccine effectively reduced Ct shedding into cervicovaginal fluids, bacterial burden at the genitourinary tract, and overall infectivity. Hence, the FPmpD-based vaccine might constitute an efficient tool to protect against Ct intravaginal infection and decrease the infection spreading.
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Dolat L, Valdivia RH. A renewed tool kit to explore Chlamydia pathogenesis: from molecular genetics to new infection models. F1000Res 2019; 8. [PMID: 31249676 PMCID: PMC6589931 DOI: 10.12688/f1000research.18832.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/12/2019] [Indexed: 12/21/2022] Open
Abstract
Chlamydia trachomatis is the most prevalent sexually transmitted bacterial pathogen and the leading cause of preventable blindness in the developing world.
C. trachomatis invades the epithelium of the conjunctiva and genital tract and replicates within an intracellular membrane-bound compartment termed the inclusion. To invade and replicate in mammalian cells,
Chlamydia remodels epithelial surfaces by reorganizing the cytoskeleton and cell–cell adhesions, reprograms membrane trafficking, and modulates cell signaling to dampen innate immune responses. If the infection ascends to the upper female genital tract, it can result in pelvic inflammatory disease and tissue scarring.
C. trachomatis infections are associated with infertility, ectopic pregnancies, the fibrotic disorder endometriosis, and potentially cancers of the cervix and uterus. Unfortunately, the molecular mechanisms by which this clinically important human pathogen subverts host cellular functions and causes disease have remained relatively poorly understood because of the dearth of molecular genetic tools to study
Chlamydiae and limitations of both
in vivo and
in vitro infection models. In this review, we discuss recent advances in the experimental molecular tool kit available to dissect
C. trachomatis infections with a special focus on
Chlamydia-induced epithelial barrier disruption by regulating the structure, function, and dynamics of epithelial cell–cell junctions.
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Affiliation(s)
- Lee Dolat
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, USA
| | - Raphael H Valdivia
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, USA
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Shaw JH, Key CE, Snider TA, Sah P, Shaw EI, Fisher DJ, Lutter EI. Genetic Inactivation of Chlamydia trachomatis Inclusion Membrane Protein CT228 Alters MYPT1 Recruitment, Extrusion Production, and Longevity of Infection. Front Cell Infect Microbiol 2018; 8:415. [PMID: 30555802 PMCID: PMC6284022 DOI: 10.3389/fcimb.2018.00415] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 11/08/2018] [Indexed: 02/01/2023] Open
Abstract
Chlamydia trachomatis is an obligate intracellular pathogen with global health and economic impact. Upon infection, C. trachomatis resides within a protective niche, the inclusion, wherein it replicates and usurps host cell machinery and resources. The inclusion membrane is the key host-pathogen interface that governs specific protein-protein interactions to manipulate host signaling pathways. At the conclusion of the infection cycle, C. trachomatis exits the host cell via lysis or extrusion. Extrusion depends on the phosphorylation state of myosin light chain 2 (MLC2); the extent of phosphorylation is determined by the ongoing opposing activities of myosin phosphatase (MYPT1) and myosin kinase (MLCK). Previously, it was shown that MYPT1 is recruited to the inclusion and interacts with CT228 for regulation of host cell egress. In this study, we generated a targeted chromosomal mutation of CT228 (L2-ΔCT228) using the TargeTron system and demonstrate a loss of MYPT1 recruitment and increase in extrusion production in vitro. Mutation of CT228 did not affect chlamydial growth in cell culture or recruitment of MLC2. Moreover, we document a delay in clearance of L2-ΔCT228 during murine intravaginal infection as well as a reduction in systemic humoral response, relative to L2-wild type. Taken together, the data suggest that loss of MYPT1 recruitment (as a result of CT228 disruption) regulates the degree of host cell exit via extrusion and affects the longevity of infection in vivo.
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Affiliation(s)
- Jennifer H. Shaw
- Department of Integrative Biology, Oklahoma State University, Stillwater, OK, United States,*Correspondence: Jennifer H. Shaw
| | - Charlotte E. Key
- Department of Integrative Biology, Oklahoma State University, Stillwater, OK, United States
| | - Timothy A. Snider
- Department of Veterinary Pathobiology, Oklahoma State University, Stillwater, OK, United States
| | - Prakash Sah
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, United States
| | - Edward I. Shaw
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, United States
| | - Derek J. Fisher
- Department of Microbiology, Southern Illinois University, Carbondale, IL, United States
| | - Erika I. Lutter
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, United States,Erika I. Lutter
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7
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Impact of Active Metabolism on Chlamydia trachomatis Elementary Body Transcript Profile and Infectivity. J Bacteriol 2018; 200:JB.00065-18. [PMID: 29735758 DOI: 10.1128/jb.00065-18] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 05/01/2018] [Indexed: 11/20/2022] Open
Abstract
Bacteria of the genus Chlamydia include the significant human pathogens Chlamydia trachomatis and C. pneumoniae All chlamydiae are obligate intracellular parasites that depend on infection of a host cell and transition through a biphasic developmental cycle. Following host cell invasion by the infectious elementary body (EB), the pathogen transitions to the replicative but noninfectious reticulate body (RB). Differentiation of the RB back to the EB is essential to generate infectious progeny. While the EB form has historically been regarded as metabolically inert, maintenance of infectivity during incubation with specific nutrients has revealed active maintenance of the infectious phenotype. Using transcriptome sequencing, we show that the transcriptome of extracellular EBs incubated under metabolically stimulating conditions does not cluster with germinating EBs but rather with the transcriptome of EBs isolated directly from infected cells. In addition, the transcriptional profile of the extracellular metabolizing EBs more closely resembled that of EB production than germination. Maintenance of infectivity of extracellular EBs was achieved by metabolizing chemically diverse compounds, including glucose 6-phosphate, ATP, and amino acids, all of which can be found in extracellular environments, including mucosal secretions. We further show that the EB cell type actively maintains infectivity in the inclusion after terminal differentiation. Overall, these findings contribute to the emerging understanding that the EB cell form is actively maintained through metabolic processes after terminal differentiation to facilitate prolonged infectivity within the inclusion and under host cell free conditions, for example, following deposition at mucosal surfaces.IMPORTANCE Chlamydiae are obligate intracellular Gram-negative bacteria that are responsible for a wide range of diseases in both animal and human hosts. According to the Centers for Disease Control and Prevention, C. trachomatis is the most frequently reported sexually transmitted infection in the United States, costing the American health care system nearly $2.4 billion annually. Every year, there are over 4 million new cases of Chlamydia infections in the United States and an estimated 100 million cases worldwide. To cause disease, Chlamydia must successfully complete its complex biphasic developmental cycle, alternating between an infectious cell form (EB) specialized for initiating entry into target cells and a replicative form (RB) specialized for creating and maintaining the intracellular replication niche. The EB cell form has historically been considered metabolically quiescent, a passive entity simply waiting for contact with a host cell to initiate the next round of infection. Recent studies and data presented here demonstrate that the EB maintains its infectious phenotype by actively metabolizing a variety of nutrients. Therefore, the EB appears to have an active role in chlamydial biology, possibly within multiple environments, such as mucosal surfaces, fomites, and inside the host cell after formation.
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Nguyen PH, Lutter EI, Hackstadt T. Chlamydia trachomatis inclusion membrane protein MrcA interacts with the inositol 1,4,5-trisphosphate receptor type 3 (ITPR3) to regulate extrusion formation. PLoS Pathog 2018; 14:e1006911. [PMID: 29543918 PMCID: PMC5854415 DOI: 10.1371/journal.ppat.1006911] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 01/30/2018] [Indexed: 11/25/2022] Open
Abstract
Chlamydia trachomatis is an obligate intracellular bacterium that replicates within a vacuole termed an inclusion. At the end of their intracellular developmental cycle, chlamydiae are released either by lysis of the host cell or extrusion of the intact inclusion. The inclusion membrane is extensively modified by the insertion of type III secreted inclusion membrane proteins, Incs, which contribute to inclusion membrane structure and facilitate host-pathogen interactions. An interaction was identified between the inclusion membrane protein, MrcA, and the Ca2+ channel inositol-1,4,5-trisphosphate receptor, type 3 (ITPR3). ITPR3 was recruited and localized to active Src-family-kinase rich microdomains on the inclusion membrane as was the Ca2+ sensor, STIM1. Disruption of MrcA by directed mutagenesis resulted in loss of ITPR3 recruitment and simultaneous reduction of chlamydial release by extrusion. Complementation of MrcA restored ITPR3 recruitment and extrusion. Inhibition of extrusion was also observed following siRNA depletion of host ITPR3 or STIM1. Chlamydial extrusion was also inhibited by the calcium chelator BAPTA-AM. Each of these treatments resulted in a concomitant reduction in phosphorylation of the myosin regulatory light chain (MLC2) and a loss of myosin motor activity at the end of the developmental cycle which is consistent with the reduced extrusion formation. These studies suggest that Ca2+ signaling pathways play an important role in regulation of release mechanisms by C. trachomatis.
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Affiliation(s)
- Phu Hai Nguyen
- Host-Parasite Interactions Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Erika I. Lutter
- Host-Parasite Interactions Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, United States of America
| | - Ted Hackstadt
- Host-Parasite Interactions Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
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Pickering H, Teng A, Faal N, Joof H, Makalo P, Cassama E, Nabicassa M, Last AR, Burr SE, Rowland-Jones SL, Thomson NR, Roberts CH, Mabey DCW, Bailey RL, Hayward RD, de la Maza LM, Holland MJ. Genome-wide profiling of humoral immunity and pathogen genes under selection identifies immune evasion tactics of Chlamydia trachomatis during ocular infection. Sci Rep 2017; 7:9634. [PMID: 28851925 PMCID: PMC5575166 DOI: 10.1038/s41598-017-09193-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 07/24/2017] [Indexed: 11/09/2022] Open
Abstract
The frequency and duration of Chlamydia trachomatis (Ct) ocular infections decrease with age, suggesting development of partial immunity. However, there is a lack of clear correlates of immunity to Ct infection in humans. We screened sera from a cohort of Gambian children followed for six-months against a Ct-proteome microarray. At genome sequence level, we detected signatures of selection from a population of ocular Ct isolates from Guinea-Bissau. Together these approaches allowed us to highlight the focus of humoral responses and hypothesise new modes of pathogen immune evasion. Children who were susceptible to frequent and/or prolonged Ct infection had a less focussed antibody response, including preferential recognition of forty-two antigens. There was evidence of positive and purifying selection across the genome, but little balancing selection. In contrast, most antigens that were associated with susceptibility were under neutral selection. These data suggest an evasion strategy in which Ct presents a large panel of irrelevant antigens to the immune system to block or misdirect protective responses. Development of a focused immune response, possibly induced through vaccination, may be an effective strategy to promote protection to Ct infection.
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Affiliation(s)
- Harry Pickering
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, United Kingdom.
| | - Andy Teng
- ImmPORT Therapeutics, Inc./Antigen Discovery Inc., 1 Technology Dr., Suite E309, Irvine, CA, 92618, United States
| | - Nkoyo Faal
- Disease Control and Elimination Theme, Medical Research Council The Gambia Unit, Fajara, Banjul, The Gambia
| | - Hassan Joof
- Disease Control and Elimination Theme, Medical Research Council The Gambia Unit, Fajara, Banjul, The Gambia
| | - Pateh Makalo
- Disease Control and Elimination Theme, Medical Research Council The Gambia Unit, Fajara, Banjul, The Gambia
| | - Eunice Cassama
- Programa Nacional de Saúde de Visão, Ministério de Saúde Publica, Bissau, Guinea-Bissau
| | - Meno Nabicassa
- Programa Nacional de Saúde de Visão, Ministério de Saúde Publica, Bissau, Guinea-Bissau
| | - Anna R Last
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, United Kingdom
| | - Sarah E Burr
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, United Kingdom.,Disease Control and Elimination Theme, Medical Research Council The Gambia Unit, Fajara, Banjul, The Gambia
| | - Sarah L Rowland-Jones
- Disease Control and Elimination Theme, Medical Research Council The Gambia Unit, Fajara, Banjul, The Gambia
| | - Nicholas R Thomson
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, United Kingdom.,Pathogen Genomics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, United Kingdom
| | - Chrissy H Roberts
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, United Kingdom
| | - David C W Mabey
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, United Kingdom
| | - Robin L Bailey
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, United Kingdom
| | - Richard D Hayward
- Institute of Structural and Molecular Biology, Birkbeck & University College London, Malet Street, London, WC1E 7HX, United Kingdom
| | - Luis M de la Maza
- Department of Pathology and Laboratory Medicine, Medical Sciences I, Room D440, University of California, Irvine, CA, 92697-4800, United States
| | - Martin J Holland
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, United Kingdom.,Disease Control and Elimination Theme, Medical Research Council The Gambia Unit, Fajara, Banjul, The Gambia
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