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Strange N, Luu L, Ong V, Wee BA, Phillips MJA, McCaughey L, Steele JR, Barlow CK, Cranfield CG, Myers G, Mazraani R, Rock C, Timms P, Huston WM. HtrA, fatty acids, and membrane protein interplay in Chlamydia trachomatis to impact stress response and trigger early cellular exit. J Bacteriol 2024; 206:e0037123. [PMID: 38445896 PMCID: PMC11025325 DOI: 10.1128/jb.00371-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 02/15/2024] [Indexed: 03/07/2024] Open
Abstract
Chlamydia trachomatis is an intracellular bacterial pathogen that undergoes a biphasic developmental cycle, consisting of intracellular reticulate bodies and extracellular infectious elementary bodies. A conserved bacterial protease, HtrA, was shown previously to be essential for Chlamydia during the reticulate body phase, using a novel inhibitor (JO146). In this study, isolates selected for the survival of JO146 treatment were found to have polymorphisms in the acyl-acyl carrier protein synthetase gene (aasC). AasC encodes the enzyme responsible for activating fatty acids from the host cell or synthesis to be incorporated into lipid bilayers. The isolates had distinct lipidomes with varied fatty acid compositions. A reduction in the lipid compositions that HtrA prefers to bind to was detected, yet HtrA and MOMP (a key outer membrane protein) were present at higher levels in the variants. Reduced progeny production and an earlier cellular exit were observed. Transcriptome analysis identified that multiple genes were downregulated in the variants especially stress and DNA processing factors. Here, we have shown that the fatty acid composition of chlamydial lipids, HtrA, and membrane proteins interplay and, when disrupted, impact chlamydial stress response that could trigger early cellular exit. IMPORTANCE Chlamydia trachomatis is an important obligate intracellular pathogen that has a unique biphasic developmental cycle. HtrA is an essential stress or virulence protease in many bacteria, with many different functions. Previously, we demonstrated that HtrA is critical for Chlamydia using a novel inhibitor. In the present study, we characterized genetic variants of Chlamydia trachomatis with reduced susceptibility to the HtrA inhibitor. The variants were changed in membrane fatty acid composition, outer membrane proteins, and transcription of stress genes. Earlier and more synchronous cellular exit was observed. Combined, this links stress response to fatty acids, membrane proteins, and HtrA interplay with the outcome of disrupted timing of chlamydial cellular exit.
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Affiliation(s)
- Natalie Strange
- School of Life Sciences, Faculty of Science, University of Technology Sydney, Ultimo, New South Wales, Australia
| | - Laurence Luu
- School of Life Sciences, Faculty of Science, University of Technology Sydney, Ultimo, New South Wales, Australia
| | - Vanissa Ong
- Faculty of Health, Queensland University of Technology, Kelvin Grove, Queensland, Australia
| | - Bryan A. Wee
- Faculty of Health, Queensland University of Technology, Kelvin Grove, Queensland, Australia
- The Roslin Institute, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Matthew J. A. Phillips
- School of Life Sciences, Faculty of Science, University of Technology Sydney, Ultimo, New South Wales, Australia
| | - Laura McCaughey
- Australian Institute for Microbiology and Infection, Faculty of Science, University of Technology Sydney, Ultimo, New South Wales, Australia
- School of Infection and Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom
| | - Joel R. Steele
- School of Life Sciences, Faculty of Science, University of Technology Sydney, Ultimo, New South Wales, Australia
- Department of Biochemistry and Molecular Biology, Monash Proteomics and Metabolomics Platform, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Christopher K. Barlow
- Department of Biochemistry and Molecular Biology, Monash Proteomics and Metabolomics Platform, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Charles G. Cranfield
- School of Life Sciences, Faculty of Science, University of Technology Sydney, Ultimo, New South Wales, Australia
| | - Garry Myers
- Australian Institute for Microbiology and Infection, Faculty of Science, University of Technology Sydney, Ultimo, New South Wales, Australia
| | - Rami Mazraani
- School of Life Sciences, Faculty of Science, University of Technology Sydney, Ultimo, New South Wales, Australia
| | - Charles Rock
- Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - Peter Timms
- Centre for Bioinnovation, University of the Sunshine Coast, Maroochydore, Queensland, Australia
| | - Wilhelmina M. Huston
- Faculty of Science, University of Technology Sydney, Ultimo, New South Wales, Australia
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Hwang J, Strange N, Mazraani R, Phillips MJ, Gamble AB, Huston WM, Tyndall JDA. Design, synthesis and biological evaluation of P2-modified proline analogues targeting the HtrA serine protease in Chlamydia. Eur J Med Chem 2021; 230:114064. [PMID: 35007862 DOI: 10.1016/j.ejmech.2021.114064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/07/2021] [Accepted: 12/18/2021] [Indexed: 11/19/2022]
Abstract
High temperature requirement A (HtrA) serine proteases have emerged as a novel class of antibacterial target, which are crucial in protein quality control and are involved in the pathogenesis of a wide array of bacterial infections. Previously, we demonstrated that HtrA in Chlamydia is essential for bacterial survival, replication and virulence. Here, we report a new series of proline (P2)-modified inhibitors of Chlamydia trachomatis HtrA (CtHtrA) developed by proline ring expansion and Cγ-substitutions. The structure-based drug optimization process was guided by molecular modelling and in vitro pharmacological evaluation of inhibitory potency, selectivity and cytotoxicity. Compound 25 from the first-generation 4-substituted proline analogues increased antiCtHtrA potency and selectivity over human neutrophil elastase (HNE) by approximately 6- and 12-fold, respectively, relative to the peptidic lead compound 1. Based on this compound, second-generation substituted proline residues containing 1,2,3-triazole moieties were synthesized by regioselective azide-alkyne click chemistry. Compound 49 demonstrated significantly improved antichlamydial activity in whole cell assays, diminishing the bacterial infectious progeny below the detection limit at the lowest dose tested. Compound 49 resulted in approximately 9- and 22-fold improvement in the inhibitory potency and selectivity relative to 1, respectively. To date, compound 49 is the most potent HtrA inhibitor developed against Chlamydia spp.
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Affiliation(s)
- Jimin Hwang
- School of Pharmacy, University of Otago, Dunedin, New Zealand
| | - Natalie Strange
- School of Life Sciences, Faculty of Science, University of Technology Sydney, New South Wales, Australia
| | - Rami Mazraani
- School of Life Sciences, Faculty of Science, University of Technology Sydney, New South Wales, Australia
| | - Matthew J Phillips
- School of Life Sciences, Faculty of Science, University of Technology Sydney, New South Wales, Australia
| | - Allan B Gamble
- School of Pharmacy, University of Otago, Dunedin, New Zealand.
| | - Wilhelmina M Huston
- School of Life Sciences, Faculty of Science, University of Technology Sydney, New South Wales, Australia.
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Mazraani R, Timms P, Hill PC, Suaalii-Sauni T, Niupulusu T, Temese SVA, Iosefa-Siitia L, Auvaa L, Tapelu SA, Motu MF, Righarts A, Walsh MS, Rombauts L, Allan JA, Horner P, Huston WM. Evaluation of a PGP3 ELISA for surveillance of the burden of Chlamydia infection in women from Australia and Samoa. Pathog Dis 2020; 77:5519228. [PMID: 31201421 PMCID: PMC6607412 DOI: 10.1093/femspd/ftz031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 06/10/2019] [Indexed: 01/10/2023] Open
Abstract
Serological assays can be used to investigate the population burden of infection and potentially sequelae from Chlamydia. We investigated the PGP3 ELISA as a sero-epidemiological tool for infection or sub-fertility in Australian and Samoan women. The PGP3 ELISA absorbance levels were compared between groups of women with infertility, fertile, and current chlamydial infections. In the Australian groups, women with chlamydial tubal factor infertility had significantly higher absorbance levels in the PGP3 ELISA compared to fertile women (P < 0.0001), but not when compared to women with current chlamydial infection (P = 0.44). In the Samoan study, where the prevalence of chlamydial infections is much higher there were significant differences in the PGP3 ELISA absorbance levels between chlamydial sub-fertile women and fertile women (P = 0.003). There was no difference between chlamydial sub-fertile women and women with a current infection (P = 0.829). The results support that the PGP3 assay is effective for sero-epidemiological analysis of burden of infection, but not for evaluation of chlamydial pathological sequelae such as infertility.
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Affiliation(s)
- Rami Mazraani
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Peter Timms
- Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore, QLD 4558, Australia
| | - Philip C Hill
- Centre for International Health, University of Otago, Dunedin, 9016, New Zealand
| | - Tamaailau Suaalii-Sauni
- School of Languages and Cultures, Victoria University of Wellington, Wellington, 2820, New Zealand
| | | | - Seiuli V A Temese
- Centre for Samoa Studies, National University of Samoa, Le Papaigalagala Campus, To'omatagi, Samoa
| | | | | | | | | | - Antoinette Righarts
- Preventive and Social Medicine, Dunedin School of Medicine, The University of Otago, Dunedin, 9016, New Zealand
| | - Michael S Walsh
- Planning, Funding and Health Outcomes, Waitemata and Auckland District Health Boards, Auckland, New Zealand
| | - Luk Rombauts
- MIMR-PH Institute of Medical Research, Monash, Australia
| | - John A Allan
- UC Health Clinical School, The Wesley Hospital, Auchenflower, Queensland, 4066, Australia
| | - Patrick Horner
- Population Health Sciences, University of Bristol, Bristol, United Kingdom
| | - Wilhelmina M Huston
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia
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