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Luís MP, Pereira IS, Bugalhão JN, Simões CN, Mota C, Romão MJ, Mota LJ. The Chlamydia trachomatis IncM Protein Interferes with Host Cell Cytokinesis, Centrosome Positioning, and Golgi Distribution and Contributes to the Stability of the Pathogen-Containing Vacuole. Infect Immun 2023; 91:e0040522. [PMID: 36877064 PMCID: PMC10112248 DOI: 10.1128/iai.00405-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 02/13/2023] [Indexed: 03/07/2023] Open
Abstract
Chlamydia trachomatis is an obligate intracellular bacterial pathogen that causes ocular and urogenital infections in humans. The ability of C. trachomatis to grow intracellularly in a pathogen-containing vacuole (known as an inclusion) depends on chlamydial effector proteins transported into the host cell by a type III secretion system. Among these effectors, several inclusion membrane proteins (Incs) insert in the vacuolar membrane. Here, we show that human cell lines infected by a C. trachomatis strain deficient for Inc CT288/CTL0540 (renamed IncM) displayed less multinucleation than when infected by IncM-producing strains (wild type or complemented). This indicated that IncM is involved in the ability of Chlamydia to inhibit host cell cytokinesis. The capacity of IncM to induce multinucleation in infected cells was shown to be conserved among its chlamydial homologues and appeared to require its two larger regions predicted to be exposed to the host cell cytosol. C. trachomatis-infected cells also displayed IncM-dependent defects in centrosome positioning, Golgi distribution around the inclusion, and morphology and stability of the inclusion. The altered morphology of inclusions containing IncM-deficient C. trachomatis was further affected by depolymerization of host cell microtubules. This was not observed after depolymerization of microfilaments, and inclusions containing wild-type C. trachomatis did not alter their morphology upon depolymerization of microtubules. Overall, these findings suggest that IncM may exert its effector function by acting directly or indirectly on host cell microtubules.
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Affiliation(s)
- Maria Pequito Luís
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- Department of Life Sciences, UCIBIO, Applied Molecular Biosciences Unit, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
| | - Inês Serrano Pereira
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- Department of Life Sciences, UCIBIO, Applied Molecular Biosciences Unit, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
| | - Joana N. Bugalhão
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- Department of Life Sciences, UCIBIO, Applied Molecular Biosciences Unit, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
| | - Catarina N. Simões
- Department of Life Sciences, UCIBIO, Applied Molecular Biosciences Unit, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- Faculty of Sciences, University of Lisbon, Lisbon, Portugal
| | - Cristiano Mota
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- Department of Chemistry, UCIBIO, Applied Molecular Biosciences Unit, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
| | - Maria João Romão
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- Department of Chemistry, UCIBIO, Applied Molecular Biosciences Unit, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
| | - Luís Jaime Mota
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
- Department of Life Sciences, UCIBIO, Applied Molecular Biosciences Unit, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal
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Amaro F, Martín-González A. Microbial warfare in the wild-the impact of protists on the evolution and virulence of bacterial pathogens. Int Microbiol 2021; 24:559-571. [PMID: 34365574 DOI: 10.1007/s10123-021-00192-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 06/03/2021] [Accepted: 06/28/2021] [Indexed: 01/01/2023]
Abstract
During the long history of co-evolution with protists, bacteria have evolved defense strategies to avoid grazing and survive phagocytosis. These mechanisms allow bacteria to exploit phagocytic cells as a protective niche in which to escape from environmental stress and even replicate. Importantly, these anti-grazing mechanisms can function as virulence factors when bacteria infect humans. Here, we discuss how protozoan predation exerts a selective pressure driving bacterial virulence and shaping their genomes, and how bacteria-protist interactions might contribute to the spread of antibiotic resistance as well. We provide examples to demonstrate that besides being voracious bacterial predators, protozoa can serve as melting pots where intracellular organisms exchange genetic information, or even "training grounds" where some pathogens become hypervirulent after passing through. In this special issue, we would like to emphasize the tremendous impact of bacteria-protist interactions on human health and the potential of amoebae as model systems to study biology and evolution of a variety of pathogens. Besides, a better understanding of bacteria-protist relationships will help us expand our current understanding of bacterial virulence and, likely, how pathogens emerge.
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Affiliation(s)
- Francisco Amaro
- Department of Genetics, Physiology and Microbiology, School of Biology, Complutense University of Madrid, 28040, Madrid, Spain.
| | - Ana Martín-González
- Department of Genetics, Physiology and Microbiology, School of Biology, Complutense University of Madrid, 28040, Madrid, Spain
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Amoebae as Targets for Toxins or Effectors Secreted by Mammalian Pathogens. Toxins (Basel) 2021; 13:toxins13080526. [PMID: 34437397 PMCID: PMC8402458 DOI: 10.3390/toxins13080526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 07/26/2021] [Accepted: 07/26/2021] [Indexed: 11/28/2022] Open
Abstract
Numerous microorganisms, pathogenic for mammals, come from the environment where they encounter predators such as free-living amoebae (FLA). The selective pressure due to this interaction could have generated virulence traits that are deleterious for amoebae and represents a weapon against mammals. Toxins are one of these powerful tools that are essential for bacteria or fungi to survive. Which amoebae are used as a model to study the effects of toxins? What amoeba functions have been reported to be disrupted by toxins and bacterial secreted factors? Do bacteria and fungi effectors affect eukaryotic cells similarly? Here, we review some studies allowing to answer these questions, highlighting the necessity to extend investigations of microbial pathogenicity, from mammals to the environmental reservoir that are amoebae.
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Kebbi-Beghdadi C, Pilloux L, Martin V, Greub G. Eukaryotic Cell Permeabilisation to Identify New Putative Chlamydial Type III Secretion System Effectors Secreted within Host Cell Cytoplasm. Microorganisms 2020; 8:microorganisms8030361. [PMID: 32138376 PMCID: PMC7143554 DOI: 10.3390/microorganisms8030361] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 02/27/2020] [Accepted: 02/28/2020] [Indexed: 02/08/2023] Open
Abstract
Chlamydia trachomatis and Waddlia chondrophila are strict intracellular bacteria belonging to the Chlamydiales order. C. trachomatis is the most frequent bacterial cause of genital and ocular infections whereas W. chondrophila is an opportunistic pathogen associated with adverse pregnancy outcomes and respiratory infections. Being strictly intracellular, these bacteria are engaged in a complex interplay with their hosts to modulate their environment and create optimal conditions for completing their life cycle. For this purpose, they possess several secretion pathways and, in particular, a Type III Secretion System (T3SS) devoted to the delivery of effector proteins in the host cell cytosol. Identifying these effectors is a crucial step in understanding the molecular basis of bacterial pathogenesis. Following incubation of infected cells with perfringolysin O, a pore-forming toxin that binds cholesterol present in plasma membranes, we analysed by mass spectrometry the protein content of the host cell cytoplasm. We identified 13 putative effectors secreted by C. trachomatis and 19 secreted by W. chondrophila. Using Y. enterocolitica as a heterologous expression and secretion system, we confirmed that four of these identified proteins are secreted by the T3SS. Two W. chondrophila T3SS effectors (hypothetical proteins Wcw_0499 and Wcw_1706) were further characterised and demonstrated to be early/mid-cycle effectors. In addition, Wcw_1706 is associated with a tetratricopeptide domain-containing protein homologous to C. trachomatis class II chaperone. Furthermore, we identified a novel C. trachomatis effector, CT460 that localises in the eukaryotic nucleus when ectopically expressed in 293 T cells.
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Affiliation(s)
| | | | | | - Gilbert Greub
- Correspondence: ; Tel.: +41-21-314-4979; Fax: +41-21-314-4060
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