1
|
Xaplanteri P, Rodis N, Potsios C. Virulence Factors of Chlamydia Spp. Involving Human Infections. Infect Dis (Lond) 2023. [DOI: 10.5772/intechopen.109742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Chlamydia spp. are the culprit of many human infections with severe complications, especially involving human eye, reproductive system, and lungs. The scope of the project is to delineate the virulence factors of the bacterium that facilitate invasion in human tissues, their mechanism of action, the ability to hide from immune system and the complications of infection. Chlamydia spp. are obligate intracellular pathogens that in their evolution, they use multiple mechanisms to enter host cell, to form the inclusion body, and to promote intracellular replication and survival. The T3SS effectors, the inclusion membrane proteins (Incs), are not only structural components of the membrane but also interfere with the host cell pathways. They also have an atypical mechanism of cell division. Description of the mechanisms of pathogenicity may lead to the development of new ways to face this major pathogen.
Collapse
|
2
|
Bugalhão JN, Mota LJ. The multiple functions of the numerous Chlamydia trachomatis secreted proteins: the tip of the iceberg. MICROBIAL CELL 2019; 6:414-449. [PMID: 31528632 PMCID: PMC6717882 DOI: 10.15698/mic2019.09.691] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Chlamydia trachomatis serovars are obligate intracellular bacterial pathogens mainly causing ocular and urogenital infections that affect millions of people worldwide and which can lead to blindness or sterility. They reside and multiply intracellularly within a membrane-bound vacuolar compartment, known as inclusion, and are characterized by a developmental cycle involving two morphologically and physiologically distinct chlamydial forms. Completion of the developmental cycle involves the secretion of > 70 C. trachomatis proteins that function in the host cell cytoplasm and nucleus, in the inclusion membrane and lumen, and in the extracellular milieu. These proteins can, for example, interfere with the host cell cytoskeleton, vesicular and non-vesicular transport, metabolism, and immune signalling. Generally, this promotes C. trachomatis invasion into, and escape from, host cells, the acquisition of nutrients by the chlamydiae, and evasion of cell-autonomous, humoral and cellular innate immunity. Here, we present an in-depth review on the current knowledge and outstanding questions about these C. trachomatis secreted proteins.
Collapse
Affiliation(s)
- Joana N Bugalhão
- UCIBIO, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Luís Jaime Mota
- UCIBIO, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Caparica, Portugal
| |
Collapse
|
3
|
Kunz TC, Götz R, Sauer M, Rudel T. Detection of Chlamydia Developmental Forms and Secreted Effectors by Expansion Microscopy. Front Cell Infect Microbiol 2019; 9:276. [PMID: 31448242 PMCID: PMC6695470 DOI: 10.3389/fcimb.2019.00276] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Accepted: 07/19/2019] [Indexed: 11/13/2022] Open
Abstract
Expansion microscopy (ExM) is a novel tool to improve the resolution of fluorescence-based microscopy that has not yet been used to visualize intracellular pathogens. Here we show the expansion of the intracellular pathogen Chlamydia trachomatis, enabling to differentiate its two distinct forms, catabolic active reticulate bodies (RB) and infectious elementary bodies (EB), on a conventional confocal microscope. We show that ExM enables the possibility to precisely locate chlamydial effector proteins, such as CPAF or Cdu1, within and outside of the chlamydial inclusion. Thus, we claim that ExM offers the possibility to address a broad range of questions and may be useful for further research on various intracellular pathogens.
Collapse
Affiliation(s)
- Tobias C Kunz
- Department of Microbiology, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Ralph Götz
- Department of Biotechnology and Biophysics, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Markus Sauer
- Department of Biotechnology and Biophysics, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Thomas Rudel
- Department of Microbiology, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| |
Collapse
|
4
|
Wen Y, Chen Y, Li L, Xu M, Tan Y, Li Y, Wang C, Chen Q, Kuang X, Wu Y. Localization and characterization of a putative cysteine desulfurase in Chlamydia psittaci. J Cell Biochem 2018; 120:4409-4422. [PMID: 30260037 DOI: 10.1002/jcb.27727] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Accepted: 08/29/2018] [Indexed: 12/20/2022]
Abstract
Chlamydia psittaci is an obligate intracellular pathogen with a biphasic developmental life cycle. It is auxotrophic for a variety of essential metabolites and obtains amino acids from eukaryotic host cells. Chlamydia can develop inside host cells within chlamydial inclusions. A pathway secreting proteins from inclusions into the host cellular cytoplasm is the type III secretion system (T3SS). The T3SS is universal among several Gram-negative bacteria. Here, we show that CPSIT_0959 of C. psittaci is expressed midcycle and secreted into the infected cellular cytoplasm via the T3SS. Recombinant CPSIT_0959 possesses cysteine desulfurase and PLP-binding activity, which removes sulfur from cysteine to produce alanine, and helps chlamydial replication. Our study shows that CPSIT_0959 improve the infectivity of offspring elementary bodies and seems to promote the replication by its product. This phenomenon has inhibited by the PLP-dependent enzymes inhibitor. Moreover, CPSIT_0959 increased expression of Bim and tBid, and decreased the mitochondrial membrane potential of host mitochondria to induce apoptosis in the latecycle for release of offspring. These results demonstrate that CPSIT_0959 has cysteine desulfurase and PLP-binding activity and is likely to contribute to apoptosis of the infected cells via a mitochondria-mediated pathway to improve the infectivity of progeny.
Collapse
Affiliation(s)
- Yating Wen
- Institute of Pathogenic Biology, Medical College, University of South China, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, China
| | - Yanbo Chen
- Department of Clinical Laboratory, Jiangmen Wuyi Traditional Chinese Medicine Hospital, Jiangmen, China
| | - Li Li
- Toxicology Laboratory, Hunan Provincial Center for Disease Control and Prevention, Changsha, China
| | - Man Xu
- Institute of Pathogenic Biology, Medical College, University of South China, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, China
| | - Yuan Tan
- Institute of Pathogenic Biology, Medical College, University of South China, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, China
| | - Yumeng Li
- Institute of Pathogenic Biology, Medical College, University of South China, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, China
| | - Chuan Wang
- Institute of Pathogenic Biology, Medical College, University of South China, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, China
| | - Qian Chen
- Institute of Pathogenic Biology, Medical College, University of South China, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, China
| | - Xingxing Kuang
- Institute of Pathogenic Biology, Medical College, University of South China, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, China
| | - Yimou Wu
- Institute of Pathogenic Biology, Medical College, University of South China, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, China
| |
Collapse
|
5
|
Wali S, Gupta R, Yu JJ, Lanka GKK, Chambers JP, Guentzel MN, Zhong G, Murthy AK, Arulanandam BP. Chlamydial protease-like activity factor mediated protection against C. trachomatis in guinea pigs. Immunol Cell Biol 2016; 95:454-460. [PMID: 27990018 PMCID: PMC5449249 DOI: 10.1038/icb.2016.122] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Revised: 12/02/2016] [Accepted: 12/06/2016] [Indexed: 01/30/2023]
Abstract
We have comprehensively demonstrated using the mouse model that intranasal immunization with recombinant chlamydial protease-like activity factor (rCPAF) leads to a significant reduction in bacterial burden, genital tract pathology and preserves fertility following intravaginal genital chlamydial challenge. In the present report, we evaluated the protective efficacy of rCPAF immunization in guinea pigs, a second animal model for genital chlamydial infection. Using a vaccination strategy similar to the mouse model, we intranasally immunized female guinea pigs with rCPAF plus CpG deoxynucleotides (CpG; as an adjuvant), and challenged intravaginally with C. trachomatis serovar D (CT-D). Immunization with rCPAF/CpG significantly reduced vaginal CT-D shedding and induced resolution of infection by day 24, compared to day 33 in CpG alone treated and challenged animals. Immunization induced robust anti-rCPAF serum IgG 2 weeks following the last immunization, and was sustained at a high level 4 weeks post challenge. Upregulation of antigen specific IFN-γ gene expression was observed in rCPAF/CpG vaccinated splenocytes. Importantly, a significant reduction in inflammation in the genital tissue in rCPAF/CpG-immunized guinea pigs compared to CpG-immunized animals was observed. Taken together, this study provides evidence of the protective efficacy of rCPAF as a vaccine candidate in a second animal model of genital chlamydial infection.
Collapse
Affiliation(s)
- Shradha Wali
- South Texas Center for Emerging Infectious Diseases and Center for Excellence in Infection Genomics, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, USA
| | - Rishein Gupta
- South Texas Center for Emerging Infectious Diseases and Center for Excellence in Infection Genomics, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, USA
| | - Jieh-Juen Yu
- South Texas Center for Emerging Infectious Diseases and Center for Excellence in Infection Genomics, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, USA
| | - Gopala Krishna Koundinya Lanka
- South Texas Center for Emerging Infectious Diseases and Center for Excellence in Infection Genomics, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, USA
| | - James P Chambers
- South Texas Center for Emerging Infectious Diseases and Center for Excellence in Infection Genomics, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, USA
| | - M Neal Guentzel
- South Texas Center for Emerging Infectious Diseases and Center for Excellence in Infection Genomics, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, USA
| | - Guangming Zhong
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Ashlesh K Murthy
- Department of Pathology, Midwestern University, Downers Grove, IL, USA
| | - Bernard P Arulanandam
- South Texas Center for Emerging Infectious Diseases and Center for Excellence in Infection Genomics, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, USA
| |
Collapse
|
6
|
Yang Z, Tang L, Shao L, Zhang Y, Zhang T, Schenken R, Valdivia R, Zhong G. The Chlamydia-Secreted Protease CPAF Promotes Chlamydial Survival in the Mouse Lower Genital Tract. Infect Immun 2016; 84:2697-702. [PMID: 27382018 PMCID: PMC4995919 DOI: 10.1128/iai.00280-16] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Accepted: 06/30/2016] [Indexed: 12/16/2022] Open
Abstract
Despite the extensive in vitro characterization of CPAF (chlamydial protease/proteasome-like activity factor), its role in chlamydial infection and pathogenesis remains unclear. We now report that a Chlamydia trachomatis strain deficient in expression of CPAF (L2-17) is no longer able to establish a successful infection in the mouse lower genital tract following an intravaginal inoculation. The L2-17 organisms were cleared from the mouse lower genital tract within a few days, while a CPAF-sufficient C. trachomatis strain (L2-5) survived in the lower genital tract for more than 3 weeks. However, both the L2-17 and L2-5 organisms maintained robust infection courses that lasted up to 4 weeks when they were directly delivered into the mouse upper genital tract. The CPAF-dependent chlamydial survival in the lower genital tract was confirmed in multiple strains of mice. Thus, we have demonstrated a critical role of CPAF in promoting C. trachomatis survival in the mouse lower genital tracts. It will be interesting to further investigate the mechanisms of the CPAF-dependent chlamydial pathogenicity.
Collapse
Affiliation(s)
- Zhangsheng Yang
- Department of Microbiology & Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Lingli Tang
- Department of Clinic Diagnosis, Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Lili Shao
- Department of Microbiology & Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Yuyang Zhang
- Department of Microbiology & Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Tianyuan Zhang
- Department of Microbiology & Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Robert Schenken
- Department of Obstetrics and Gynecology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Raphael Valdivia
- Duke Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Guangming Zhong
- Department of Microbiology & Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| |
Collapse
|
7
|
Yang Z, Tang L, Zhou Z, Zhong G. Neutralizing antichlamydial activity of complement by chlamydia-secreted protease CPAF. Microbes Infect 2016; 18:669-674. [PMID: 27436813 DOI: 10.1016/j.micinf.2016.07.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 06/22/2016] [Accepted: 07/05/2016] [Indexed: 01/19/2023]
Abstract
Ascending infection by sexually transmitted Chlamydia trachomatis is required for chlamydial induction of tubal pathology. To achieve ascension, the C. trachomatis organisms may have to spread from cell to cell, which inevitably exposes the organisms to extracellular mucosal effectors such as complement factors that are known to possess strong antichlamydial activities. Here, we report that the chlamydia-secreted protease CPAF efficiently neutralized complement factor C3-dependent antichlamydial activity. The neutralization was dependent on the proteolytic activity of CPAF and correlated with the CPAF-mediated degradation of complement factor C3 and factor B. As a result, CPAF preferentially inhibited the alternative complement activation pathway. The significance and limitation of these observations were discussed.
Collapse
Affiliation(s)
- Zhangsheng Yang
- Department of Microbiology & Immunology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
| | - Lingli Tang
- Department of Clinic Diagnosis, Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Zhiguang Zhou
- Department of Endocrinology, Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Guangming Zhong
- Department of Microbiology & Immunology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA.
| |
Collapse
|
8
|
Abstract
Chlamydia spp. are important causes of human disease for which no effective vaccine exists. These obligate intracellular pathogens replicate in a specialized membrane compartment and use a large arsenal of secreted effectors to survive in the hostile intracellular environment of the host. In this Review, we summarize the progress in decoding the interactions between Chlamydia spp. and their hosts that has been made possible by recent technological advances in chlamydial proteomics and genetics. The field is now poised to decipher the molecular mechanisms that underlie the intimate interactions between Chlamydia spp. and their hosts, which will open up many exciting avenues of research for these medically important pathogens.
Collapse
|
9
|
Chlamydial plasmid-encoded virulence factor Pgp3 neutralizes the antichlamydial activity of human cathelicidin LL-37. Infect Immun 2015; 83:4701-9. [PMID: 26416907 DOI: 10.1128/iai.00746-15] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 09/16/2015] [Indexed: 11/20/2022] Open
Abstract
Chlamydia trachomatis infection in the lower genital tract can ascend to and cause pathologies in the upper genital tract, potentially leading to severe complications, such as tubal infertility. However, chlamydial organisms depleted of plasmid or deficient in the plasmid-encoded Pgp3 are attenuated in ascending infection and no longer are able to induce the upper genital tract pathologies, indicating a significant role of Pgp3 in chlamydial pathogenesis. We now report that C. trachomatis Pgp3 can neutralize the antichlamydial activity of human cathelicidin LL-37, a host antimicrobial peptide secreted by both genital tract epithelial cells and infiltrating neutrophils. Pgp3 bound to and formed stable complexes with LL-37. We further showed that the middle region of Pgp3 (Pgp3m) was responsible for both the binding to and neutralization of LL-37, suggesting that Pgp3m can be targeted for attenuating chlamydial pathogenicity or developed for blocking LL-37-involved non-genital-tract pathologies, such as rosacea and psoriasis. Thus, the current study has provided significant information for both understanding the mechanisms of chlamydial pathogenesis and developing novel therapeutic agents.
Collapse
|
10
|
Bavoil PM, Byrne GI. Analysis of CPAF mutants: new functions, new questions (the ins and outs of a chlamydial protease). Pathog Dis 2015; 71:287-91. [PMID: 24942261 DOI: 10.1111/2049-632x.12194] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 06/06/2014] [Indexed: 12/18/2022] Open
Abstract
The role of the chlamydial protease CPAF, previously described as a secreted serine protease processing a wealth of host and chlamydial proteins to promote chlamydial intracellular growth, has recently been questioned by studies from the groups of Tan and Sütterlin, who demonstrated that the reported proteolysis of almost a dozen substrates by CPAF occurred during preparation of cell lysates rather than in intact cells. Valdivia et al. have now compared near-isogenic pairs of CPAF-deficient and secretion-deficient mutants of Chlamydia trachomatis and their wild-type parent. Their report, published in this issue of Pathogens and Disease, is a landmark study in the emerging era of Chlamydia genetics. The results of Tan and Sütterlin are confirmed with a few additions. While CPAF's role in pathogenesis is diminished considerably from these studies, CPAF remains an important factor in chlamydial biology as (1) CPAF mutants produce less infectious yield than wild type; and (2) CPAF is responsible for proteolytic cleavage of vimentin and LAP-1, but only after lysis of the inclusion membrane, not upon CPAF secretion to the cytosol. Here, we briefly review the evidence in support of CPAF's active secretion from the mid-to-late inclusion and conclude that new experimentation to establish whether or not CPAF is actively secreted should precede any new investigation of CPAF's cellular activities during mid-to-late development.
Collapse
Affiliation(s)
- Patrik M Bavoil
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, MD, USA
| | | |
Collapse
|
11
|
Characterization of CPAF critical residues and secretion during Chlamydia trachomatis infection. Infect Immun 2015; 83:2234-41. [PMID: 25776755 DOI: 10.1128/iai.00275-15] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Accepted: 03/11/2015] [Indexed: 11/20/2022] Open
Abstract
CPAF (chlamydial protease-like activity factor), a Chlamydia serine protease, is activated via proximity-induced intermolecular dimerization that triggers processing and removal of an inhibitory peptide occupying the CPAF substrate-binding groove. An active CPAF is a homodimer of two identical intramolecular heterodimers, each consisting of 29-kDa N-terminal and 35-kDa C-terminal fragments. However, critical residues for CPAF intermolecular dimerization, catalytic activity, and processing were defined in cell-free systems. Complementation of a CPAF-deficient chlamydial organism with a plasmid-encoded CPAF has enabled us to characterize CPAF during infection. The transformants expressing CPAF mutated at intermolecular dimerization, catalytic, or cleavage residues still produced active CPAF, although at a lower efficiency, indicating that CPAF can tolerate more mutations inside Chlamydia-infected cells than in cell-free systems. Only by simultaneously mutating both intermolecular dimerization and catalytic residues was CPAF activation completely blocked during infection, both indicating the importance of the critical residues identified in the cell-free systems and exploring the limit of CPAF's tolerance for mutations in the intracellular environment. We further found that active CPAF was always detected in the host cell cytoplasm while nonactive CPAF was restricted to within the chlamydial inclusions, regardless of how the infected cell samples were treated. Thus, CPAF translocation into the host cell cytoplasm correlates with CPAF enzymatic activity and is not altered by sample treatment conditions. These observations have provided new evidence for CPAF activation and translocation, which should encourage continued investigation of CPAF in chlamydial pathogenesis.
Collapse
|
12
|
Structural basis of the proteolytic and chaperone activity of Chlamydia trachomatis CT441. J Bacteriol 2014; 197:211-8. [PMID: 25349155 DOI: 10.1128/jb.02140-14] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Chlamydia trachomatis is the most prevalent cause of preventable blindness worldwide and a major reason for infectious infertility in females. Several bacterial factors have been implicated in the pathogenesis of C. trachomatis. Combining structural and mutational analysis, we have shown that the proteolytic function of CT441 depends on a conserved Ser/Lys/Gln catalytic triad and a functional substrate-binding site within a flexible PDZ (postsynaptic density of 95 kDa, discs large, and zonula occludens) domain. Previously, it has been suggested that CT441 is involved in modulating estrogen signaling responses of the host cell. Our results show that although in vitro CT441 exhibits proteolytic activity against SRAP1, a coactivator of estrogen receptor α, CT441-mediated SRAP1 degradation is not observed during the intracellular developmental cycle before host cells are lysed and infectious chlamydiae are released. Most compellingly, we have newly identified a chaperone activity of CT441, indicating a role of CT441 in prokaryotic protein quality control processes.
Collapse
|
13
|
Tan M, Sütterlin C. The Chlamydia protease CPAF: caution, precautions and function. Pathog Dis 2014; 72:7-9. [PMID: 25146758 DOI: 10.1111/2049-632x.12213] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 08/14/2014] [Indexed: 01/24/2023] Open
Affiliation(s)
- Ming Tan
- Department of Microbiology and Molecular Genetics, UC Irvine, Irvine, CA, USA; Department of Medicine, UC Irvine, Irvine, CA, USA.
| | | |
Collapse
|
14
|
Häcker G, Heuer D, Ojcius DM. Is the hoopla over CPAF justified? Pathog Dis 2014; 72:1-2. [PMID: 25113036 DOI: 10.1111/2049-632x.12211] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 08/04/2014] [Indexed: 01/19/2023] Open
Affiliation(s)
- Georg Häcker
- Institute of Medical Microbiology and Hygiene, University Medical Centre Freiburg, Freiburg, Germany.
| | | | | |
Collapse
|
15
|
Grieshaber SS, Grieshaber NA. The role of the chlamydial effector CPAF in the induction of genomic instability. Pathog Dis 2014; 72:5-6. [PMID: 25082267 DOI: 10.1111/2049-632x.12207] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
|
16
|
Snavely EA, Kokes M, Dunn JD, Saka HA, Nguyen BD, Bastidas RJ, McCafferty DG, Valdivia RH. Reassessing the role of the secreted protease CPAF in Chlamydia trachomatis infection through genetic approaches. Pathog Dis 2014; 71:336-51. [PMID: 24838663 DOI: 10.1111/2049-632x.12179] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 04/10/2014] [Accepted: 04/10/2014] [Indexed: 12/30/2022] Open
Abstract
The secreted Chlamydia protease CPAF cleaves a defined set of mammalian and Chlamydia proteins in vitro. As a result, this protease has been proposed to modulate a range of bacterial and host cellular functions. However, it has recently come into question the extent to which many of its identified substrates constitute bona fide targets of proteolysis in infected host cell rather than artifacts of postlysis degradation. Here, we clarify the role played by CPAF in cellular models of infection by analyzing Chlamydia trachomatis mutants deficient for CPAF activity. Using reverse genetic approaches, we identified two C. trachomatis strains possessing nonsense, loss-of-function mutations in cpa (CT858) and a third strain containing a mutation in type II secretion (T2S) machinery that inhibited CPAF activity by blocking zymogen secretion and subsequent proteolytic maturation into the active hydrolase. HeLa cells infected with T2S(-) or CPAF(-) C. trachomatis mutants lacked detectable in vitro CPAF proteolytic activity and were not defective for cellular traits that have been previously attributed to CPAF activity, including resistance to staurosporine-induced apoptosis, Golgi fragmentation, altered NFκB-dependent gene expression, and resistance to reinfection. However, CPAF-deficient mutants did display impaired generation of infectious elementary bodies (EBs), indicating an important role for this protease in the full replicative potential of C. trachomatis. In addition, we provide compelling evidence in live cells that CPAF-mediated protein processing of at least two host protein targets, vimentin filaments and the nuclear envelope protein lamin-associated protein-1 (LAP1), occurs rapidly after the loss of the inclusion membrane integrity, but before loss of plasma membrane permeability and cell lysis. CPAF-dependent processing of host proteins correlates with a loss of inclusion membrane integrity, and so we propose that CPAF plays a role late in infection, possibly during the stages leading to the dismantling of the infected cell prior to the release of EBs during cell lysis.
Collapse
Affiliation(s)
- Emily A Snavely
- Department of Molecular Genetics and Microbiology, Center for Microbial Pathogenesis, Duke University Medical Center, Durham, NC, USA
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Ojcius DM. Another year of microbial pathogens and the host immune response. Microbes Infect 2014; 16:1. [PMID: 24434009 DOI: 10.1016/j.micinf.2013.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 12/20/2013] [Indexed: 10/25/2022]
Affiliation(s)
- David M Ojcius
- Health Sciences Research Institute, University of California, Merced, USA.
| |
Collapse
|