Comprehensive in silico prediction and analysis of chlamydial outer membrane proteins reflects evolution and life style of the Chlamydiae

Heinz, Eva; Tischler, Patrick; Rattei, Thomas; Myers, Garry S. A.; Wagner, Michael; Horn, Matthias

doi:10.1186/1471-2164-10-634

Cited by 31 publications

(47 citation statements)

References 110 publications

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“…Although, no homolog to MOMP could be identified in the P. acanthamoebae or in the P. amoebophila genomes, a putative cysteine-rich MOMP-family is present in the W. chondrophila genome [20], [24], [38]. However, no protein of this family was identified in the present work, most probably because we had, on purpose, chosen extraction and isolation conditions which should leave the putative waddlial disulphide linked matrix as an insoluble complex.…”

Section: Discussionmentioning

confidence: 73%

Identification of Immunogenic Proteins of Waddlia chondrophila

et al. 2012

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Evidence is growing for a role of Waddlia chondrophila as an agent of adverse pregnancy outcomes in both humans and ruminants. This emerging pathogen, member of the order Chlamydiales, is also implicated in bronchiolitis and lower respiratory tract infections. Until now, the serological diagnosis of W. chondrophila infection has mainly relied on manually intensive tests including micro-immunofluorescence and Western blotting. Thus, there is an urgent need to establish reliable high throughput serological assays. Using a combined genomic and proteomic approach, we detected 57 immunogenic proteins of W. chondrophila, of which 17 were analysed by mass spectrometry. Two novel hypothetical proteins, Wim3 and Wim4, were expressed as recombinant proteins in Escherichia coli, purified and used as antigens in an ELISA test. Both proteins were recognized by sera of rabbits immunized with W. chondrophila as well as by human W. chondrophila positive sera but not by rabbit pre-immune sera nor human W. chondrophila negative sera. These results demonstrated that the approach chosen is suitable to identify immunogenic proteins that can be used to develop a serological test. This latter will be a valuable tool to further clarify the pathogenic potential of W. chondrophila.

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Section: Discussionmentioning

confidence: 73%

Identification of Immunogenic Proteins of Waddlia chondrophila

et al. 2012

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“…The inclusion membrane might also contribute to host specificity and play a crucial role in the uptake of nutrients from the host cell (42). In this study we raised the question of whether this unique group of proteins is also used by the chlamydia-related amoeba symbiont P. amoebophila, which does not share various other classic chlamydial virulence factors, such as, e.g., the polymorphic membrane proteins or the translocated actin-recruiting protein, with the Chlamydiaceae (22). In addition, in contrast to the Chlamydiaceae, P. amoebophila remains in single-cell inclusions and stably coexists with its host.…”

Section: Resultsmentioning

confidence: 99%

Inclusion Membrane Proteins ofProtochlamydia amoebophilaUWE25 Reveal a Conserved Mechanism for Host Cell Interaction among theChlamydiae

et al. 2010

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Chlamydiae are a group of obligate intracellular bacteria comprising several important human pathogens. Inside the eukaryotic cell, chlamydiae remain within a host-derived vesicular compartment, termed the inclusion. They modify the inclusion membrane through insertion of unique proteins, which are involved in interaction with and manipulation of the host cell. Among chlamydiae, inclusion membrane proteins have been exclusively found in members of the family Chlamydiaceae, which predominantly infect mammalian and avian hosts. Here, the presence of inclusion membrane proteins in Protochlamydia amoebophila UWE25, a chlamydial endosymbiont of free-living amoebae, is reported. A genome-wide screening for secondary structure motifs resulted in the identification of 23 putative inclusion membrane proteins for this organism. Immunofluorescence analysis demonstrated that five of these proteins were expressed, and four of them could be localized to a halo surrounding the intracellular bacteria. Colocalization studies showed an almost complete overlap of the signals obtained for the four putative inclusion membrane proteins, and immuno-transmission electron microscopy unambiguously demonstrated their location in the inclusion membrane. The presence of inclusion membrane proteins (designated IncA, IncQ, IncR, and IncS) in P. amoebophila shows that this strategy for host cell interaction is conserved among the chlamydiae and is used by chlamydial symbionts and pathogens alike.Chlamydiae were once considered a small group of very closely related bacteria which form an evolutionarily well-separated lineage in the tree of life. These obligate intracellular bacteria infect a broad spectrum of at least 60 eukaryotic host organisms including both invertebrates and vertebrates. Until recently, the family Chlamydiaceae was the only described chlamydial family, which is exclusively comprised of human and animal pathogens. It includes Chlamydia trachomatis, the most prevalent sexually transmitted bacteria worldwide, with over 90 million new cases of infection per year (56), and the world's leading cause of preventable blindness (57). The other major human pathogen among the chlamydiae, Chlamydophila pneumoniae (basonym, Chlamydia pneumoniae) (15), causes community-acquired pneumonia and is also implicated in several chronic diseases such as arteriosclerosis and multiple sclerosis (33, 38). The discovery of several chlamydia-like endosymbionts in amoebae in the late 1990s represented the first evidence for a much larger diversity of chlamydiae in the environment (3,7,17,27). Since then, numerous new chlamydial organisms were discovered, which led to the description of several new families (9,25,30).A characteristic feature of all chlamydiae is the developmental cycle, which includes morphologically and physiologically distinct developmental forms (1, 37). Infection of host cells starts with the attachment of the infectious form of the chlamydiae, the elementary body (EB), to a host cell and uptake by a phagocytosis-like mechanism. Onc...

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“…It is noteworthy that the "nearest neighbor" chlamydial organism in this article, the amoeba endosymbiont "Ca. Protochlamydia amoebophila," possesses only a single candidate gene encoding a Pmp protein (49). It is generally considered likely that Pmp proteins are key virulence factors, probably playing a role in antigenic variation and/or host adhesion.…”

Section: Regional Trp Hot Spots Exemplified By Polymorphic Membrane Pmentioning

confidence: 99%

The AlternativeTranslational Profile That Underlies the Immune-Evasive State of Persistence in Chlamydiaceae Exploits Differential Tryptophan Contents of the Protein Repertoire

Xie

Bonner

et al. 2012

Microbiol Mol Biol Rev

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SUMMARY One form of immune evasion is a developmental state called “persistence” whereby chlamydial pathogens respond to the host-mediated withdrawal of l -tryptophan (Trp). A sophisticated survival mode of reversible quiescence is implemented. A mechanism has evolved which suppresses gene products necessary for rapid pathogen proliferation but allows expression of gene products that underlie the morphological and developmental characteristics of persistence. This switch from one translational profile to an alternative translational profile of newly synthesized proteins is proposed to be accomplished by maximizing the Trp content of some proteins needed for rapid proliferation (e.g., ADP/ATP translocase, hexose-phosphate transporter, phosphoenolpyruvate [PEP] carboxykinase, the Trp transporter, the Pmp protein superfamily for cell adhesion and antigenic variation, and components of the cell division pathway) while minimizing the Trp content of other proteins supporting the state of persistence. The Trp starvation mechanism is best understood in the human- Chlamydia trachomatis relationship, but the similarity of up-Trp and down-Trp proteomic profiles in all of the pathogenic Chlamydiaceae suggests that Trp availability is an underlying cue relied upon by this family of pathogens to trigger developmental transitions. The biochemically expensive pathogen strategy of selectively increased Trp usage to guide the translational profile can be leveraged significantly with minimal overall Trp usage by (i) regional concentration of Trp residue placements, (ii) amplified Trp content of a single protein that is required for expression or maturation of multiple proteins with low Trp content, and (iii) Achilles'-heel vulnerabilities of complex pathways to high Trp content of one or a few enzymes.

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Comprehensive in silico prediction and analysis of chlamydial outer membrane proteins reflects evolution and life style of the Chlamydiae

Cited by 31 publications

References 110 publications

Identification of Immunogenic Proteins of Waddlia chondrophila

Identification of Immunogenic Proteins of Waddlia chondrophila

Inclusion Membrane Proteins ofProtochlamydia amoebophilaUWE25 Reveal a Conserved Mechanism for Host Cell Interaction among theChlamydiae

The AlternativeTranslational Profile That Underlies the Immune-Evasive State of Persistence in Chlamydiaceae Exploits Differential Tryptophan Contents of the Protein Repertoire

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