Abstract:
:The clinical and histopathological manifestations of syphilis and the invasive behavior of Treponema pallidum in tissue culture systems reflect the propensity for treponemes to migrate through skin, hematogenously disseminate, and invade targeted tissues. Treponemal motility is believed to be essential to this process and thereby an important facet of syphilis pathogenesis. By analogy with other bacterial pathogens, it is plausible that treponemal motility and tissue invasion are modulated by sensory transduction events associated with chemotactic responses. Recent studies have demonstrated the existence in T. pallidum of accessory molecules typically associated with sensory transduction events involving methyl-accepting chemotaxis proteins (MCPs). Intrinsic radiolabeling of T. pallidum in vitro with L-[methyl-3H] methionine revealed one methylated treponemal polypeptide with an apparent molecular mass of 64 kDa. A degenerate oligonucleotide probe corresponding to a highly conserved C-terminal domain within Bacillus subtilis and Escherichia coli MCPs was used in Southern blotting of T. pallidum DNA to identify and subsequently clone a putative T. pallidum MCP gene (mcp1). Computer analyses predicted a near-consensus promoter upstream of mcp1, and primer extension analysis employing T. pallidum RNA revealed a transcriptional initiation site. T. pallidum mcp1 encoded a 579-amino-acid (64.6-kDa) polypeptide which was highly homologous to at least 69 other known or putative sensory transducer proteins, with the highest degrees of homology existing between the C terminus of mcp1 and the C-terminal (signaling) domains of the other bacterial MCPs. Other salient features of Mcp1 included (i) six potential membrane-spanning domains at the N terminus, (ii) two predicted alpha-helical coiled coil regions containing at least three putative methylation sites, and (iii) homologies with two ligand-binding domains (LI-1 and LI-2) of the E. coli MCPs Trg and Tar. This study is the first to provide both metabolic and genetic evidence for an MCP sensory transducer in T. pallidum. The combined findings prompt key questions regarding the relationship(s) among sensory transduction, regulation of endoflagellar rotation, and chemotactic responses (in particular, the role of glucose) during virulence expression by T. pallidum.
journal_name
Infect Immunjournal_title
Infection and immunityauthors
Hagman KE,Porcella SF,Popova TG,Norgard MVdoi
10.1128/IAI.65.5.1701-1709.1997subject
Has Abstractpub_date
1997-05-01 00:00:00pages
1701-9issue
5eissn
0019-9567issn
1098-5522journal_volume
65pub_type
杂志文章abstract::Streptococcus pyogenes secretes a specific immunoglobulin G (IgG)-protease, SpeB, as well as the IgG glycan-hydrolyzing enzyme EndoS. Here we show that SpeB also degrades IgA, IgM, IgD, and IgE. We also show that EndoS only hydrolyzes the glycan moiety on native but not denatured IgG. Thus, SpeB has a broad immunoglob...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.69.11.7187-7189.2001
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abstract::Human gingival fibroblasts were exposed in culture to cell extracts of different black-pigmented Bacteroides species, and their growth was monitored by determining thymidine uptake and counting cells. Of the Bacteroides species tested (B. gingivalis, B. asaccharolyticus, and B. intermedius), B. gingivalis gave the ext...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.55.1.201-205.1987
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journal_title:Infection and immunity
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doi:
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abstract::The pattern of invasion of human hair in vitro by the dermatophyte Microsporum gypseum was studied by transmission and scanning electron microscopy. Mycelia that invaded the hair cortex through the edge of cuticles showed a flattened "frond" growth in contrast to the filamentous form seen on ordinary laboratory media....
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.38.2.706-715.1982
更新日期:1982-11-01 00:00:00
abstract::Isolates of Thermoplasma acidophilum were divided into serological groups based on immunodiffusion studies of solubilized-membrane preparations. ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.10.1.280-281.1974
更新日期:1974-07-01 00:00:00
abstract::Antigen-specific T-cell responses and histopathological changes were studied in mice experimentally inoculated with Borrelia burgdorferi B31. Inbred mice with different H-2 haplotypes and/or different genetic backgrounds were inoculated with B. burgdorferi organisms and tested for antigen-specific T-cell responses in ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.57.1.41-47.1989
更新日期:1989-01-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.64.9.3703-3712.1996
更新日期:1996-09-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00204-09
更新日期:2009-07-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.69.12.7535-7543.2001
更新日期:2001-12-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.67.1.88-93.1999
更新日期:1999-01-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.67.3.1424-1431.1999
更新日期:1999-03-01 00:00:00
abstract::Ers has been qualified as the PrfA-like transcriptional regulator of Enterococcus faecalis. In a previous study we reported that Ers is important for the survival within macrophages of this opportunist pathogenic bacterium. In the present work we have used proteomic and microarray expression profiling of E. faecalis J...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00161-08
更新日期:2008-07-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.57.6.1865-1867.1989
更新日期:1989-06-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.72.10.5963-5971.2004
更新日期:2004-10-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.34.1.184-191.1981
更新日期:1981-10-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.55.8.1792-1800.1987
更新日期:1987-08-01 00:00:00
abstract::The pH 6 antigen (Psa) of Yersinia pestis consists of fimbriae with adhesive properties of potential importance for the pathogenesis of plague, including pneumonic plague. The Psa fimbriae mediate bacterial binding to human alveolar epithelial cells. The Psa fimbriae bound mostly to one component present in the total ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01153-06
更新日期:2007-03-01 00:00:00
abstract::Whole-genome sequencing analysis of ∼800 strains of group A Streptococcus (GAS) found that the gene encoding the multiple virulence gene regulator of GAS (mga) is highly polymorphic in serotype M59 strains but not in strains of other serotypes. To help understand the molecular mechanism of gene regulation by Mga and i...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.03023-14
更新日期:2015-06-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.24.2.394-398.1979
更新日期:1979-05-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.52.1.323-325.1986
更新日期:1986-04-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.8.3206-3212.1994
更新日期:1994-08-01 00:00:00
abstract::Immunomodulatory agents potentially represent a new class of broad-spectrum antimicrobials. Here, we demonstrate that prophylaxis with immunomodulatory cytosine-phosphate-guanidine (CpG) oligodeoxynucleotide (ODN), a toll-like receptor 9 (TLR9) agonist, confers protection against Yersinia pestis, the etiologic agent o...
journal_title:Infection and immunity
pub_type: 杂志文章
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更新日期:2013-06-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.23.2.432-437.1979
更新日期:1979-02-01 00:00:00
abstract::Endotoxin-treated mice exhibit a rapid rise in the level of the serum amyloid A (SAA) protein, but this effect is not observed in endotoxin-resistant C3H/HeJ mice. To evaluate the role of lymphoid cells in the production of SAA protein, C3H/HeJ mice were adoptively transfused with endotoxin-sensitive (C3H/HeN) bone ma...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.23.1.181-183.1979
更新日期:1979-01-01 00:00:00
abstract::Anti-NMDA receptor (NMDAR) autoantibodies have been postulated to play a role in the pathogenesis of NMDAR hypofunction, which contributes to the etiology of psychotic symptoms. Toxoplasma gondii is a pathogen implicated in psychiatric disorders and associated with elevation of NMDAR autoantibodies. However, it remain...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00398-18
更新日期:2018-09-21 00:00:00
abstract::Actinobacillus pleuropneumoniae, the causative agent of swine pleuropneumonia, secretes a hemolytic activity which is thought to be a factor involved in the pathogenesis of the disease. The biosynthesis of hemolysin by serotype 1 strain 4074 was strongly dependent on the activity of free Ca2+ in the growth medium. At ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.56.10.2570-2575.1988
更新日期:1988-10-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01210-06
更新日期:2006-12-01 00:00:00
abstract::Borrelia burgdorferi is a causative agent of Lyme disease, the most common arthropod-borne disease in the United States. B. burgdorferi evades host immune defenses to establish a persistent, disseminated infection. Previous work showed that P66-deficient B. burgdorferi (Δp66) is cleared quickly after inoculation in mi...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00186-17
更新日期:2018-01-22 00:00:00
abstract::A substance with potent decomplementation activity was isolated from staphylococcal culture supernatants by polyethylene glycol precipitation, DEAE-ion-exchange and Sephacryl chromatography, and preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purified substance exhibited all the characterist...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.47.1.47-51.1985
更新日期:1985-01-01 00:00:00