Abstract:
:The primary effector for Shigella invasion of epithelial cells is IpaC, which is secreted via a type III secretion system. We recently reported that the IpaC N terminus is required for type III secretion and possibly other functions. In this study, mutagenesis was used to identify an N-terminal secretion signal and to determine the functional importance of the rest of the IpaC N terminus. The 15 N-terminal amino acids target IpaC for secretion by Shigella flexneri, and placing additional amino acids at the N terminus does not interfere with IpaC secretion. Furthermore, amino acid sequences with no relationship to the native IpaC secretion signal can also direct its secretion. Deletions introduced beyond amino acid 20 have no effect on secretion and do not adversely affect IpaC function in vivo until they extend beyond residue 50, at which point invasion function is completely eliminated. Deletions introduced at amino acid 100 and extending toward the N terminus reduce IpaC's invasion function but do not eliminate it until they extend to the N-terminal side of residue 80, indicating that a region from amino acid 50 to 80 is critical for IpaC invasion function. To explore this further, the ability of an IpaC N-terminal peptide to associate in vitro with its translocon partner IpaB and its chaperone IpgC was studied. The N-terminal peptide binds tightly to IpaB, but the IpaC central hydrophobic region also appears to participate in this binding. The N-terminal peptide also associates with the chaperone IpgC and IpaB is competitive for this interaction. Based on additional biophysical data, we propose that a region between amino acids 50 and 80 is required for chaperone binding, and that the IpaB binding domain is located downstream from, and possibly overlapping, this region. From these data, we propose that the secretion signal, chaperone binding region, and IpaB binding domain are located at the IpaC N terminus and are essential for presentation of IpaC to host cells during bacterial entry; however, IpaC effector activity may be located elsewhere.
journal_name
Infect Immunjournal_title
Infection and immunityauthors
Harrington AT,Hearn PD,Picking WL,Barker JR,Wessel A,Picking WDdoi
10.1128/iai.71.3.1255-1264.2003keywords:
subject
Has Abstractpub_date
2003-03-01 00:00:00pages
1255-64issue
3eissn
0019-9567issn
1098-5522journal_volume
71pub_type
杂志文章abstract::Experimental infection of mice with a virulent strain of Mycobacterium avium leads to a slowly progressive disease, which we have previously shown culminates in loss of gamma interferon (IFN-gamma) production by T lymphocytes and death of the animals approximately 40 weeks after infection. Here we investigated the cha...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.70.1.27-35.2002
更新日期:2002-01-01 00:00:00
abstract::Immunization with ribosomal preparations from Haemophilus influenzae type b elicited protective immunity in mice. Ribosomes from disrupted cells where isolated by differential centrifugation using sodium dodecyl sulfate. The washed ribosomes contained 25% protein and 75% ribonucleic acid and sedimented as a single pea...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.15.2.453-460.1977
更新日期:1977-02-01 00:00:00
abstract::Hamster respiratory epithelial cells were cultured in a monolayer format, and 20% of the cells were ciliated. Mycoplasma pneumoniae attached to the epithelial cells in a neuraminidase-specific fashion and induced ciliostasis and cytonecrosis. ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.21.1.333-336.1978
更新日期:1978-07-01 00:00:00
abstract::We demonstrate that transcription of the Staphylococcus aureus collagen adhesin gene (cna) is temporally regulated, with expression being highest in exponentially growing cultures and falling to almost undetectable levels as cultures enter the post-exponential-growth phase. The temporal regulation of cna transcription...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.65.4.1536-1540.1997
更新日期:1997-04-01 00:00:00
abstract::We have isolated three genes, ARG57, SER57, and LYS1, on the basis of their function in Candida albicans. A C. albicans transformation vector containing the C. albicans URA3 gene, a Candida ARS sequence, and a portion of the Saccharomyces cerevisiae 2 microns circle containing the replication origin was constructed. C...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.60.3.876-884.1992
更新日期:1992-03-01 00:00:00
abstract::A solid-phase radioimmunoassay, applying whole Mycobacterium leprae as antigen and radiolabeled protein A from Staphylococcus aureus as antibody-detecting reagent, was used for the determination of specific immunoglobulin G (IgG) and IgM antibody responses in leprosy patients. High IgG anti-M. leprae antibody levels w...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.36.3.885-892.1982
更新日期:1982-06-01 00:00:00
abstract::A major surface antigen of Trichomonas vaginalis was purified by using three independently derived monoclonal antibodies (two immunoglobulin M and one immunoglobulin G1) prepared against T. vaginalis PHS-2J. A 115,000-molecular-weight antigen and one or more components with a molecular weight of 58,000 to 64,000 were ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.49.2.270-274.1985
更新日期:1985-08-01 00:00:00
abstract::The complete nucleotide sequence of a 612-base-pair DNA fragment containing the gene for the major fimbrial subunit of CS3 of enterotoxigenic Escherichia coli is presented. A possible promoter region, a ribosome-binding site, and two potential signal peptidase cleavage sites are indicated. Unlike the best-studied fimb...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.56.12.3297-3300.1988
更新日期:1988-12-01 00:00:00
abstract::Streptococcus pneumoniae, a Gram-positive bacterial pathogen, causes pneumonia, meningitis, and septicemia. Innate immune responses are critical for the control and pathology of pneumococcal infections. It has been demonstrated that S. pneumoniae induces the production of type I interferons (IFNs) by host cells and th...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01572-14
更新日期:2014-06-01 00:00:00
abstract::The porcine immunoglobulins M (IgM), A (IgA), and G (IgG) were isolated and purified and some of the properties of the porcine milk IgA were examined. Monospecific antisera which were prepared against these immunoglobulins in rabbits were then used to absorb a particular class of immunoglobulin from sow serum, colostr...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.6.4.600-609.1972
更新日期:1972-10-01 00:00:00
abstract::T lymphocyte subpopulations in the peripheral blood of children with congenital cytomegalovirus infections and in controls were enumerated with monoclonal antibodies. Infants of less than 1 year of age with symptomatic infections showed significant increases in the proportion of suppressor cells and decreases in the r...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.41.3.1380-1382.1983
更新日期:1983-09-01 00:00:00
abstract::Chlamydia trachomatis L2 is an obligate intracellular microorganism with a unique biphasic life cycle. The extracellular form, the elementary body (EB), is infectious but metabolically inactive. Attachment of EBs to host cells is medicated by a heparan sulfate-like glycosaminoglycan. Following attachment, the EB is in...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.11.4900-4908.1994
更新日期:1994-11-01 00:00:00
abstract::In the last few years, the great impact of antimicrobial peptides on infectious disease susceptibility and natural resistance has been reported. In some cases, susceptibility to diseases is related to antimicrobial peptide polymorphisms and gene copy numbers, but for the vast majority of infectious diseases, these phe...
journal_title:Infection and immunity
pub_type: 杂志文章,评审
doi:10.1128/IAI.01515-08
更新日期:2009-11-01 00:00:00
abstract::Toxin B from Clostridium difficile is cytopathic in vitro for various types of cells, including polymorphonuclear cells, lymphocytes, and monocytes. Since intestine lamina propria is rich in macrophages, we studied the effect of toxin B on human monocytes and on human macrophages generated in vitro by long-term cultur...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.61.3.1082-1090.1993
更新日期:1993-03-01 00:00:00
abstract::Monoclonal antibodies to the capsular polysaccharide of Cryptococcus neoformans produce distinct capsular reactions and have biological activities that are determined by serotype specificity. In the present study, polyclonal rabbit anticapsular antibodies were cross-absorbed to produce serotype specificities similar t...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.69.2.1189-1191.2001
更新日期:2001-02-01 00:00:00
abstract::Rabbit endogenous pyrogens occurred in two forms. One was an apparently single protein with a pI of 7.3; the other was a family of proteins with pI values of 4.5 to 5.0. We selected two of the latter, with pI values of 4.6 and 4.72, as representative of the group and compared them with the pI 7.3 pyrogen. Antisera rai...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.34.1.177-183.1981
更新日期:1981-10-01 00:00:00
abstract::Infectious pancreatic necrosis virus was stable for 10 days at 4 C in stream and well water, after which the virus had a half-life of 7.5 days. At 15 C, the virus was stable for 5 days, and then had a half-life between 5 and 6 days. Viral antigen in infected cells developed much more slowly at 4 C than at 20 C. Infect...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.11.6.1409-1412.1975
更新日期:1975-06-01 00:00:00
abstract::The fliA gene of Legionella pneumophila encoding the alternative sigma(28) factor was inactivated by introducing a kanamycin resistance cassette. Electron microscopy and Western blot analysis revealed that the fliA mutant strain is aflagellate and expresses no flagellin. Reporter gene assays indicated that the flaA pr...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.70.3.1604-1608.2002
更新日期:2002-03-01 00:00:00
abstract::Citrobacter rodentium is an attaching and effacing pathogen which causes transmissible colonic hyperplasia in mice. Infection with C. rodentium serves as a model for infection of humans with enteropathogenic and enterohemorrhagic Escherichia coli. To identify novel colonization factors of C. rodentium, we screened a s...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00770-08
更新日期:2008-11-01 00:00:00
abstract::Escherichia coli is the most common cause of urinary tract infection. Elevated blood and urine interleukin-6 (IL-6) levels have been shown in inflammatory urinary tract diseases. The role of IL-6 in mediating the urodynamic dysfunction in response to E. coli-induced urinary tract infection has not yet been fully eluci...
journal_title:Infection and immunity
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doi:10.1128/IAI.00013-09
更新日期:2009-08-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.68.1.214-220.2000
更新日期:2000-01-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.20.3.827-835.1978
更新日期:1978-06-01 00:00:00
abstract::Toxigenic Vibrio cholerae strains are lysogens of CTXPhi, a filamentous phage which encodes cholera toxin. The receptor for CTXPhi for invading V. cholerae cells is the toxin-coregulated pilus (TCP), the genes for which reside in a larger genetic element, the TCP pathogenicity island. We analyzed 146 CTX-negative stra...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.66.12.5819-5825.1998
更新日期:1998-12-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00575-16
更新日期:2016-09-19 00:00:00
abstract::In an earlier report, we had described the isolation and characterization of autolysis-defective mutants of Staphylococcus aureus (N. Mani, P. Tobin, and R.K. Jayaswal, J. Bacteriol. 175:1493-1499, 1993). In the study reported here, an autolysis-defective mutant showed attenuated virulence in a rat model of experiment...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.4.1406-1409.1994
更新日期:1994-04-01 00:00:00
abstract::Mutant cultures that lacked the ability to produce filamentous hemagglutinin were obtained by UV irradiation of Bordetella pertussis strain 18-323. Various biological activities of these mutants were compared with those of the parent culture. It was found that the leukocytosis-promoting, histamine-sensitizing, and mou...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.35.3.1018-1023.1982
更新日期:1982-03-01 00:00:00
abstract::Lysogenic conversion of Shigella flexneri type antigens was studied with the aid of wild-type and thermosensitive mutant phages. With all wild-type phages, the appearance of glycosylated antigen was accompanied by the appearance of polyprenyl phosphate glucose synthetase activity. With some of the mutant phages, the a...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.14.6.1290-1292.1976
更新日期:1976-12-01 00:00:00
abstract::As reported elsewhere, an enterotoxigenic strain of Escherichia coli serotype O25:K98:NM was epidemiologically incriminated as the etiological agent in a shipboard outbreak of diarrheal illness. This enterotoxigenic E. coli strain and possibly other enteric isolates were found to produce heat-labile toxin and not heat...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.24.3.793-797.1979
更新日期:1979-06-01 00:00:00
abstract::An array of pro- and anti-inflammatory mediators of the innate immune system was analyzed in stool, urine, and rectal mucosa samples from adults and children with shigellosis to better understand their role in recovery from and in the immunopathogenesis of the disease. Increased concentrations of lactoferrin (Lf), mye...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.68.6.3620-3629.2000
更新日期:2000-06-01 00:00:00
abstract::A secreted nuclease, SsnA, was identified in the virulent Streptococcus suis isolate SX332 and subsequently in each of the type strains of capsular serotypes 1 through 9. Screening of 258 porcine clinical isolates from surface (nasal mucosa or palatine tonsil) or internal (joint, brain or other internal organ) locatio...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.72.2.774-781.2004
更新日期:2004-02-01 00:00:00