Abstract:
:ExoU is a potent effector protein that causes rapid host cell death upon injection by the type III secretion system of Pseudomonas aeruginosa. The N-terminal half of ExoU contains a patatin-like phospholipase A(2) (PLA(2)) domain that requires the host cell cofactor superoxide dismutase 1 (SOD1) for activation, while the C-terminal 137 amino acids constitute a membrane localization domain (MLD). Previous studies had utilized insertion and deletion mutations to show that portions of the MLD are required for membrane localization and catalytic activity. Here we further characterize this domain by identifying six residues that are essential for ExoU activity. Substitutions at each of these positions resulted in abrogation of membrane targeting, decreased ExoU-mediated cytotoxicity, and reductions in PLA(2) activity. Likewise, each of the six MLD residues was necessary for full virulence in cell culture and murine models of acute pneumonia. Purified recombinant ExoU proteins with substitutions at five of the six residues were not activated by SOD1, suggesting that these five residues are critical for activation by this cofactor. Interestingly, these same five ExoU proteins were partially activated by HeLa cell extracts, suggesting that a host cell cofactor other than SOD1 is capable of modulating the activity of ExoU. These findings add to our understanding of the role of the MLD in ExoU-mediated virulence.
journal_name
Infect Immunjournal_title
Infection and immunityauthors
Veesenmeyer JL,Howell H,Halavaty AS,Ahrens S,Anderson WF,Hauser ARdoi
10.1128/IAI.00223-10subject
Has Abstractpub_date
2010-08-01 00:00:00pages
3346-57issue
8eissn
0019-9567issn
1098-5522pii
IAI.00223-10journal_volume
78pub_type
杂志文章abstract::Studies were carried out to determine whether treatment of mice with the synthetic adjuvant muramyl dipeptide afforded any resistance to infection with the obligate intracellular protozoan Toxoplasma gondii. Marked resistance to lethal challenge infection was observed in CBA but not C57BL/6 mice pretreated with muramy...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.31.2.716-722.1981
更新日期:1981-02-01 00:00:00
abstract::Oligosaccharide (OS)-protein conjugates are promising candidate vaccines against encapsulated bacteria, such as Haemophilus influenzae, Neisseria meningitidis, and Streptococcus pneumoniae. Although the effects of several variables such as OS chain length and protein carrier have been studied, little is known about th...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.71.12.6915-6920.2003
更新日期:2003-12-01 00:00:00
abstract::We have previously identified two K88ac adhesion receptors (210 and 240 kDa) which are present in membrane preparations from adhesive but not nonadhesive porcine intestinal brush border cells; these adhesin receptors are postulated to be important determinants of the susceptibility of pigs to K88ac+ enterotoxigenic Es...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.12.5404-5410.1994
更新日期:1994-12-01 00:00:00
abstract::Infection with Histoplasma capsulatum results in a subclinical infection in immunocompetent hosts due to an effective cellular immune response. By contrast, immunodeficient individuals can have a severe disseminated and potentially fatal disease. In a previous study, it was demonstrated that normal mice infected intra...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.65.3.936-942.1997
更新日期:1997-03-01 00:00:00
abstract::Studies on the innate immune response against microbial infections in Drosophila melanogaster involve mutant strains and their reference strains that act as experimental controls. We used five standard D. melanogaster laboratory reference strains (Oregon R, w1118, Canton-S, Cinnabar Brown, and Yellow White [YW]) and i...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.02318-14
更新日期:2014-10-01 00:00:00
abstract::Bordetella dermonecrotizing toxin (DNT) stimulates the assembly of actin stress fibers and focal adhesions by deamidating Gln63 of the small GTPase Rho. To clarify the functional and structural organization of DNT, we cloned and sequenced the DNT gene and examined the functions of various DNT mutants. Our analyses of ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.67.8.3727-3732.1999
更新日期:1999-08-01 00:00:00
abstract::Enterotoxigenic Escherichia coli (ETEC) is a major cause of traveler's diarrhea as well as of endemic diarrhea and stunting in children in developing areas. However, a small-mammal model has been badly needed to better understand and assess mechanisms, vaccines, and interventions. We report a murine model of ETEC diar...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00183-18
更新日期:2018-06-21 00:00:00
abstract::Escherichia coli C25 maintained population levels of 10(9) to 10(10) per g of cecum and translocated to 100% of the middle mesenteric lymph nodes in gnotobiotic mice monoassociated with E. coli C25. Intragastric inoculation of these mice with the cecal contents from specific-pathogen-free mice reduced the population l...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:
更新日期:1980-09-01 00:00:00
abstract::Alternate modalities for the treatment of Mycobacterium tuberculosis are needed due to the rise in numbers of immunosuppressed individuals at risk for serious disease and the increasing prevalence of multidrug-resistant isolates. Interleukin-12 (IL-12) has been shown to improve immune responses against M. tuberculosis...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.72.5.2976-2988.2004
更新日期:2004-05-01 00:00:00
abstract::The she gene of Shigella flexneri 2a, which also harbors the internal enterotoxin genes set1A and set1B (F. R. Noriega, GenBank accession no. U35656, 1995) encodes a homolog of the virulence-related immunoglobulin A (IgA) protease-like family of secreted proteins, Tsh, EspC, SepA, and Hap, from an avian pathogenic Esc...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.65.11.4606-4614.1997
更新日期:1997-11-01 00:00:00
abstract::Akabane virus (a Bunyavirus) has been associated with epizootics of congenital deformities in cattle, sheep, and goats. Experimental studies using mouse-adapted virus inoculated intravenously into pregnant sheep gave an inapparent infection. Neutralizing antibodies were detected on day 5, and peaks in the titer were s...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.15.1.254-262.1977
更新日期:1977-01-01 00:00:00
abstract::Campylobacter rectus is a putative periodontopathogen which expresses a proteinaceous surface layer (S-layer) external to the outer membrane. S-layers are considered to play a protective role for the microorganism in hostile environments. The S-layer proteins from six different C. rectus strains (five human isolates a...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.65.2.478-483.1997
更新日期:1997-02-01 00:00:00
abstract::The ScpC protease of Streptococcus pyogenes degrades interleukin-8 (IL-8), a chemokine that mediates neutrophil transmigration and activation. The ability to degrade IL-8 differs dramatically among clinical isolates of S. pyogenes. Bacteria expressing ScpC overcome immune clearance by preventing the recruitment of neu...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00128-08
更新日期:2008-09-01 00:00:00
abstract::Yersinia pestis causes a rapid, lethal disease referred to as plague. Y. pestis actively inhibits the innate immune system to generate a noninflammatory environment during early stages of infection to promote colonization. The ability of Y. pestis to create this early noninflammatory environment is in part due to the ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00909-19
更新日期:2020-02-20 00:00:00
abstract::Diverse pathogens have evolved to survive and replicate in the endosomes or phagosomes of the host cells and establish persistent infection. Ehrlichiae are Gram-negative, intracellular bacteria that are transmitted by ticks. Ehrlichiae reside in the endosomes of the host phagocytic or endothelial cells and establish p...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.02101-14
更新日期:2014-10-01 00:00:00
abstract::Intravenous injection of rat anti-mouse gamma interferon (IFN-gamma) monoclonal antibody as well as rabbit anti-mouse tumor necrosis factor (TNF) antibody into mice which had received a sublethal infection with Listeria monocytogenes cells resulted in acceleration of listeriosis. Endogenous IFN-gamma seemed to be prod...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.57.11.3331-3337.1989
更新日期:1989-11-01 00:00:00
abstract::The mechanisms that govern the initial interaction between Paracoccidioides brasiliensis, a primary dimorphic fungal pathogen, and cells of the innate immunity need to be clarified. Our previous studies showed that Toll-like receptor 2 (TLR2) and TLR4 regulate the initial interaction of fungal cells with macrophages a...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00375-10
更新日期:2011-06-01 00:00:00
abstract::The P2 porin protein is the major outer membrane protein of nontypeable Haemophilus influenzae and is a potential target of a protective immune response. Nine monoclonal antibodies (MAbs) to P2 were developed by immunizing mice with nontypeable H. influenzae whole organisms. Each MAb reacted exclusively with the homol...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.9.3712-3722.1994
更新日期:1994-09-01 00:00:00
abstract::A preparation procedure for scanning electron microscopy was developed by which gononcoccal colonies can be studied directly on the agar surface. After glutaraldehyde fixation directly in petri dishes, small agar pieces were cut out and dehydrated stepwise in increasing concentrations of ethanol. The blocks were there...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.12.3.630-637.1975
更新日期:1975-09-01 00:00:00
abstract::Salmonella choleraesuis chi 3781, an attenuated [delta cya-12 delta(crp-cdt)19] mutant, was electroporated with the plasmid pBA31-R7, which codes for the expression of a 31-kDa protein from Brucella abortus (BCSP31). Recombinant S. choleraesuis chi 3781 stably maintained the pBA31-R7 plasmid and continued to express t...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.61.2.610-618.1993
更新日期:1993-02-01 00:00:00
abstract::Whole cells, morphological components, and various extracts of Candida albicans were tested for toxicity by methods involving biological activities ordinarily used to characterize bacterial endotoxin. Fungal preparations exerted several of these activities, but only at much higher dose levels than those required for b...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.6.4.616-627.1972
更新日期:1972-10-01 00:00:00
abstract::The Staphylococcus aureus repeat (STAR) element is a sequence identified in two intergenic regions in S. aureus. The element is found in 13 to 21 copies in individual S. aureus strains, and elements in the homologous intergenic location are variable in length. The element sequence consists of several small and unusual...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.68.4.2344-2348.2000
更新日期:2000-04-01 00:00:00
abstract::The antigenicity of Erysipelothrix rhusiopathiae T28 (serotype 2) was investigated. Antigens were solubilized from the cell surface with detergents. By means of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting it was shown that the molecular weight of the main antigenic component--a nonprot...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.52.3.818-822.1986
更新日期:1986-06-01 00:00:00
abstract::Virulent strains of Yersinia enterocolitica and their plasmidless, avirulent derivatives were examined for their cell surface properties. Increased surface charge and hydrophobicity of Y. enterocolitica were found to be associated with the possession of a 40- to 48-megadalton plasmid. These surface properties were exp...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.44.2.540-543.1984
更新日期:1984-05-01 00:00:00
abstract::The surface antigen makeup of metacyclic trypomastigote forms of strain G of Trypanosoma cruzi, which produce a subpatent infection in mice, differed from those of the virulent strains Y and CL. A 100,000-molecular-weight protein, barely detectable on the Y or CL cell surface, appeared as the main surface antigen of t...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.40.2.836-839.1983
更新日期:1983-05-01 00:00:00
abstract::Mice with a null deletion mutation in the gamma interferon (IFN-gamma) receptor gene were used to study the role of IFN-gamma responsiveness during experimental pulmonary cryptococcosis. Cryptococcus neoformans was inoculated intratracheally into mice lacking the IFN-gamma receptor gene (IFN-gammaR-/-) and into contro...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.73.3.1788-1796.2005
更新日期:2005-03-01 00:00:00
abstract::The major antigenic determinants of the lipoglycans from Acholeplasma granularum and Acholeplasma axanthum were found to be the oligosaccharide sequences Glcp(beta 1 leads to 2)-Glcp(alpha 1 leads to 4)-Glcp and Glcp(beta 1 leads to 2)-Glcp(beta 1 leads to 2)-Glcp, respectively. The disaccharides sophorose and maltose...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.40.2.629-632.1983
更新日期:1983-05-01 00:00:00
abstract::One-day-old chicks were infected orally with two strains of weakly hemolytic spirochetes isolated from a human and a pig with intestinal spirochetosis. These spirochetosis both colonized birds, attached end-on to their cecal enterocytes, induced watery diarrhea, and significantly depressed growth rates. Cultures of Se...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.63.9.3705-3710.1995
更新日期:1995-09-01 00:00:00
abstract::Bartonella bacilliformis is the etiologic agent of Oroya fever in humans. Flagellum-mediated motility has been postulated as a major virulence factor for invasion of host cells. To address this hypothesis, we purified and characterized flagella from strain KC584 and then assessed their role in human erythrocyte associ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.61.12.4962-4971.1993
更新日期:1993-12-01 00:00:00
abstract::Clostridium perfringens enterotoxin caused a 26 to 41% reduction in the rate of oxygen consumption by rat liver mitochondria when various tricarboxylic acid cycle intermediates were used as substrate. However, P/O ratios were unaltered. ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.15.3.999-1001.1977
更新日期:1977-03-01 00:00:00