Abstract:
:Legionella pneumophila is ingested by both human macrophages and amoebae, and it multiplies within similar endocytic compartments in both eukaryotic species. Inhibitors of eukaryotic protein synthesis, such as cycloheximide and emetine, had no effect on the uptake of L. pneumophila by macrophages but completely abolished ingestion by the amoeba Hartmannella vermiformis. Therefore, host cell protein synthesis is required for the bacterium to infect the amoeba but not human macrophages. To identify proteins expressed by H. vermiformis upon contact with L. pneumophila, we radiolabeled amoebal proteins after contact with bacteria in bacteriostatic concentrations of tetracycline to inhibit bacterial protein synthesis. We analyzed protein expression by two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis and found that 33 amoebal proteins were induced; 12 of these were not detected in resting amoebae. Eleven other amoebal proteins were repressed; four of them became undetectable. In contrast, no phenotypic changes were observed in H. vermiformis upon contact with Escherichia coli or heat-killed L. pneumophila. An isogenic, avirulent variant of L. pneumophila, incapable of infecting either macrophages or amoebae, induced a different pattern of protein expression upon contact with H. vermiformis. Our data showed that amoebae manifested a specific phenotypic response upon contact with virulent L. pneumophila. This phenotypic modulation may be necessary for uptake of the bacteria into an endocytic compartment that permits bacterial survival and multiplication.
journal_name
Infect Immunjournal_title
Infection and immunityauthors
abu Kwaik Y,Fields BS,Engleberg NCdoi
10.1128/IAI.62.5.1860-1866.1994subject
Has Abstractpub_date
1994-05-01 00:00:00pages
1860-6issue
5eissn
0019-9567issn
1098-5522journal_volume
62pub_type
杂志文章abstract::An antigenic complex has been isolated in a highly purified from from the Melvin strain of Neisseria gonorrhoeae. The complex has a molecular weight of 9.3 x 10(6) and on sodium dodecyl sulfate-polyacrylamide gel electrophoresis was found to consist of several subunits; the most predominant had the following molecular...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.25.2.635-644.1979
更新日期:1979-08-01 00:00:00
abstract::Infection with Mycobacterium avium subsp. paratuberculosis is associated with high levels of morbidity, decreased production, and early culling in dairy cattle. Clinical symptoms of Johne's disease include persistent diarrhea, inappetence, and resultant weight loss due to chronic inflammation of the small intestine. A...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.71.11.6479-6486.2003
更新日期:2003-11-01 00:00:00
abstract::The genes of the lic1 operon (lic1A to lic1D) are responsible for incorporation of phosphocholine (PCho) into the lipopolysaccharide (LPS) of Haemophilus influenzae. PCho plays a multifaceted role in the commensal and pathogenic lifestyles of a range of mucosal pathogens, including H. influenzae. Structural studies of...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00748-07
更新日期:2008-02-01 00:00:00
abstract::Randomly bred guinea pigs were infected with Listeria monocytogenes using the intracardial, intravenous and intraperitoneal routes of infection. Doses of Listeria ranged from 5 to 1,000 x the 50% lethal dose based on the 50% lethal dose for intracardially injected Listeria. A complete necropsy was performed on all ani...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.15.3.916-924.1977
更新日期:1977-03-01 00:00:00
abstract::Fasciola hepatica is a prevalent helminth parasite of livestock. Infection results in polarization of the host's immune response and generation of type 2 helper (Th2) immune responses, which are known to be inhibitory to Th1 responses. Bovine tuberculosis (BTB) is a bacterial disease of economic and zoonotic importanc...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01445-06
更新日期:2007-03-01 00:00:00
abstract::Brucella spp. are gram-negative intracellular pathogens that survive and multiply within phagocytic cells of their hosts. Smooth organisms present O polysaccharides (OPS) on their surface. These OPS help the bacteria avoid the bactericidal action of serum. The wboA gene, coding for the enzyme glycosyltransferase, is e...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.69.7.4407-4416.2001
更新日期:2001-07-01 00:00:00
abstract::Two distinct and complementary pathways, one mediated by perforin and the other dependent upon CD95 (Fas), effect cell-mediated cytotoxicity. We examined the relative roles of these pathways in host defenses against the intracellular bacterial pathogen Listeria monocytogenes by using murine listeriosis as a model syst...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:
更新日期:1998-09-01 00:00:00
abstract::Nontypeable Haemophilus influenzae (NTHi) initiates infection by colonizing the upper respiratory tract and is a common cause of localized respiratory tract disease. Previous work has established that the NTHi HMW1 and HMW2 proteins are potent adhesins that mediate efficient in vitro adherence to cultured human respir...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00153-16
更新日期:2016-09-19 00:00:00
abstract::Porphyromonas gingivalis, a bacterium associated with active chronic periodontitis lesions, produces several proteolytic enzymes that are thought to be involved in host colonization, perturbation of the immune system, and tissue destruction. The aim of the present study was to investigate the contribution of Arg- and ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.69.8.5166-5172.2001
更新日期:2001-08-01 00:00:00
abstract::The heat-labile enterotoxin (LT) of Escherichia coli is localized in the periplasm of the bacterial cell. Growth of an LT-producing strain of E. coli in the presence of bile salts, in concentrations within the range found in the human small intestine, caused leakage of LT into the culture medium. This leakage could be...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.59.1.168-171.1991
更新日期:1991-01-01 00:00:00
abstract::The pulmonary immune response protects healthy individuals against Pneumocystis pneumonia (PcP). However, the immune response also drives immunopathogenesis in patients who develop severe PcP, and it is generally accepted that optimal treatment requires combination strategies that promote fungal killing and also provi...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00640-19
更新日期:2020-01-22 00:00:00
abstract::Streptococcus equi and Streptococcus zooepidemicus are major etiological agents of upper and lower airway disease in horses. Despite the considerable animal suffering and economic burden associated with these diseases, the factors that contribute to the virulence of these equine pathogens have not been extensively inv...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.68.10.6048-6051.2000
更新日期:2000-10-01 00:00:00
abstract::Polymorphonuclear leukocytes (PMN) isolated from human blood were exposed to various levels of hydrogen sulfide. The effect on respiratory burst, myeloperoxidase activity, and capacity to phagocytose and kill bacteria were studied. A 1-h exposure of the PMN to 1 mM sulfide did not decrease their myeloperoxidase activi...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.57.9.2776-2781.1989
更新日期:1989-09-01 00:00:00
abstract::We have investigated the possibility that nitric oxide (NO) synthesis may affect the course of a trypanosome infection via T-cell responses using mice deficient in inducible NO synthase (iNOS). Parasitemia levels increased at the same rate in both iNOS-deficient homozygous and control heterozygous mice, and peak paras...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.67.7.3334-3338.1999
更新日期:1999-07-01 00:00:00
abstract::The cellular source of interleukin-6 (IL-6) during infection of mice with Listeria monocytogenes was investigated both in vitro and in vivo. Peritoneal cells taken at intervals from infected mice and cultured in vitro without added stimulus produced high titers of IL-6 peaking 2 days postinfection in a time course sim...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.61.6.2626-2631.1993
更新日期:1993-06-01 00:00:00
abstract::Infection of inbred mouse strains with Borrelia burgdorferi results in the development of experimental Lyme arthritis. The degree of arthritic pathology has been suggested to correlate with the level of spirochete burden within tissues. To investigate this further, we infected resistant DBA/2 (DBA) and susceptible C3H...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.66.5.2065-2071.1998
更新日期:1998-05-01 00:00:00
abstract::Twenty-six Pseudomonas aeruginosa strains from patients with cystic fibrosis were typed by the Fisher immunotyping scheme. Only 6 strains were agglutinated by a single typing serum, whereas 15 strains were agglutinated with more than one serum and 5 were not agglutinated by any serum. Neither the polyagglutinable nor ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.42.1.170-177.1983
更新日期:1983-10-01 00:00:00
abstract::We show in this study that toxin production in Clostridium difficile is altered in cells which can no longer form flagellar filaments. The impact of inactivation of fliC, CD0240, fliF, fliG, fliM, and flhB-fliR flagellar genes upon toxin levels in culture supernatants was assessed using cell-based cytotoxicity assay, ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00224-12
更新日期:2012-10-01 00:00:00
abstract::The mechanism by which recombinant murine gamma interferon (rMuIFN-gamma) and bacterial lipopolysaccharide (LPS) activate mouse resident splenic macrophages to inhibit the intracellular growth of the fungus Histoplasma capsulatum was examined. Growth inhibition depended on L-arginine metabolism. The growth inhibitory ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.5.1940-1945.1994
更新日期:1994-05-01 00:00:00
abstract::Bordetella bronchiseptica is a Gram-negative bacterium that infects and causes disease in a wide variety of animals. B. bronchiseptica also infects humans, thereby demonstrating zoonotic transmission. An extensive characterization of human B. bronchiseptica isolates is needed to better understand the distinct genetic ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01453-13
更新日期:2014-04-01 00:00:00
abstract::The adipocytokine leptin links nutritional status to immune function. Leptin signaling protects from amebiasis, but the molecular mechanism is not understood. We developed an in vitro model of ameba-host cell interaction to test the hypothesis that leptin prevents ameba-induced apoptosis in host epithelial cells. We d...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.06140-11
更新日期:2012-05-01 00:00:00
abstract::We have developed a rapid, continuous method for real-time monitoring of biofilms, both in vitro and in a mouse infection model, through noninvasive imaging of bioluminescent bacteria colonized on Teflon catheters. Two important biofilm-forming bacterial pathogens, Staphylococcus aureus and Pseudomonas aeruginosa, wer...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.71.2.882-890.2003
更新日期:2003-02-01 00:00:00
abstract::Group A streptococcal pyrogenic exotoxins types A, B, and C and staphylococcal pyrogenic exotoxin were shown to be potent nonspecific T-lymphocyte mitogens. Adherent cell populations did not significantly affect the nonspecific mitogenicity. ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.25.3.1075-1077.1979
更新日期:1979-09-01 00:00:00
abstract::A progressive increase in infections with multiresistant Enterococcus faecium has been reported, especially in cancer patients and neutropenic patients. Despite its increasing importance as a nosocomial pathogen, knowledge of the pathogenesis of E. faecium infections is highly limited. In this study, we investigated t...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00863-08
更新日期:2009-01-01 00:00:00
abstract::Infection with highly pathogenic Streptococcus suis can cause septic shock, which is characterized by high levels of inflammatory cytokines and a high mortality rate. Our previous study indicated that TREM-1 (triggering receptor expressed on myeloid cells 1) was upregulated in swine spleen cells in response to S. suis...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00440-15
更新日期:2015-08-01 00:00:00
abstract::Mycobacterium tuberculosis grows within the phagocytic vacuoles of macrophages, where it encounters a moderately acidic and possibly nutrient-restricted environment. Other mycobacterial species encounter acidic conditions in soil and aquatic environments. We have evaluated the influence of pH and divalent cation level...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.68.8.4518-4522.2000
更新日期:2000-08-01 00:00:00
abstract::Group A streptococci (GAS) are highly prevalent human pathogens whose primary ecological niche is the superficial epithelial layers of the throat and/or skin. Many GAS strains with a strong tendency to cause pharyngitis are distinct from strains that tend to cause impetigo; thus, genetic differences between them may c...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00374-17
更新日期:2017-10-18 00:00:00
abstract::The Streptococcus mutans serotype c gtfA gene encodes a 55-kilodalton sucrose-hydrolyzing enzyme. Analysis of S. mutans gtfA mutants revealed that the mutant strains were specifically impaired in the ability to use melibiose as a sole carbon source. S. mutans gtfA mutant strains synthesized less alpha-galactosidase ac...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.57.3.992-995.1989
更新日期:1989-03-01 00:00:00
abstract::Fibronectin-binding proteins mediate Staphylococcus aureus internalization into nonphagocytic cells in vitro. We have investigated whether fibronectin-binding proteins are virulence factors in the pathogenesis of pneumonia by using S. aureus strain 8325-4 and isogenic mutants in which fibronectin-binding proteins were...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.70.7.3865-3873.2002
更新日期:2002-07-01 00:00:00
abstract::We compared the susceptibilities of Chlamydia trachomatis elementary bodies (EBs) to human defensin HNP-2 and porcine protegrin PG-1, cysteine-rich beta-sheet antimicrobial peptides produced by mammalian leukocytes. Although both peptides protected McCoy cell monolayers from infection by chlamydial EBs, protegrins wer...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.64.3.709-713.1996
更新日期:1996-03-01 00:00:00