Abstract:
:The kinetics of Bacillus anthracis toxin production in culture and its lethal activity in rats, mice, and guinea pigs were investigated. Lethal toxin activity was produced in vitro throughout exponential growth at essentially identical rates in both encapsulated virulent and nonencapsulated avirulent strains. The two toxin proteins which produce lethality when in combination, lethal factor (LF) and protective antigen (PA), could be quantitated directly from culture fluids by rocket immunoelectrophoresis. Using purified preparations of these proteins, we determined that a combination of 8 micrograms of LF and 40 micrograms of PA was required for a maximal rate of killing (39 to 40 min) in Fischer 344 rats (250 to 300 g). Conversely, a minimum of 0.6 microgram of LF and 3 micrograms of PA was required for lethality. The 50% lethal dose for Hartley guinea pigs was 50 micrograms of LF and 250 micrograms of PA, and for Swiss mice it was 2.5 micrograms of LF and 12.5 micrograms of PA. Analyses classically reserved for enzyme kinetic studies were used to study the kinetics of lethal activity in the rat model after intravenous injection of LF-PA mixtures. The amounts of LF and PA which were required to give half the rate of killing (i.e., double the minimum time to death) were 1.2 and 5.8 micrograms, respectively. A theoretical minimum time to death was determined to be 38 min. A third anthrax toxin component, edema factor, was shown to inhibit lethal toxin activity. Edema factor could not be quantitated by rocket immunoelectrophoresis because the protein did not form distinct precipitin bands with available antisera.
journal_name
Infect Immunjournal_title
Infection and immunityauthors
Ezzell JW,Ivins BE,Leppla SHdoi
10.1128/IAI.45.3.761-767.1984subject
Has Abstractpub_date
1984-09-01 00:00:00pages
761-7issue
3eissn
0019-9567issn
1098-5522journal_volume
45pub_type
杂志文章abstract::The interaction between bacteria and fibronectin is believed to play an important role in the pathogenicity of clinically important Gram-positive cocci. In the present study, we identified a gene encoding a predicted fibronectin-binding protein of Enterococcus faecium (fnm), a homologue of Streptococcus pneumoniae pav...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00885-15
更新日期:2015-12-01 00:00:00
abstract::Trichinella spiralis creates a unique intracellular habitat in striated muscle. We report that a proteoglycan, syndecan-1, is induced early in infection yet is not essential for habitat development and exerts a modest influence on the immune response. This report is the first to address the requirement for a specific ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.74.3.1941-1943.2006
更新日期:2006-03-01 00:00:00
abstract::Exoenzyme S (ExoS), an ADP-ribosylating enzyme produced by the opportunistic pathogen Pseudomonas aeruginosa, is directly translocated into eukaryotic cells by bacterial contact. Within the cell, ExoS ADP-ribosylates the cell signaling protein Ras and causes inhibition of DNA synthesis and alterations in cytoskeletal ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.67.6.2847-2854.1999
更新日期:1999-06-01 00:00:00
abstract::We identified a T-cell determinant of the 35-kDa antigen of Mycobacterium leprae which is discriminatory against cross-sensitization by its closely related homologue in Mycobacterium avium. From synthetic peptides covering the entire sequence, those with the highest affinity and permissive binding to purified HLA-DR m...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.67.3.1501-1504.1999
更新日期:1999-03-01 00:00:00
abstract::At pH 7.4 and in the presence of NaHCO3, human milk and bovine colostrum inhibited the growth of Escherichia coli O111. Adding sufficient iron to saturate the iron-binding capacity of the lactoferrin present in the milk or colostrum prevented bacteriostasis. At pH 6.8 neither molk nor colostrum inhibited E. coli 0111....
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.15.2.396-401.1977
更新日期:1977-02-01 00:00:00
abstract::Cholera toxin (CT) is a potent adjuvant for mucosal vaccination; however, its mechanism of action has not been clarified completely. It is well established that peripheral monocytes differentiate into dendritic cells (DCs) both in vitro and in vivo and that monocytes are the in vivo precursors of mucosal CD103(-) proi...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01181-10
更新日期:2011-03-01 00:00:00
abstract::The epitope specificities of 13 hybridomas secreting monoclonal antibodies (MAbs) specific for pertussis toxin (PT) is described. Hybridoma lines were derived by the fusion of spleen cells from mice immunized with native PT, Formalin-detoxified PT, or isolated PT subunits (S1 to S5) with the myeloma line X63-Ag8.653. ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.57.9.2660-2665.1989
更新日期:1989-09-01 00:00:00
abstract::Binding of the complement-downregulating protein factor H (fH) to the surface of the meningococcus is important for survival of the organism in human serum. The meningococcal vaccine candidate factor H binding protein (fHbp) is an important ligand for human fH. While some fHbp-specific monoclonal antibodies (MAbs) blo...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.05182-11
更新日期:2011-09-01 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
abstract::Listeria monocytogenes is an intracellular bacterial pathogen that invades epithelial cells by subverting two cellular receptors, E-cadherin and Met. We recently identified type II phosphatidylinositol 4-kinases alpha and beta (PI4KIIalpha and PI4KIIbeta) as being required for bacterial entry downstream of Met. In thi...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00661-09
更新日期:2010-01-01 00:00:00
abstract::The target organs of infection in guinea pigs with asymptomatic acquired or congenital syphilis were identified by PCR and in some cases by rabbit infectivity test (RIT). The prevalence of Treponema pallidum DNA was examined in the following seven organs: the inguinal and mesenteric lymph nodes, spleen, liver, kidney,...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.64.8.3174-3179.1996
更新日期:1996-08-01 00:00:00
abstract::Chronic granulomatous disease (CGD) is a genetic disorder of NADPH oxidase in which phagocytes are defective in generating reactive oxidants. CGD patients suffer from recurrent infections and exuberant and persistent tissue granuloma formation. We hypothesized that abnormal granulomata in CGD may result from aberrant ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:
更新日期:1999-04-01 00:00:00
abstract::Group A streptococci isolated from skin adhere in greater numbers to human skin epithelial cells than to cells obtained from buccal mucosa whereas streptococci isolated from a throat tend to adhere in greater numbers to buccal epithelial cells than to skin epithelial cells in vitro. M protein-producing strains of grou...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.18.2.555-557.1977
更新日期:1977-11-01 00:00:00
abstract::Adoptive immunity is poorly expressed in normal syngeneic mice. This phenomenon was studied by using experimental antituberculosis immunity as a model system representing pure cell-mediated immunity. Expression of adoptive immunity was facilitated by pretreating recipients with sublethal ionizing radiation (500 rads) ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.41.1.257-263.1983
更新日期:1983-07-01 00:00:00
abstract::Toxin A (TcdA) and toxin B (TcdB) are major virulence factors of Clostridium difficile. These two toxins intoxicate cultured cells by similar mechanisms, and TcdB generally is more potent than TcdA in cultured cells. The exact reason for this difference is unclear. Here, we report that the cellular effects of TcdA can...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01577-08
更新日期:2009-06-01 00:00:00
abstract::Actinobacillus actinomycetemcomitans is the etiologic agent of localized aggressive periodontitis, a rapidly progressing oral disease that occurs in adolescents. A. actinomycetemcomitans can also cause systemic disease, including infective endocarditis. In early work on A. actinomycetemcomitans workers concluded that ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.74.4.2015-2021.2006
更新日期:2006-04-01 00:00:00
abstract::The cytotoxic effects of bacterial lipopolysaccharides (LPS) on mouse leukocytes have been examined in vivo and in vitro. Intraperitoneal injection of LPS into C57BL/6 mice greatly reduced the recovery of mononuclear cells; LPS was cytotoxic for macrophages, but had a mitogenic effect on lymphocytes. Similar effects o...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.21.1.310-319.1978
更新日期:1978-07-01 00:00:00
abstract::GNA33 is a membrane-bound lipoprotein with murein hydrolase activity that is present in all Neisseria species and well conserved in different meningococcal isolates. The protein shows 33% identity to a lytic transglycolase (MltA) from Escherichia coli and has been shown to be involved in the degradation of both insolu...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.72.4.1914-1919.2004
更新日期:2004-04-01 00:00:00
abstract::The intestinal mucosa forms the first line of defense against infections mediated by enteric pathogens such as salmonellae. Here we exploited intestinal "organoids" (iHOs) generated from human induced pluripotent stem cells (hIPSCs) to explore the interaction of Salmonella enterica serovar Typhimurium with iHOs. Imagi...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00161-15
更新日期:2015-07-01 00:00:00
abstract::Strains H37Ra and H37Rv, attenuated and virulent variants, respectively, of the original human strain H37 of Mycobacterium tuberculosis, were used to infect cultures of mouse peritoneal macrophages. Bacterial viability of each strain was assessed over a 2-week period, and the cellular response to H37Ra during the firs...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.10.4.742-746.1974
更新日期:1974-10-01 00:00:00
abstract::Antigen-presenting cells (APCs) are key players in the induction and regulation of immune responses. In Plasmodium falciparum malaria, determination of which cells and pathways are activated in the network of APCs remains elusive. We therefore investigated the effects of a controlled human malaria infection in healthy...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00473-15
更新日期:2015-09-01 00:00:00
abstract::Escherichia coli heat-stable enterotoxin (ST) appears to cause intestinal fluid secretion by activating intestinal particulate guanylate cyclase. Recent studies suggest that chlorpromazine and quinacrine reduce the intestinal secretory response to ST and activation of guanylate cyclase by ST. We have examined the effe...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.35.2.483-488.1982
更新日期:1982-02-01 00:00:00
abstract::Attachment of Mycobacterium avium subsp. paratuberculosis to host tissue and penetration of mucosal surfaces are pivotal events in the pathogenesis of Johne's disease. Fibronectin (FN) binding is required for attachment and internalization of several mycobacteria by epithelial cells in vitro. The objective of this stu...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.69.4.2075-2082.2001
更新日期:2001-04-01 00:00:00
abstract::Urease from ureaplasmas was purified by immunoaffinity chromatography, and the N-terminal amino acid sequence was determined for two of the three subunits. These sequences were used to design primers for a polymerase chain reaction (PCR) that amplified most of the gene coding for one of the subunits. By using a novel ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.59.7.2463-2469.1991
更新日期:1991-07-01 00:00:00
abstract::The interaction between human neutrophils and wild-type Bordetella pertussis or mutants expressing altered lipopolysaccharide or lacking virulence factors-pertussis toxin, adenylate cyclase toxin, dermonecrotic toxin, filamentous hemagglutinin (FHA), pertactin, or BrkA-was examined. In the absence of antibodies, the w...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.68.3.1735-1739.2000
更新日期:2000-03-01 00:00:00
abstract::In vivo- and in vitro-grown Mycoplasma hyopneumoniae organisms were inoculated onto newborn piglet tracheal organ cultures to provide a model for interaction of this organism with ciliated respiratory epithelium. Ciliostasis and loss of cilia in tracheal rings were induced by M. hyopneumoniae grown in vivo and with lo...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.12.5312-5318.1994
更新日期:1994-12-01 00:00:00
abstract::In experimental visceral leishmaniasis, in which the tissue macrophage is the target, in vivo responsiveness to conventional chemotherapy (pentavalent antimony [Sb]) requires a T-cell-dependent mechanism. To determine if this mechanism involves gamma interferon (IFN-gamma)-induced activation and/or specific IFN-gamma-...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.68.1.288-293.2000
更新日期:2000-01-01 00:00:00
abstract::In vivo expression of pili by Escherichia coli in the urine of 41 adults with lower urinary tract infections was analyzed by immunostaining with polyclonal antiserum to type 1 and P pili. Type 1 pili were detected in 31 of 41 urine specimens, while P pili were detected in 6 of 18 specimens. The piliation status of bac...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.57.6.1656-1662.1989
更新日期:1989-06-01 00:00:00
abstract::Expression of virulence determinants by Bordetella pertussis, the primary etiological agent of whooping cough, is regulated by the BvgAS two-component regulatory system. The role of a second two-component regulatory system, encoded by risAS, in this process is not defined. Here, we show that mutation of B. pertussis r...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.73.9.5995-6004.2005
更新日期:2005-09-01 00:00:00
abstract::Some strains of Streptococcus mutans were found to recognize and bind collagen type I. Binding of 125I-labeled collagen type I was specific in that collagen types I and II, but not unrelated proteins, were able to inhibit binding of the labeled ligand to bacteria. Collagen binding to S. mutans was partially reversible...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.61.10.4119-4125.1993
更新日期:1993-10-01 00:00:00