Abstract:
:Tuberculosis remains a leading killer worldwide, and new approaches for its treatment and prevention are urgently needed. This effort will benefit greatly from a better understanding of gene regulation in Mycobacterium tuberculosis, particularly with respect to this pathogen's response to its host environment. We examined the behavior of two promoters from the divergently transcribed M. tuberculosis genes acr/hspX/Rv2031c (alpha-crystallin homolog) and Rv2032/acg (acr-coregulated gene) by using a promoter-GFP fusion assay in Mycobacterium bovis BCG. We found that Rv2032 is a novel macrophage-induced gene whose expression is coregulated with that of acr. Relative levels of intracellular induction for both promoters were significantly affected by shallow standing versus shaking bacterial culture conditions prior to macrophage infection, and both promoters were strongly induced under low oxygen conditions. Deletion analyses showed that DNA sequences within a 43-bp region were required for expression of these promoters under all conditions. Multiple sequence alignment and database searches performed with PROBE indicated that Rv2032 is one of eight M. tuberculosis genes of previously unknown function that belong to an unusual superfamily of classical nitroreductases, which may have a role for bacteria within the host environment. These findings show that mycobacterial culture conditions can greatly influence the results and interpretation of subsequent gene regulation experiments. We propose that these differences might be exploited for dissection of the regulatory factors that affect mycobacterial gene expression within the host.
journal_name
Infect Immunjournal_title
Infection and immunityauthors
Purkayastha A,McCue LA,McDonough KAdoi
10.1128/iai.70.3.1518-1529.2002keywords:
subject
Has Abstractpub_date
2002-03-01 00:00:00pages
1518-29issue
3eissn
0019-9567issn
1098-5522journal_volume
70pub_type
杂志文章abstract::Cultured mammalian cells extend the time of survival of Treponema pallidum (Nichols strain). Various parameters that have been previously shown to enhance treponemal survival in vitro were examined for influences on the interaction of T. pallidum with cultured cells. With cells derived from normal rabbit testes, the t...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.15.2.444-452.1977
更新日期:1977-02-01 00:00:00
abstract::Pathogenic Leptospira spp. are likely to encounter higher concentrations of reactive oxygen species induced by the host innate immune response. In this study, we characterized Leptospira interrogans catalase (KatE), the only annotated catalase found within pathogenic Leptospira species, by assessing its role in resist...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00466-12
更新日期:2012-11-01 00:00:00
abstract::Lower genital tract infection with Chlamydia trachomatis and C. muridarum can induce long-lasting hydrosalpinx in the upper genital tract of women and female mice, respectively. However, A/J mice were highly resistant to induction of long-lasting hydrosalpinx by C. muridarum. We further compared host inflammatory resp...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00055-14
更新日期:2014-07-01 00:00:00
abstract::The hallmarks of enteropathogenic Escherichia coli (EPEC) infection are formation of attaching and effacing (A/E) lesions on mucosal surfaces and actin-rich pedestals on cultured cells, both of which are dependent on the type III secretion system effector Tir. Following translocation into cultured cells and clustering...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00291-15
更新日期:2015-09-01 00:00:00
abstract::To test the importance of lipopolysaccharide (LPS) and adhesin as major antigens in vaccination against rabbit enteropathogenic Escherichia coli (EPEC)-like E. coli O103 infection, we used two nonpathogenic wild-type strains to immunize rabbits at weaning. One of these strains (C127) harbors the O103 LPS but does not ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.60.7.2702-2709.1992
更新日期:1992-07-01 00:00:00
abstract::In malarial infections of primates, the spleen has been shown to modulate parasite antigen expression on the surfaces of infected erythrocytes. The processes affected include cytoadherence, which is central to the pathophysiology of severe falciparum malaria, and the related phenomenon of rosette formation. In this st...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.60.6.2225-2228.1992
更新日期:1992-06-01 00:00:00
abstract::Resistance to phagocytosis is a hallmark of virulent Streptococcus pyogenes (group A streptococcus). Surface-bound C5a peptidase reduces recruitment of phagocytes to the site of infection, and hyaluronic acid capsules and/or the M protein limit the uptake of streptococci. In this study the relative impact of M and M-l...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.66.11.5399-5405.1998
更新日期:1998-11-01 00:00:00
abstract::We investigated the effects of peripheral blood mononuclear cells expanded with irrelevant control and mycobacterial antigens on the intracellular growth of Mycobacterium bovis bacillus Calmette-Guérin (BCG) in human macrophages. More than 90% of the cells present after 1 week of in vitro expansion were CD3(+). T cell...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.71.4.1763-1773.2003
更新日期:2003-04-01 00:00:00
abstract::Iron acquisition from the host is an important step in the pathogenic process. While Yersinia pestis has multiple iron transporters, the yersiniabactin (Ybt) siderophore-dependent system plays a major role in iron acquisition in vitro and in vivo. In this study, we determined that the Ybt system is required for the us...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01236-09
更新日期:2010-05-01 00:00:00
abstract::Reduced-minus-oxidized difference spectra of sonically treated virulent Treponema pallidum disclosed cytochromes of the b anc c types as well as large amounts of flavoprotein. Difference spectra of the carbon monoxide-binding pigment identified cytochrome o as the terminal oxidase. Physiological reduction of the cytoc...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.16.3.885-890.1977
更新日期:1977-06-01 00:00:00
abstract::Pneumonic tularemia is a life-threatening disease caused by inhalation of the highly infectious intracellular bacterium Francisella tularensis. The most serious form of the disease associated with the type A strains can be prevented in experimental animals through vaccination with the attenuated live vaccine strain (L...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00605-10
更新日期:2011-04-01 00:00:00
abstract::Attachment and ingestion of Mycobacterium avium subsp. paratuberculosis by two epithelial cell lines were enhanced by soluble fibronectin (FN). Peptide blocking of the FN attachment protein (FAP-P) inhibited the internalization of M. avium subsp. paratuberculosis. Disruption of FAP-P expression significantly reduced a...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.70.5.2670-2675.2002
更新日期:2002-05-01 00:00:00
abstract::Wild-type Vibrio cholerae of both El Tor and classical biotypes (strains N16961 and 395, respectively) and nonmotile mutant derivatives with and without flagellar structures were characterized in three different animal models: (i) the rabbit ileal loop, (ii) the removable intestinal tie adult rabbit diarrhea (RITARD) ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.59.8.2727-2736.1991
更新日期:1991-08-01 00:00:00
abstract::In mice infected with virulent blood (trypomastigote) forms of Trypanosoma cruzi, complement depletion with cobra venom factor caused a marked exacerbation of the disease evidenced by significantly increased parasitemia levels and early mortality as compared with those of untreated infected animals. The effect was gre...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.11.1.86-91.1975
更新日期:1975-01-01 00:00:00
abstract::We have previously shown that a pneumococcal surface protein A (PspA)-based vaccine containing DNA plasmid encoding the Flt3 ligand (FL) gene (pFL) as a nasal adjuvant prevented nasal carriage of Streptococcus pneumoniae. In this study, we further investigated the safety and efficacy of this nasal vaccine for the indu...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01360-10
更新日期:2011-07-01 00:00:00
abstract::Suitability of the rhesus monkey (Macaca mulatta) as an experimental host for evaluation of vaccines against airborne infection with Mycobacterium tuberculosis strain H37Rv was investigated. Nonvaccinated monkeys were exposed to estimated doses of 12, 25, or 49 units of H37Rv in a modified Henderson apparatus, and the...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.2.5.574-582.1970
更新日期:1970-11-01 00:00:00
abstract::No effective therapy exists for Cryptosporidium parvum, a coccidial protozoan parasite that causes severe diarrhea in patients with AIDS. The role of microtubules in parasite invasion of host cells was investigated by incubating 10(7) oocysts with a HT 29.74 cell line for 24 h in the presence of microtubule-disrupting...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.61.11.4888-4890.1993
更新日期:1993-11-01 00:00:00
abstract::Pathogenic members of the Yersinia genus require the translocator protein LcrV for proper function of the type III secretion apparatus, which is crucial for virulence. LcrV has also been reported to play an independent immunosuppressive role via the induction of interleukin-10 (IL-10) through stimulation of Toll-like ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01644-06
更新日期:2007-07-01 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::Outer surface protein A (OspA) of the Lyme disease spirochete is primarily produced in the tick vector. OspA, which is a receptor for attaching spirochetes to the tick gut, is down regulated as the spirochetes leave the tick and enter the mammalian host. Although OspA is not a major antigen produced in the mammal, the...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01307-06
更新日期:2007-06-01 00:00:00
abstract::The relative roles of serum factors required for opsonization of type XIV Streptococcus pneumoniae were investigated by means of luminol-enhanced chemiluminescence (CL), bactericidal, and immunofluorescence assays employing adult sera containing high (>1,000 ng of antibody nitrogen per ml) or low (<200 ng of antibody ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.35.3.800-808.1982
更新日期:1982-03-01 00:00:00
abstract::Understanding the regulation of human immune responses is critical for vaccine development and treating infectious diseases. We have previously shown that simultaneous engagement of the T cell receptor (TCR) and complement regulator CD46 on human CD4(+) T cells in the presence of interleukin-2 (IL-2) induces potent se...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00513-10
更新日期:2010-12-01 00:00:00
abstract::FcRgamma and interleukin-10 (IL-10) are both required for chronic disease in C57BL/6 mice with Leishmania mexicana parasite infection. FcRgamma is a component of several different FcRs and may be a component of some T-cell receptors. The initial antibody response to L. mexicana is an immunoglobulin G1 (IgG1) response,...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00316-07
更新日期:2008-02-01 00:00:00
abstract::Germination of Bacillus anthracis Sterne and plasmidless Delta-Sterne endospores was dramatically enhanced in RAW264.7 macrophage-like cells, while germination of nonpathogenic Bacillus endospores was not. Elimination of gerS, a germinant receptor locus, caused a complete loss of cell-enhanced germination, implicating...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.70.10.5870-5872.2002
更新日期:2002-10-01 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::The gene encoding a nitric oxide reductase has been identified in Neisseria gonorrhoeae. The norB gene product shares significant identity with the nitric oxide reductases in Ralstonia eutropha and Synechocystis sp. and, like those organisms, the gonococcus lacks a norC homolog. The gonococcal norB gene was found to b...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.68.9.5241-5246.2000
更新日期:2000-09-01 00:00:00
abstract::A protein factor which induces high levels of gamma interferon (IFN-gamma) in resting splenic nonadherent cells was isolated from the sera of mice with generalized inflammation caused by endotoxic shock. The factor was highly purified by ammonium sulfate precipitation followed by ion-exchange column chromatography on ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.61.1.64-70.1993
更新日期:1993-01-01 00:00:00
abstract::Cell walls from Streptococcus mutans were prepared by conventional technique and subjected to a series of extraction procedures involving classical protein solvents. The extracted walls contained several non-peptidoglycan amino acids and were also amenable to radiolabeling with [125I]sodium iodide and chloramine T. Th...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.28.1.118-126.1980
更新日期:1980-04-01 00:00:00
abstract::Borrelia burgdorferi, the causative agent of Lyme arthritis, does not produce any exported proteases capable of degrading extracellular matrix despite the fact that it is able to disseminate from a skin insertion site to infect multiple organs. Prior studies have shown that B. burgdorferi induces the host protease, ma...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00214-09
更新日期:2009-07-01 00:00:00
abstract::Onchocerca volvulus, a human parasitic nematode, is the third leading cause of preventable blindness worldwide. This study describes the molecular cloning of a novel superoxide dismutase (SOD) from the parasite. This putative O. volvulus extracellular SOD (OvEcSOD) is 628 nucleotides (nt) long, including a 22-nt 5' sp...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.2.713-716.1994
更新日期:1994-02-01 00:00:00