Abstract:
:Legionella pneumophila, the gram-negative agent of Legionnaires' disease, possesses type IV pili and a type II protein secretion (Lsp) system, both of which are dependent upon the PilD prepilin peptidase. By analyzing multiple pilD mutants and various types of Lsp mutants as well as performing trans-complementation of these mutants, we have confirmed that PilD and type II secretion genes are required for L. pneumophila infection of both amoebae and human macrophages. Based upon a complete analysis of lspDE, lspF, and lspG mutants, we found that the type II system controls the secretion of protease, RNase, lipase, phospholipase A, phospholipase C, lysophospholipase A, and tartrate-sensitive and tartrate-resistant acid phosphatase activities and influences the appearance of colonies. Examination of the developing L. pneumophila genome database indicated that the organism has two other loci (lspC and lspLM) that are predicted to promote secretion and thus a set of genes that is comparable to the type II secretion genes in other gram-negative bacteria. In contrast to lsp mutants, L. pneumophila pilus mutants lacking either the PilQ secretin, the PspA pseudopilin, or pilin were not defective for colonial growth, secreted activities, or intracellular replication. L. pneumophila dot/icm mutants were also not impaired for type II-dependent exoenzymes. Upon intratracheal inoculation into A/J mice, lspDE, lspF, and pilD mutants, but not pilus mutants, exhibited a reduced ability to grow in the lung, as measured by competition assays. The lspF mutant was also defective in an in vivo kinetic assay. Examination of infected mouse sera revealed that type II secreted proteins are expressed in vivo. Thus, the L. pneumophila Lsp system is a virulence factor and the only type II secretion system linked to intracellular infection.
journal_name
Infect Immunjournal_title
Infection and immunityauthors
Rossier O,Starkenburg SR,Cianciotto NPdoi
10.1128/iai.72.1.310-321.2004keywords:
subject
Has Abstractpub_date
2004-01-01 00:00:00pages
310-21issue
1eissn
0019-9567issn
1098-5522journal_volume
72pub_type
杂志文章abstract::Exposure to bacterial superantigens such as staphylococcal enterotoxin B (SEB) leads to the induction of toxic shock syndrome which results in multiorgan failure, including liver damage. In the present study, we investigated the role of CD44 in SEB-induced liver injury. Injection of SEB into d-galactosamine-sensitized...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.73.1.50-61.2005
更新日期:2005-01-01 00:00:00
abstract::Gram-negative organisms incorporate hydroxy fatty acids into the lipid A moiety of lipopolysaccharide (LPS), and in the case of some members of the family Enterobacteriaceae, hydroxy fatty acids are incorporated exclusively into lipid A. However, a limited number of Bacteroides species have been shown to incorporate s...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.9.3753-3760.1994
更新日期:1994-09-01 00:00:00
abstract::Pseudomonas aeruginosa bacteremia in cancer patients develops from initial gastrointestinal (GI) colonization with translocation into the bloodstream in the setting of chemotherapy-induced neutropenia and GI mucosal damage. We established a reproducible mouse model of P. aeruginosa GI colonization and systemic spread ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.73.4.2262-2272.2005
更新日期:2005-04-01 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::Bioluminescent reporter assays have been widely used to study the effect of Toxoplasma gondii on host gene expression. In the present study, we extend these studies by engineering novel reporter cell lines containing a gamma-activated sequence (GAS) element driving firefly luciferase (FLUC). In RAW264.7 macrophages, T...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00077-16
更新日期:2016-06-23 00:00:00
abstract::A total of five bacteriological samples from the periodontal pockets of two sisters with localized juvenile periodontitis and their mother with advanced periodontitis was studied. Gram-negative anaerobic rods were predominant in the samples. Bacteroides intermedius and Bacteroides loescheii were the most predominant s...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.45.1.118-121.1984
更新日期:1984-07-01 00:00:00
abstract::The purpose of this study was to localize antigenic regions on the flagellin protein of Campylobacter jejuni 81116. This strain has two flagellin genes, flaA and flaB, which are 95% identical; only flaA seems to be expressed in motile C. jejuni 81116 cells. Fragments of flaA and flaB were cloned in the bacterial expre...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.59.3.1100-1105.1991
更新日期:1991-03-01 00:00:00
abstract::Toxicity of lipopolysaccharide (LPS) (endotoxin) is, to a large extent, mediated by the activation of monocytes/macrophages and subsequent release of monokines, such as interleukin-1 (IL-1) and tumor necrosis factor alpha (TNF-alpha). It is known that LPS binds readily to serum lipoproteins and that LPS-lipoprotein co...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.57.7.2237-2245.1989
更新日期:1989-07-01 00:00:00
abstract::In order to develop a new system for the analysis of capsular biosynthetic pathways we have explored the possibility of expressing type 3 capsular polysaccharide (CPS) from the pathogen Streptococcus pneumoniae in Lactococcus lactis, an unencapsulated lactic acid bacterium being developed as a vaccine delivery vehicle...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.68.6.3251-3260.2000
更新日期:2000-06-01 00:00:00
abstract::Aspergillus species are saprophytic molds causing life-threatening invasive fungal infections in the immunocompromised host. Innate immune recognition, in particular, the mechanisms of opsonization and complement activation, has been reported to be an integral part of the defense against fungi. We have shown that the ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00032-13
更新日期:2013-05-01 00:00:00
abstract::The genes for outer membrane protein P2 of four nontypeable Haemophilus influenzae strains were cloned and sequenced. The derived amino acid sequences were compared with the outer membrane protein P2 sequence from H. influenzae type b MinnA and the sequences of P2 from three additional nontypeable H. influenzae strain...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.6.2639-2643.1994
更新日期:1994-06-01 00:00:00
abstract::The production of delta-toxin is supposed to be responsible for various pathophysiological effects during infection with Staphylococcus aureus. We compared the effects of delta-toxin with the structurally related bee venom toxin melittin on granulocyte functions and inflammatory mediator release. Delta-toxin and melit...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.58.6.1653-1659.1990
更新日期:1990-06-01 00:00:00
abstract::Yersinia species pathogenic to humans have been extensively characterized with respect to type III secretion and its essential role in virulence. This study concerns the twin arginine translocation (Tat) pathway utilized by gram-negative bacteria to secrete folded proteins across the bacterial inner membrane into the ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.74.3.1768-1776.2006
更新日期:2006-03-01 00:00:00
abstract::Because of the association of the group A streptococcal pyrogenic exotoxins (SPEs) with erythrogenic toxin used in the classical Dick test, the involvement of the SPEs in production of erythematous skin reactions was assessed. Unless they had been presensitized, young adult rabbits failed to show skin reactions after ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.26.2.467-472.1979
更新日期:1979-11-01 00:00:00
abstract::Murine monoclonal antibodies were generated against streptolysin O. One out of 10 tested immunoglobulin clones exhibited strong neutralizing activity; in solution, the presence of approximately two to four antibody molecules per toxin monomer effected 50% neutralization of hemolytic toxin activity. An enzyme-linked im...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.54.3.641-645.1986
更新日期:1986-12-01 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::Gamma interferon (IFN-gamma)-activated macrophages use an alternative processing mechanism to present Salmonella antigens to CD8(+) T lymphocytes. This pathway involves processing of antigen in a vacuolar compartment followed by secretion and loading of antigenic peptides to major histocompatibility complex class I (M...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.73.7.3937-3944.2005
更新日期:2005-07-01 00:00:00
abstract::Dissemination of Leishmania within the host is related to parasites undergoing unchecked proliferation. We therefore studied the effects of oxidant generating systems on promastigote multiplication by (i) direct determinations of organism proliferation and (ii) the incorporation of [3H]uracil into promastigote nucleop...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.36.3.1023-1027.1982
更新日期:1982-06-01 00:00:00
abstract::Formation of compact colonies of Staphylococcus aureus in serum-soft agar is mainly a result of a reaction between protein A and the Fc-part of immunoglobulin G and not a clumping factor-fibrinogen reaction. ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.6.4.583-586.1972
更新日期:1972-10-01 00:00:00
abstract::The two enteropathogens Yersinia pseudotuberculosis and Yersinia enterocolitica penetrate eukaryotic cells in vitro through invasin, a surface-exposed protein. In contrast, Yersinia pestis, the causative agent of plague, is unable to enter mammalian cell lines, although the inv gene is present on its chromosome. Altho...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.64.1.375-379.1996
更新日期:1996-01-01 00:00:00
abstract::Ferrets which had been orally dosed with 5 mg of Staphylococcal enterotoxin B (SEB) responded with an increase in subcutaneous temperature. At 75 min, the subcutaneous temperature was significantly higher (+ 0.9 degrees C +/- 0.38 degrees C, P < 0.007) than in control animals. Animals dosed with 1 or 2 mg of SEB respo...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.68.4.2386-2389.2000
更新日期:2000-04-01 00:00:00
abstract::Athymic nude mice (nu/nu), heterozygous litter mates (nu/+), and thymic reconstituted homozygous animals (nu/nu TxR) were infected with Trypanosoma rhodesiense. A reduced parasitemia and prolonged survival were observed in the nu/nu animals after infection and cure or after immunization with irradiated organisms. Thes...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.20.3.714-720.1978
更新日期:1978-06-01 00:00:00
abstract::Bacteroides spp. may contribute to the chronicity of mixed infections by affecting the normal functions of polymorphonuclear leukocytes (PMN). This study evaluated the physiologic and biochemical responses of human peripheral blood PMN to a variety of strains of the oral periodontal pathogen Porphyromonas (Bacteroides...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.59.9.3134-3142.1991
更新日期:1991-09-01 00:00:00
abstract::Streptococcus pneumoniae is a fermentative microorganism and causes serious diseases in humans, including otitis media, bacteremia, meningitis, and pneumonia. However, the mechanisms enabling pneumococcal survival in the host and causing disease in different tissues are incompletely understood. The available evidence ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.02005-14
更新日期:2014-12-01 00:00:00
abstract::Endotoxemia in rats is associated with the accumulation of neutrophils (polymorphonuclear leukocytes) within the airspaces of the lung. Polymorphonuclear leukocyte influx appears to be regulated by the intrapulmonary accumulation of chemotactic activity. Since alveolar macrophages (AMS) are prevalent cells in the airs...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.57.3.810-816.1989
更新日期:1989-03-01 00:00:00
abstract::Expression of ace (adhesin to collagen of Enterococcus faecalis), encoding a virulence factor in endocarditis and urinary tract infection models, has been shown to increase under certain conditions, such as in the presence of serum, bile salts, urine, and collagen and at 46 °C. However, the mechanism of ace/Ace regula...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.02587-14
更新日期:2015-01-01 00:00:00
abstract::An analysis of which component of lipopolysaccharide, the lipid or the polysaccharide, is mitogenic for mouse B-lymphocytes has been performed. A purified glycolipid derived from a rough mutant of Salmonella minnesota (R595) that does not contain any o-polysaccharide at all is more mitogenic than an intact lipopolysac...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.8.3.406-411.1973
更新日期:1973-09-01 00:00:00
abstract::The fibronectin-degrading ability of 116, mainly oral, strains was assayed by using plasma-derived fibronectin adsorbed to a polystyrene surface. Ability to degrade fibronectin was revealed in strains of Bacteroides gingivalis, Bacteroides intermedius, Bacteroides loeschii, Staphylococcus aureus, Staphylococcus epider...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.51.2.707-711.1986
更新日期:1986-02-01 00:00:00
abstract::Rabbits immunized with group B type III, group C, and Streptococcus pneumoniae type XIV streptococcal vaccines developed autoantibodies reactive with autologous and isologous erythrocytes and human O-positive erythrocytes at reduced temperatures. The cold agglutinin antibodies were present in both the immunoglobulin M...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.41.1.205-213.1983
更新日期:1983-07-01 00:00:00
abstract::In nature, mixed Borrelia burgdorferi infections are common and possibly can be acquired by either superinfection or coinfection. Superinfection by heterologous B. burgdorferi strains has been established experimentally, although the ability of homologous B. burgdorferi clones to superinfect a host has not been studie...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01817-14
更新日期:2014-11-01 00:00:00