Abstract:
:Microbial survival in a host is usually dependent on the ability of a pathogen to undergo changes that promote escape from host defense mechanisms. The human-pathogenic fungus Cryptococcus neoformans undergoes phenotypic switching in vivo that promotes persistence in tissue. By microarray and real-time PCR analyses, the allergen 1 gene (ALL1) was found to be downregulated in the hypervirulent mucoid switch variant, both during logarithmic growth and during intracellular growth in macrophages. The ALL1 gene encodes a small cytoplasmic protein that is involved in capsule formation. Growth of an all1Delta gene deletion mutant was normal. Similar to cells of the mucoid switch variant, all1Delta cells produced a larger polysaccharide capsule than cells of the smooth parent and the complemented strain produced, and the enlarged capsule inhibited macrophage phagocytosis. The mutant exhibited a modest defect in capsule induction compared to all of the other variants. In animal models the phenotype of the all1Delta mutant mimicked the hypervirulent phenotype of the mucoid switch variant, which is characterized by decreased host survival and elevated intracranial pressure. Decreased survival is likely the result of both an ineffective cell-mediated immune response and impaired phagocytosis by macrophages. Consequently, we concluded that, unlike loss of most virulence-associated genes, where loss of gene function results in attenuated virulence, loss of the ALL1 gene enhances virulence by altering the host-pathogen interaction and thereby impairing clearance. Our data identified the first cryptococcal gene associated with elevated intracranial pressure and support the hypothesis that an environmental opportunistic pathogen has modified its virulence in vivo by epigenetic downregulation of gene function.
journal_name
Infect Immunjournal_title
Infection and immunityauthors
Jain N,Li L,Hsueh YP,Guerrero A,Heitman J,Goldman DL,Fries BCdoi
10.1128/IAI.01079-08subject
Has Abstractpub_date
2009-01-01 00:00:00pages
128-40issue
1eissn
0019-9567issn
1098-5522pii
IAI.01079-08journal_volume
77pub_type
杂志文章abstract::Transgenic tobacco plants stably expressing recombinant FaeG, which is the major subunit and adhesin of K88ad fimbriae, were obtained. Analysis of sera from immunized mice indicates that in mice, the immunogenicity induced by plant-derived FaeG protein is comparable to that generated with traditional approaches. ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.71.9.5436-5439.2003
更新日期:2003-09-01 00:00:00
abstract::Cigarette smoke exposure increases the risk of pulmonary and invasive infections caused by Streptococcus pneumoniae, the most commonly isolated organism from patients with community-acquired pneumonia. Despite this association, the mechanisms by which cigarette smoke exposure diminishes host defense against S. pneumon...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00963-09
更新日期:2010-03-01 00:00:00
abstract::Humoral immune responses in experimental African trypanosomiasis were assessed in rabbits infected with Trypanosoma rhodesiense. Immune complexes as measured by a Clq binding assay or a Clq solid-phase assay were detected by day 10 and increased progressively through day 28. Immune complexes analyzed by double diffusi...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.33.2.407-414.1981
更新日期:1981-08-01 00:00:00
abstract::Increased resistance to infection with Brucella abortus 2308 resulted when recombinant murine gamma interferon (rMuIFN-gamma) was given to mice both before and during infection but not when given only before infection. Mice given rMuIFN-gamma had enhanced peritoneal and splenic macrophage bactericidal activity against...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.60.10.4407-4409.1992
更新日期:1992-10-01 00:00:00
abstract::The susceptibility of HeLa cells to Mycoplasma pneumoniae-induced injury was examined. Infections were initiated with relatively low mycoplasma doses, carried out in a culture medium incapable of supporting M. pneumoniae replication in the absence of host cells, and monitored for up to 10 days. Under these conditions,...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.56.8.2054-2059.1988
更新日期:1988-08-01 00:00:00
abstract::Shigella flexneri is a gram-negative bacterium that causes bacillary dysentery in humans that is characterized by an acute inflammatory response of the colon. The fate of phagocytes that are infected in vitro with virulent Shigella has been the subject of some investigation and debate. In this study we found that viru...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.73.1.504-513.2005
更新日期:2005-01-01 00:00:00
abstract::Cytomegalovirus (CMV) infections are common in renal transplant recipients. We studied 23 recipients prospectively to determine whether infections by other herpes-group and non-herpes-group viruses were also present. Sera, obtained at the time of surgery and periodically thereafter, were tested for antibody to CMV, he...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.14.4.970-975.1976
更新日期:1976-10-01 00:00:00
abstract::We measured the microbicidal peptides MCP-1 and MCP-2 in rabbit alveolar macrophages (AM), comparing rabbits pretreated with complete Freund adjuvant with untreated control animals. Levels of MCP-1 increased from 4.7 +/- 0.6 microgram/10(7) resident AM to 13.2 +/- 0.1 microgram/10(7) complete Freund adjuvant-elicited ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.33.3.775-778.1981
更新日期:1981-09-01 00:00:00
abstract::Recombinant adenylate cyclase toxoids are shown to deliver inserted foreign CD4(+)-T-cell epitopes into the major histocompatibility complex class II presentation pathway, inducing a specific CD4(+)-T-cell response in vivo and yielding in vitro stimulation of specific CD4(+) T cells at a 100-times-higher molar efficie...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:
更新日期:2002-02-01 00:00:00
abstract::We examined the immunobiological responses to Histoplasma capsulatum in lungs of gamma interferon (IFN-gamma) knockout mice (GKO mice). Naive GKO mice succumbed by day 9 to intranasal challenge with 2.5 x 10(6) yeasts, whereas all wild-type (WT) mice survived for 45 days. Compared to lungs of WT mice, the lungs of acu...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.65.7.2564-2569.1997
更新日期:1997-07-01 00:00:00
abstract::A murine respiratory infection model was used to study the mechanism of protective immunity to Bordetella pertussis. We found that nude mice, which are deficient in T cells, developed a persistent infection and failed to clear the bacteria after aerosol inoculation. In contrast, normal adult nonimmune mice cleared a r...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.61.2.399-410.1993
更新日期:1993-02-01 00:00:00
abstract::Groups of mice were immunized either subcutaneously or intranasally with purified Brucella melitensis lipopolysaccharide (LPS) or with LPS as a noncovalent complex with Neisseria meningitidis group B outer membrane protein (LPS-GBOMP). Control mice were inoculated with sterile saline. Two doses of vaccine were given 4...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00331-06
更新日期:2006-10-01 00:00:00
abstract::The immunoprophylactic effect of chemically inactivated Pseudomonas aeruginosa exotoxin A in experimental pseudomonas infections was studied. Exotoxin A toxoids were prepared by Formalin (f-TXD) or glutaraldehyde (g-TXD) treatment. Immunization of mice with three or four doses (10 micrograms each) of f-TXD and the syn...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.32.2.681-689.1981
更新日期:1981-05-01 00:00:00
abstract::Bacillus anthracis, the causative agent of anthrax, relies on multiple virulence factors to subvert the host immune defense. Using Caenorhabditis elegans as an infection model, we screened approximately 5,000 transposon mutants of B. anthracis Sterne for decreased virulence. One of the attenuated mutants resulted in l...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01614-13
更新日期:2014-03-01 00:00:00
abstract::Cells of Candida albicans strain WO-1 and related strains switch frequently and reversibly between a white-colony-forming unit (white phase) and a gray-colony-forming unit (opaque phase). Cells in the budding white phase exhibit the usual smooth round phenotype observed in other C. albicans strains, but cells in the b...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.57.2.458-467.1989
更新日期:1989-02-01 00:00:00
abstract::Phytohemagglutinin is able to trigger interferon synthesis in spleen cell cultures from nude (nu/nu) mice as effectively as in splenic cell cultures from haired, control (nu/+), thymus-bearing mice. A minor theta-bearing cell population present in the spleen of nude mice appears essential to phytohemagglutinin interfe...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.21.3.966-972.1978
更新日期:1978-09-01 00:00:00
abstract::The 260-kDa galactose-inhibitable lectin of Entamoeba histolytica mediates binding of amebic trophozoites to purified colonic mucins and intestinal epithelial cells. Parenteral immunization of Lewis rats with immuno-affinity-purified lectin with Freund's adjuvant and then intra-Peyer's patch inoculation of lectin with...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.63.2.686-689.1995
更新日期:1995-02-01 00:00:00
abstract::The secretion of aspartic proteases (Saps) has long been recognized as a virulence-associated trait of the pathogenic yeast Candida albicans. In this study, we report that different recombinant Saps, including Sap1, Sap2, Sap3, and Sap6, have differing abilities to induce secretion of proinflammatory cytokines by huma...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00789-10
更新日期:2010-11-01 00:00:00
abstract::Toxoplasma gondii is an obligate intracellular parasite that resides in the cytoplasm of its host in a unique membrane-bound vacuole known as the parasitophorous vacuole (PV). The membrane surrounding the parasite is remodeled by the dense granules, secretory organelles that release an array of proteins into the vacuo...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00782-08
更新日期:2008-11-01 00:00:00
abstract::Staphylococcus aureus is one of the pathogens most frequently isolated in device-related infections. S. aureus is equipped with surface-associated proteins promoting specific binding to matrix molecules. Clumping factor A (ClfA, encoded by clfA) mediates adhesion to fibrinogen. Whereas the contribution of ClfA to path...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.70.6.2758-2762.2002
更新日期:2002-06-01 00:00:00
abstract::The type III secretion system (T3SS) encoded by the Salmonella pathogenicity island 2 (SPI2) has a central role in systemic infections by Salmonella enterica and for the intracellular phenotype. Intracellular S. enterica uses the SPI2-encoded T3SS to translocate a set of effector proteins into the host cell, which mod...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.72.5.2879-2888.2004
更新日期:2004-05-01 00:00:00
abstract::Bovine septicemic Escherichia coli 31A agglutinates bovine, rabbit, and human erythrocytes and adheres in vitro to the brush border of bovine or ovine intestinal epithelial cells and to the human colon carcinoma Caco-2 cell line. The adhesion and hemagglutination of E. coli 31A are mediated by a chromosome-encoded fim...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.64.1.332-342.1996
更新日期:1996-01-01 00:00:00
abstract::Thirty percent of Streptococcus pneumoniae isolates contain pilus islet 1, coding for a pilus composed of the backbone subunit RrgB and two ancillary proteins, RrgA and RrgC. RrgA is the major determinant of in vitro adhesion associated with pilus 1, is protective in vivo in mouse models, and exists in two variants (c...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00601-10
更新日期:2010-12-01 00:00:00
abstract::Pneumolysin is a 471-amino-acid toxin produced by Streptococcus pneumoniae which has both cytolytic and complement activation properties. We have constructed a derivative of the type 2 S. pneumoniae strain D39 in which the portion of the pneumolysin gene encoding amino acids 55 to 437 has been deleted in-frame. The vi...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.67.2.981-985.1999
更新日期:1999-02-01 00:00:00
abstract::It was shown that a strain of Serratia liquefaciens harbors a conjugative R-plasmid responsible for reistance to the following 14 antibiotics: ampicillin, carbenicillin, cephalothin, butirosin, neomycin, paramomycin, kanamycin, lividomycin, gentamicin, tobramycin, streptomycin, tetracycline, sulfonamide, and chloramph...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:
更新日期:1980-06-01 00:00:00
abstract::A substance with potent decomplementation activity was isolated from staphylococcal culture supernatants by polyethylene glycol precipitation, DEAE-ion-exchange and Sephacryl chromatography, and preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purified substance exhibited all the characterist...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.47.1.47-51.1985
更新日期:1985-01-01 00:00:00
abstract::Stimulated polymorphonuclear leukocytes have been shown by this laboratory to release a reactive-oxygen species (ROS) which is detectable in the supernatant and is capable of oxidizing reduced glutathione and reacting with methionine (Sagone et al., Blood 63:96-104, 1984). This ROS is dependent on H2O2 and heme for it...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.43.3.846-849.1984
更新日期:1984-03-01 00:00:00
abstract::In this study, the efficacy of bactericidal/permeability-increasing protein (BPI) was assessed in a rat model of chronic otitis media with effusion. BPI injection prevented disturbance of the mucociliary clearance system of the middle ear. Hence, it is postulated that BPI can be a new therapy for chronic otitis media ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.68.5.2992-2994.2000
更新日期:2000-05-01 00:00:00
abstract::Burkholderia cenocepacia strain K56-2 typically has rough colony morphology on agar medium; however, shiny colony variants (shv) can appear spontaneously. These shv all had a minimum of 50% reduction in biomass formation and were generally avirulent in an alfalfa seedling infection model. Three shv-K56-2 S15, K56-2 S7...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00874-07
更新日期:2008-01-01 00:00:00
abstract::Mycoplasma genitalium is a sexually transmitted pathogen associated with several acute and chronic reproductive tract disease syndromes in men and women. To evaluate the suitability of a pig-tailed macaque model of M. genitalium infection, we inoculated a pilot animal with M. genitalium strain G37 in the uterine cervi...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01322-12
更新日期:2013-08-01 00:00:00