Biomaterial Database

Expression and transcriptional control of the Salmonella typhimurium Ipf fimbrial operon by phase variation. 1998

T L Norris, and R A Kingsley, and A J Bümler

Department of Medical Microbiology and Immunology, College of Medicine, Texas A&M University, College Station 77843-1114, USA.

The lpf operon mediates adhesion of Salmonella typhimurium to murine Peyer's patches. To investigate expression of this virulence factor, a transcriptional fusion between the lpf operon and the genes lacZYA of Escherichia coli was constructed and introduced into the S. typhimurium chromosome. The resulting strain yielded both Lac+ and Lac- colony phenotypes. Alternation between Lac+ (phase ON) and Lac- (phase OFF) phenotypes occurred by a heritable phase variation mechanism, as inoculation of broth cultures with bacteria picked from a Lac+ colony gave rise to a considerably higher proportion of Lac+ colonies than inoculation with bacteria picked from a Lac- colony. During growth in vitro, phase transition from ON to OFF and from OFF to ON occurred at rates 6.8 x 10(-3) and 2.4 x 10(-4) events per cell per generation respectively. In a murine intestinal organ culture model, selection for the ON expression state occurred when attached bacteria were recovered from Peyer's patches, suggesting that Lac phase variation correlated with expression of lpf mediated adherence. Selection for either the ON or the OFF expression state of the Ipf operon in vivo was studied in mice immunized with either GST or GST-LpfA fusion protein. A strong selection against phase ON cells occurred only in animals immunized with GST-LpfA. The ability of animals immunized with GST-LpfA to distinguish between phase ON and phase OFF bacteria provided evidence for the presence of LpfA fimbrial protein in phase ON cells and for its exposure to the immune system.

UI	MeSH Term	Description	Entries
D007114	Immunization	Deliberate stimulation of the host's immune response. ACTIVE IMMUNIZATION involves administration of ANTIGENS or IMMUNOLOGIC ADJUVANTS. PASSIVE IMMUNIZATION involves administration of IMMUNE SERA or LYMPHOCYTES or their extracts (e.g., transfer factor, immune RNA) or transplantation of immunocompetent cell producing tissue (thymus or bone marrow).	Immunologic Stimulation,Immunostimulation,Sensitization, Immunologic,Variolation,Immunologic Sensitization,Immunological Stimulation,Sensitization, Immunological,Stimulation, Immunologic,Immunizations,Immunological Sensitization,Immunological Sensitizations,Immunological Stimulations,Sensitizations, Immunological,Stimulation, Immunological,Stimulations, Immunological,Variolations
D008807	Mice, Inbred BALB C	An inbred strain of mouse that is widely used in IMMUNOLOGY studies and cancer research.	BALB C Mice, Inbred,BALB C Mouse, Inbred,Inbred BALB C Mice,Inbred BALB C Mouse,Mice, BALB C,Mouse, BALB C,Mouse, Inbred BALB C,BALB C Mice,BALB C Mouse
D009876	Operon	In bacteria, a group of metabolically related genes, with a common promoter, whose transcription into a single polycistronic MESSENGER RNA is under the control of an OPERATOR REGION.	Operons
D010861	Fimbriae, Bacterial	Thin, hairlike appendages, 1 to 20 microns in length and often occurring in large numbers, present on the cells of gram-negative bacteria, particularly Enterobacteriaceae and Neisseria. Unlike flagella, they do not possess motility, but being protein (pilin) in nature, they possess antigenic and hemagglutinating properties. They are of medical importance because some fimbriae mediate the attachment of bacteria to cells via adhesins (ADHESINS, BACTERIAL). Bacterial fimbriae refer to common pili, to be distinguished from the preferred use of "pili", which is confined to sex pili (PILI, SEX).	Bacterial Fimbriae,Bacterial Pili,Common Fimbriae,Common Pili,Pili, Bacterial,Pili, Common,Bacterial Fimbria,Bacterial Pilus,Common Fimbria,Common Pilus,Fimbria, Bacterial,Pilus, Bacterial,Fimbria, Common,Fimbriae, Common,Pilus, Common
D011993	Recombinant Fusion Proteins	Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.	Fusion Proteins, Recombinant,Recombinant Chimeric Protein,Recombinant Fusion Protein,Recombinant Hybrid Protein,Chimeric Proteins, Recombinant,Hybrid Proteins, Recombinant,Recombinant Chimeric Proteins,Recombinant Hybrid Proteins,Chimeric Protein, Recombinant,Fusion Protein, Recombinant,Hybrid Protein, Recombinant,Protein, Recombinant Chimeric,Protein, Recombinant Fusion,Protein, Recombinant Hybrid,Proteins, Recombinant Chimeric,Proteins, Recombinant Fusion,Proteins, Recombinant Hybrid
D005260	Female		Females
D005982	Glutathione Transferase	A transferase that catalyzes the addition of aliphatic, aromatic, or heterocyclic FREE RADICALS as well as EPOXIDES and arene oxides to GLUTATHIONE. Addition takes place at the SULFUR. It also catalyzes the reduction of polyol nitrate by glutathione to polyol and nitrite.	Glutathione S-Alkyltransferase,Glutathione S-Aryltransferase,Glutathione S-Epoxidetransferase,Ligandins,S-Hydroxyalkyl Glutathione Lyase,Glutathione Organic Nitrate Ester Reductase,Glutathione S-Transferase,Glutathione S-Transferase 3,Glutathione S-Transferase A,Glutathione S-Transferase B,Glutathione S-Transferase C,Glutathione S-Transferase III,Glutathione S-Transferase P,Glutathione Transferase E,Glutathione Transferase mu,Glutathione Transferases,Heme Transfer Protein,Ligandin,Yb-Glutathione-S-Transferase,Glutathione Lyase, S-Hydroxyalkyl,Glutathione S Alkyltransferase,Glutathione S Aryltransferase,Glutathione S Epoxidetransferase,Glutathione S Transferase,Glutathione S Transferase 3,Glutathione S Transferase A,Glutathione S Transferase B,Glutathione S Transferase C,Glutathione S Transferase III,Glutathione S Transferase P,Lyase, S-Hydroxyalkyl Glutathione,P, Glutathione S-Transferase,Protein, Heme Transfer,S Hydroxyalkyl Glutathione Lyase,S-Alkyltransferase, Glutathione,S-Aryltransferase, Glutathione,S-Epoxidetransferase, Glutathione,S-Transferase 3, Glutathione,S-Transferase A, Glutathione,S-Transferase B, Glutathione,S-Transferase C, Glutathione,S-Transferase III, Glutathione,S-Transferase P, Glutathione,S-Transferase, Glutathione,Transfer Protein, Heme,Transferase E, Glutathione,Transferase mu, Glutathione,Transferase, Glutathione,Transferases, Glutathione
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012486	Salmonella typhimurium	A serotype of Salmonella enterica that is a frequent agent of Salmonella gastroenteritis in humans. It also causes PARATYPHOID FEVER.	Salmonella typhimurium LT2
D014158	Transcription, Genetic	The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.	Genetic Transcription