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      1. Author :
        Srivastava, Amit; Henneke, Philipp; Visintin, Alberto; Morse, Sarah C; Martin, Victoria; Watkins, Claire; Paton, James C; Wessels, Michael R; Golenbock, Douglas T; Malley, Richard
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2005
      5. Publication :
        Infection and immunity
      6. Products :
      7. Volume :
        73
      8. Issue :
        10
      9. Page Numbers :
        6479-6487
      10. Research Area :
        N/A
      11. Keywords :
        Amino Acid Chloromethyl Ketones; Animals; Apoptosis; Bacterial Proteins; Caspases; Lipopolysaccharides; Macrophages; Mice; Mice, Inbred Strains; Nasopharynx; Pneumococcal Infections; Streptococcus pneumoniae; Streptolysins; Xen10
      12. Abstract :
        Pneumolysin, the cholesterol-dependent cytolysin of Streptococcus pneumoniae, induces inflammatory and apoptotic events in mammalian cells. Toll-like receptor 4 (TLR4) confers resistance to pneumococcal infection via its interaction with pneumolysin, but the underlying mechanisms remain to be identified. In the present study, we found that pneumolysin-induced apoptosis is also mediated by TLR4 and confers protection against invasive disease. The interaction between TLR4 and pneumolysin is direct and specific; ligand-binding studies demonstrated that pneumolysin binds to TLR4 but not to TLR2. Involvement of TLR4 in pneumolysin-induced apoptosis was demonstrated in several complementary experiments. First, macrophages from wild-type mice were significantly more prone to pneumolysin-induced apoptosis than cells from TLR4-defective mice. In gain-of-function experiments, we found that epithelial cells expressing TLR4 and stimulated with pneumolysin were more likely to undergo apoptosis than cells expressing TLR2. A specific TLR4 antagonist, B1287, reduced pneumolysin-mediated apoptosis in wild-type cells. This apoptotic response was also partially caspase dependent as preincubation of cells with the pan-caspase inhibitor zVAD-fmk reduced pneumolysin-induced apoptosis. Finally, in a mouse model of pneumococcal infection, pneumolysin-producing pneumococci elicited significantly more upper respiratory tract cell apoptosis in wild-type mice than in TLR4-defective mice, and blocking apoptosis by administration of zVAD-fmk to wild-type mice resulted in a significant increase in mortality following nasopharyngeal pneumococcal exposure. Overall, our results strongly suggest that protection against pneumococcal disease is dependent on the TLR4-mediated enhancement of pneumolysin-induced apoptosis.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/16177320
      14. Call Number :
        PKI @ catherine.lautenschlager @
      15. Serial :
        10001
      1. Author :
        Mann, B.; Orihuela, C.; Antikainen, J.; Gao, G.; Sublett, J.; Korhonen, T. K.; Tuomanen, E.
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2006
      5. Publication :
        Infection and Immunity
      6. Products :
      7. Volume :
        74
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        IVIS, Xenogen, Xen7
      12. Abstract :
        Members of the choline binding protein (Cbp) family are noncovalently bound to phosphorylcholine residues on the surface of Streptococcus pneumoniae. It has been suggested that CbpG plays a role in adherence and increase virulence both at the mucosal surface and in the bloodstream, but the function of this protein has been unclear. A new sequence analysis indicated that CbpG is a possible member of the S1 family of multifunctional surface-associated serine proteases. Clinical isolates contained two alleles of cbpG, and one-third of the strains expressed a truncated protein lacking the C-terminal, cell wall-anchoring choline binding domain. CbpG on the surface of pneumococci (full length) or released into the supernatant (truncated) showed proteolytic activity for fibronectin and casein, as did CbpG expressed on lactobacilli or as a purified full-length or truncated recombinant protein. Recombinant CbpG (rCbpG)-coated beads adhered to eukaryotic cells, and TIGR4 mutants lacking CbpG or having a truncated CbpG protein showed decreased adherence in vitro and attenuation of disease in mouse challenge models of colonization, pneumonia, and bacteremia. Immunization with rCbpG was protective in an animal model of colonization and sepsis. We propose that CbpG is a multifunctional surface protein that in the cell-attached or secreted form cleaves host extracellular matrix and in the cell-attached form participates in bacterial adherence. This is the first example of distinct functions in virulence that are dependent on natural variation in expression of a choline binding domain.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/16428724
      14. Call Number :
        140887
      15. Serial :
        6992
      1. Author :
        Orihuela, C. J.; Radin, J. N.; Sublett, J. E.; Gao, G.; Kaushal, D.; Tuomanen, E. I.
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2004
      5. Publication :
        Infection and Immunity
      6. Products :
      7. Volume :
        72
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        IVIS, Xenogen, Xen7, Xen35
      12. Abstract :
        Streptococcus pneumoniae is a leading cause of invasive bacterial disease. This is the first study to examine the expression of S. pneumoniae genes in vivo by using whole-genome microarrays available from The Institute for Genomic Research. Total RNA was collected from pneumococci isolated from infected blood, infected cerebrospinal fluid, and bacteria attached to a pharyngeal epithelial cell line in vitro. Microarray analysis of pneumococcal genes expressed in these models identified body site-specific patterns of expression for virulence factors, transporters, transcription factors, translation-associated proteins, metabolism, and genes with unknown function. Contributions to virulence predicted for several unknown genes with enhanced expression in vivo were confirmed by insertion duplication mutagenesis and challenge of mice with the mutants. Finally, we cross-referenced our results with previous studies that used signature-tagged mutagenesis and differential fluorescence induction to identify genes that are potentially required by a broad range of pneumococcal strains for invasive disease.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/15385455
      14. Call Number :
        141856
      15. Serial :
        6874
      1. Author :
        Orihuela, Carlos J; Gao, Geli; Francis, Kevin P; Yu, Jun; Tuomanen, Elaine I
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2004
      5. Publication :
        The Journal of infectious diseases
      6. Products :
      7. Volume :
        190
      8. Issue :
        9
      9. Page Numbers :
        1661-1669
      10. Research Area :
        N/A
      11. Keywords :
        Animals; Bacteremia; Bacterial Proteins; Cerebrospinal Fluid; Disease Models, Animal; Female; Lung; Meningitis, Pneumococcal; Mice; Mice, Inbred BALB C; Mutation; N-Acetylmuramoyl-L-alanine Amidase; Nasopharynx; Neuraminidase; Pneumococcal Infections; Pneumonia, Pneumococcal; Pyruvate Oxidase; Streptococcus pneumoniae; Streptolysins; Virulence Factors; Xen7
      12. Abstract :
        We assessed the ability of Streptococcus pneumoniae mutants deficient in either choline binding protein A (CbpA), pneumolysin (Pln), pyruvate oxidase (SpxB), autolysin (LytA), pneumococcal surface protein A, or neuraminidase A (NanA) to replicate in distinct anatomical sites and translocate from one site to the next. Intranasal, intratracheal, and intravenous models of disease were assessed in 4-week-old BALB/cJ mice by quantitation of bacterial titers in the relevant organs. Mice were also observed by use of real-time bioluminescent imaging (BLI). BLI allowed visualization of the bacteria in sites not tested by sampling. All mutants were created in D39 Xen7, a fully virulent derivative of capsular type 2 strain D39 that contains an optimized luxABCDE cassette. NanA, SpxB, and, to a lesser extent, CbpA contributed to prolonged nasopharyngeal colonization, whereas CbpA and NanA contributed to the transition to the lower respiratory tract. Once lung infection was established, Pln, SpxB, and LytA contributed to bacterial replication in the lungs and translocation to the bloodstream. In the bloodstream, only Pln and LytA were required for high-titer replication, whereas CbpA was required for invasion of the cerebrospinal fluid. We conclude that transitions between body sites require virulence determinants distinct from those involved in organ-specific replication.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/15478073
      14. Call Number :
        PKI @ catherine.lautenschlager @
      15. Serial :
        10002
      1. Author :
        Park, H. S.; Cleary, P. P.
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2005
      5. Publication :
        Infection and Immunity
      6. Products :
      7. Volume :
        73
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        IVIS, Xenogen, Xen20
      12. Abstract :
        C5a peptidase, also called SCPA (surface-bound C5a peptidase), is a surface-bound protein on group A streptococci (GAS), etiologic agents for a variety of human diseases including pharyngitis, impetigo, toxic shock, and necrotizing fasciitis, as well as the postinfection sequelae rheumatic fever and rheumatic heart disease. This protein is highly conserved among different serotypes and is also expressed in human isolates of group B, C, and G streptococci. Human tonsils are the primary reservoirs for GAS, maintaining endemic disease across the globe. We recently reported that GAS preferentially target nasal mucosa-associated lymphoid tissue (NALT) in mice, a tissue functionally analogous to human tonsils. Experiments using a C5a peptidase loss-of-function mutant and an intranasal infection model showed that this protease is required for efficient colonization of NALT. An effective vaccine should prevent infection of this secondary lymphoid tissue; therefore, the potential of anti-SCPA antibodies to protect against streptococcal infection of NALT was investigated. Experiments showed that GAS colonization of NALT was significantly reduced following intranasal immunization of mice with recombinant SCPA protein administered alone or with cholera toxin, whereas a high degree of GAS colonization of NALT was observed in control mice immunized with phosphate-buffered saline only. Moreover, administration of anti-SCPA serum by the intranasal route protected mice against streptococcal infection. These results suggest that intranasal immunization with SCPA would prevent colonization and infection of human tonsils, thereby eliminating potential reservoirs that maintain endemic disease.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/16299278
      14. Call Number :
        141964
      15. Serial :
        5327
      1. Author :
        Chung, HM; Cartwright, MM; Bortz, DM; Jackson, TL; Younger, JG
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2008
      5. Publication :
        Shock
      6. Products :
      7. Volume :
        30
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        IVIS, Xenogen, Xen39
      12. Abstract :
        Unlike many localized infections, the development and resolution of bacteremia involves physical and immunological interactions between many anatomic sites. In an effort to better understand these interactions, we developed a computational model of bacteremia as a dynamical system fashioned after multicompartmental pharmacodynamic models, incorporating bacterial proliferation and clearance in the blood, liver, spleen, and lungs, and the transport of pathogens between these sites. A system of four first-order homogeneous ODEs was developed. Blood and organ bacterial burdens were measured at various time points from 3 to 48 h postinoculation using an LD25 murine model of Staphylococcus epidermidis bacteremia. Using these empiric data, solutions to the mathematical model were recovered. A bootstrap resampling method was used to generate 95% confidence intervals around the solved parameters. The validity of the model was examined in parallel experiments using animals acutely immunocompromised with cyclophosphamide; the model captured abnormalities in bacterial partitioning previously described with this antineoplastic agent. Lastly, the approach was used to explore possible benefits to clinically observed hyperdynamic blood flow during sepsis: in simulation, normal mice, but not those treated with cyclophosphamide, enjoyed significantly more rapid bacterial clearance from the bloodstream under hyperdynamic conditions.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/18317411
      14. Call Number :
        136975
      15. Serial :
        5976
      1. Author :
        Nguyen, V. H.; Kim, H. S.; Ha, J. M.; Hong, Y.; Choy, H. E.; Min, J. J.
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2010
      5. Publication :
        Cancer Res
      6. Products :
      7. Volume :
        70
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Animals, Blotting, Western, Xen26, Cell Line, Tumor, Diagnostic Imaging/methods, Gene Therapy/*methods, Genetic Engineering/*methods, Genetic Vectors/*therapeutic use, Humans, Male, Mice, Mice, Inbred BALB C, Neoplasms/*therapy, Perforin/*genetics/therapeutic use, Promoter Regions, Genetic, Salmonella typhimurium/*genetics, bcl-Associated Death Protein/genetics IVIS, Xenogen
      12. Abstract :
        Tumor-targeting bacteria have been studied in terms of their ability to visualize the infection pathway (through imaging probes) or to carry therapeutic molecules to tumors. To integrate these monitoring and therapeutic functions, we engineered attenuated Salmonella typhimurium defective in guanosine 5'-diphosphate-3'-diphosphate synthesis to carry cytotoxic proteins (cytolysin A) and express reporter genes. We successfully visualized the therapeutic process with these engineered bacteria in mice and found that they often mediated complete tumor (CT-26) eradication on cytotoxic gene induction. Furthermore, treatment with the engineered bacteria markedly suppressed metastatic tumor growth.
      13. URL :
        http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=20028866
      14. Call Number :
        141643
      15. Serial :
        6246
      1. Author :
        Min, Jung-Joon; Nguyen, Vu H.; Gambhir, Sanjiv S.
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2010
      5. Publication :
        Nuclear Medicine and Molecular Imaging
      6. Products :
      7. Volume :
        44
      8. Issue :
        1
      9. Page Numbers :
        15-24
      10. Research Area :
        N/A
      11. Keywords :
        Cancer; Cardiology; Gene delivery vector; Gene Therapy; Imaging / Radiology; Molecular Imaging; Nuclear Medicine; Oncology; Orthopedics; Xen26
      12. Abstract :
        Cancer persists as one of the most devastating diseases in the world. Problems including metastasis and tumor resistance to chemotherapy and radiotherapy have seriously limited the therapeutic effects of present clinical treatments. To overcome these limitations, cancer gene therapy has been developed over the last two decades for a broad spectrum of applications, from gene replacement and knockdown to vaccination, each with different requirements for gene delivery. So far, a number of genes and delivery vectors have been investigated, and significant progress has been made with several gene therapy modalities in clinical trials. Viral vectors and synthetic liposomes have emerged as the vehicles of choice for many applications. However, both have limitations and risks that restrict gene therapy applications, including the complexity of production, limited packaging capacity, and unfavorable immunological features. While continuing to improve these vectors, it is important to investigate other options, particularly nonviral biological agents such as bacteria, bacteriophages, and bacteria-like particles. Recently, many molecular imaging techniques for safe, repeated, and high-resolution in vivo imaging of gene expression have been employed to assess vector-mediated gene expression in living subjects. In this review, molecular imaging techniques for monitoring biological gene delivery vehicles are described, and the specific use of these methods at different steps is illustrated. Linking molecular imaging to gene therapy will eventually help to develop novel gene delivery vehicles for preclinical study and support the development of future human applications.
      13. URL :
        http://link.springer.com/article/10.1007/s13139-009-0006-3
      14. Call Number :
        PKI @ catherine.lautenschlager @
      15. Serial :
        10003
      1. Author :
        Curbelo, J; Moulton, K; Willard, S
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2010
      5. Publication :
        Theriogenology
      6. Products :
      7. Volume :
        73
      8. Issue :
        1
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        Animals; Cattle; Escherichia coli; Female; Genitalia, Female; Optical Phenomena; Photons; Xen14
      12. Abstract :
        The objectives of this study were to (1) characterize the photonic properties of Escherichia coli-Xen14 and (2) conduct photonic imaging of E. coli-Xen14 within bovine reproductive tract segments (RTS) ex vivo (Bos indicus). E. coli-Xen14 was grown for 24h in Luria Bertani medium (LB), with or without kanamycin (KAN). Every 24h, for an 8-d interval, inoculums were imaged and photonic emissions (PE) collected. Inoculums were subcultured and plated daily to determine the colony forming units (CFU) and ratio of photon emitters to nonemitters. In the second objective, abattoir-derived bovine reproductive tracts (n=9) were separated into posterior and anterior vagina, cervix, uterine body, and uterine horns. Two concentrations (3.2x10(8) and 3.2x10(6) CFU/200microL for relative [High] and [Low], respectively) of E. coli-Xen14 were placed in translucent tubes for detection of PE through RTS. The CFU did not differ (P=0.31) over time with or without KAN presence; they remained stable with 99.93% and 99.98% photon emitters, respectively. However, PE were lower (P<0.0001) in cultures containing KAN than in those containing no KAN (629.8+/-117.7 vs. 3012.0+/-423.5 relative lights units per second [RLU/sec], respectively). On average, the percentage of PE between RTS, for both concentrations, was higher (P<0.05) in the uterine body. In summary, E. coli-Xen14 remained stable with respect to the proportions of photon emitters with or without KAN (used to selectively culture E. coli-Xen14). However, KAN presence suppressed photonic activity. The ability to detect PE through various segments of the reproductive tract demonstrated the feasibility of monitoring the presence of E. coli-Xen14 in the bovine reproductive tract ex vivo.
      13. URL :
        http://www.ncbi.nlm.nih.gov/pubmed/19819541
      14. Call Number :
        PKI @ catherine.lautenschlager @
      15. Serial :
        10004
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