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Full-Text Articles in Medicine and Health Sciences
Neutrophils From Both Susceptible And Resistant Mice Efficiently Kill Opsonized Listeria Monocytogenes, Michelle G. Pitts, Travis A. Combs, Sarah E. F. D'Orazio
Neutrophils From Both Susceptible And Resistant Mice Efficiently Kill Opsonized Listeria Monocytogenes, Michelle G. Pitts, Travis A. Combs, Sarah E. F. D'Orazio
Microbiology, Immunology, and Molecular Genetics Faculty Publications
Inbred mouse strains differ in their susceptibility to infection with the facultative intracellular bacterium Listeria monocytogenes, largely due to delayed or deficient innate immune responses. Previous antibody depletion studies suggested that neutrophils (polymorphonuclear leukocytes [PMN]) were particularly important for clearance in the liver, but the ability of PMN from susceptible and resistant mice to directly kill L. monocytogenes has not been examined. In this study, we showed that PMN infiltrated the livers of BALB/c/By/J (BALB/c) and C57BL/6 (B6) mice in similar numbers and that both cell types readily migrated toward leukotriene B4 in an in vitro chemotaxis assay. However, …
Intracellular Listeria Monocytogenes Comprises A Minimal But Vital Fraction Of The Intestinal Burden Following Foodborne Infection, Grant S. Jones, Kate M. Bussell, Tanya Myers-Morales, Abigail M. Fieldhouse, Elsa N. Bou Ghanem, Sarah E. F. D'Orazio
Intracellular Listeria Monocytogenes Comprises A Minimal But Vital Fraction Of The Intestinal Burden Following Foodborne Infection, Grant S. Jones, Kate M. Bussell, Tanya Myers-Morales, Abigail M. Fieldhouse, Elsa N. Bou Ghanem, Sarah E. F. D'Orazio
Microbiology, Immunology, and Molecular Genetics Faculty Publications
Listeria monocytogenes is a highly adaptive bacterium that replicates as a free-living saprophyte in the environment as well as a facultative intracellular pathogen that causes invasive foodborne infections. The intracellular life cycle of L. monocytogenes is considered to be its primary virulence determinant during mammalian infection; however, the proportion of L. monocytogenes that is intracellular in vivo has not been studied extensively. In this report, we demonstrate that the majority of wild-type (strain EGDe) and mouse-adapted (InlAm-expressing) L. monocytogenes recovered from the mesenteric lymph nodes (MLN) was extracellular within the first few days after foodborne infection. In addition, …
Caspase-3 Mediates The Pathogenic Effect Of Yersinia Pestis Yopm In Liver Of C57bl/6 Mice And Contributes To Yopm's Function In Spleen, Zhan Ye, Amanda A. Gorman, Annette M. Uittenbogaard, Tanya Myers-Morales, Alan M. Kaplan, Donald A. Cohen, Susan C. Straley
Caspase-3 Mediates The Pathogenic Effect Of Yersinia Pestis Yopm In Liver Of C57bl/6 Mice And Contributes To Yopm's Function In Spleen, Zhan Ye, Amanda A. Gorman, Annette M. Uittenbogaard, Tanya Myers-Morales, Alan M. Kaplan, Donald A. Cohen, Susan C. Straley
Microbiology, Immunology, and Molecular Genetics Faculty Publications
The virulence protein YopM of the plague bacterium Yersinia pestis has different dominant effects in liver and spleen. Previous studies focused on spleen, where YopM inhibits accumulation of inflammatory dendritic cells. In the present study we focused on liver, where PMN function may be directly undermined by YopM without changes in inflammatory cell numbers in the initial days of infection, and foci of inflammation are easily identified. Mice were infected with parent and ΔyopM-1 Y. pestis KIM5, and effects of YopM were assessed by immunohistochemistry and determinations of bacterial viable numbers in organs. The bacteria were found …
Regulation Of Hepatic Gene Expression During Liver Development And Disease, Hui Ren
Regulation Of Hepatic Gene Expression During Liver Development And Disease, Hui Ren
Theses and Dissertations--Microbiology, Immunology, and Molecular Genetics
My first project was to investigate the role of Hepatocyte Nuclear Factor 1 (HNF1) and Nuclear Factor I (NFI) on alpha-fetoprotein (AFP) promoter activity during liver development. AFP is highly expressed in the fetal liver, silenced at birth, and remains at very low levels in the adult liver. A GA substitution located at -119 of the human AFP promoter is associated with hereditary persistence of AFP (HPAFP) expression in the adult liver (Hum Molec Genet, 1993, 2:379). The -120 region harbors overlapping binding sites for HNF1 and NFI. While it has been shown that the GA substitution increases HNF1 binding, …
H2-M3-Restricted Cd8+ T Cells Are Not Required For Mhc Class Ib-Restricted Immunity Against Listeria Monocytogenes, Sarah E. F. D'Orazio, Christine A. Shaw, Michael N. Starnbach
H2-M3-Restricted Cd8+ T Cells Are Not Required For Mhc Class Ib-Restricted Immunity Against Listeria Monocytogenes, Sarah E. F. D'Orazio, Christine A. Shaw, Michael N. Starnbach
Microbiology, Immunology, and Molecular Genetics Faculty Publications
Studies using major histocompatibility complex (MHC)-Ia–deficient mice have shown that MHC-Ib–restricted CD8+ T cells can clear infections caused by intracellular pathogens such as Listeria monocytogenes. M3-restricted CD8+ T cells, which recognize short hydrophobic N-formylated peptides, appear to comprise a substantial portion of the MHC-Ib–restricted T cell response in the mouse model of L. monocytogenes infection. In this study, we isolated formyltransferase (fmt) mutant strains of L. monocytogenes that lacked the ability to add formyl groups to nascent polypeptides. These fmt mutant Listeria strains did not produce antigens that could be recognized by M3-restricted T …
The Toxoplasma Gondii Protein Rop2 Mediates Host Organelle Association With The Parasitophorous Vacuole Membrane, Anthony P. Sinai, Keith A. Joiner
The Toxoplasma Gondii Protein Rop2 Mediates Host Organelle Association With The Parasitophorous Vacuole Membrane, Anthony P. Sinai, Keith A. Joiner
Microbiology, Immunology, and Molecular Genetics Faculty Publications
Toxoplasma gondii replicates within a specialized vacuole surrounded by the parasitophorous vacuole membrane (PVM). The PVM forms intimate interactions with host mitochondria and endoplasmic reticulum (ER) in a process termed PVM–organelle association. In this study we identify a likely mediator of this process, the parasite protein ROP2. ROP2, which is localized to the PVM, is secreted from anterior organelles termed rhoptries during parasite invasion into host cells. The NH2-terminal domain of ROP2 (ROP2hc) within the PVM is exposed to the host cell cytosol, and has characteristics of a mitochondrial targeting signal. In in vitro assays, ROP2hc is …