Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Medicine and Health Sciences
Staphylococcus Aureus Biofilms Induce Macrophage Dysfunction Through Leukocidin Ab And Alpha-Toxin., Tyler D. Scherr, Mark L. Hanke, Ouwen Huang, David B.A. James, Alexander R. Horswill, Kenneth W. Bayles, Paul D. Fey, Victor J. Torres, Tammy Kielian
Staphylococcus Aureus Biofilms Induce Macrophage Dysfunction Through Leukocidin Ab And Alpha-Toxin., Tyler D. Scherr, Mark L. Hanke, Ouwen Huang, David B.A. James, Alexander R. Horswill, Kenneth W. Bayles, Paul D. Fey, Victor J. Torres, Tammy Kielian
Journal Articles: Pathology and Microbiology
UNLABELLED: The macrophage response to planktonic Staphylococcus aureus involves the induction of proinflammatory microbicidal activity. However, S. aureus biofilms can interfere with these responses in part by polarizing macrophages toward an anti-inflammatory profibrotic phenotype. Here we demonstrate that conditioned medium from mature S. aureus biofilms inhibited macrophage phagocytosis and induced cytotoxicity, suggesting the involvement of a secreted factor(s). Iterative testing found the active factor(s) to be proteinaceous and partially agr-dependent. Quantitative mass spectrometry identified alpha-toxin (Hla) and leukocidin AB (LukAB) as critical molecules secreted by S. aureus biofilms that inhibit murine macrophage phagocytosis and promote cytotoxicity. A role for Hla …
Loss Of Cbl And Cbl-B Ubiquitin Ligases Abrogates Hematopoietic Stem Cell Quiescence And Sensitizes Leukemic Disease To Chemotherapy., Wei An, Scott A. Nadeau, Bhopal C. Mohapatra, Dan Feng, Neha Zutshi, Matthew D. Storck, Priyanka Arya, James E. Talmadge, Jane L. Meza, Vimla Band, Hamid Band
Loss Of Cbl And Cbl-B Ubiquitin Ligases Abrogates Hematopoietic Stem Cell Quiescence And Sensitizes Leukemic Disease To Chemotherapy., Wei An, Scott A. Nadeau, Bhopal C. Mohapatra, Dan Feng, Neha Zutshi, Matthew D. Storck, Priyanka Arya, James E. Talmadge, Jane L. Meza, Vimla Band, Hamid Band
Journal Articles: Pathology and Microbiology
Cbl and Cbl-b are tyrosine kinase-directed RING finger type ubiquitin ligases (E3s) that negatively regulate cellular activation pathways. E3 activity-disrupting human Cbl mutations are associated with myeloproliferative disorders (MPD) that are reproduced in mice with Cbl RING finger mutant knock-in or hematopoietic Cbl and Cbl-b double knockout. However, the role of Cbl proteins in hematopoietic stem cell (HSC) homeostasis, especially in the context of MPD is unclear. Here we demonstrate that HSC expansion and MPD development upon combined Cbl and Cbl-b deletion are dependent on HSCs. Cell cycle analysis demonstrated that DKO HSCs exhibit reduced quiescence associated with compromised reconstitution …
Antiviral Activity Of The Human Cathelicidin, Ll-37, And Derived Peptides On Seasonal And Pandemic Influenza A Viruses., Shweta Tripathi, Guangshun Wang, Mitchell White, Li Qi, Jeffery Taubenberger, Kevan L. Hartshorn
Antiviral Activity Of The Human Cathelicidin, Ll-37, And Derived Peptides On Seasonal And Pandemic Influenza A Viruses., Shweta Tripathi, Guangshun Wang, Mitchell White, Li Qi, Jeffery Taubenberger, Kevan L. Hartshorn
Journal Articles: Pathology and Microbiology
Human LL-37, a cationic antimicrobial peptide, was recently shown to have antiviral activity against influenza A virus (IAV) strains in vitro and in vivo. In this study we compared the anti-influenza activity of LL-37 with that of several fragments derived from LL-37. We first tested the peptides against a seasonal H3N2 strain and the mouse adapted H1N1 strain, PR-8. The N-terminal fragment, LL-23, had slight neutralizing activity against these strains. In LL-23V9 serine 9 is substituted by valine creating a continuous hydrophobic surface. LL-23V9 has been shown to have increased anti-bacterial activity compared to LL-23 and we now show slightly …