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Full-Text Articles in Organisms

Regulation Of Mhc Ii Trafficking And Expression By Host And Viral Factors, Alex Lac Jul 2022

Regulation Of Mhc Ii Trafficking And Expression By Host And Viral Factors, Alex Lac

Electronic Thesis and Dissertation Repository

Antigen presentation by major histocompatibility complex class II (MHC II) to the adaptive immune system is crucial for mounting sterilizing immune responses. This central role has made antigen presentation a target for antagonism by many pathogens. Notably, infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) decrease MHC II expression in several immune cells. The mechanisms responsible for this suppression are unknown but involves either redirecting MHC II molecules away from the cell surface or inhibiting MHC II expression. To understand how pathogens manipulate intracellular MHC II trafficking, we first investigated the role of the Golgi trafficking regulator, ERC1, in …


Granulocyte Colony-Stimulating Factor: Its Role In Gut-Homing Macrophage Generation And Colitis, And Production By Probiotics, Shahab Meshkibaf May 2015

Granulocyte Colony-Stimulating Factor: Its Role In Gut-Homing Macrophage Generation And Colitis, And Production By Probiotics, Shahab Meshkibaf

Electronic Thesis and Dissertation Repository

The pleiotropic cytokine granulocyte-colony stimulatory factor (G-CSF) is mainly required for the generation of neutrophils, but its role in macrophage generation has also been reported. In addition, G-CSF is effective for the down-regulation of inflammatory cytokines and ameliorating gut disorders, such as colitis. However, the G-CSF function in macrophage generation and gut immunity remains unclear. The first focus of this thesis was to assess the role of G-CSF in macrophage generation and its contribution to gut immunity. G-CSF was found to promote the generation of Gr-1high/F4/80+ macrophages in macrophage (M)-CSF-treated bone marrow cells, most likely through suppressing cell death. Gr-1high …


Characterization Of Staphylococcus Aureus Lipase, Vithooshan Vijayakumaran Aug 2013

Characterization Of Staphylococcus Aureus Lipase, Vithooshan Vijayakumaran

Electronic Thesis and Dissertation Repository

USA300, a strain of community-associated methicillin resistant Staphylococcus aureus (CA-MRSA), has become prevalent in the community. Colonization of human skin requires mechanisms that allow this bacterium to overcome the innate immune defenses on the skin, including secretion of antimicrobial lipids. Antimicrobial lipids inhibit S. aureus growth and induce the staphylococcal proteolytic cascade, producing aureolysin (Aur) which processes the lipase glycerol ester hydrolase (Geh). Nearly all S. aureus strains secrete Geh, yet little information exists concerning its function. Using purified Aur and Geh we confirm that aureolysin processes proGeh to Geh. We then confirmed that geh was required for lipase activity …


Human Adenovirus E1a Binds And Retasks Cellular Hbre1, Blocking Interferon Signalling And Activating Virus Early Gene Transcription, Gregory J. Fonseca Jun 2013

Human Adenovirus E1a Binds And Retasks Cellular Hbre1, Blocking Interferon Signalling And Activating Virus Early Gene Transcription, Gregory J. Fonseca

Electronic Thesis and Dissertation Repository

Upon infection, human adenovirus (HAdV) must block interferon signaling and activate the expression of its early genes to reprogram the cellular environment to support virus replication. During the initial phase of infection, these processes are orchestrated by the first HAdV gene expressed during infection, early region 1A (E1A). E1A binds and appropriates components of the cellular transcriptional machinery to modulate cellular gene transcription and activate viral early genes transcription. We have identified hBre1/RNF20 as a novel target of E1A. hBre1 is an E3 ubiquitin ligase which acts with the Ube2b E2 conjugase and accessory factors RNF40 and WAC1 to monoubiquitinate …