Project description:Episodic Ebola virus (EBOV) outbreaks, such as the current one in West Africa, emphasize the critical need for novel antivirals against this highly pathogenic virus. Here, we demonstrate that interferon gamma (IFNγ) prevents morbidity and mortality associated with EBOV infection when administered to mice either 24 hours prior to or 2 hours following EBOV infection. Microarray studies with IFNγ-stimulated human macrophages identified novel interferon-stimulated genes (ISGs) that inhibit EBOV infection upon ectopic expression. IFNγ treatment reduced viral RNA levels in macrophages to a similar degree as cells treated with the protein synthesis inhibitor, cycloheximide, suggesting that IFNγ treatment inhibits genome replication. As IFNγ treatment robustly protects mice against EBOV infection, we propose that this FDA-approved drug may serve as a useful prophylactic or therapeutic strategy during EBOV outbreaks, contributing to the currently limited arsenal of filovirus antivirals.
Project description:Episodic Ebola virus (EBOV) outbreaks, such as the current one in West Africa, emphasize the critical need for novel antivirals against this highly pathogenic virus. Here, we demonstrate that interferon gamma (IFNγ) prevents morbidity and mortality associated with EBOV infection when administered to mice either 24 hours prior to or 2 hours following EBOV infection. Microarray studies with IFNγ-stimulated human macrophages identified novel interferon-stimulated genes (ISGs) that inhibit EBOV infection upon ectopic expression. IFNγ treatment reduced viral RNA levels in macrophages to a similar degree as cells treated with the protein synthesis inhibitor, cycloheximide, suggesting that IFNγ treatment inhibits genome replication. As IFNγ treatment robustly protects mice against EBOV infection, we propose that this FDA-approved drug may serve as a useful prophylactic or therapeutic strategy during EBOV outbreaks, contributing to the currently limited arsenal of filovirus antivirals.
Project description:The purpose of this experiment was to obtain samples for mRNA analysis in IHH cells infected with Zaire Ebola virus and mutants: Zaire Ebola virus: This wild-type Ebola virus - strain Mayinga - was isolated from a fatal human case in Zaire (now known as the Democratic Republic of Congo) in 1976 Zaire Ebola virus, VP35 R312A possesses a R312A mutation in the VP35 protein. Zaire Ebola virus, delta sGP. Lacks the ability to produce non-structural protein, the secreted glycoprotein (sGP). Zaire Ebola virus, delta mucin. Lacks the mucin-like domain (MLD), which contains both N-linked and O-linked glycosylation sites, for the glycoproteins. Overview of Experiment: Cells: Immortalized Human Hepatocytes (IHH); seed 60,000 cells per well in a 24-well plate. Infected with a multiplicity of infection (MOI) of 0.5. After infection, 3x wash with PBS and replace with 5% FCS DMEM without NaPyr or NEAA. Time matched mocks done in triplicate from same cell stock as rest of samples. Time Points = 0, 6, 12, 24, 48, and 72 hrs post infection in triplicate.
Project description:The purpose of this experiment was to obtain samples for mRNA analysis in IHH cells infected with Zaire Ebola virus and mutants: Zaire Ebola virus: This wild-type Ebola virus - strain Mayinga - was isolated from a fatal human case in Zaire (now known as the Democratic Republic of Congo) in 1976 Zaire Ebola virus, VP35 R312A possesses a R312A mutation in the VP35 protein. Zaire Ebola virus, delta sGP. Lacks the ability to produce non-structural protein, the secreted glycoprotein (sGP). Zaire Ebola virus, delta mucin. Lacks the mucin-like domain (MLD), which contains both N-linked and O-linked glycosylation sites, for the glycoproteins. Overview of Experiment: Cells: Immortalized Human Hepatocytes (IHH); seed 60,000 cells per well in a 24-well plate. Infected with a multiplicity of infection (MOI) of 0.5. After infection, 3x wash with PBS and replace with 5% FCS DMEM without NaPyr or NEAA. Time matched mocks done in triplicate from same cell stock as rest of samples. Time Points = 0, 6, 12, 24, 48, and 72 hrs post infection in triplicate.
Project description:Mycobacterium tuberculosis (MTB) is a major global cause of mortality, responsible for over a million deaths each year. Despite this burden, natural immunity prevents disease in more than 90% of exposed individuals. Previous studies have identified interferon-gamma (IFN-γ) as a key regulator of innate immune defense against MTB. Here, we investigate the impact of IFN-γ timing on macrophage-mediated control of MTB infection. We demonstrate that IFN-γ exposure before infection enhances macrophage antibacterial activity, whereas post-infection exposure does not. Further analysis of this phenotype revealed a strong association between c-Myc signaling and macrophage function in MTB control, as identified through unbiased in vitro systems approaches. Given the difficulty of perturbing c-Myc in primary cells, we developed a lentiviral system for c-Myc inhibition and overexpression. We profiled both datasets (IFN-γ timing and c-Myc inhibition) to characterize the resulting transcriptional shifts.
Project description:The cytokine interferon-γ is a principal effector of macrophage activation and immune resistance to mycobacterial infection; however, pathogenic mycobacteria are capable of surviving in interferon-γ-activated macrophages by largely unknown mechanisms. We found that interferon-γ specifically bound to pathogenic mycobacteria and enhanced their growth in culture. Proteomic and electron microscopy analyses revealed that interferon-γ directly triggers proliferative activity and virulence phenotype in pathogenic mycobacteria that allow them to survive and grow inside macrophages. These findings suggest that pathogenic mycobacteria may have evolved eukaryotic-like signal transduction mechanisms to recognize host-protective immune activation.