• The Role of GCN2-Dependent Metabolic Stress in Type-2 Inflammation Within the Lung

      Bradley, Jillian; Department of Biochemistry and Molecular Biology (2015-06)
      Determining the control mechanisms behind the development of type-1 and type-2 inflammation could hand us the key to treating inflammatory pathologies like asthma, allergy, and cancer. One potential mechanism is the IDO-GCN2 nutrient stress-sensing pathway that has been implicated during pregnancy, bacterial infections, and others. We have determined that during type-2 inflammation IDO is induced and depletes the environment of tryptophan, this lack of tryptophan then activates GCN2. GCN2, especially when activated in the M2 macrophage subset, helps to regulate the cytokine production, cellular infiltrate, antibody production, and T-cell proliferation, activation, and differentiation. These effect culminate into regulating the overall lung pathology. This study suggests a novel type-2 inflammatory control mechanism through the GCN2 signaling pathway, and provides a potential therapeutic target for treatment of type-2 pathologies, like helminth infection, asthma, allergy, and cancers.
    • The Role of Tumor Necrosis Factor Alpha (TNF-a) In the Eyes and Brain of HSV-1 Infected Euthymic BALB/C Mice

      Fields, Mark A; Department of Biochemistry and Molecular Biology (2007-12)
      After uniocular anterior chamber (AC) inoculation of HSV-1, virus and TNFalpha (TNF-a) are detected in the eyes and brain o f HSV-1 infected euthymic BALB/c mice. The overall goal o f this study was to investigate the role o f TN F-a in the eyes and brain o f HSV-1 infected BALB/c mice. Mice were treated with thalidomide for TN F-a inhibition or injected with clodronate liposomes to deplete macrophages, and the AC of one eye (ipsilateral) was injected with HSV-1 (KOS). In thalidomide-treated mice, both suprachiasmatic nuclei (SCN) were infected by day 5 p.i. and the titer of virus in the SCN contralateral to the side o f injection was increased. In macrophage depleted mice, both SCN were infected at day 6 p.i. and the titer o f virus in the SCN o f these mice was increased at day 6 and 7 p.i. compared with controls. The titer o f virus in the contralateral (uninoculated) eye o f macrophage depleted mice was increased at day 7 p.i. The results o f these studies suggest that TN F-a plays a role in limiting virus replication in the SCN o f euthymic BALB/c mice and that one source of TN F-a is macrophages. In order to further investigate the role of TNF-a, a recombinant o f HSV-1 (KOS77VF) was constructed that produces TNF-a constitutively. Euthymic BALB/c mice were injected in one anterior chamber with the TNF-a recombinant, with a recombinant containing the pCI plasmid, with a recombinant rescue virus, or with the parental virus. Mice from each group were sacrificed on day 1-9 p.i. and the uninjected eyes were removed. In the uninjected eye o f KOSTNF -infected mice, TN F-a expression was increased and there were more viral antigen positive cells and immune inflammatory cells. There was earlier microscopic evidence o f retinal infection and destruction in these mice. In addition, the titer o f virus in the uninjected eye was significantly increased in KOSTiVF-infected mice on day 7 p.i. compared with KOSpCI, KOS6{irescue, or with KOS6/? infected mice. These results suggest that overproduction o f TN F-a by HSV-1 (KOS7WF) facilitates spread o f virus infection in the eye through increased inflammation and TNF-a-mediated damage to retinal cells.