Publications by authors named "Vivian J"

Myelin loss induces neural dysfunction and contributes to the pathophysiology of neurodegenerative diseases, injury conditions, and aging. Because remyelination is often incomplete, better understanding endogenous remyelination and developing remyelination therapies that restore neural function are clinical imperatives. Here, we use in vivo two-photon microscopy and electrophysiology to study the dynamics of endogenous and therapeutic-induced cortical remyelination and functional recovery after cuprizone-mediated demyelination in mice.

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Article Synopsis
  • Genetic variation in immune responses, particularly related to HLA and KIR genes, influences how First Nations peoples are affected by infectious diseases.
  • HLA-A24:02 and the KIR3DL1 receptor have evolved in First Nations populations, showcasing a significant adaptation through natural selection.
  • The KIR3DL1114 allele, unique to Oceania, demonstrates a strong interaction with HLA-A24:02, which enhances immune response, thus highlighting the importance of immunogenetic studies in understanding disease susceptibility.
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Background: Major histocompatibility complex class-1-related protein (MR1), unlike human leukocyte antigen (HLA) class-1, was until recently considered to be monomorphic. MR1 presents metabolites in the context of host responses to bacterial infection. MR1-restricted TCRs specific to tumor cells have been described, raising interest in their potential therapeutic application for cancer treatment.

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Myelin loss induces deficits in action potential propagation that result in neural dysfunction and contribute to the pathophysiology of neurodegenerative diseases, injury conditions, and aging. Because remyelination is often incomplete, better understanding endogenous remyelination and developing remyelination therapies that seek to restore neural function are clinical imperatives. Here, we used two-photon microscopy and electrophysiology to study the dynamics of endogenous and therapeutic-induced cortical remyelination and functional recovery after cuprizone-mediated demyelination in mice.

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The central immunological role of HLA class I (HLA-I) in presenting peptide Ags to cellular components of the immune system has been the focus of intense study for >60 y. A confounding factor in the study of HLA-I has been the extreme polymorphism of these molecules. The mAb W6/32 has been a fundamental reagent bypassing the issue of polymorphism by recognizing an epitope that is conserved across diverse HLA-I allotypes.

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In Colombia, the long-lasting internal conflict heavily shaped the socio-ecological context and imposed relationships that persisted after the peace agreement was signed in 2016. One question of interest is whether policies or interventions conceived to attain desirable goals for the post-conflict society may be effective or, rather, if the constraints imposed by the conflict scenario might produce unintended effects, either on the environmental or the social side. To explore this issue, we envisaged the socio-ecological system as a parsimonious set of characteristic ecological and social variables within the conflict-related framework and reconstructed their interactions, exploiting elicitation-based information and the literature.

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KIR3DL1 is a polymorphic inhibitory Natural Killer (NK) cell receptor that recognizes Human Leukocyte Antigen (HLA) class I allotypes that contain the Bw4 motif. Structural analyses have shown that in addition to residues 77-83 that span the Bw4 motif, polymorphism at other sites throughout the HLA molecule can influence the interaction with KIR3DL1. Given the extensive polymorphism of both KIR3DL1 and HLA class I, we built a machine learning prediction model to describe the influence of allotypic variation on the binding of KIR3DL1 to HLA class I.

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The heterodimeric natural killer cells antigen CD94 (CD94)-NKG2-A/NKG2-B type II integral membrane protein (NKG2A) receptor family expressed on human and mouse natural killer (NK) cells monitors global major histocompatibility complex (MHC) class I cell surface expression levels through binding to MHC class Ia-derived leader sequence peptides presented by HLA class I histocompatibility antigen, alpha chain E (HLA-E; in humans) or H-2 class I histocompatibility antigen, D-37 (Qa-1; in mice). Although the molecular basis underpinning human CD94-NKG2A recognition of HLA-E is known, the equivalent interaction in the murine setting is not. By determining the high-resolution crystal structure of murine CD94-NKG2A in complex with Qa-1 presenting the Qa-1 determinant modifier peptide (QDM), we resolved the mode of binding.

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Placental development involves coordinated expansion and differentiation of trophoblast cell lineages possessing specialized functions. Among the differentiated trophoblast cell lineages are invasive trophoblast cells, which exit the placenta and invade the uterus, where they restructure the uterine parenchyma and facilitate remodeling of uterine spiral arteries. The rat exhibits deep intrauterine trophoblast cell invasion, a feature shared with human placentation, and is also amenable to gene manipulation using genome-editing techniques.

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TANK-binding kinase 1 (TBK1) is a key signalling component in the production of type-I interferons, which have essential antiviral activities, including against SARS-CoV-2. TBK1, and its homologue IκB kinase-ε (IKKε), can also induce pro-inflammatory responses that contribute to pathogen clearance. While initially protective, sustained engagement of type-I interferons is associated with damaging hyper-inflammation found in severe COVID-19 patients.

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The aromatase-Cre recombinase (Cyp19-Cre) transgenic mouse model has been extensively used for placenta-specific gene inactivation. In a pilot study, we observed unexpected phenotypes using this mouse strain, which prompted an extensive characterization of Cyp19-Cre placental phenotypes using ROSA transgenic reporter mice. The two strains were mated to generate bi-transgenic Cyp19-Cre;ROSA mice following a standard transgenic breeding scheme, and placental and fetal tissues were analyzed on embryonic day 17.

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Introduction: Mitochondrial dysfunction is observed in Alzheimer's disease (AD). Altered mitochondrial respiration, cytochrome oxidase (COX) Vmax, and mitophagy are observed in human subjects and animal models of AD. Models derived from induced pluripotent stem cells (iPSCs) may not recapitulate these phenotypes after reprogramming from differentiated adult cells.

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Placental development involves coordinated expansion and differentiation of trophoblast cell lineages possessing specialized functions. Among the differentiated trophoblast cell lineages are invasive trophoblast cells, which exit the placenta and invade into the uterus where they restructure the uterine parenchyma and facilitate remodeling of uterine spiral arteries. The rat exhibits deep intrauterine trophoblast cell invasion, a feature shared with human placentation, and is also amenable to gene manipulation using genome editing techniques.

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Type III interferons (IFN-lambdas, IFN-λs) are important antiviral cytokines that can also modulate immune responses by acting through a heterodimeric receptor composed of the specific and limited expressed IFN-λR1 chain and the ubiquitous IL-10R2 chain, which is shared with IL-10 family cytokines. Conflicting data have been reported regarding which cells express the IFN-λR1 subunit and directly respond to IFN-λs. This is, in part, owing to transcript levels of the IFN-λR1 gene, , not always correlating with cell surface protein levels.

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Allopurinol (ALP) is a successful drug used in the treatment of gout. However, this drug has been implicated in hypersensitivity reactions that can cause severe to life-threatening reactions such as Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). Individuals who carry the human leukocyte antigen (HLA)-B*58:01 allotype are at higher risk of experiencing a hypersensitivity reaction (odds ratios ranging from 5.

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Most human killer cell immunoglobulin-like receptors (KIR) are expressed by natural killer (NK) cells and recognize HLA class I molecules as ligands. KIR3DL3 is a conserved but polymorphic inhibitory KIR recognizing a B7 family ligand, HHLA2, and is implicated for immune checkpoint targeting. The expression profile and biological function of KIR3DL3 have been somewhat elusive, so we searched extensively for KIR3DL3 transcripts, revealing highly enriched expression in γδ and CD8 T cells rather than NK cells.

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Epitope-specific immunotherapies have enabled the targeted treatment of a variety of diseases, ranging from cancer, infection, and autoimmune disorders. For CD8 T cell-based therapies, the precise identification of immunogenic peptides presented by human leukocyte antigen (HLA) class I is essential which can be achieved by immunopeptidomics. Here, using lentivirus-mediated transduction and cell sorting approaches, we present a method to engineer a cell line that does not express its native HLA but instead expresses an HLA of interest (in this instance HLA-A*02:01).

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Psoriasis is a chronic skin disease characterized by hyperproliferative epidermal lesions infiltrated by autoreactive T cells. Individuals expressing the human leukocyte antigen (HLA) C∗06:02 allele are at highest risk for developing psoriasis. An autoreactive T cell clone (termed Vα3S1/Vβ13S1) isolated from psoriatic plaques is selective for HLA-C∗06:02, presenting a peptide derived from the melanocyte-specific autoantigen ADAMTSL5 (VRSRRCLRL).

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Understanding the contributions of mitochondrial genetics to disease pathogenesis is facilitated by a new and unique model-the mitochondrial-nuclear exchange mouse. Here we report the rationale for their development, the methods used to create them, and a brief summary of how MNX mice have been used to understand the contributions of mitochondrial DNA in multiple diseases, focusing on cancer metastasis. Polymorphisms in mtDNA which distinguish mouse strains exert intrinsic and extrinsic effects on metastasis efficiency by altering epigenetic marks in the nuclear genome, changing production of reactive oxygen species, altering the microbiota, and influencing immune responses to cancer cells.

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DNA comprises molecular information stored in genetic and epigenetic bases, both of which are vital to our understanding of biology. Most DNA sequencing approaches address either genetics or epigenetics and thus capture incomplete information. Methods widely used to detect epigenetic DNA bases fail to capture common C-to-T mutations or distinguish 5-methylcytosine from 5-hydroxymethylcytosine.

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Polycystic kidney disease (PKD) is characterized by the formation and progressive enlargement of fluid-filled cysts due to abnormal cell proliferation. Cyclic AMP agonists, including arginine vasopressin, stimulate ERK-dependent proliferation of cystic cells, but not normal kidney cells. Previously, B-Raf proto-oncogene (BRAF), a MAPK kinase kinase that activates MEK-ERK signaling, was shown to be a central intermediate in the cAMP mitogenic response.

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Kernicterus is a permanent condition caused by brain damage from bilirubin toxicity. Dystonia is one of the most debilitating symptoms of kernicterus and results from damage to the globus pallidus (GP). One potential therapeutic strategy to treat dystonia in kernicterus is to replace lost GP neurons and restore basal ganglia circuits through stem cell transplantation.

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