Christopher Hall

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How different immune cell compartments contribute to a successful immune response is central to fully understanding the mechanisms behind normal processes such as tissue repair and the pathology of inflammatory diseases. However, the ability to observe and characterize such interactions, in real-time, within a living vertebrate has proved elusive. Recently,(More)
Neutrophils are typically the first responders in host defense against invading pathogens, which they destroy by both oxidative and nonoxidative mechanisms. However, despite a longstanding recognition of neutrophil presence at disease sites in tuberculosis, their role in defense against mycobacteria is unclear. Here we exploit the genetic tractability and(More)
Lipid accumulation in arteries induces vascular inflammation and atherosclerosis, the major cause of heart attack and stroke in humans. Extreme hyperlipidemia induced in mice and rabbits enables modeling many aspects of human atherosclerosis, but microscopic examination of plaques is possible only postmortem. Here we report that feeding adult zebrafish(More)
Blood cells of an adult vertebrate are continuously generated by hematopoietic stem cells (HSCs) that originate during embryonic life within the aorta-gonad-mesonephros region. There is now compelling in vivo evidence that HSCs are generated from aortic endothelial cells and that this process is critically regulated by the transcription factor Runx1. By(More)
Evidence suggests the bactericidal activity of mitochondria-derived reactive oxygen species (mROS) directly contributes to killing phagocytozed bacteria. Infection-responsive components that regulate this process remain incompletely understood. We describe a role for the mitochondria-localizing enzyme encoded by Immunoresponsive gene 1 (IRG1) during the(More)
Pseudomonas aeruginosa is an opportunistic human pathogen that can cause serious infection in those with deficient or impaired phagocytes. We have developed the optically transparent and genetically tractable zebrafish embryo as a model for systemic P. aeruginosa infection. Despite lacking adaptive immunity at this developmental stage, zebrafish embryos(More)
Granulocyte colony-stimulating factor receptor (GCSFR) signaling participates in the production of neutrophilic granulocytes during normal hematopoietic development, with a particularly important role during emergency hematopoiesis. This study describes the characterization of the zebrafish gcsf and gcsfr genes, which showed broad conservation and similar(More)
Hematopoietic stem cells (HSCs) are rare multipotent cells that contribute to all blood lineages. During inflammatory stress, hematopoietic stem and progenitor cells (HSPCs) can be stimulated to proliferate and differentiate into the required immune cell lineages. Manipulating signaling pathways that alter HSPC capacity holds great promise in the treatment(More)
Inflammatory bowel disease (IBD), in the form of Crohn's disease (CD) or ulcerative colitis (UC), is a debilitating chronic immune disorder of the intestine. A complex etiology resulting from dysfunctional interactions between the intestinal immune system and its microflora, influenced by host genetic susceptibility, makes disease modeling challenging.(More)
Lymphangiogenesis induced during tumor growth contributes to metastasis. Genetic and chemical screens using the zebrafish model have the potential to enhance our understanding of lymphangiogenesis, and lead to the discovery of pharmacological agents with activity in the lymphatic system. Large-scale screening of lymphatic development in the whole zebrafish(More)