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Britton, W. J. J.

Publications and source records attributed to Britton, W. J. J..

2 recordsLinked to original sources

Inhibition of infection-induced vascular permeability modulates host leukocyte recruitment to Mycobacterium marinum granulomas in zebrafish

Mycobacterial granuloma formation involves significant stromal remodeling and the growth of leaky, granuloma-associated vasculature. These permeable blood vessels aid mycobacterial growth, as anti-angiogenic or vascular normalizing therapies are beneficial host-directed therapies in pre-clinical models of tuberculosis. Here we demonstrate that vascular normalization through vascular endothelial-protein tyrosine phosphatase inhibition decreases granuloma hypoxia, the opposite effect of hypoxia-inducing anti-angiogenic therapy. Vascular normalization leads to increased T cell and decreased neutrophil recruitment to granulomas, correlates of a protective immune response against mycobacterial infection.

immunology↗

Heme oxygenase limits mycobacterial infection-induced ferroptosis

Iron homeostasis is essential for both sides of the host-pathogen interface. Restricting access of iron slows bacterial growth while iron is also a necessary co-factor for host immunity. Heme oxygenase 1 (HMOX1) is a critical regulator of iron homeostasis that catalyses the liberation of iron during degradation of heme. It is also a stress-responsive protein that can be rapidly upregulated and confers protection to the host. Although a protective role of HMOX1 has been demonstrated in a variety of diseases, the role of HMOX1 in Mycobacterium tuberculosis infection is equivocal across experiments with different host-pathogen combinations. Here we use the natural host-pathogen pairing of the zebrafish-Mycobacterium marinum infection platform to study the role of zebrafish heme oxygenase in mycobacterial infection. We identify zebrafish Hmox1a as the relevant functional paralog of mammalian HMOX1 and demonstrate a conserved role for Hmox1a in protecting the host from mycobacterial infection. Using genetic and chemical tools, we show zebrafish Hmox1a protects the host against mycobacterial infection by reducing infection-induced iron accumulation and ferroptosis.

immunology↗