Publications by authors named "Taylor Dagenais"

To control community transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the 2020 global pandemic, most countries implemented strategies based on direct human testing, face covering, and surface disinfection. Under the assumption that the main route of transmission includes aerosols and respiratory droplets, efforts to detect SARS-CoV-2 in fomites have focused on locations suspected of high prevalence (e.g.

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The opportunistic human pathogen initiates invasive growth through a programmed germination process that progresses from dormant spore to swollen spore (SS) to germling (GL) and ultimately invasive hyphal growth. We find a lipoxygenase with considerable homology to human Alox5 and Alox15, LoxB, that impacts the transitions of programmed spore germination. Overexpression of () increases germination with rapid advance to the GL stage.

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Secondary metabolite (SM) production in filamentous fungi is mechanistically associated with chromatin remodeling of specific SM clusters. One locus recently shown to be involved in SM suppression in Aspergillus nidulans was CclA, a member of the histone 3 lysine 4 methylating COMPASS complex. Here we examine loss of CclA and a putative H3K4 demethylase, HdmA, in the human pathogen Aspergillus fumigatus.

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Aspergillus fumigatus is the causal agent of the life-threatening disease invasive aspergillosis. A. fumigatus laeA deletants, aberrant in toxin biosynthesis and spore development, are decreased in virulence.

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Th1 cell responses to the variant surface glycoprotein (VSG) of African trypanosomes play a critical role in controlling infection through the production of IFN-gamma, but the role of APCs in the induction and regulation of T cell-mediated protection is poorly understood. In this study, we have investigated the Ag presentation capabilities of dendritic cells (DCs) and macrophages during early trypanosome infection in relatively resistant responder and susceptible nonresponder mouse strains. Splenic DCs appeared to be the primary cell responsible for activating naive VSG-specific Th cell responses in resistant responder animals through the coordinated up-regulation of costimulatory molecules, secretion of IL-12, and presentation of VSG peptides to T cells in vivo.

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Aspergillus species are globally ubiquitous saprophytes found in a variety of ecological niches. Almost 200 species of aspergilli have been identified, less than 20 of which are known to cause human disease. Among them, Aspergillus fumigatus is the most prevalent and is largely responsible for the increased incidence of invasive aspergillosis (IA) in the immunocompromised patient population.

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Histone deacetylases (HDACs) play an important role in regulation of gene expression through histone modifications. Here we show that the Aspergillus fumigatus HDAC HdaA is involved in regulation of secondary metabolite production and is required for normal germination and vegetative growth. Deletion of the hdaA gene increased the production of several secondary metabolites but decreased production of gliotoxin whereas over-expression hdaA increased production of gliotoxin.

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Cryptococcus neoformans was first described as a human fungal pathogen more than a century ago. One aspect of the C. neoformans infectious life cycle that has been the subject of earnest debate is whether the spores are pathogenic.

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Variable subregions within the variant surface glycoprotein (VSG) coat displayed by African trypanosomes are predicted sites for T- and B-cell recognition. Hypervariable subregion 1 (HV-1) is localized to an internal amphipathic alpha helix in VSG monomers and may have evolved due to selective pressure by host T-cell responses to epitopes within this subregion. The prediction of T-cell receptor-reactive sites and major histocompatibility complex class II binding motifs within the HV-1 subregion, coupled with the conservation of amino acid residues in other regions of the molecule sufficient to maintain secondary and tertiary VSG structure, prompted us to test the hypothesis that Th cells may preferentially recognize HV-1 subregion peptides.

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In most species, chromatin remodeling mediates critical biological processes ranging from development to disease states. In fungi within the genus Aspergillus, chromatin remodeling may regulate expression of metabolic gene clusters, but other processes regulated by chromatin structure remain to be elucidated. In many eukaryotic species, methylation of lysine 9 of histone 3 (H3K9) is a hallmark of heterochromatin formation and subsequent gene silencing.

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Oxygenated fatty acids, or oxylipins, play an essential role in physiological signaling and developmental processes in animals, plants, and fungi. Previous characterization of three Aspergillus fumigatus dioxygenases (PpoA, PpoB, and PpoC), similar in sequence to mammalian cyclooxygenases, showed that PpoA is responsible for the production of the oxylipins 8R-hydroperoxyoctadecadienoic acid and 5S,8R-dihydroxy-9Z,12Z-octadecadienoic acid and that PpoC is responsible for 10R-hydroxy-8E,12Z-hydroperoxyoctadecadienoic acid. Here, Delta ppo mutants were characterized to elucidate the role of fungal dioxygenases in A.

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