8 research outputs found

    Integrin-Mediated Host Cell Invasion by Type 1–Piliated Uropathogenic Escherichia coli

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    Uropathogenic Escherichia coli (UPEC), the primary causative agent of urinary tract infections, typically express filamentous adhesive organelles called type 1 pili that mediate both bacterial attachment to and invasion of bladder urothelial cells. Several host proteins have previously been identified as receptors for type 1 pili, but none have been conclusively shown to promote UPEC entry into host bladder cells. Using overlay assays with FimH, the purified type 1 pilus adhesin, and mass spectroscopy, we have identified β1 and α3 integrins as key host receptors for UPEC. FimH recognizes N-linked oligosaccharides on these receptors, which are expressed throughout the urothelium. In a bladder cell culture system, β1 and α3 integrin receptors co-localize with invading type 1–piliated bacteria and F-actin. FimH-mediated bacterial invasion of host bladder cells is inhibited by β1 and α3 integrin–specific antibodies and by disruption of the β1 integrin gene in the GD25 fibroblast cell line. Phosphorylation site mutations within the cytoplasmic tail of β1 integrin that alter integrin signaling also variably affect UPEC entry into host cells, by either attenuating or boosting invasion frequencies. Furthermore, focal adhesion and Src family kinases, which propagate integrin-linked signaling and downstream cytoskeletal rearrangements, are shown to be required for FimH-dependent bacterial invasion of target host cells. Cumulatively, these results indicate that β1 and α3 integrins are functionally important receptors for type 1 pili–expressing bacteria within the urinary tract and possibly at other sites within the host

    Defining Terms Used for Animals Working in Support Roles for People with Support Needs

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    The nomenclature used to describe animals working in roles supporting people can be confusing. The same term may be used to describe different roles, or two terms may mean the same thing. This confusion is evident among researchers, practitioners, and end users. Because certain animal roles are provided with legal protections and/or government-funding support in some jurisdictions, it is necessary to clearly define the existing terms to avoid confusion. The aim of this paper is to provide operationalized definitions for nine terms, which would be useful in many world regions: “assistance animal”, “companion animal”, “educational/school support animal”, “emotional support animal”, “facility animal”, “service animal”, “skilled companion animal”, “therapy animal”, and “visiting/visitation animal”. At the International Society for Anthrozoology (ISAZ) conferences in 2018 and 2020, over 100 delegates participated in workshops to define these terms, many of whom co-authored this paper. Through an iterative process, we have defined the nine terms and explained how they differ from each other. We recommend phasing out two terms (i.e., “skilled companion animal” and “service animal”) due to overlap with other terms that could potentially exacerbate confusion. The implications for several regions of the world are discussed
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