Bovine leukemia virus (BLV) causes enzootic bovine leukosis, the most common neoplastic disease in cattle. We previously reported the development and protocol of the luminescence syncytium induction assay (LuSIA), a method for evaluating BLV infectivity based on CC81-GREMG cells. These cells form syncytia expressing enhanced green fluorescent protein when co-cultured with BLV-infected cells. Recently, we confirmed CAT1/SLC7A1 functions as a receptor of BLV. Here, we focused on CAT1/SLC7A1 to increase the sensitivity of LuSIA. We constructed a bovine CAT1-expressing plasmid and established a new CC81-GREMG-derived reporter cell line highly expressing bovine CAT1 (CC81-GREMG-CAT1). The new LuSIA protocol using CC81-GREMG-CAT1 cells measures cell-to-cell infectivity and cell-free infectivity of BLV faster and with greater sensitivity than the previous protocol using CC81-GREMG. The new LuSIA protocol is quantitative and more sensitive than the previous assay based on CC81-GREMG cells and will facilitate the development of several new BLV assays.

中文翻译：

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牛白血病病毒受体SLC7A1 / CAT1的过表达在发光合胞体诱导测定（LuSIA）上增强了细胞对BLV感染的敏感性。

牛白血病病毒（BLV）引起牛源性牛白血病，这是牛中最常见的肿瘤性疾病。我们先前报道了发光合胞体诱导测定法（LuSIA）的开发和协议，该方法是一种基于CC81-GREMG细胞评估BLV感染性的方法。当与感染BLV的细胞共培养时，这些细胞形成合胞体表达增强的绿色荧光蛋白。最近，我们证实CAT1 / SLC7A1作为BLV的受体。在这里，我们集中于CAT1 / SLC7A1来提高LuSIA的灵敏度。我们构建了表达牛CAT1的质粒，并建立了一个新的CC81-GREMG衍生的报告细胞系，该细胞高度表达牛CAT1（CC81-GREMG-CAT1）。与使用CC81-GREMG的先前协议相比，使用CC81-GREMG-CAT1细胞的新LuSIA协议可更快，更灵敏地测量BLV的细胞间感染性和无细胞感染性。新的LuSIA方案比基于CC81-GREMG细胞的以前的测定具有定量和敏感性更高的特点，将有助于开发几种新的BLV测定。