The detection of bluetongue virus (BTV) antigens in formalin-fixed tissues has been challenging; therefore, only a limited number of studies on suitable immunohistochemical approaches have been reported. This study details the successful application of antibodies for the immunohistochemical detection of BTV in BSR variant baby hamster kidney cells (BHK-BSR) and infected sheep lungs that were formalin-fixed and paraffin-embedded (FFPE). BTV reactive antibodies raised against non-structural (NS) proteins 1, 2, and 3/3a and viral structural protein 7 (VP7) were first evaluated on FFPE BTV-infected cell pellets for their ability to detect BTV serotype 1 (BTV-1). Antibodies that were successful in immunolabelling BTV-1 infected cell pellets were further tested, using similar methods, to determine their broader immunoreactivity against a diverse range of BTV and other orbiviruses. Antibodies specific for NS1, NS2, and NS3/3a were able to detect all BTV isolates tested, and the VP7 antibody cross-reacted with all BTV isolates, except BTV-15. The NS1 antibodies were BTV serogroup-specific, while the NS2, NS3/3a, and VP7 antibodies demonstrated immunologic cross-reactivity to related orbiviruses. These antibodies also detected viral antigens in BTV-3 infected sheep lung. This study demonstrates the utility of FFPE-infected cell pellets for the development and validation of BTV immunohistochemistry.

中文翻译：

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评估蓝舌病毒（BTV）抗体的BTV和其他Orbiviruses的免疫组织化学检测。

在福尔马林固定的组织中检测蓝舌病毒（BTV）抗原具有挑战性。因此，关于适合的免疫组织化学方法的研究仅报道了有限的一部分。这项研究详细介绍了抗体在BSR变异小仓鼠肾细胞（BHK-BSR）和福尔马林固定和石蜡包埋（FFPE）的感染绵羊肺中成功应用BTV的抗体的应用。首先针对FFPE BTV感染的细胞沉淀物评估针对非结构性（NS）蛋白1、2和3 / 3a以及病毒结构蛋白7（VP7）产生的BTV反应性抗体检测BTV血清型1（BTV-1 ）。使用相似的方法进一步成功测试了成功免疫标记BTV-1感染细胞沉淀的抗体，以确定它们对各种BTV和其他双病毒的更广泛的免疫反应性。对NS1，NS2和NS3 / 3a具特异性的抗体能够检测所有测试的BTV分离株，并且VP7抗体与除BTV-15之外的所有BTV分离株发生交叉反应。NS1抗体是BTV血清群特异性的，而NS2，NS3 / 3a和VP7抗体表现出与相关bibivirus的免疫交叉反应性。这些抗体还在被BTV-3感染的绵羊肺中检测到病毒抗原。这项研究证明了FFPE感染的细胞沉淀在BTV免疫组织化学的开发和验证中的实用性。NS1抗体是BTV血清群特异性的，而NS2，NS3 / 3a和VP7抗体表现出与相关bibivirus的免疫交叉反应性。这些抗体还在被BTV-3感染的绵羊肺中检测到病毒抗原。这项研究证明了FFPE感染的细胞沉淀在BTV免疫组织化学的开发和验证中的实用性。NS1抗体是BTV血清群特异性的，而NS2，NS3 / 3a和VP7抗体表现出与相关bibivirus的免疫交叉反应性。这些抗体还在被BTV-3感染的绵羊肺中检测到病毒抗原。这项研究证明了FFPE感染的细胞沉淀在BTV免疫组织化学的开发和验证中的实用性。