Avian leukosis virus subgroup J (ALV-J) is an important pathogen for various neoplasms and causes significant economic losses in the poultry industry. Serological detection of specific antibodies against ALV-J infection is important for successful clinical diagnosis. Here, a 293F stable cell line was established to stably express gp85 protein. In this cell line, gp85 protein was expressed at approximately 30 mg/L. A subgroup-specific indirect enzyme-linked immunosorbent assay (iELISA) was developed using ALV-J gp85 protein as coated antigen to detect antibodies against ALV-J. The sensitivity of the iELISA (1:51200 diluted in serum) was 16 times more than that of indirect immunofluorescence assay (IFA; 1:3200 diluted in serum). Moreover, there was no crossreactivity with antibodies against other common avian viruses and other avian leukosis virus subgroups, such as subgroups A and B. The practicality of the iELISA was further evaluated by experimental infection and clinical samples. The results from experimental infection indicated that anti-ALV-J antibodies were readily detected by iELISA as early as 4 weeks after ALV-J infection, and positive antibodies were detected until 20 weeks, with an antibody-positive rate of 11.1% to 33.3%. Moreover, analysis of clinical samples showed that 9.49% of samples were positive for anti-ALV-J antibodies, and the concordance rate of iELISA and IFA was 99.24%. Overall, these results suggested that the subgroup-specific iELISA developed in this study had good sensitivity, specificity, and feasibility. This iELISA will be very useful for epidemiological surveillance, diagnosis, and eradication of ALV-J in poultry farms.

中文翻译：

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基于gp85蛋白的亚组特异性间接酶联免疫吸附测定的开发和评估，用于检测抗亚J禽白血病病毒抗体。

禽白血病病毒J亚组（ALV-J）是各种肿瘤的重要病原体，在禽业中造成重大经济损失。血清学检测抗ALV-J感染的特异性抗体对于成功的临床诊断很重要。在此，建立了稳定表达gp85蛋白的293F稳定细胞系。在该细胞系中，gp85蛋白的表达量约为30 mg / L。使用ALV-J gp85蛋白作为包被抗原开发了亚组特异性间接酶联免疫吸附测定（iELISA），以检测针对ALV-J的抗体。iELISA（在血清中以1：51200稀释）的灵敏度是间接免疫荧光测定法（IFA；在血清中以1：3200稀释）的灵敏度的16倍。此外，与其他常见禽病毒和其他禽白血病病毒亚组（例如A和B组）的抗体没有交叉反应。通过实验感染和临床样品进一步评估了iELISA的实用性。实验感染的结果表明，早在ALV-J感染后4周，就可以通过iELISA轻松检测到抗ALV-J抗体，直到20周才检测到阳性抗体，抗体阳性率为11.1％至33.3％ 。此外，对临床样品的分析表明，有9.49％的样品抗ALV-J抗体呈阳性，iELISA和IFA的符合率为99.24％。总体而言，这些结果表明，在这项研究中开发的亚组特异性iELISA具有良好的敏感性，特异性和可行性。