College of Animal Science and Veterinary Medicine, Inner Mongolia Agricultural University, Huhhot, 010018, China.
Virol Sin. 2012 Apr;27(2):83-92. doi: 10.1007/s12250-012-3222-4. Epub 2012 Apr 11.
Endogenous beta retroviruses (enJSRV) are highly homologous with Jaagsiekte sheep retrovirus (exJSRV), this exogenous retrovirus is the aetiological agent of ovine pulmonary adenocarcinoma (OPA). The aim of this study was to clarify the function of enJSRV and the immunological mechanisms of its corresponding antibody, that is undetectable in JSRV-infected ovine serum. The expression of enJSRV envelope protein and Hyal-2 mRNA in immune organs and lungs of ovine fetuses and lambs were analyzed by Real-Time reverse transcription PCR and In Situ Hybridization using specific probes. In Situ Hybridization results indicated that the enJSRV envelope protein and Hyal-2 mRNA were expressed in thymus, spleen, mesenteric lymph nodes and lungs at different times, while no positive signals were detected in the negative controls. On the other hand, results from Real-Time reverse transcription PCR analysis showed that in 130d fetuses and 3d newborn lambs the enJSRV mRNA levels were much higher in organs associated with the immune system than that in lungs, especially in the thymus and spleen, but levels of Hyal-2 mRNA expression was not significantly different in all collected tissue. These results provided evidence from an immunology point of view to understand why the circulating antibodies against exJSRV are undetectable in JSRV-infected ovine, and will help to unravel the pathogenesis of JSRV-infected ovine.
内源性β逆转录病毒（enJSRV）与绵羊肺腺瘤病逆转录病毒（exJSRV）高度同源，这种外源性逆转录病毒是绵羊肺腺瘤病（OPA）的病原体。本研究旨在阐明 enJSRV 的功能及其相应抗体的免疫机制，即在 JSRV 感染的绵羊血清中无法检测到该抗体。通过实时逆转录 PCR 和使用特异性探针的原位杂交，分析了 enJSRV 包膜蛋白和 Hyal-2mRNA 在胎儿和羔羊免疫器官和肺部的表达。原位杂交结果表明，enJSRV 包膜蛋白和 Hyal-2mRNA 在不同时间在胸腺、脾、肠系膜淋巴结和肺部表达，而阴性对照中未检测到阳性信号。另一方面，实时逆转录 PCR 分析结果显示，在 130d 胎儿和 3d 新生羔羊中，与免疫系统相关的器官中的 enJSRVmRNA 水平明显高于肺部，尤其是在胸腺和脾，但在所有采集的组织中，Hyal-2mRNA 表达水平没有显著差异。这些结果从免疫学角度提供了证据，解释了为什么在 JSRV 感染的绵羊中无法检测到针对 exJSRV 的循环抗体，并有助于揭示 JSRV 感染绵羊的发病机制。
