Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan; Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
Western Livestock Hygiene Service Center, Kagawa Prefectural Government, Zentsuji, Japan.
Poult Sci. 2021 Nov;100(11):101461. doi: 10.1016/j.psj.2021.101461. Epub 2021 Sep 2.
Marek's disease virus (MDV) causes malignant lymphomas in chickens (Marek's disease; MD). Although MD has caused significant economic losses to the poultry industry, currently, its occurrence in the field is effectively controlled by vaccination. However, the genetic characteristics of MDV strains have changed, and the poultry industry has experienced MD outbreaks in vaccinated chickens because of enhanced virulence. Meq, an oncoprotein of MDV, is a key transcription factor correlated with the tumorigenesis in MD. Animal experiments using recombinant MDV revealed that distinct polymorphisms in Meq affect the virulence of MDV strains. Meq containing an insertion or deletion is present in some MDV strains. In the 2010s, field strains that encode Meq containing the deletion (S-Meq) were reported. In this study, we characterized the genetic features of S-Meq detected in a Japanese MDV strain and analyzed its transactivation activity to investigate S-Meq's protein function. S-Meq lacked 41 amino acids, and the deletion was at the same position as those observed in other countries. In addition, S-Meq exhibited higher transactivation activity than Meq from other MDV strains circulating in Japan. These results suggest that the deletion in the transactivation domain may enhance the Meq protein's function. Further investigation is needed to clarify whether the deletion in the transactivation domain of Meq affects MDV's virulence.
马立克氏病病毒（MDV）可引起鸡的恶性淋巴瘤（马立克氏病；MD）。尽管 MD 给家禽业造成了重大的经济损失，但目前通过疫苗接种有效地控制了其在野外的发生。然而，MDV 毒株的遗传特征已经发生了变化，由于毒力增强，家禽业在接种疫苗的鸡中经历了 MD 爆发。MDV 的致癌蛋白 Meq 是与 MD 肿瘤发生相关的关键转录因子。使用重组 MDV 的动物实验表明，Meq 中的不同多态性影响 MDV 毒株的毒力。一些 MDV 毒株中存在含有插入或缺失的 Meq。在 2010 年代，报告了编码含有缺失（S-Meq）的 Meq 的田间毒株。在本研究中，我们对在日本 MDV 株中检测到的 S-Meq 的遗传特征进行了表征，并分析了其反式激活活性，以研究 S-Meq 的蛋白功能。S-Meq 缺失了 41 个氨基酸，缺失位置与其他国家观察到的位置相同。此外，S-Meq 的反式激活活性高于日本流行的其他 MDV 株的 Meq。这些结果表明，反式激活结构域中的缺失可能增强了 Meq 蛋白的功能。需要进一步研究以阐明 Meq 反式激活结构域中的缺失是否影响 MDV 的毒力。
