Gao Qiming, Zhu Kongda, Sun Wanli, Li Shun, Wang Yixin, Chang Shuang, Zhao Peng
College of Veterinary Medicine, Shandong Agricultural University, Tai'an, 271018, China; Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Tai'an, 271018, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Tai'an, 271018, China.
College of Veterinary Medicine, Shandong Agricultural University, Tai'an, 271018, China; Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Tai'an, 271018, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Tai'an, 271018, China.
Poult Sci. 2024 Dec;103(12):104427. doi: 10.1016/j.psj.2024.104427. Epub 2024 Oct 13.
Marek's disease virus (MDV) is an extremely widespread avian immunosuppressive virus. In recent years, many reports have shown that there are still cases of MDV infection and immunosuppression after immunization with the vaccine. Consequently, there is a need to develop alternative complementary approaches for strengthening the efficacy of MDV prevention and control measures. Lentinan (LNT) is a macromolecular compound with immune-enhancing activity extracted from shiitake mushrooms. To explore the value and effectiveness of administering LNT through drinking water in the prevention and control of MDV, this study first observed the effects of high and low doses of LNT on weight gain, organ development, viral replication, and antibody titer of an avian influenza virus subtype H9 (AIV-H9) inactivated vaccine in specific pathogen-free (SPF) chicks infected with the wild strain of MDV. The results showed that both high and low doses of LNT significantly alleviated the weight gain retardation and liver and spleen enlargement caused by MDV infection, and significantly inhibited the replication of MDV in SPF chicks (P < 0.05), compared with the MDV-positive control group, both high and low doses of LNT significantly increased the antibody titer of AIV-H9 after immunization with inactivated AIV-H9 vaccine (P < 0.0001). On this basis, we also observed the effects of a chicken Marek's disease meq gene deletion live vaccine (SC9-1 strain), administered alone or in combination with LNT, on MDV infections of varying virulence in Hy-Line Brown chicks. The results showed that combined administration of LNT and the SC9-1 vaccine resulted in a significant alleviation of weight gain retardation and liver and spleen enlargement due to MDV infection (P < 0.05), as well as a significant inhibition of MDV replication and release in Hy-Line Brown chicks compared to the vaccine alone (P < 0.0001). These findings suggest that LNT not only alleviates the adverse effects of MDV infection in chickens but also enhances the efficacy of MDV vaccination, offering a potential auxiliary measure for controlling MDV infection.
马立克氏病病毒（MDV）是一种极为广泛传播的禽类免疫抑制病毒。近年来，许多报告表明，使用疫苗免疫后仍存在MDV感染和免疫抑制的病例。因此，需要开发替代的补充方法来增强MDV防控措施的效果。香菇多糖（LNT）是一种从香菇中提取的具有免疫增强活性的大分子化合物。为了探索通过饮水给予LNT在MDV防控中的价值和有效性，本研究首先观察了高剂量和低剂量LNT对感染MDV野生株的无特定病原体（SPF）雏鸡体重增加、器官发育、病毒复制以及H9亚型禽流感病毒（AIV-H9）灭活疫苗抗体效价的影响。结果表明，与MDV阳性对照组相比，高剂量和低剂量的LNT均显著减轻了MDV感染引起的体重增加迟缓以及肝脏和脾脏肿大，并显著抑制了SPF雏鸡体内MDV的复制（P<0.05），高剂量和低剂量的LNT均显著提高了用AIV-H9灭活疫苗免疫后AIV-H9的抗体效价（P<0.0001）。在此基础上，我们还观察了单独或与LNT联合使用鸡马立克氏病meq基因缺失活疫苗（SC9-1株）对海兰褐雏鸡不同毒力MDV感染的影响。结果表明，与单独使用疫苗相比，LNT与SC9-1疫苗联合使用可显著减轻MDV感染引起的体重增加迟缓以及肝脏和脾脏肿大（P<0.05），并显著抑制海兰褐雏鸡体内MDV的复制和释放（P<0.0001）。这些发现表明，LNT不仅可以减轻MDV感染对鸡的不利影响，还可以提高MDV疫苗接种的效果，为控制MDV感染提供了一种潜在的辅助措施。
