The Affiliated Hospital of Qingdao University and The Biomedical Sciences Institute of Qingdao University (Qingdao Branch of SJTU Bio-X Institutes), Qingdao University, Qingdao, Shandong Province 266003, China.
College of Animal Science and Technology, Shandong Agricultural University, Tai'an, Shandong Province 271018, China.
Poult Sci. 2019 Sep 1;98(9):3514-3522. doi: 10.3382/ps/pez179.
Fowl adenovirus serotype 4 (FAdV-4) is the causative agent of hydropericardium syndrome. To clarify the effects of FAdV-4 on immune organs in birds, we conducted a detailed examination of dynamic morphology and damage mechanisms in chickens randomly divided into 4 groups (FAdV-4, vaccination, FAdV-4 plus vaccination, and control). FAdV-4 caused the depletion of lymphocytes and subsequent growth impairment in the thymus and bursa. Chickens infected with FAdV-4 and subjected to vaccination experienced greater inhibition of antibody responses to inactivated vaccines against Newcastle disease and avian influenza virus subtype H9 than uninfected and vaccinated chickens. The mechanisms underlying adenovirus-mediated lymphoid organ damage were further investigated via transferase-mediated dUTP nick-end labeling and apoptotic genes transcription analyses. Notably, lymphocytes apoptosis in lymphoid organs and expression of specific gene transcripts was significantly upregulated after infection (P < 0.05). Furthermore, increased expression of interleukin (IL)-6, IL-8, and tumor necrosis factor (TNF)-α mRNA was observed (P < 0.05), compared to the control group. Our collective findings suggested that FAdV-4 caused structural and functional damage of immune organs via apoptosis along with induction of a severe inflammatory response.
禽腺病毒血清型 4（FAdV-4）是引起心包积水综合征的病原体。为了阐明 FAdV-4 对禽类免疫器官的影响，我们将鸡随机分为 4 组（FAdV-4、疫苗接种、FAdV-4 加疫苗接种和对照组）进行了详细的动态形态学和损伤机制检查。FAdV-4 导致胸腺和腔上囊中淋巴细胞耗竭，随后生长受损。感染 FAdV-4 并接种疫苗的鸡对新城疫和禽流感病毒亚型 H9 的灭活疫苗的抗体反应抑制作用大于未感染和接种疫苗的鸡。通过转移酶介导的 dUTP 缺口末端标记和凋亡基因转录分析进一步研究了腺病毒介导的淋巴器官损伤的机制。值得注意的是，感染后淋巴器官中淋巴细胞凋亡和特定基因转录物的表达显著上调（P<0.05）。与对照组相比，还观察到白细胞介素（IL）-6、IL-8 和肿瘤坏死因子（TNF）-α mRNA 的表达增加（P<0.05）。我们的研究结果表明，FAdV-4 通过凋亡和诱导严重的炎症反应导致免疫器官的结构和功能损伤。
