马立克氏病病毒对鸡肿瘤相关基因TNFSF13B和ST18表达水平的影响

Differential expression of tumor-related genes TNFSF13B and ST18 in chickens infected with Marek's disease virus

将150只1日龄雏鸡随机分成2组,100只作为攻毒组,50只作为对照组。攻毒组腹腔注射2 000PFU的马立克氏病病毒(MDV)-GA细胞毒0.2mL;对照组注射同等剂量的病毒稀释液。2组鸡严格隔离,在相同条件的负压隔离器中饲养。攻毒后60d,屠宰所有存活鸡。在对照组中取4个正常鸡的脾脏(HS);在攻毒组中取4个感染MDV后产生肿瘤鸡的脾脏(TS)及4个感染MDV后未产生肿瘤并表现为健康鸡的脾脏(ANS),并对TNFSF13B和ST18基因在这些脾脏组织中的表达水平进行荧光定量分析。结果表明,肿瘤相关基因TNFSF13B和ST18的表达在产生肿瘤鸡的脾脏中都是显著性下调的。MDV通过抑制宿主TNFSF13B基因的表达来抑制B细胞分化、成熟进而对宿主免疫系统进行抑制;同时MDV通过下调肿瘤抑制基因ST18的表达,促使机体肿瘤发生。在对MDV有明显抵抗能力的鸡(ANS组)中,TNFSF13B和ST18的表达水平与对照组健康鸡基本一致,表明这2个基因在MDV抗病过程中起着重要作用。

One hundred and fifty 1-day-old chicks were divided into two groups randomly.Exprimental group（100 chicks） were infected intraperitoneally with 2 000 plaque-forming units（PFU） of the MDV-GA.The uninfected control group（50 chicks） were injected with the same dosage of diluent（0.2 mL）.The two groups were housed in separate cages in the same filtered-air,positive-pressure isolation rooms.At the end of trial period（60 d.p.i.）,we dissected all the survivals,and chose healthy spleens（HS） from four age-matched uninfected chickens,tumorous spleens（TS） from four MDV-infected chickens,and apparently normal spleens（ANS） from four survivals for detecting the expression levels of TNFSF13B and ST18 genes by qRT-PCR.The tumor-related genes TNFSF13B and ST18 were significantly down-regulated in TS samples,indicating that MDV could decrease the expression level of TNFSF13B to suppress B cells differentiation and maturation and thereby impaired the host immune system.Meanwhile,MDV down-regulated the expression of ST18 gene and induced the development of tumors.We also found the expression levels of TNFSF13B and ST18 in ANS samples were consistent with those in HS samples,showing the two genes could play an important role in MDV resistant activites of the hosts.