Marek's disease (MD) is a contagious disease of domestic chickens caused by MD viruses. MD has been controlled primarily by vaccinations, yet sporadic outbreaks of MD take place worldwide. Commonly used MD vaccines include HVT, SB-1 and CVI988/Rispens and their efficacies are reportedly dependent of multiple factors including host genetics. Our previous studies showed protective efficacy of a MD vaccine can differ drastically from one chicken line to the next. Advanced understanding on the underlying genetic and epigenetic factors that modulate vaccine efficacy would greatly improve the strategy in design and development of more potent vaccines. Two highly inbred lines of White Leghorn were inoculated with HVT and CVI988/Rispens. Bursa samples were taken 26 days post-vaccination and subjected to small RNA sequencing analysis to profile microRNAs (miRNA). A total of 589 and 519 miRNAs was identified in one line, known as line 63, 490 and 630 miRNAs were identified in the other, known as line 72, in response to HVT or CVI988/Rispens inoculation, respectively. HVT and CVI988/Rispens induced mutually exclusive 4 and 13 differentially expressed (DE) miRNAs in line 63 birds in contrast to a non-vaccinated group of the same line. HVT failed to induce any DE miRNA and CVI988/Rispens induced a single DE miRNA in line 72 birds. Thousands of target genes for the DE miRNAs were predicted, which were enriched in a variety of gene ontology terms and pathways. This finding suggests the epigenetic factor, microRNA, is highly likely involved in modulating vaccine protective efficacy in chicken.

中文翻译：

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马立克氏病疫苗在White Leghorn的原发性淋巴器官法氏囊中诱导已知和新型microRNA的差异表达。

马立克氏病（MD）是由MD病毒引起的家禽传染病。MD主要由疫苗控制，但是MD的零星爆发在世界范围内发生。常用的MD疫苗包括HVT，SB-1和CVI988 / Rispens，据报道其功效取决于多种因素，包括宿主遗传学。我们以前的研究表明，MD疫苗的保护功效可能在一条鸡系与另一条鸡系之间大不相同。对调节疫苗功效的潜在遗传和表观遗传因素的深入了解将大大改善设计和开发更有效疫苗的策略。用HVT和CVI988 / Rispens接种了两个高度近交的White Leghorn系。疫苗接种后26天采集囊囊样本，并进行小RNA测序分析，以分析microRNA（miRNA）。在一个品系中，分别响应HVT或CVI988 / Rispens接种，共鉴定出589和519个miRNA，称为品系63、490和630。与同一系的未接种组相比，HVT和CVI988 / Rispens在系63禽中诱导了互斥的4和13差异表达（DE）miRNA。HVT无法诱导任何DE miRNA，而CVI988 / Rispens在72羽禽中诱导了单个DE miRNA。预测了DE miRNA的数千个靶基因，这些靶基因富含各种基因本体论术语和途径。这一发现表明表观遗传因子microRNA，