Marek’s disease vaccines-induced differential expression of known and novel microRNAs in primary lymphoid organ bursae of White Leghorn

Authors: ZHANG, LEI - Chinese Academy Of Agricultural Sciences; ZHU, CHEN - Michigan State University; Heidari, Mohammad; DONG, KUNZHE - Augusta University; CHANG, SHUANG - Shandong Agricultural University; XIE, QINGMEI - South China Agricultural University; Zhang, Huanmin

Submitted to: BioMed Central (BMC) Veterinary Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/27/2020
Publication Date: 2/24/2020
Citation: Zhang, L., Zhu, C., Heidari, M., Dong, K., Chang, S., Xie, Q., Zhang, H. 2020. Marek’s disease vaccines-induced differential expression of known and novel microRNAs in primary lymphoid organ bursae of White Leghorn. BioMed Central (BMC) Veterinary Research. 51:19. https://doi.org/10.1186/s13567-020-00746-4.
DOI: https://doi.org/10.1186/s13567-020-00746-4

Interpretive Summary: Marek’s disease (MD) is a contagious disease of domestic chickens caused by an avian virus commonly known as Marek’s disease virus (MDV). MD has been controlled primarily by wide use of MD vaccines, yet MD remains a serious threat to the poultry industry and continues to cost the industry over $2 billion per year. The commonly used MD vaccines include HVT, SB-1 and CVI988/Rispens. MD vaccine efficiency is dependent of multiple factors including host genetics. This study was focused on investigating a class of non-coding small RNAs, which, unlike other commonly known RNAs that code for protein to fulfill a physiological function, do not code any product themselves, but directly or indirectly modulate the coding genes’ function. Hundreds of such small RNAs were identified in this study and a small portion of those may play important roles influencing vaccine protection efficiency in chicken against tumor development.

Technical Abstract: 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.