The Interplay Between MDV and HVT Affects Viral miRNA Expression

• Published in: Avian diseases 2013-06, Vol.57 (2s1), p.372-379
• Main Authors: Goher, Mohamed, Hicks, Julie A, Liu, Hsiao-Ching
• Format: Article
• Language: English
• Subjects: Animals; Chickens; Coinfection - virology; Gallid herpesvirus 2; Herpesviridae; Herpesvirus; Herpesvirus 1, Meleagrid - genetics; Herpesvirus 1, Meleagrid - metabolism; Herpesvirus 2, Gallid - genetics; Herpesvirus 2, Gallid - metabolism; High-Throughput Nucleotide Sequencing - veterinary; HVT; immune response; Infections; Marek Disease - virology; Marek Disease Vaccines - administration & dosage; MD5; MDV1; MicroRNA; MicroRNAs - genetics; MicroRNAs - metabolism; Pavo; Poultry Diseases - virology; Real-Time Polymerase Chain Reaction - veterinary; Regular s; Reverse transcriptase polymerase chain reaction; RNA; RNA, Viral - genetics; RNA, Viral - metabolism; Sequence Analysis, RNA - veterinary; Specific Pathogen-Free Organisms; Spleen; Spleen - virology; Vaccination; Viral diseases; Viruses
• ISSN: 0005-2086; 1938-4351; 1938-4351
• DOI: 10.1637/10440-110112-Reg.1

It is well established that herpesviruses encode numerous microRNAs (miRNAs) and that these virally encoded small RNAs play multiple roles in infection. The present study was undertaken to determine how co-infection of a pathogenic MDV serotype one (MDV1) strain (MD5) and a vaccine strain (herpesvirus of turkeys [HVT]) alters viral miRNA expression in vivo. We first used small RNA deep sequencing to identify MDV1-encoded miRNAs that are expressed in tumorigenic spleens of MDV1-infected birds. The expression patterns of these miRNAs were then further assessed at an early time point (7 days postinfection [dpi]) and a late time point (42 dpi) in birds with and without HVT vaccination using real-time PCR (RT-PCR). Additionally, the effect of MDV1 co-infection on HVT-encoded miRNAs was determined using RT-PCR. A diverse population of miRNAs was expressed in MDV-induced tumorigenic spleens at 42 dpi, with 18 of the 26 known mature miRNAs represented. Of these, both mdv1-miR-M4-5p and mdv1-miR-M2-3p were the most highly expressed miRNAs. RT-PCR analysis further revealed that nine MDV miRNAs were differentially expressed between 7 dpi and 42 dpi infected spleens. At 7 dpi, three miRNAs were differentially expressed between the spleens of birds co-infected with HVT and MD5 compared with birds singly infected with MD5, whereas at 42 dpi, nine miRNAs were differentially expressed. At 7 dpi, the expression of seven HVT-encoded miRNAs was affected in the spleens of co-infected birds compared with birds only receiving the HVT vaccine. At 42 dpi, six HVT-encoded miRNAs were differentially expressed between the two groups. Target prediction analysis suggests that these differentially expressed viral miRNAs are involved in regulating several cellular processes, including cell proliferation and the adaptive immune response. La interacción entre el virus de Marek y el herpesvirus de los pavos afecta a la expresión de micro ARN viral. Está bien establecido que los herpesvirus codifican numerosos micro ARN (con las siglas en inglés miRNAs) y que estas pequeñas moléculas de ARN codificadas viralmente juegan múltiples papeles en la infección. El presente estudio se realizó para determinar como la co-infección entre una cepa patógena (MD5) del virus de Marek serotipo 1 (MDV1) y una cepa vacunal (herpesvirus de los pavos [HVT]) altera la expresión de los genes micro ARN viral in vivo. Se utilizó por primera vez la secuenciación profunda de moléculas pequeñas de ARN para identifica