Small RNA deep sequencing identifies viral   microRNAs during malignant catarrhal fever   induced by alcelaphine herpesvirus 1.
Alcelaphine herpesvirus 1 (AlHV-1) is a c-herpesvirus (c-HV) carried asymptomatically by wildebeest. Upon cross-species transmission, AlHV-1 induces a fatal lymphoproliferative disease named malignant catarrhal fever (MCF) in many ruminants, including cattle, and the rabbit model. Latency has been shown to be essential for MCF induction. However, the mechanisms causing the activation and proliferation of infected CD8+T cells are unknown. Many c-HVs express microRNAs (miRNAs). These small non-coding RNAs can regulate expression of host or viral target genes involved in various pathways and are thought to facilitate viral infection and/or mediate activation and proliferation of infected lymphocytes. The AlHV-1 genome has been predicted to encode a large number of miRNAs. However, their precise contribution in viral infection and pathogenesis in vivo remains unknown. Here, using cloning and sequencing of small RNAs we identified 36 potential miRNAs expressed in a lymphoblastoid cell line propagated from a calf infected with AlHV-1 and developing MCF. Among the sequenced candidate miRNAs, 32 were expressed on the reverse strand of the genome in two main clusters. The expression of these 32 viral miRNAs was further validated using Northern blot and quantitative reverse transcription PCR in lymphoid organs of MCF developing calves or rabbits. To determine the concerted contribution in MCF of 28 viralmiRNAs clustered in the non-protein-coding region of the AlHV-1 genome, a recombinant virus was produced. The absence of these 28 miRNAs did not affect viral growth in vitro or MCF induction in rabbits, indicating that the AlHV-1 miRNAs clustered in this non-protein-coding genomic region are dispensable for MCF induction.
Fundamental and Applied Research in Animals and Health (FARAH), Immunology-Vaccinology, Faculty of Veterinary Medicine (B43b), University of Liège, Belgium.
Océane
O
Sorel
Architecture et Réactivité de l'ARN - UPR 9002, Institut de Biologie Moléculaire et Cellulaire du CNRS, Université de Strasbourg, 15 rue René Descartes, F-67084 Strasbourg Cedex, France.
Lee
L
Tuddenham
Fundamental and Applied Research in Animals and Health (FARAH), Immunology-Vaccinology, Faculty of Veterinary Medicine (B43b), University of Liège, Belgium.
Françoise
F
Myster
Fundamental and Applied Research in Animals and Health (FARAH), Immunology-Vaccinology, Faculty of Veterinary Medicine (B43b), University of Liège, Belgium.
Leonor
L
Palmeira
Veterinary and Agrochemical Research Center (CODA-CERVA), Brussels, Belgium.
Pierre
P
Kerkhofs
Architecture et Réactivité de l'ARN - UPR 9002, Institut de Biologie Moléculaire et Cellulaire du CNRS, Université de Strasbourg, 15 rue René Descartes, F-67084 Strasbourg Cedex, France.
Sébastien
S
Pfeffer
Fundamental and Applied Research in Animals and Health (FARAH), Immunology-Vaccinology, Faculty of Veterinary Medicine (B43b), University of Liège, Belgium.
Alain
A
Vanderplasschen
Fundamental and Applied Research in Animals and Health (FARAH), Immunology-Vaccinology, Faculty of Veterinary Medicine (B43b), University of Liège, Belgium.
Benjamin G
BG
Dewals
D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000821:virology*; D018142:Gammaherpesvirinae / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D006566:Herpesviridae Infections / Q000662:veterinary* / Q000821:virology; D059014:High-Throughput Nucleotide Sequencing; D008304:Malignant Catarrh / Q000821:virology*; D035683:MicroRNAs / Q000235:genetics*; D012367:RNA, Viral / Q000235:genetics*; D011817:Rabbits
D035683:MicroRNAs; D012367:RNA, Viral