MDV-induced differential microRNA expression in the primary lymphoid organ of thymus

Authors: Heidari, Mohammad; Zhang, Huanmin; SUNKARA, LAKSHMI - Clemson University

Submitted to: Microbial Pathogenesis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/19/2022
Publication Date: 7/30/2022
Citation: Heidari, M., Zhang, H., Sunkara, L. 2022. MDV-induced differential microRNA expression in the primary lymphoid organ of thymus. Microbial Pathogenesis. 170. Article 105688. https://doi.org/10.1016/j.micpath.2022.105688.
DOI: https://doi.org/10.1016/j.micpath.2022.105688

Interpretive Summary: Marek's disease virus (MDV) is the etiological agent of Marek's disease (MD) in domestic chickens. Clinical signs of MD include depression, weight loss, atrophy of lymphoid organs, and visceral tumors. MicroRNAs are a class of short and single-stranded RNAs that regulate gene expression by suppression or degradation of mRNA. Herpesviruses, including MDV, encode for microRNAs that are known to play essential roles in viral pathogenicity and evasion of immune responses. In this study, we performed chicken microRNA sequencing in thymuses of control and MDV-infected chickens of two MD-resistant and susceptible lines at 21 days post infection. Thymus is a non-tumorous lymphoid organ that undergoes severe atrophy due to MDV-induced destruction of T cells. Sequence analysis identified a total 654 chicken microRNAs in the thymuses of control and MDV-infected birds of both lines. Of these, 453 were novel and 205 were known microRNAs. All novel microRNAs mapped to chicken genome with no sequence homology to existing microRNAs in the chicken microRNA data base. Comparative analysis between the thymuses of control and infected birds of resistant and susceptible lines identified 78 differentially expressed microRNAs that might provide insights into the mechanism of thymus atrophy and resistance or susceptibility to MD.

Technical Abstract: Marek’s disease virus (MDV), a highly contagious cell associated virus, is the etiological agent of Marek’s disease (MD), a lymphoproliferative, ubiquitous, and neuropathic disease of domestic chickens. Clinical signs of MD include transient paralysis, bursal/thymic atrophy, and T cell lymphomas. MicroRNAs (miRNAs) are a class of short, single-stranded, non-coding RNAs that regulate gene expression by transcriptional suppression or mRNA degradation. Herpesviruses, including MDV, encode for miRNAs that are known to play essential roles in viral pathogenicity, oncogenesis, and evasion of immune responses. In this study, we performed host miRNA sequencing in thymi of control and MDV-infected chickens of two MD-resistant (63) and susceptible (72) lines at 21 days post infection. Thymus is a non-tumorous lymphoid organ that undergoes severe atrophy due to MDV-induced apoptotic mediated destruction of T cells. Sequence analysis identified a total 654 chicken miRNAs in the thymuses of control and MDV-infected birds of both lines. Of these, 453 were novel and 205 were known microRNAs. All novel miRNAs mapped to chicken genome with no sequence homology to existing miRNAs in the chicken miRbase. Comparative analysis between the thymi of control and infected birds of resistant and susceptible lines identified 78 differentially expressed microRNAs that might provide insights into mechanism of thymus atrophy.