Vaccines with live, low-virulence Newcastle disease virus (NDV) strains are still the most accepted prevention and control strategies for combating Newcastle disease (ND), a major viral disease that hampers the development of the poultry industry worldwide. However, the mechanism underlying vaccine-mediated innate cell immune responses remains unclear. Here, a high-throughput Illumina sequencing approach was employed to determine cellular miRNA expression profiles in chicken macrophages infected with the LaSota virus, a widely used vaccine strain for mass vaccination programs against ND in poultry. Compared to the control group, 112 and 115 differentially expressed (DE) miRNAs were identified at 24 hpi (hours post inoculation) and 48 hpi, respectively. Meanwhile, 174 DE miRNAs were identified between 24 hpi and 48 hpi. Furthermore, 12 upregulated and 6 downregulated DE miRNAs were observed in common at 24 and 48 hpi compared with 0 hpi. In addition, target prediction and functional analysis of these DE miRNAs revealed significant enrichment for several signaling pathways, especially in the immune-related genes and pathways, such as the RIG-I-like receptor signaling pathway, NOD-like receptor signaling pathway, and mitogen-activated protein kinase (MAPK) signaling pathway. Our findings not only lay the foundations for further investigating the roles and regulatory mechanisms of miRNA in vaccine-mediated innate cellular immune responses, but also extend new insights into the interactions between the host and NDV infection.
Keywords: LaSota; Newcastle disease virus; chicken macrophages; microRNA; vaccine strain.