Objective Damage on the spleens of mice inoculated with pseudorabies virus (PRV) and pathological regulatory mechanism of the infection were studied, to lay a theoretical foundation for the immune escape mechanism and antiviral targets screening of PRV.

Method BALB/c mice were inoculated with the PRV variant strain SX-2018, along with healthy ones as control, prior to histopathological observations and transcriptomic sequencing on spleens of the animals.

Result SX-2018-infected mice showed significant injury on the spleens with the characteristic lymphocyte necrosis in the parenchyma and increased macrophages. The transcriptomic sequencing on the tissue cells identified 299 upregulated and 357 downregulated differentially expressed genes (DEGs). The gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analyses indicated that these DEGs were predominantly enriched in the cytokine-cytokine receptor interaction and mitogen-activated protein kinase (MAPK) signaling pathways. Seven representative DEGs were subsequently validated by fluorescence quantitative PCR (qPCR) to yield a highly consistent result with RNA-seq.

Conclusion The PRV-infected mice exhibited significant structural pathology on spleen with disrupted homeostasis of immune cell subsets. The infection was closely associated with the dysregulated gene expressions in cytokine–cytokine receptor interaction and MAPK signaling pathways of the animal.