Transcriptome Analysis Reveals Host Peripheral Blood Mononuclear Cells Response to Mpox Virus Infection

Mpox virus (MPXV), a member of the <i>Orthopoxvirus</i> genus in the Poxviridae family, has long been endemic in Africa. The interaction between MPXV infection and peripheral immune responses is of great significance. However, the activation of signaling pathways and molecular changes in peripheral blood mononuclear cells (PBMCs) following MPXV infection remain poorly understood. This study evaluated the transcriptomic profiles of rabbit PBMCs during the mpox acute and recovery phases. The results showed that MPXV infection significantly altered the transcriptomic profiles of PBMCs. At 6 days post-infection, pathways related to pathogenic infection and IL-1 response were enriched, while at 14 days post-infection, the T cell receptor signaling pathway was enriched. During the mpox acute phase, inflammatory cytokines in serum such as IL-1α, IL-1β, IL-8, and IL-21 were upregulated, while MMP-9 and NCAM-1 were downregulated. In rabbits and rhesus monkeys, key genes upregulated in common during the mpox acute period were associated with the interferon pathway (e.g., the <i>ISG15</i>, <i>OAS</i>, and <i>IFIT</i> families), while downregulated genes were related to B-cell activation and differentiation (e.g., the <i>MS4A1</i> and <i>FCRL</i> families). Additionally, rabbits developed protective immunity against reinfection, with neutralizing antibodies effectively activated. These findings provide insights into the molecular characteristics of PBMCs changes in in vivo models of MPXV infection, and offer references for the diagnosis, vaccine development, and therapeutic research of mpox.