Phylogenetic and Molecular Evolutionary Insights into Monkeypox Virus Circulation in Shenzhen, China, 2023-2024.

The 2022 global mpox outbreak highlighted the risk of sustained human-to-human transmission of monkeypox virus (MPXV) in non-endemic regions, yet genomic surveillance in Asia, particularly in China, remains limited. This study conducted horizontal genomic surveillance of MPXV in Shenzhen from 2023 to 2024 to characterize the phylogenetic structure, mutational patterns, and adaptive evolution of locally circulating strains. Phylogenetic analysis showed 95.2% of strains belonged to the dominant lineage C.1.1, with 4.8% in lineage E.3, forming three distinct genetic clusters that indicate multiple independent introductions and established local transmission chains. Whole-genome mutational analysis identified 146 single-nucleotide polymorphisms (SNPs), 81.5% of which carried APOBEC3-mediated mutation signatures (TC > TT and GA > AA), reflecting host-driven antiviral editing. Notably, dynamic changes in low-complexity regions (LCRs) were observed, implying potential roles in genome plasticity and adaptive evolution. Functional analysis revealed non-synonymous substitution biases in host-interacting proteins OPG064, OPG145, and OPG210, while replication protein OPG105 remained conserved. Structural modeling identified critical substitutions in OPG002 (S54F), OPG016 (R84K), and OPG036 (R48C) that may enhance immune evasion by modulating TNF-α signaling, NKG2D engagement, and Type I interferon antagonism. These findings illuminate unique MPXV evolutionary dynamics in Shenzhen, emphasizing continuous genomic surveillance for non-endemic outbreak preparedness.