New research from Dr. Rebecca P Sumner at the University of Surrey uncovers key biological differences between the global MPXV lineage B and its ancestral lineage A, which remains endemic in Africa.
While both strains replicate similarly in human cells, the global MPXV strain shows reduced extracellular viral spread and lower virulence, aligning with milder disease presentation observed in patients. Surprisingly, both viruses effectively suppress antiviral responses but trigger strong inflammatory cytokine responses not seen in other orthopoxviruses.
Notably, the global strain exhibits defects in innate immune control, including higher IFNβ induction and increased immune signaling, possibly contributing to its attenuation and enhanced human-to-human transmission. These findings suggest that APOBEC3-mediated mutations not only mark MPXV evolution but actively shape its virulence.
A big thank you to Dr. Sumner and her team for their valuable insights into MPXV evolution and immune interactions!
