Vaccinia virus envelope protein D8 (D8)

Vaccinia virus envelope protein D8 is a viral transmembrane protein found on the intracellular mature virion (IMV) of vaccinia virus and other orthopoxviruses. D8 acts as an adhesion molecule, binding specifically to chondroitin sulfate glycosaminoglycans on host cell surfaces, with highest affinity for chondroitin sulfate E (CS-E). The protein adopts a carbonic anhydrase-like fold but is not an enzyme; instead, the central positively charged crevice mediates host glycosaminoglycan binding. D8 is a major immunodominant antigen, strongly targeted by the antibody response following smallpox vaccination, and key for viral entry. Structural studies reveal oligomerization and epitope mapping for antibody binding and neutralization. D8 is also explored for engineered diagnostic tools leveraging its specific binding to CS-E, a proposed biomarker in some cancers. - The gene encoding D8 is D8L. - D8 is not essential for vaccinia virus replication in vitro but contributes to viral fitness during infection. - Neutralizing antibodies (both monoclonal and polyclonal) block its receptor interaction and are the basis for protective immunity after vaccination. All information is based on peer-reviewed structural, immunological, and virological studies.

Other names

D8D8L proteinVaccinia virus D8LIMV envelope protein D8

Neutralizing antibodies block D8’s binding to cell-surface chondroitin sulfate, thereby inhibiting viral entry into host cells.