Parvovirus B19 VP1 unique region (B19V VP1u)

The Parvovirus B19 VP1 unique region (VP1u) is a critical structural component of the viral capsid, located at the N-terminus of the VP1 protein. Unlike the more abundant VP2 protein, VP1u is essential for viral infectivity due to its secreted phospholipase A2 (sPLA2)-like enzymatic activity, which facilitates the escape of the virus from the endosome into the cytosol. Beyond its enzymatic role, VP1u is involved in binding to specific cellular receptors on erythroid progenitor cells, mediating the internalization of the virus. Because it is highly immunogenic and contains the primary epitopes for neutralizing antibodies, VP1u is a major focus for the development of vaccines and antiviral therapies. Inhibiting the PLA2 activity or blocking the VP1u-mediated entry pathway represents a viable strategy for treating severe Parvovirus B19-related complications such as transient aplastic crisis and chronic anemia in immunocompromised patients.

Other names

VP1 unique regionB19V VP1u proteinParvovirus B19 VP1uPhospholipase A2-like domain of VP1

Neutralization of viral entry and inhibition of phospholipase A2-mediated endosomal escape by specific antibodies.