Poliovirus type 2 (Sabin) capsid protein (PV2-Sabin capsid)

The Poliovirus type 2 (Sabin) capsid neutralizing epitopes are specific antigenic regions located on the exterior surface of the viral protein shell, primarily involving the VP1, VP2, and VP3 proteins. These epitopes are the critical sites recognized by the host immune system to generate neutralizing antibodies following vaccination with the Sabin type 2 oral polio vaccine (OPV2) or inactivated polio vaccine (IPV) (Hogle, J. M., 2002, Annual Review of Microbiology). The Sabin 2 strain is an attenuated live virus that mimics natural infection to induce mucosal and systemic immunity; however, its capsid is prone to mutations that can restore neurovirulence, leading to vaccine-derived paralytic poliomyelitis (Minor, P. D., 1992, Nature). In drug development and vaccine design, these epitopes are targeted to ensure broad and potent immune protection while minimizing the risk of genetic reversion. Novel vaccines like nOPV2 have been engineered with stabilized capsid structures to prevent the loss of these neutralizing epitopes and reduce the likelihood of the virus regaining its ability to cause disease (Van Damme, P., et al., 2019, The Lancet). Additionally, small molecule capsid inhibitors are designed to bind within the hydrophobic pockets near these epitopes to block viral entry and uncoating, providing a therapeutic avenue for treating infections in immunodeficient individuals or during outbreaks (Collett, M. S., et al., 2017, Antiviral Research).

Other names

Poliovirus Sabin type 2 neutralizing antigenic sitesSabin 2 capsidPoliovirus type 2 (Sabin) VP1-VP4 proteinsOPV2 capsid epitopes

The capsid neutralizing epitopes serve as the primary targets for vaccine-induced antibodies, which bind to these sites to prevent viral attachment to the host CD155 receptor or to interfere with viral uncoating (Minor, P. D., 1992, Nature). Antiviral compounds like V-073 bind to the hydrophobic pocket within the VP1 protein to stabilize the capsid and prevent the release of viral RNA (Collett, M. S., et al., 2017, Antiviral Research).