Characterization of the enterovirus 71 VP1 protein as a vaccine candidate.

Enterovirus 71 (EV71) is an important agent responsible for hand-foot-and-mouth disease (HFMD), which can cause severe neurological complications and death in children. However, there is no specific treatment for EV71 infection, and a safe and effective vaccine is needed urgently. In this study, an effective and economical method for the production of EV71-VP1 protein was developed, and the VP1 protein was evaluated in humoral and cellular immune responses as an EV71 vaccine. The results revealed that the VP1 protein induced high titers of cross-neutralizing antibodies for different EV71 subtypes, and elicited significant splenocyte proliferation. The high levels of IFN-r and IL-10 showed the VP1 protein induced a mixed Th1 and Th2 immune response. Vaccinated female mice could confer protection in their neonatal offspring. Compared with the inactivated EV71, the VP1 protein elicited similar humoral and cellular responses, but the engineered protein is safer, less expensive and can be produced more efficiently. Therefore, EV71-VP1 protein can induce effective immunologic protection against EV71 and is an ideal candidate against EV71 infection.

Characterization of the enterovirus 71 P1 polyprotein expressed in Pichia pastor as a candidate vaccine.

Human enterovirus 71 (EV71) plays an important role in hand, foot, and mouth disease (HFMD), which recently caused the death of hundreds of children in the Asia-Pacific region. However, there are no specific treatments available for EV71 infections; thus, a safe and effective vaccine is needed urgently. In this study, we developed an effective and economical method for producing EV71 polyprotein (P1 protein) in Pichia pastoris. Furthermore, we evaluated the potential of P1 protein as a candidate vaccine against EV71 virus. The data revealed that P1 protein induced persistent high cross-neutralization antibodies for different EV71 subtypes, and elicited significant splenocyte proliferation. The high levels of interleukin-10(IL-10) and interferon-gamma (IFN-γ) showed that P1 protein induced Th1 and Th2 immune responses. Interestingly, vaccinating female mice with the P1 protein conferred cross-protection against different EV71 subtypes to their neonatal offspring.Compared with heat-inactivated EV71, the P1 protein elicited improved humoral and cellular immune responses and showed good cross-protection with different EV71 subtypes. Therefore, the EV71-P1 protein produced by P. pastoris is a promising candidate vaccine against EV71.