Protective Immunity Induced by Immunization with Baculovirus, Virus-like Particle, and Vaccinia Virus Expressing the AMA1 of Plasmodium berghei.

Abstract

Heterologous prime–boost immunization regimens using various vaccine platforms demonstrated promising results against infectious diseases. Here, mice were sequentially immunized with the recombinant baculovirus (rBV), virus-like particle (VLP), and recombinant vaccinia virus (rVV) vaccines expressing the Plasmodium berghei apical membrane antigen 1 (AMA1) for protective efficacy evaluation. The rBV_V_rVV heterologous immunization regimen elicited high levels of parasite-specific IgG, IgG2a, and IgG2b antibody responses in sera. Upon P. berghei challenge infection, proliferations of germinal center B cells in the inguinal lymph nodes, as well as blood CD4+ and CD8+ T cells were induced. More importantly, rBV_V_rVV immunization significantly diminished the parasitemia and prevented drastic bodyweight loss in mice post-challenge infection with P. berghei. Our findings revealed that immunization with rBV, VLP, and rVV expressing the AMA1 conferred protection against P. berghei infection, providing evidence for the potential implementation of this strategy.