IAI Accepts, published online ahead of print on 9 November 2009

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Google Scholar Articles by Yoshida, S. Articles by Yokomine, T. PubMed PubMed Citation Articles by Yoshida, S. Articles by Yokomine, T.

 Previous Article  |  Next Article 

Infect. Immun. doi:10.1128/IAI.00877-09
Copyright (c) 2009, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

Baculovirus-based nasal drop vaccine confers complete protection against malaria by natural boosting of vaccine-induced antibodies in mice

Shigeto Yoshida^*, Hitomi Araki, and Takashi Yokomine

Division of Medical Zoology, Department of Infection and Immunity, Jichi Medical University, Tochigi 329-0498, Japan

^* To whom correspondence should be addressed. Email: shigeto{at}jichi.ac.jp.

Blood-stage malaria parasites ablate memory B cells generated by vaccination in mice, resulting in diminishing natural boosting of vaccine-induced antibody responses to infection. Here we show the development of a new baculovirus-based Plasmodium yoelii 19-kDa carboxyl terminus of merozoite surface protein 1 (PyMSP1₁₉) vaccine capable of circumventing the tactics of parasites in a murine model. The baculovirus-based vaccine displayed PyMSP1₁₉ on the surface of the virus envelope in its native three-dimensional structure. Needle-free intranasal immunization of mice with the baculovirus-based vaccine induced strong systemic humoral immune responses with high titers of PyMSP1₁₉-specific antibodies. Most importantly, this vaccine conferred complete protection by natural boosting of vaccine-induced PyMSP1₁₉-specific antibody responses shortly after challenge. The protective mechanism is a mixed Th1/Th2-type immunity, which is associated with the TLR9-dependent pathway. The present study offers a novel strategy for the development of malaria blood-stage vaccines capable of naturally boosting vaccine-induced antibody responses to infection.