Previous Article | Next Article ![]()
Infection and Immunity, May 2009, p. 1782-1789, Vol. 77, No. 5
0019-9567/09/$08.00+0 doi:10.1128/IAI.01226-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.
,
Division of Medical Zoology, Department of Infection and Immunity, Jichi Medical University, Tochigi 329-0498, Japan,1 Microbiological Research Institute, Otsuka Pharmaceutical Co. Ltd., Tokushima 771-0192, Japan2
Received 7 October 2008/ Returned for modification 12 November 2008/ Accepted 6 February 2009
We have previously shown that a recombinant baculovirus that displays Plasmodium berghei circumsporozoite protein (PbCSP), a homolog of the leading human malaria vaccine candidate, on the viral envelope protected 60% of mice against P. berghei infection. Here, we describe a second-generation baculovirus vaccine based on the "baculovirus dual expression system," which drives PbCSP expression by a dual promoter that consists of tandemly arranged baculovirus-derived polyhedrin and mammal-derived cytomegalovirus promoters. The baculovirus-based PbCSP vaccine not only displayed PbCSP on the viral envelope but also expressed PbCSP upon transduction of mammalian cells. Immunization with the baculovirus-based PbCSP vaccine elicited high PbCSP-specific antibody titers (predominantly immunoglobulin G1 [IgG1] and IgG2a) and PbCSP-specific CD8+ T-cell responses without extraneous immunological adjuvants in mice, indicating that there was induction of both Th1 and Th2 responses (a mixed Th1/Th2 response). Importantly, upon intramuscular inoculation, the baculovirus-based PbCSP vaccine conferred complete protection against sporozoite challenge. Thus, the baculovirus-based PbCSP vaccine induced strong protective immune responses against preerythrocytic parasites. These results introduce a novel concept for the baculovirus dual expression system that functions as both a subunit vaccine and a DNA vaccine and offer a promising new alternative to current human vaccine delivery platforms.
Published ahead of print on 17 February 2009.
Supplemental material for this article may be found at http://iai.asm.org/.
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»