A heterologous prime-boost vaccination regimen using ORFF DNA and recombinant ORFF protein confers protective immunity against experimental visceral leishmaniasis.
J Infect Dis 2005;
191:2130-7. [PMID:
15898000 DOI:
10.1086/430348]
[Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2004] [Accepted: 01/26/2005] [Indexed: 11/03/2022] Open
Abstract
OBJECTIVE
We describe the effectiveness of a prime-boost vaccination regimen using the open-reading frame (ORFF) gene from the LD1 locus of Leishmania donovani.
METHODS
A group of BALB/c mice was immunized with the plasmid carrying the gene for ORFF (F/pcDNA 3.1) and given a booster dose of either the same DNA vaccine or a vaccine with a recombinant ORFF (rORFF) protein. Another group of BALB/c mice was immunized and given a booster dose of the rORFF protein vaccine. The protective efficacies of these vaccine formulations were compared after challenge with L. donovani stationary-phase promastigotes.
RESULTS
Mice given the prime-boost vaccination regimen had an enhanced reduction in parasite load (75%-80%), compared with that in mice given only the rORFF protein vaccine (45%-60%). However, the protective response induced in the prime-boost group was not more than that elicited in the DNA vaccine group. Immunization with only the rORFF protein vaccine did not induce the typical T helper response, whereas priming with the DNA vaccine resulted in enhanced production of immunoglobulin G2a and interferon- gamma . Furthermore, priming with the DNA vaccine also led to enhanced proliferation of splenocytes, suggesting subsequent expansion of antigen-specific T cells.
CONCLUSIONS
The heterologous prime-boost vaccination strategy may be utilized for visceral leishmaniasis.
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