INDUCTION OF ANTIMALARIAL TRANSMISSION-BLOCKING IMMUNITY WITH A RECOMBINANT OOKINETE SURFACE-ANTIGEN OF PLASMODIUM-BERGHEI PRODUCED IN SILKWORM LARVAE USING THE BACULOVIRUS EXPRESSION VECTOR SYSTEM

Citation
H. Matsuoka et al., INDUCTION OF ANTIMALARIAL TRANSMISSION-BLOCKING IMMUNITY WITH A RECOMBINANT OOKINETE SURFACE-ANTIGEN OF PLASMODIUM-BERGHEI PRODUCED IN SILKWORM LARVAE USING THE BACULOVIRUS EXPRESSION VECTOR SYSTEM, Vaccine, 14(2), 1996, pp. 120-126
Citations number
32
Categorie Soggetti
Immunology
Journal title
ISSN journal
0264410X
Volume
14
Issue
2
Year of publication
1996
Pages
120 - 126
Database
ISI
SICI code
0264-410X(1996)14:2<120:IOATIW>2.0.ZU;2-U
Abstract
We have studied Pbs21, a major ookinete surface protein of Plasmodium berghei, for the development of a model transmission blocking immunoge n. lit the mouse recombinant Pbs21 expressed in the Escherichia coli e xpression system (EcrPbs21) is not as effective in inducing transmissi on blocking antibodies as native Pbs21 (nPbs21), possibly because of d ifferences in post-translational processing between EcrPbs21 and nPbs2 1. In an attempt to improve the efficacy of the recombinant molecule, we describe here the use of a baculovirus expression vector system in the silkworm Bombyx mori. Following an injection of recombinant baculo virus containing Pbs21 cDNA, B. mori larvae produced recombinant Pbs21 (BmrPbs21) with a molecular weight indistinguishable from nPbs21. Fif ty micrograms of BmrPbs21 could be purified from the hemolymph of each infected larva using affinity chromatography. Immunization of Balb/c mice with BmrPbs21 induced high anti-BmrPbs21 and anti-ookinete antibo dies but low anti-EcrPbs21 antibody. In contrast, EcrPbs21 induced hig h anti-EcrPbs21 antibody but low anti-BmrPbs21 and anti-ookinete antib odies This suggests that most B-cell epitopes on nPbs21 are conformati onal and that many of the linear epitopes in EcrPbs21 are not normally exposed in nPbs21. Oocyst formation in Anopheles stephensi mosquitoes , which fed on mice immunized with purified BmrPbs21 and infected with P. berghei, was blocked by 85.5-97.1%. These results suggest that the baculovirus-silkworm system produces useful quantities of recombinant Pbs21 which in limited studies is structurally and immunogenically in distinguishable from the native molecule.