A
fusion protein, from P. falciparum Glutamate-rich
protein(GLURP) genetically coupled to P. falciparum Merozoite
surface protein 3 (MSP3) was produced in
Lactococcus lactis as a secreted recombinant GLURP-MSP3
hybrid protein and experiments showed that the GLURP-part of the
hybrid increased the overall
antibody response. Immunizations with the
hybrid protein consistently generated a stronger
antibody response against the individual GLURP and MSP3 domains than a mixture of the two recombinant molecules injected at one site or the individual recombinant molecules injected simultaneously at two different sites. The difference was most pronounced for the MSP3-
specific antibody response suggesting that
T cell epitopes located in the GLURP RO-region provide help for B-
cell epitopes in the MSP3 region. Moverover, when the animals were injected with a mixture of GLURP and MSP3, individual mice tended to
mount a predominant
antibody response against either molecule: in some animals GLURP was immunodominant whereas in other animals MSP3 was the dominant
immunogen. Additionally, the hybrid was also more antigenic than the individual recombinant proteins since the ELISA-
titer of naturally occurring IgG antibodies, in clinically