MSP-1p42-specific antibodies impact growth and development of intra-erythrocytic parasites of Plasmodium falciparum. - Related Articles
MSP-1p42-specific antibodies impact growth and development of intra-erythrocytic parasites of Plasmodium falciparum.
Malar J. 2009 Aug 3;8(1):183
Authors: Bergmann-Leitner ES, Duncan EH, Angov E
ABSTRACT: BACKGROUND: Antibodies are the main effector molecules in the defense against blood stages of the malaria parasite Plasmodium falciparum. Understanding the mechanisms by which vaccine-induced anti-blood stage antibodies work in protecting against malaria is essential for vaccine design and testing. METHODS: The effects of MSP1p42-specific antibodies on the development of blood stage parasites were studied using microscopy, flow cytometry and the pLDH assay, as a measure of metabolic activity. To determine strain-specific effects, if present, allele-specific antibodies and various parasite strains were employed RESULTS: The mode of action of anti-MSP-1p42 antibodies differs among the parasite strains tested: anti-MSP-1p42 antisera act mainly through invasion-inhibitory mechanisms against FVO parasites, by either preventing schizonts from rupturing or agglutinating merozoites upon their release. The same antibodies do not prevent the rupture of 3D7 schizonts; instead they agglutinate merozoites and arrest the development of young parasites at the early trophozoite stage, thus acting through invasion- and growth inhibitory mechanisms. The second key finding of this study is that antibodies have access to the intra-erythrocytic parasite, as evidenced by the labeling of developing merozoites with fluorochrome-conjugated anti-MSP-1p42 antibodies. Access to the parasite through this route likely allows antibodies to exert their inhibitory activities on maturing schizonts leading to their inability to rupture and be released from infectious merozoites. CONCLUSION: The identification of various mechanisms by which anti-MSP-1 antibodies inhibit parasite growth emphasizes the importance of functional assays when evaluating malaria vaccines and may open new venues for immunotherapy and vaccine development.
PMID: 19650894 [PubMed - as supplied by publisher] [PubMed-Malaria]