Poster: Metabolic Engineering
Abs #
994: Transgenic expression of the malaria surface antigens, MSP142 & MSP119, in plant seeds
|
|
Presenter: |
Lau, On-Sun , onsunlau@yahoo.com.hk | Authors | Lau, On-Sun (A) Ng, Wang-Kit (A) Chang, Sandra P. (B) Sun, Samuel S.M. (A) | | Affiliations: |
(A): Department of Biology, The Chinese University of Hong Kong,Hong Kong
(B): Department of Tropical Medicine and Medical Microbiology, University of Hawaii,USA
| |
|
Malaria is the world's most important tropical parasitic disease and protozoa Plasmodium falciparum causes the most serious form of human malaria. The merozoite surface proteins MSP142 & MSP119 of P. falciparum are the leading malaria vaccine candidates. We are interested in using plants as expression system for their production. Our previous work on their expression in plants has not been successful, even at the transcriptional level, probably due to the numerous transcript-destabilizing sequences in the protozoa's genes. This has led to the modification of the cDNAs to avoid those signals and optimize their codon usages. Further, two sets of expression vectors were developed to optimize the expression, stability, and accumulation of the modified MSP142 & MSP119 proteins in transgenic plants. They were constructed by fusing the modified cDNAs either with the sequence of a highly expressed and stable plant protein (Lysine-rich protein from Winged bean) or the phaseolin targeting tetrapeptide signal (AFVY). These two sets of expression constructs, driven by the seed-specific phaseolin promoter, were studied using Arabidopsis as a model plant system. Expression of these genes has been detected for both of the constructs by northern & western blotting. Remarkably, the recombinant MSP142 with the targeting signal maintains its natural antigenicity, being recognized by sera from patients infected with P. vivax. We are currently determining the sub-cellular localization of the recombinant proteins for further studies on its accumulation in transgenic seeds. (Supported by an AoE grant from the UGC-HKSAR).
|
|
