New Drugs and Drug Resistance in Malaria: Molecular Genetic Analysis

摘要

Drug resistance has emerged as a major problem in the treatment of all microbialagents and in many cancer chemotherapies. Drug resistance has become particularly acute in malaria where resistance to chloroquine, the cheapest and most efficacious antimalaria has spread throughout the endemic parts of the world and resistance to other antimalarials is rapidly developing and spreading. The goal of this work is to understand the mechanism of drug resistance and to eventually use that information to develop new aproaches to chemotherapy. The approach we have taken is to develop a method for the functional analysis of genes in the malaria parasite. This methodology has proven invaluable in the analysis of drug resistance in other microbial systems, including our own recent work in leishmaniasis and particularly in multidrug resistance neoplastic cells. The initial aim of this work will be to test the function of genes implicated in drug resistance. This is a multistep process in which we first developed a method for the introduction and transient expression of foreign DNA into the parasite, we then developed a method for the stable introduction of DNA using selectable markers and finally, we have developed methods to test the role of the malaria MDR like genes in drug resistance and in other parasite functions using overexpression and gene knockout by homologous recombination. In parallel, we have continued development of the functional complementation system in yeast in which we are expressing the pfmdrl gene. This system could prove extremely useful in testing drugs as potential resistance reversers.