Mosquitoes by transmitting several viral and parasitic diseases still represent one of major health threats for billions of individuals living in third world countries. The most effective measure to deal with the problem of disease transmitted by these insects is the release of harmful insecticides in the environment. However the use of pesticides has economical and ecological costs that are not always acceptable. DNA technology could potentially enable the development of mosquitoes. carrying a trans-gene that confers a non permissive phenotype for disease transmission. To reach this objective several scientific and technical problems have yet to be overcome:i)the means of introducing manipulated DNA into the mosquito germ line.ii)the identification of the genes that when expressed in the mosquito would interfere with virus and parasite replication or maturation and iii)development of DNA vectors able to target gene expression to specific mosquito tissues. We Propose to perform a series of experiments aimed at the identification of a mosquito promoter/ enhancer sequence specific for the cells of the intestinal lineage that should be used to target the expression in the gut lumen of antibodies with malaria transmission blocking activity.The ralionale of designing the expression (and secretion) of the trans-gene to the mosquito intestinal cells is based on the fact these cells are first exposed to the parasite that also undergo maturation and replication in the gut environment in contact with the secreted products of the intestinal cells. Furthermore the expression of the trans-gene in a tissue specific manner should not disturb the function of other tissues and organs. The resulting mosquitoes would most likely retain a normal behavior and fitness which should enable them to compete with the wild type strains and to propagate the non vectorial Phenotype.The experimental activily that is needed to reach these objectives includes: i)identification of mosquito genes that are specifically transcribed in the gutcells ii) identification of the upstream regulatory DNA sequences that drive gut specific transcription, iii) developmentof DNA vector able to induce the expression of a reporter gene only in mosquito gut cells.iv) production of transgenic mosquitoes.v)isolation of the coding sequences of P. falciparum gametocytes antibodies.
Funding SchemeCSC - Cost-sharing contracts
21040 Rio De Janeiro
SW7 2AZ London
L3 5QA Liverpool