Malaria immunity and vaccination (Scripps)

As it is possible to induce non-strain specific immunity to malaria, immunization from a single strain of PF should confer immunity to all strains. Moreover, as an immune animal"s serum can cure a PF-infected animal, antibodies from immune animals should bind with PF components to stimulate immunity. This research will attempt to identify and obtain PF-specific surface proteins that stimulate immunity from the erythrocytic form of merozoites, the invasive form of PF parasites. Merozoites will be isolated from synchronized cultures, solubilized in detergent, and fractionated. Use of isoelectric focusing and SDS gradient acrylic gels will insure fraction purity. Antisera will be produced against PF surface proteins. Sera determined to inhibit parasite growth in vitro will be tested for their ability to cure PF-infested owl monkeys. Antisera will also be used to establish microorganism clones containing recombinant deoxyribonucleic acid in order to produce immunologically active proteins. If messenger ribonuecleic acid (mRNA) can be isolated from protein-coded parasites, the mRNA could be inserted into microorganisms and yeasts to produce the parasite antigen without using human blood components. The antigen will be tested by injection into sublethally irradiated mice. After 3 weeks, spleen cells from immunized mice will be boosted with antigen. Repetition of this procedure will expand the number of PF-responsive cells and will test the antigen"s immunological ability. Mice sera with high antibody levels will be tested for their ability to inhibit parasite growth in vitro and in vivo. Hybridomas will be produced from the spleens of mice with effective sera and examined through inhibition assays. Amendment of 6/12/87 doubles funding, extends PACD 2 years through FY89, and transfers SP implementation from Scripps to the Agouron Institute, located in La Jolla, California. Agouron is the only U.S. institute dealing with peptides from the cDNA library constructed from poly A+ fraction of the RNA isolates from trophozoite/schizont Honduras I isolates of P. falciparum. (PD-AAZ-334)