Isolating and Characterizing Genes of Liver Stage Antigens with Vaccine Potential
Abstract
A 175 kDa Plasmodium falciparum blood stage antigen which binds to erythrocytes and to merozoites, designated EBA-175, appears to be involved in the initial attachment of the merozoite to the erythrocyte, and it has been postulated that antibodies to EBA-175 could inhibit merozoite reinvasion. We have characterized and sequenced a 1.8 kilobase EBA-175 gene fragment cloned in lambda gtll. The clone was identified by monospecific antibodies selected from malaria immune monkey serum by affinity purification with EBA-175 adsorbed to nitrocellulose. Monospecific antibodies were then selected from malaria immune monkey serum by affinity purification with EBA-175 adsorbed to nitrocellulose. Monospecific antibodies were then selected from malaria immune monkey serum by affinity purification with the expressed protein of the gene fragment and identified authentic EBA-175 in immunoblots. Southern analyses of genomic DNA digested with restriction enzymes Hind III or Xba I and probed with the cloned EBA-175 gene fragment showed no restriction fragment length polymorphism in 5 of 6 geographically distinct isolates of P. falciparum. Based on the deduced amino acid sequence of this EBA-175 gene fragment, several peptides were selected, synthesized, coupled to carrier molecules, and used for immunization studies. This work will enable evaluation of EBA-175 as a vaccine candidate. (AW)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 14, 1989
- Accession Number
- ADA215315
Entities
People
- Betty K. Sim
Organizations
- Johns Hopkins University