Serine repeat antigen (SERA5) is predominantly expressed among the SERA multigene family of Plasmodium falciparum, and the acquired antibody titers correlate with serum inhibition of the parasite growth.

Abstract

The Plasmodium falciparum serine repeat antigen (SERA) is one of the blood stage malaria vaccine candidates. The malaria genome project has revealed that SERA is a member of the SERA multigene family consisting of eight SERA homologues clustered on chromosome 2 and one SERA homologue on chromosome 9. Northern blotting and real time quantitative reverse transcription-PCR with five independent parasite strains, including three allelic representative forms of the SERA gene, have shown that all of the SERA homologues are transcribed most actively at trophozoite and schizont stages and that SERA5 (SERA/SERP) is transcribed predominantly among the family. Polyclonal antibodies were raised against recombinant proteins representing the N-terminal portions of four significantly transcribed SERA homologues (SERA3 to -6) in the center of the cluster on chromosome 2. Using these antibodies, indirect immunofluorescence microscopy detected the expression of SERA3 to -6, with similar localization, in all trophozoite- and schizont-infected erythrocytes. We have examined 40 sera from Ugandan adults for their antibody reactivity and found that enzyme-linked immunosorbent assay titer against SERA5 N-terminal domain, but not against other SERA proteins, is positively correlated with the inhibition of in vitro parasite growth by individual sera. Our data confirm the usefulness of the N-terminal domain of SERA5 as a promising malaria candidate vaccine.

• Authors: Sayaka Aoki, Jie Li, Sawako Itagaki, Brenda A Okech, Thomas G Egwang, Hiroyuki Matsuoka, Nirianne Marie Q Palacpac, Toshihide Mitamura, Toshihiro Horii
• Journal: The Journal of biological chemistry (J Biol Chem) Vol. 277 Issue 49 Pg. 47533-40 (Dec 06 2002) ISSN: 0021-9258 [Print] United States
• PMID: 12244052 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S., Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Antigens, Protozoan
• Malaria Vaccines
• RNA, Messenger
• Recombinant Proteins

Topics

• Adult
• Animals
• Antigens, Protozoan (biosynthesis, genetics)
• Blotting, Northern
• Blotting, Western
• Enzyme-Linked Immunosorbent Assay
• Erythrocytes (parasitology)
• Humans
• Malaria Vaccines (metabolism)
• Microscopy, Fluorescence
• Models, Genetic
• Multigene Family
• Plasmids (metabolism)
• Plasmodium falciparum (genetics, metabolism)
• Protein Binding
• Protein Structure, Tertiary
• RNA, Messenger (metabolism)
• Recombinant Proteins (metabolism)
• Reverse Transcriptase Polymerase Chain Reaction
• Transcription, Genetic