Screening of novel malaria DNA vaccine candidates using full-length cDNA library.
No licensed malaria vaccine exists, in spite of intensive development efforts. We have been investigating development of a DNA vaccine to prevent malaria infection. To date, we have established a full-length cDNA expression library from the erythrocytic-stage murine malaria parasite, Plasmodium berghei. We found that immunization of mice with combined 2000 clones significantly prolonged survival after challenge infection and that splenocytes from the immunized mice showed parasite-specific cytokine production. We determined the 5'-end one-pass sequence of these clones and mapped a draft genomic sequence for P. berghei for use in screening vaccine candidates for efficacy. In this study, we annotated these cDNA clones by comparing them with the genomic sequence of Plasmodium falciparum. We then divided them into several subsets based on their characteristics and examined their protective effects against malaria infection. Consequently, we selected 104 clones that strongly induced specific IgG production and decreased the mortality rate in the early phase. Most of these 104 clones coded for unknown proteins. The results suggest that these clones represent potential novel malaria vaccine candidates.
Department of Medical Genomics, Graduate School of Frontier Sciences, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan; Research Institute for Biological Sciences, Tokyo University of Science, 2669 Yamazaki, Noda, Chiba 278-0022, Japan; Laboratory of Systems Biology, Center for Experimental Medicine and Systems Biology, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan. Electronic address: shibui@mgs.k.u-tokyo.ac.jp.
Akiko
A
Shibui
Susumu
S
Nakae
Junichi
J
Watanabe
Yoshitaka
Y
Sato
Mohammed E M
ME
Tolba
Junko
J
Doi
Takashi
T
Shiibashi
Sadao
S
Nogami
Sumio
S
Sugano
Nobumichi
N
Hozumi
D000818:Animals; D019470:Biolistics; D002874:Chromosome Mapping; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D005260:Female; D018503:Genome, Protozoan / Q000235:genetics / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood; D008288:Malaria / Q000517:prevention & control*; D017780:Malaria Vaccines / Q000592:standards*; D051379:Mice; D008807:Mice, Inbred BALB C; D008813:Mice, Inbred ICR; D010957:Plasmids / Q000235:genetics / Q000276:immunology; D010962:Plasmodium berghei / Q000235:genetics / Q000276:immunology*; D051381:Rats; D017208:Rats, Wistar; D013047:Specific Pathogen-Free Organisms; D019444:Vaccines, DNA / Q000592:standards*
D016207:Cytokines; D007074:Immunoglobulin G; D017780:Malaria Vaccines; D019444:Vaccines, DNA
DNA vaccine; Expression library immunization; Malaria; Screening