title: Sequence polymorphisms of Plasmodium vivax tryptophan and alanine rich antigen (PvTARAg55).
abstract: Since PvTARAg55 protein (PvTARAg55) of Plasmodium vivax (P. vivax) is expressed during the parasite's sporozoite stage, it was strongly suggested, as a potential candidate for the development of a vaccine against malaria. PvTARAg55 polymorphisms were examined among isolates from various locations in Asian countries mainly; thus the current study could set the valuable baseline data for the development of a vaccine and clinical trials. A total of 59 samples were collected from Asian countries and one isolate from Africa. PvTARAg55 gene from 59 isolates was amplified, sequenced, and analyzed. PvTARAg55 contained a highly conserved tryptophan-rich domain (TRD) and a variable alanine-rich domain (ARD). In comparison to the Sal-1 strain, 10 allelic types of PvTARAg55 were found among 59 isolates. The main observed variations were the insertions and deletions of repeated sequences in the Ala-rich domain. Four types of GGVAAAP repeats were found at codon 324. Interestingly, GGVAAAP was found to be majority of Sal-1 type in the world. Two repeats (x2) were found in isolates from Korea, China, and India. Type of total deletion of GGVAAAP and three repeat (x3) were found from Indonesia isolates. Furthermore, "second insertion repeats"—with one or two repeats—were found with AFGAPSGFAPRP amino acid sequences at codon 338. Two repeats (x2) of AFGAPSGFAPRP were found in Indonesia, and PNG isolates. Finally, a "third repeat" was present with TTVNPEA amino acid sequences at codon 429 (the Indonesian isolates had three TTVNPEA sequences at that position). Isolates from ROK revealed "conserved sequences" in tryptophan-rich domain of PvTARAg55 with single amino acid substitutions (M180I). Hence, the extensive antigenic diversity of PvTARAg55 should be taken in account during the vaccine development.
authors.affiliation: Department of Laboratory Medicine, Brain Korea 21 Graduate School of Medicine, College of Medicine, Korea University, Seoul, Republic of Korea.
authors.forename: Jin Woo
authors.initials: JW
authors.lastname: Jang
authors.affiliation: The Armed Forces Medical School, Daejeon, Republic of Korea.
authors.forename: Seung Gyu
authors.initials: SG
authors.lastname: Yun
authors.affiliation: Department of Laboratory Medicine, Brain Korea 21 Graduate School of Medicine, College of Medicine, Korea University, Seoul, Republic of Korea.
authors.forename: Mi-Kyung
authors.initials: MK
authors.lastname: Woo
authors.affiliation: Department of Medical Environmental Biology and Topical Medicine, Kangwon National University School of Medicine, Chuncheon, Gangwon-do, Republic of Korea.
authors.forename: Eun Taek
authors.initials: ET
authors.lastname: Han
authors.affiliation: Department of Medical Environmental Biology and Topical Medicine, Kangwon National University School of Medicine, Chuncheon, Gangwon-do, Republic of Korea; Jiangsu Institute of Parasitic Diseases, Key Laboratory on Technology for Parasitic Disease Prevention and Control, Ministry of Health, Wuxi 214064, People's Republic of China.
authors.forename: Feng
authors.initials: F
authors.lastname: Lu
authors.affiliation: Jiangsu Institute of Parasitic Diseases, Key Laboratory on Technology for Parasitic Disease Prevention and Control, Ministry of Health, Wuxi 214064, People's Republic of China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Gao
authors.affiliation: Department of Laboratory Medicine, Brain Korea 21 Graduate School of Medicine, College of Medicine, Korea University, Seoul, Republic of Korea.
authors.forename: Soo Young
authors.initials: SY
authors.lastname: Yoon
authors.affiliation: College of BionanoTechnology, Gachon Bionano Research Institute & Gachon Medical Research Institute, Gachon University, Seongnam-si, Gyeonggi Do, Republic of Korea.
authors.forename: Seong Soo A
authors.initials: SS
authors.lastname: An
authors.affiliation: Department of Laboratory Medicine, Brain Korea 21 Graduate School of Medicine, College of Medicine, Korea University, Seoul, Republic of Korea. Electronic address: malarim@korea.ac.kr.
authors.forename: Chae Seung
authors.initials: CS
authors.lastname: Lim
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000953:Antigens, Protozoan / Q000235:genetics*; D002681:China; D017124:Conserved Sequence; D016054:DNA, Protozoan / Q000235:genetics*; D006801:Humans; D007194:India; D017780:Malaria Vaccines / Q000276:immunology; D016780:Malaria, Vivax / Q000517:prevention & control*; D010966:Plasmodium vivax / Q000235:genetics* / Q000276:immunology; D011110:Polymorphism, Genetic; D056910:Republic of Korea
chemical_list: D000953:Antigens, Protozoan; D016054:DNA, Protozoan; D017780:Malaria Vaccines
keywords: Korea; Malaria vaccine; Plasmodium vivax; Polymorphism; PvTARAg55