title: IgG subclasses pattern and high-avidity antibody to the C-terminal region of merozoite surface protein 1 of Plasmodium vivax in an unstable hypoendemic region in Iran.
abstract: The C-terminal region of Plasmodium vivax merozoite surface protein 1 (PvMSP-1(19)) is a leading vaccine candidate for inclusion in a polyvalent malaria vaccine. In the present study, the IgG subclasses profile and the avidity of IgG to PvMSP-1(19) were evaluated in individuals (n=94) naturally exposed to P. vivax parasite in malaria endemic areas in Chabahar districts, Iran. In individuals with patent P. vivax malaria, 86.1% was sero-positive to PvMSP-1(19) and IgG1 (81.9%) was the predominant subclass. In addition, to determine the persistence of specific IgG, IgG1 and IgG3 antibodies to PvMSP-1(19), the frequency of antibodies was determined in the infected subjects (n=74) after treatment with standard chloroquine and it was detected that the frequency of responders was significantly reduced to 51.3%, 51% and 16.2%, respectively. The antigen-binding avidity of IgG antibodies to PvMSP-1(19) was measured in sero-positive sera and the high-avidity of IgG, IgG1 and IgG3 was found in 66.6%, 61% and 47% of the infected subjects with P. vivax, respectively. The present result shows that individuals who exposed to vivax malaria in the endemic region in Iran develop antibodies with high-avidity to PvMSP-1(19). These results could help to understand the interactions between the host and P. vivax parasite in development of MSP-1(19)-based vaccine.
authors.affiliation: Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran.
authors.forename: Akram Abouie
authors.initials: AA
authors.lastname: Mehrizi
authors.forename: Sedigheh
authors.initials: S
authors.lastname: Zakeri
authors.forename: Ali-Hatef
authors.initials: AH
authors.lastname: Salmanian
authors.forename: Mohammad Hossein
authors.initials: MH
authors.lastname: Sanati
authors.forename: Navid Dinparast
authors.initials: ND
authors.lastname: Djadid
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood* / Q000145:classification; D000915:Antibody Affinity; D002648:Child; D002675:Child, Preschool; D019353:Endemic Diseases; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood* / Q000145:classification; D007223:Infant; D007492:Iran / Q000453:epidemiology; D016780:Malaria, Vivax / Q000453:epidemiology* / Q000276:immunology*; D008297:Male; D020066:Merozoite Surface Protein 1 / Q000276:immunology*; D008875:Middle Aged; D010966:Plasmodium vivax / Q000276:immunology*; D055815:Young Adult
chemical_list: D000913:Antibodies, Protozoan; D007074:Immunoglobulin G; D020066:Merozoite Surface Protein 1