title: A comparative study of natural immune responses against Plasmodium vivax C-terminal merozoite surface protein-1 (PvMSP-1) and apical membrane antigen-1 (PvAMA-1) in two endemic settings.
abstract: The mechanisms of cellular and humoral immune responses against P. vivax parasite remain poorly understood. Several malaria immunological studies have been conducted in endemic regions where both P. falciparum and P. vivax parasites co-exist. In this study, a comparative analysis of immunity to Plasmodium vivax antigens in different geography and incidence of Plasmodium spp. infection was performed. We characterised antibodies against two P. vivax antigens, PvMSP-1 and PvAMA-1, and the cross-reactivity between these antigens using plasma from acute malaria infected patients living in the central region of China and in the western border of Thailand. P. vivax endemicity is found in central China whereas both P. vivax and P. falciparum are endemic in Thailand. There was an increased level of anti-PvMSP-1/anti-PvAMA-1 in both populations. An elevated level of antibodies to total P. vivax proteins and low level of antibodies to total P. falciparum proteins was found in acute P. vivax infected Chinese, suggesting antibody cross-reactivity between the two species. P. vivax infected Thai patients had both anti-P. vivax and anti-P. falciparum antibodies as expected since both species are present in Thailand. More information on humoral and cell mediated immunity during acute P. vivax-infection in the area where only single P. vivax species existed is of great interest in the relation of building up anti-disease severity caused by P. falciparum. This knowledge will support vaccine development in the future.
authors.affiliation: Department of Parasitology, Bengbu Medical College, Anhui 233030, China ; Anhui Key Laboratory of Infection and Immunity at Bengbu Medical College, Anhui 233030, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Xia
authors.affiliation: Department of Parasitology, Bengbu Medical College, Anhui 233030, China ; Anhui Key Laboratory of Infection and Immunity at Bengbu Medical College, Anhui 233030, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Fang
authors.affiliation: Center for Research and Innovation, Faculty of Medical Technology, Mahidol University, Bangkok 10700, Thailand ; Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok 10700, Thailand.
authors.forename: Kulachart
authors.initials: K
authors.lastname: Jangpatarapongsa
authors.affiliation: Department of Parasitology, Bengbu Medical College, Anhui 233030, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Zhiyong
authors.affiliation: Department of Entomology, Pennsylvania State University, PA 16802, USA.
authors.forename: Liwang
authors.initials: L
authors.lastname: Cui
authors.affiliation: Department of Immunology, Bengbu Medical College, Anhui 233030, China.
authors.forename: Baiqing
authors.initials: B
authors.lastname: Li
authors.affiliation: Center for Research and Innovation, Faculty of Medical Technology, Mahidol University, Bangkok 10700, Thailand.
authors.forename: Rachanee
authors.initials: R
authors.lastname: Udomsangpetch
keywords: Plasmodium falciparum; Plasmodium vivax; antibody to malaria; malaria immunity