Naturally Acquired Antibody Responses to the C-Terminal Region of Merozoite Surface Protein 1 ofPlasmodium vivaxin Korea

Abstract

We expressed a protein in Saccharomyces cerevisiae in order to evaluate the humoral immune responses to the C-terminal region of the merozoite surface protein 1 of Plasmodium vivax. This protein (Pv200 18 ) had a molecular mass of 18 kDa and was reactive with the sera of individuals with patent vivax malaria on immunoblotting analysis. The levels of immunoglobulin M (IgM) and IgG antibodies against Pv200 18 were measured in 421 patients with vivax malaria (patient group), 528 healthy individuals from areas of nonendemicity (control group 1), and 470 healthy individuals from areas of endemicity (control group 2), using the indirect enzyme-linked immunosorbent assay (ELISA) method. To study the longevity of the antibodies, 20 subjects from the patient group were also tested for the antibody levels once a month for 1 year. When the cutoff values for seropositivity were determined as the mean ؉ 3 ؋ standard deviation of the antibody levels in control group 1, both IgG and IgM antibody levels were negative in 98.5% (465 of 472) of control group 2. The IgG and IgM antibodies were positive in 88.1% (371 of 421) and 94.5% (398 of 421) of the patient group, respectively. The IgM antibody became negative 2 to 4 months after the onset of symptoms, whereas the IgG antibody usually remained positive for more than 5 months. In conclusion, indirect ELISA using Pv200 18 expressed in S. cerevisiae may be a useful diagnostic method for vivax malaria.

Comparative recognition by human IgG antibodies of recombinant proteins representing three asexual erythrocytic stage vaccine candidates of Plasmodium vivax

“…This data suggests that multiple infections provide a boost to the production of specific antibodies confirming recent observations obtained in other studies in distinct endemic areas of Brazilian Amazon (Ceravolo et al 2005, Tran et al 2005). In the case of PvMSP1 19 , specific IgG responses developed faster after a single exposition to malaria infection, also confirming previous observations of distinct groups that PvMSP1 19 is highly immunogenic during natural human infections (Park et al 2001, Lim et al 2002, Rodrigues et al 2003, Morais et al 2005, Wickramarachchi et al 2007). …”

Humoral responses against the C-terminal region of merozoite surface protein 1 can be remembered for more than 30�years in persons exposed to Plasmodium vivax

“…With the advent of effective insecticides and anti-malarial drugs, malaria prevalence has been dramatically diminished and no case of indigenous malaria was reported from 1979 to 1993. However, one vivax malaria case was reported in 1993 and the number of cases increased sharply to 107 cases in 1995, 1,734 cases in 1997 and 3,628 cases in 1999 (Ree 1998;Park et al 2001). Most of them were soldiers and residents near the DMZ, the border of South Korea and North Korea.…”

“…PvMSP1c expands through to the N-terminal sequence of 17 amino acid residues and excludes the C-terminal transmembrane domain. Over 98% of P. vivax malaria patients were found to have humoral responses against PvMSP1c (Lim et al 2002;Park et al 2001). In this paper, we evaluated which antibody isotypes would react to this antigen in the sera of malaria patients.…”

“…Previously, we have expressed a C-terminal region of P. vivax MSP1 (PvMSP1c) in Saccharomyces cerevisiae and in Escherichia coli, without any proteolytic cleavages, and determined its antigenic characteristics in acute malaria patients (Kaslow and Kumar 1996;Park et al 2001;Lim et al 2002). PvMSP1c is a protein that includes the MSP1 19 region of P. vivax but with surrounding regions that are different from those of PvMSP1 19 (Soares et al 1999).…”

Fatores de risco, distribuição espacial e perspectivas de controle da malária: estudo longitudinal em uma comunidade rural da Amazônia (Granada, Acre).

“…A imunogenicidade das diferentes regiões da PvMSP-1 tem sido estudada desde a década de noventa, com o intuito de se identificar uma região da molécula que desencadeie imunidade protetora. Após estudos iniciais da estrutura primária da PvMSP-1 identificando regiões conservadas e variáveis (Del Portillo, 1991) e sua imunogenicidade (Mancilla et al, 1994), estudos subseqüentes mostraram que a porção N-terminal (ICB2-5) é pouco reconhecida em infecções naturalmente adquiridas (Soares et al, 1997), enquanto a região conservada C-terminal (MSP-1 19 ) é bastante imunogênica Soares et al, 1997;Fraser et al, 1997;Soares et al, 1999a;Park et al, 2001;Nogueira et al, 2006;Barbedo et al, 2007;Ladeia-Andrade et al, 2007, Zeirek et al, 2008. Embora usando uma porção distinta da região N-terminal que inclui apenas parte do antígeno recombinante ICB2-5 utilizado por outros autores, nossos dados confirmam o baixo reconhecimento humoral da região não-conservada da PvMSP-1, bem como da alta imunogenicidade da região conservada C-terminal.…”