Plasmodium falciparum: IgG subclass antibody response to merozoite surface protein-1 among Amazonian gold miners, in relation to infection status and disease expression

• Published in: Experimental parasitology Vol. 109; no. 2; pp. 124 - 134
• Main Authors: Scopel, Kézia K.G., Fontes, Cor J.F., Ferreira, Marcelo U., Braga, Érika M.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.02.2005; Elsevier
• Subjects: Adolescent; Adult; analysis of variance; Animals; ANOVA; Antibodies; Antibodies, Protozoan - biosynthesis; Antibodies, Protozoan - blood; Antibodies, Protozoan - classification; antigen presenting cell; Antigenic diversity; APC; Base Sequence; Biological and medical sciences; Brazil; Carrier State - immunology; Child; Child, Preschool; Clinical immunity; Cross-Sectional Studies; degrees of freedom; DNA, Protozoan - chemistry; EGF; ELISA; Enzyme-Linked Immunosorbent Assay; epidermal growth factor; Female; Fundamental and applied biological sciences. Psychology; Genetic Variation; glutathione- S-transferase; GST; Humans; Immunoglobulin G - biosynthesis; Immunoglobulin G - blood; Immunoglobulin G - classification; Life cycle. Host-agent relationship. Pathogenesis; Malaria parasites; Malaria, Falciparum - immunology; Male; Merozoite Surface Protein 1 - genetics; Merozoite Surface Protein 1 - immunology; merozoite surface protein-1; Middle Aged; Mining; Molecular Sequence Data; MSP-1; MSP-1 19; PCR; Plasmodium falciparum; Plasmodium falciparum - genetics; Plasmodium falciparum - immunology; Polymerase Chain Reaction; Protozoa; reactivity index; Recombinant Proteins - genetics; Recombinant Proteins - immunology; the 19-kDa C-terminal domain of merozoite surface proteins-1; Brazil; South America, Amazonia; Protozoa; df; EGF; Antibodies; GST; Clinical immunity; MSP-1; MSP-1 19; APC; ANOVA; RI; Malaria parasites; Antigenic diversity; PCR; ELISA; Gold; Apicomplexa; Disease; Antibody; IgG; Parasite; Protein; Infection; Plasmodium falciparum; Merozoite
• ISSN: 0014-4894; 1090-2449
• DOI: 10.1016/j.exppara.2004.12.002

The merozoite surface protein-1 (MSP-1) of Plasmodium falciparum comprises two major targets of antibody-mediated immunity: the polymorphic block 2 and the 19-kDa C-terminal domain MSP-1 19. Here, we measured antibodies to three block 2 variants and MSP-1 19 among Amazonian gold miners and examined the repertoire of block 2 variants in local parasites. Main findings were as follows: (1) Only seven different block 2 variants were found in 18 DNA sequences analyzed. (2) No major difference was observed in IgG subclass distribution of antibodies from symptomatic P. falciparum-infected patients, asymptomatic parasite carriers, and non-infected subjects. (3) Antibodies to all block 2 antigens, but not to MSP-1 19, were biased towards IgG3 across different strata of cumulative malaria exposure. (4) Similar proportions of symptomatic and asymptomatic subjects failed to recognize the block 2 variant expressed by infecting parasites. These negative results underscore the limits of conventional antibody assays to evaluate clinical immunity to malaria.