title: Pattern of antibodies to the Duffy binding like domain of Plasmodium falciparum antigen Pf332 in Senegalese individuals.
abstract: Acquisition of antibodies against blood stage antigens is crucial in malaria immunity and the Plasmodium falciparum antigen Pf332, which is present in close association with the infected red blood cell membrane, is one such antigen. In this study, the antibody response to a Duffy binding like fragment of Pf332, termed Pf332-DBL was investigated in sera from naturally exposed individuals living in Dielmo village, Senegal, with regard to immunoglobulin classes (IgG, IgM, IgE) and IgG subclasses (IgG1-4). While the levels of IgM, IgG, IgG1 and IgG2 only displayed a moderate trend to increase with age, Pf332-DBL specific IgG3 levels increased significantly in the older villagers. In multivariate analysis, when controlling for confounding factors, and in a linear model with a Poisson distribution, anti-Pf332-DBL IgG3 as well as the ratio of cytophilic to non cytophilic anti-Pf332-DBL antibodies were found significantly associated with a reduced risk of malaria attack. This association was also present when the IgG3:IgG1 ratio was tested. Finally, two subgroups of villagers with the same mean age, were delineated by IgG3 concentrations either lower or higher than the median value. A total of 45.2% of the individuals with low anti-Pf332-DBL-IgG3 levels but only 21.4% of the villagers in the group with high levels of such antibodies had a clinical malaria attack during a period of 3 years of continuous follow-up after the blood sampling. In conclusion, Pf332-DBL induces naturally the acquisition of antibodies, and Pf332-DBL-specific IgG3 appears to be associated with protection against malaria in this endemic setting.
authors.affiliation: Department of Immunology, Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden. Electronic address: balogunh@gmail.com.
authors.forename: Halima A
authors.initials: HA
authors.lastname: Balogun
authors.affiliation: Department of Immunology, Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden.
authors.forename: Nancy
authors.initials: N
authors.lastname: Awah
authors.affiliation: Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden.
authors.forename: Sandra
authors.initials: S
authors.lastname: Nilsson
authors.affiliation: Institut Pasteur de Madagascar, Antananarivo, Madagascar.
authors.forename: Christophe
authors.initials: C
authors.lastname: Rogier
authors.affiliation: Institute de Recherches pour le Développement, Montpellier, France.
authors.forename: Jean-Francois
authors.initials: JF
authors.lastname: Trape
authors.affiliation: Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden; Laboratory of Parasitology, Institute of Pathogen Biology, Chinese Academy of Medical Sciences, Beijing 100730, China.
authors.forename: Qijun
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Immunology Unit, Pasteur Institut de Dakar, Senegal and Unité de Génétique fonctionnelle des maladies infectieuses, Institut Pasteur, Paris, France. Electronic address: christian.roussilhon@pasteur.fr.
authors.forename: Christian
authors.initials: C
authors.lastname: Roussilhon
authors.affiliation: Department of Immunology, Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden.
authors.forename: Klavs
authors.initials: K
authors.lastname: Berzins
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000913:Antibodies, Protozoan / Q000097:blood*; D000953:Antigens, Protozoan / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D016778:Malaria, Falciparum / Q000276:immunology* / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D010963:Plasmodium falciparum / Q000276:immunology*; D015800:Protozoan Proteins / Q000276:immunology*; D011956:Receptors, Cell Surface / Q000276:immunology*; D012675:Senegal; D055815:Young Adult
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; C066001:Duffy antigen binding protein, Plasmodium; D007074:Immunoglobulin G; D015800:Protozoan Proteins; D011956:Receptors, Cell Surface; C073415:antigen Pf332, Plasmodium
keywords: Antibody response; IgG3 subclass; Immunity; Malaria attack; Pf332-DBL