title: Regulation of antigen-specific immunoglobulin G subclasses in response to conserved and polymorphic Plasmodium falciparum antigens in an in vitro model.
abstract: Cytophilic antibodies (Abs) play a critical role in protection against Plasmodium falciparum blood stages, yet little is known about the parameters regulating production of these Abs. We used an in vitro culture system to study the subclass distribution of antigen (Ag)-specific immunoglobulin G (IgG) produced by peripheral blood mononuclear cells (PBMCs) from individuals exposed to P. falciparum or unexposed individuals. PBMCs, cultivated with or without cytokines and exogenous CD40/CD40L signals, were stimulated with a crude parasite extract, recombinant vaccine candidates derived from conserved Ags (19-kDa C terminus of merozoite surface protein 1 [MSP1(19)], R23, and PfEB200), or recombinant Ags derived from the polymorphic Ags MSP1 block 2 and MSP2. No P. falciparum-specific Ab production was detected in PBMCs from unexposed individuals. PBMCs from donors exposed frequently to P. falciparum infections produced multiple IgG subclasses when they were stimulated with the parasite extract but usually only one IgG subclass when they were stimulated with a recombinant Ag. Optimal Ab production required addition of interleukin-2 (IL-2) and IL-10 for all antigenic preparations. The IgG subclass distribution was both donor and Ag dependent and was only minimally influenced by the exogenous cytokine environment. In vitro IgG production and subclass distribution correlated with plasma Abs to some Ags (MSP1(19), R23, and MSP2) but not others (PfEB200 and the three MSP1 block 2-derived Ags). Data presented here suggest that intrinsic properties of the protein Ag itself play a major role in determining the subclass of the Ab response, which has important implications for rational design of vaccine delivery.
authors: Laboratoire d'Immunologie. Laboratoire d'Epidémiologie du Paludisme, Institut Pasteur de Dakar, Dakar, Senegal. Olivier.Garraud@univ-st-etienne.fr
authors: Olivier
authors: O
authors: Garraud
authors: Ronald
authors: R
authors: Perraut
authors: Ababacar
authors: A
authors: Diouf
authors: Wilfrid S
authors: WS
authors: Nambei
authors: Adama
authors: A
authors: Tall
authors: André
authors: A
authors: Spiegel
authors: Shirley
authors: S
authors: Longacre
authors: David C
authors: DC
authors: Kaslow
authors: Hélène
authors: H
authors: Jouin
authors: Denise
authors: D
authors: Mattei
authors: Gina M
authors: GM
authors: Engler
authors: Thomas B
authors: TB
authors: Nutman
authors: Eleanor M
authors: EM
authors: Riley
authors: Odile
authors: O
authors: Mercereau-Puijalon
mesh_terms: D000328:Adult; D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology*; D000953:Antigens, Protozoan / Q000276:immunology*; D002478:Cells, Cultured; D017124:Conserved Sequence; D016207:Cytokines / Q000276:immunology; D019353:Endemic Diseases; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D007132:Immunoglobulin Isotypes / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000276:immunology; D016778:Malaria, Falciparum / Q000097:blood / Q000453:epidemiology / Q000276:immunology*; D008297:Male; D020066:Merozoite Surface Protein 1 / Q000235:genetics / Q000276:immunology*; D018448:Models, Immunological; D010963:Plasmodium falciparum / Q000276:immunology*; D011110:Polymorphism, Genetic; D015800:Protozoan Proteins / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology; D012675:Senegal / Q000453:epidemiology
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D016207:Cytokines; D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes; D020066:Merozoite Surface Protein 1; D015800:Protozoan Proteins; D011993:Recombinant Fusion Proteins; C065974:merozoite surface protein 2, Plasmodium