Immunoglobulin G (IgG) responses to Plasmodium falciparum glycosylphosphatidylinositols are short-lived and predominantly of the IgG3 subclass.
The induction of neutralizing immunity to Plasmodium falciparum toxins by vaccination has been proposed as a preventive strategy to limit the severity of malaria. For this approach to be successful, generation of a sustained immune response would be necessary. This study shows that immunoglobulin G (IgG)-subclass responses elicited by the proposed P. falciparum toxin glycosylphosphatidylinositol (GPI) in Papua New Guinean subjects 5-60 years old predominantly involve IgG(3), with a lesser contribution from IgG(1) and an absence of IgG(2) and IgG(4). IgG(3) levels declined sharply within 6 weeks of pharmacological clearance of parasitemia in all subjects, whereas a significant decrease in IgG(1) levels was seen only in subjects < or =19 years old. Because the natural antibody response to P. falciparum GPIs is skewed toward the short-lived IgG(3) subclass, a vaccination strategy with GPI analogues would likely require augmentation by costimulatory molecules, to induce a more persistent anti-GPI response.
Boutlis
Craig S
CS
Infectious Diseases Division, Menzies School of Health Research, Darwin, Australia.
Fagan
Peter K
PK
Gowda
D Channe
DC
Lagog
Moses
M
Mgone
Charles S
CS
Bockarie
Moses J
MJ
Anstey
Nicholas M
NM
D000293:Adolescent; D000328:Adult; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000953:Antigens, Protozoan / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D017261:Glycosylphosphatidylinositols / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood* / Q000145:classification; D016778:Malaria, Falciparum / Q000276:immunology / Q000517:prevention & control; D008875:Middle Aged; D010219:Papua New Guinea; D010963:Plasmodium falciparum / Q000276:immunology*; D016052:Protozoan Vaccines / Q000008:administration & dosage / Q000276:immunology
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D017261:Glycosylphosphatidylinositols; D007074:Immunoglobulin G; D016052:Protozoan Vaccines