Functional memory B cells and long-lived plasma cells are generated after a single Plasmodium chabaudi infection in mice.
Antibodies have long been shown to play a critical role in naturally acquired immunity to malaria, but it has been suggested that Plasmodium-specific antibodies in humans may not be long lived. The cellular mechanisms underlying B cell and antibody responses are difficult to study in human infections; therefore, we have investigated the kinetics, duration and characteristics of the Plasmodium-specific memory B cell response in an infection of P. chabaudi in mice. Memory B cells and plasma cells specific for the C-terminal region of Merozoite Surface Protein 1 were detectable for more than eight months following primary infection. Furthermore, a classical memory response comprised predominantly of the T-cell dependent isotypes IgG2c, IgG2b and IgG1 was elicited upon rechallenge with the homologous parasite, confirming the generation of functional memory B cells. Using cyclophosphamide treatment to discriminate between long-lived and short-lived plasma cells, we demonstrated long-lived cells secreting Plasmodium-specific IgG in both bone marrow and in spleens of infected mice. The presence of these long-lived cells was independent of the presence of chronic infection, as removal of parasites with anti-malarial drugs had no impact on their numbers. Thus, in this model of malaria, both functional Plasmodium-specific memory B cells and long-lived plasma cells can be generated, suggesting that defects in generating these cell populations may not be the reason for generating short-lived antibody responses.
Ndungu
Francis Maina
FM
Division of Parasitology, MRC National Institute for Medical Research, London, United Kingdom.
Cadman
Emma Tamsin
ET
Coulcher
Joshua
J
Nduati
Eunice
E
Couper
Elisabeth
E
Macdonald
Douglas William
DW
Ng
Dorothy
D
Langhorne
Jean
J
D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology*; D000917:Antibody Formation / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D002469:Cell Separation; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D007156:Immunologic Memory / Q000276:immunology*; D008288:Malaria / Q000276:immunology*; D020066:Merozoite Surface Protein 1 / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D010950:Plasma Cells / Q000276:immunology*; D016788:Plasmodium chabaudi / Q000276:immunology
D000913:Antibodies, Protozoan; D020066:Merozoite Surface Protein 1