Secretion of parasite-specific immunoglobulin G by purified blood B lymphocytes from immune individuals after in vitro stimulation with recombinant Plasmodium falciparum merozoite surface protein-119 antigen.
The C-terminal 19 000 MW fragment of merozoite surface protein-1 (MSP119) is one of the most promising candidate antigens for a malaria vaccine. Baculovirus recombinant Plasmodium falciparum MSP119 has been used to define conditions for the in vitro production of specific antibodies by purified human blood B cells in a culture system where T-cell signals were provided by the engagement of CD40 molecules and exogenous cytokines. MSP119 preferentially induced surface immunoglobulin G (IgG) -positive (sgamma+) B lymphocytes from P. falciparum-immune donors to differentiate and produce antigen-specific IgG. In contrast, naïve B cells or cells from non-immune donors could not be induced to secrete parasite-specific IgG in vitro. Although IgG secretion was obtained in the absence of exogenous cytokines, it was dependent on B-cell-derived interleukin-10 (IL-10) and/or B-cell factor(s) under the control of IL-10, since IgG levels were significantly decreased in the presence of neutralizing anti-IL-10 antibodies. These results demonstrate at the cellular level that a single malaria vaccine candidate polypeptide can direct parasite-specific antibody production mediated by the secretion of potentiating factors.
Garraud
O
O
Unité d'Immunologie, Institut Pasteur de Dakar, Senegal.
Diouf
A
A
Holm
I
I
Nguer
C M
CM
Spiegel
A
A
Perraut
R
R
Longacre
S
S
D000328:Adult; D000818:Animals; D000913:Antibodies, Protozoan / Q000096:biosynthesis*; D001402:B-Lymphocytes / Q000276:immunology*; D019013:CD40 Antigens / Q000276:immunology; D018929:Cell Culture Techniques; D016207:Cytokines / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis*; D016753:Interleukin-10 / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D020066:Merozoite Surface Protein 1 / Q000276:immunology*; D010963:Plasmodium falciparum / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology
D000913:Antibodies, Protozoan; D019013:CD40 Antigens; D016207:Cytokines; D007074:Immunoglobulin G; D020066:Merozoite Surface Protein 1; D011994:Recombinant Proteins; D016753:Interleukin-10