title: Human TcR gamma delta+ lymphocyte response on primary exposure to Plasmodium falciparum.
abstract: In 29 patients experiencing their first P. falciparum malarial attack, blood levels of TcR gamma delta+ lymphocytes were studied from the onset of infection to up to 6-9 months later. Blood TcR gamma delta+ lymphocytes, revealed using the TcR delta 1 monoclonal antibody (MoAb), were increased both in absolute and relative numbers. Alterations lasted for up to 3-4 months following the attack. A Ti gamma A/BB3 reactive V gamma 9 subset was preferentially amplified. In vitro, TcR gamma delta+ lymphocytes from both malaria-sensitized and unprimed donors responded to P. falciparum schizont extract (PFSE). PFSE-stimulated polyclonal T cell lines consisted principally in TcR gamma delta+ cells with a Ti gamma A+/BB3+ phenotype. Several TcR gamma delta+ T cell clones obtained from patients recovering from acute malarial attack were maintained in the presence of PFSE and autologous irradiated PBL. They belong to the V gamma 9 subset. In long-term cultures, TcR gamma delta+ clones progressively lost their capacity to react to PFSE antigen while they were able to proliferate and to exert cytotoxic activity in response to autologous TcR alpha beta+, PFSE-specific T lymphocyte clones. This suggests that regulatory interactions occur between activated TcR gamma delta+ and TcR alpha beta+ cells generated by P. falciparum. Sequential variations in blood TcR gamma delta+ and TcR alpha beta+ lymphocyte levels after primary exposure to P. falciparum suggest that such regulatory interactions may occur in vivo.
authors.affiliation: Laboratory of Experimental Parasitology, Institute Pasteur, Paris, France.
authors.forename: C
authors.initials: C
authors.lastname: Roussilhon
authors.forename: M
authors.initials: M
authors.lastname: Agrapart
authors.forename: P
authors.initials: P
authors.lastname: Guglielmi
authors.forename: A
authors.initials: A
authors.lastname: Bensussan
authors.forename: P
authors.initials: P
authors.lastname: Brasseur
authors.forename: J J
authors.initials: JJ
authors.lastname: Ballet
mesh_terms: D000208:Acute Disease; D000328:Adult; D000818:Animals; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D016778:Malaria, Falciparum / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010963:Plasmodium falciparum / Q000276:immunology*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000032:analysis; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000032:analysis*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta