title: Nonpolymorphic regions of p190, a protein of the Plasmodium falciparum erythrocytic stage, contain both T and B cell epitopes.
abstract: Two conserved regions from the genetically polymorphic p190 molecule of the malaria parasite Plasmodium falciparum have previously been expressed in Escherichia coli as separate polypeptides (190.L and 190.M) or as a single fusion protein (190.N). In the present study we investigated whether human B and T lymphocytes recognize these conserved regions. The more amino-terminal region, 190.L (corresponding to residues 188-363 of the encoded protein sequence) reacted preferentially with sera from donors living in a malaria-endemic area. Also, EBV-transformed B cells, from a healthy donor living in a malaria-mesoendemic area, were fused with a human-mouse hybrid line (SPM4-0), yielding two hybridomas whose products recognized both 190.L and the fusion protein 190.N, but not the 190.M polypeptide. A large number of p190-specific T cell clones were obtained from PBMC of a noninfected donor, after in vitro stimulation with the recombinant fusion protein 190.N. The clones reacted with intact, parasite-derived p190, as well as either 190.L or 190.M. Four clones that recognized the more amino-terminal fragment also responded to infected E. According to these results the more amino-terminal conserved sequences of p190 have the requisites to be immunogenic in humans.
mesh_terms: D000328:Adult; D000818:Animals; D000911:Antibodies, Monoclonal; D000937:Antigen-Antibody Reactions; D000944:Antigens, Differentiation, B-Lymphocyte / Q000032:analysis* / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis* / Q000276:immunology; D000953:Antigens, Protozoan / Q000276:immunology* / Q000302:isolation & purification; D001402:B-Lymphocytes / Q000276:immunology; D000939:Epitopes / Q000032:analysis / Q000276:immunology; D004912:Erythrocytes / Q000032:analysis / Q000469:parasitology*; D006801:Humans; D007106:Immune Sera; D010963:Plasmodium falciparum / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000944:Antigens, Differentiation, B-Lymphocyte; D000945:Antigens, Differentiation, T-Lymphocyte; D000953:Antigens, Protozoan; D000939:Epitopes; D007106:Immune Sera