title: Antibodies against the Plasmodium falciparum glutamate-rich protein from naturally exposed individuals living in a Brazilian malaria-endemic area can inhibit in vitro parasite growth.
abstract: The glutamate-rich protein (GLURP) is an exoantigen expressed in all stages of the Plasmodium falciparum life cycle in humans. Anti-GLURP antibodies can inhibit parasite growth in the presence of monocytes via antibody-dependent cellular inhibition (ADCI), and a major parasite-inhibitory region has been found in the N-terminal R0 region of the protein. Herein, we describe the antiplasmodial activity of anti-GLURP antibodies present in the sera from individuals naturally exposed to malaria in a Brazilian malaria-endemic area. The anti-R0 antibodies showed a potent inhibitory effect on the growth of P. falciparum in vitro, both in the presence (ADCI) and absence (GI) of monocytes. The inhibitory effect on parasite growth was comparable to the effect of IgGs purified from pooled sera from hyperimmune African individuals. Interestingly, in the ADCI test, higher levels of tumour necrosis factor alpha (TNF-α) were observed in the supernatant from cultures with higher parasitemias. Our data suggest that the antibody response induced by GLURP-R0 in naturally exposed individuals may have an important role in controlling parasitemia because these antibodies are able to inhibit the in vitro growth of P. falciparum with or without the cooperation from monocytes. Our results also indicate that TNF-α may not be relevant for the inhibitory effect on P. falciparum in vitro growth.
authors: Laboratório de Pesquisas em Malária, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro, RJ, Brasil. riccio@ioc.fiocruz.br
authors: Lilian Rose
authors: LR
authors: Pratt-Riccio
authors: Cesare
authors: C
authors: Bianco
authors: Paulo Renato Rivas
authors: PR
authors: Totino
authors: Daiana De Souza
authors: Dde S
authors: Perce-Da-Silva
authors: Luciene Aquino
authors: LA
authors: Silva
authors: Evelyn Kety Pratt
authors: EK
authors: Riccio
authors: Vítor
authors: V
authors: Ennes-Vidal
authors: Ana Gisele Costa
authors: AG
authors: Neves-Ferreira
authors: Jonas
authors: J
authors: Perales
authors: Surza Lucia Gonçalves
authors: SL
authors: Da Rocha
authors: Fabrício
authors: F
authors: Dias-Da-Silva
authors: Maria de Fátima
authors: Mde F
authors: Ferreira-da-Cruz
authors: Cláudio Tadeu
authors: CT
authors: Daniel-Ribeiro
authors: Joseli
authors: J
authors: De Oliveira-Ferreira
authors: Michael
authors: M
authors: Theisen
authors: Leonardo José De Moura
authors: LJ
authors: Carvalho
authors: Dalma Maria
authors: DM
authors: Banic
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000913:Antibodies, Protozoan / Q000276:immunology*; D019353:Endemic Diseases; D004797:Enzyme-Linked Immunosorbent Assay; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D016778:Malaria, Falciparum / Q000097:blood / Q000276:immunology / Q000469:parasitology*; D008875:Middle Aged; D018512:Parasitemia; D010963:Plasmodium falciparum / Q000254:growth & development* / Q000276:immunology; D015800:Protozoan Proteins / Q000037:antagonists & inhibitors / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D055815:Young Adult
chemical_list: D000913:Antibodies, Protozoan; D007074:Immunoglobulin G; D015800:Protozoan Proteins; D014409:Tumor Necrosis Factor-alpha; C072492:glutamate-rich protein, Plasmodium