IgG antibody response against Plasmodium falciparum aminopeptidase 1 antigen in Gabonese children living in Makokou and Franceville

摘要

The search for novel chemical classes of anti‐malarial compounds to cope with the current state of chemoresistance of malaria parasites has led to the identification of Plasmodium falciparum aminopeptidase 1 (PfA‐M1) as a new therapeutic target. PfA‐M1, known to be involved in the hemoglobin digestion cascade which helps to provide most of the amino acids necessary to the parasite’s metabolism, is currently considered as a promising target for anti‐malarial chemotherapy. However, its immunogenic properties have not yet been tested in the Gabonese population. In Gabon, the prevalence of malaria remains three times higher in semi‐urban areas (60·12%) than in urban areas (17·06%). We show that malaria‐specific PfA‐M1 antibodies are present in children and increase with the level of infection. Children living in semi‐urban areas have higher anti‐PfA‐M1 antibody titers (0·14 ± 0·02 AU) than those living in urban areas (0·08 ± 0·02 AU, P = 0·03), and their antibody titers increase with age (P < 0·0001). Moreover, anti‐PfA‐M1 antibody titers decrease in children with hyperparasitemia (0·027 ± 0·055 AU) but they remain high in children with low parasite density (0·21 ± 0·034 AU, P = 0·034). In conclusion, our results suggest that malaria‐specific PfA‐M1 antibodies may play an important role in the immune response of the host against P. falciparum in Gabonese children. Further studies on the role of PfA‐M1 during anemia are needed.