Analysis of Human Antibodies to Erythrocyte Binding Antigen 175 Peptide 4 of Plasmodium falciparum

Synthetic Antigens Derived from Plasmodium falciparum Sporozoite, Liver, and Blood Stages: Naturally Acquired Immune Response and Human Leukocyte Antigen Associations in Individuals Living in a Brazilian Endemic Area

“…In the present study, we noted that EBA mainly induced an IgG1 antibody response, and the levels of this IgG1 antibody response showed a positive correlation with age, consistent with previous reports showing that this P. falciparum protein predominantly induced the IgG1 subclass and that the levels of IgG1 against EBA correlated positively with age. 79,80 However, our results differ from those described by others who reported a predominance of the IgG1 and IgG3 subclasses in children living in malaria-endemic areas of Gabon and Mozambique. 15,79 The HLA class II molecules, originally called immune response genes, play an essential role in stimulating the immune response by binding and presenting antigen peptides to CD4+ T lymphocytes.…”

Age-Dependent IgG Subclass Responses to Plasmodium falciparum EBA-175 Are Differentially Associated with Incidence of Malaria in Mozambican Children

“…The kinetics of decay of maternal IgG antibodies and the kinetics of acquisition of infant IgG antibodies, but not of IgM, varied for each antigen studied. The isotype patterns resembled what has been described previously, but the significant induction of noncytophilic IgG4 by EBA-175 at age 2 years represents a novel finding (34,54).…”

Differential Antibody Responses to Plasmodium falciparum Invasion Ligand Proteins in Individuals Living in Malaria-Endemic Areas in Brazil and Cameroon

“…39 Notably, a retrospective analysis of naturally acquired antibodies to a synthetic peptide from EBA-175 peptide 4 carried out in Gabon has shown that the overall prevalence rates of antibodies to a linear epitope of EBA-175, EBA-175 peptide 4, were 85.2% and that the antibody response was associated with immunity against clinical malaria. 20 Moreover, antibodies to EBA-175 peptide 4 were inhibitory in growth-inhibition assays in vitro. 19 Future studies using full-length EBA-181 region II recombinant protein, that is functional in binding to RBCs, in growth-inhibition assays with serum samples containing differential patterns of anti-EBA antibodies on laboratory and field isolates from distinct geographic areas that have defined invasion pathways, in addition to determining antibody responses by ELISA, would discern the role of receptor heterogeneity on the EBA ligand-specific antibody responses.…”

“…18,19 Additionally, IgG1 antibodies to EBA-175 peptide 4 are associated with protection against clinical malaria. 20 We and others have shown that the majority of P. falciparum parasites in the endemic areas of India and Brazil are not dependent on neuraminidase-sensitive invasion pathways, of which the interaction of EBA-175 with GPA is the major pathway. [21][22][23] Importantly, the targeted disruption of the eba-175 gene was not lethal but instead caused switching to a GPA-independent alternative invasion pathway.…”