Protection against Plasmodium falciparum challenge induced in Aotus monkeys by liver-stage antigen-3-derived long synthetic peptides.

The vaccine potential of Plasmodium falciparum liver stage antigen-3 (LSA3) was investigated in Aotus monkeys using two long synthetic peptides corresponding respectively to an N-terminal non-repeat peptide (NRP) and repeat 2 (R2) region of the LSA3, adjuvanted by ASO2. Both 100-222 (NRP) and 501-596 repeat peptides induced effector B- and T-cell responses in terms of antigen-driven antibodies and/or specific IFN-gamma secretion. Animals challenged with P.

Use of long synthetic peptides to study the antigenicity and immunogenicity of the Plasmodium vivax circumsporozoite protein.

Three long synthetic peptides corresponding to amino (N), repeat (R) and carboxyl (C) regions of the Plasmodium vivax circumsporozoite (CS) protein were synthesised and used to assess their potential as vaccine candidates. Antigenicity studies were carried out using human blood samples from residents of a malaria-endemic area of Colombia, and immunogenicity was tested in Aotus monkeys. The N and C peptides spanned the total native amino and carboxyl flanking regions, whereas the R peptide corresponded to a construct based on the first central nona-peptide repeated in tandem three times and colinearly linked to a universal T-cell epitope (ptt-30) derived from tetanus toxin.

Heterogeneity, geographic distribution, and pathogenicity of serodemes of Leishmania viannia in Colombia.

Leishmania Viannia strains from 1,092 patients who acquired dermal leishmaniasis in endemic regions of Colombia were analyzed for expression of species and subgenus specific epitopes. Eight monoclonal antibodies prepared against membranes of the major species of the Viannia subgenus and previously shown to distinguish these species, recognized low molecular mass (< 45kD) membrane components. Thirteen widely but non-uniformly distributed serodemes were identified: one unique to L.

Identification of HLA-A2 restricted CD8(+) T-lymphocyte responses to Plasmodium vivax circumsporozoite protein in individuals naturally exposed to malaria.

Specific CD8(-) T-lymphocyte (CTL) activity against Plasmodium pre-erythrocytic stages (P-ES) derived antigens is considered one of the most important mechanisms for malaria protection. Plasmodium vivax is the second most prevalent human malaria parasite species distributed worldwide. Although several CTL epitopes have been identified in Plasmodium falciparum P-ES derived antigens, none has been described for P.