Plasmodium vivax Cell Traversal Protein for Ookinetes and Sporozoites (PvCelTOS) gene sequence and potential epitopes are highly conserved among isolates from different regions of Brazilian Amazon.
The Plasmodium vivax Cell-traversal protein for ookinetes and sporozoites (PvCelTOS) plays an important role in the traversal of host cells. Although essential to PvCelTOS progress as a vaccine candidate, its genetic diversity remains uncharted. Therefore, we investigated the PvCelTOS genetic polymorphism in 119 field isolates from five different regions of Brazilian Amazon (Manaus, Novo Repartimento, Porto Velho, Plácido de Castro and Oiapoque). Moreover, we also evaluated the potential impact of non-synonymous mutations found in the predicted structure and epitopes of PvCelTOS. The field isolates showed high similarity (99.3% of bp) with the reference Sal-1 strain, presenting only four Single-Nucleotide Polymorphisms (SNP) at positions 24A, 28A, 109A and 352C. The frequency of synonymous C109A (82%) was higher than all others (p<0.0001). However, the non-synonymous G28A and G352C were observed in 9.2% and 11.7% isolates. The great majority of the isolates (79.8%) revealed complete amino acid sequence homology with Sal-1, 10.9% presented complete homology with Brazil I and two undescribed PvCelTOS sequences were observed in 9.2% field isolates. Concerning the prediction analysis, the N-terminal substitution (Gly10Ser) was predicted to be within a B-cell epitope (PvCelTOS Accession Nos. AB194053.1) and exposed at the protein surface, while the Val118Leu substitution was not a predicted epitope. Therefore, our data suggest that although G28A SNP might interfere in potential B-cell epitopes at PvCelTOS N-terminal region the gene sequence is highly conserved among the isolates from different geographic regions, which is an important feature to be taken into account when evaluating its potential as a vaccine candidate.
Laboratory of Immunoparasitology, Oswaldo Cruz Institute, Fiocruz, Rio de Janeiro, Rio de Janeiro, Brazil.
Lana
L
Bitencourt Chaves
Laboratory of Clinical Immunology, Oswaldo Cruz Institute, Fiocruz, Rio de Janeiro, Rio de Janeiro, Brazil.
Daiana de Souza
DS
Perce-da-Silva
Laboratory of Immunoparasitology, Oswaldo Cruz Institute, Fiocruz, Rio de Janeiro, Rio de Janeiro, Brazil.
Rodrigo Nunes
RN
Rodrigues-da-Silva
Computational Modeling Group - FIOCRUZ - CE, Fortaleza, Brazil.
João Hermínio
JH
Martins da Silva
Laboratory of Tropical Diseases - Prof. Luiz Jacintho da Silva, Department of Genetics, Evolution and Bioagents, University of Campinas, Campinas, São Paulo, Brazil.
Gustavo Capatti
GC
Cassiano
Malaria Immunogenetic Laboratory, Instituto Evandro Chagas, Ananindeua, Pará, Brazil.
Ricardo Luiz Dantas
RL
Machado
Laboratory of Malaria Research, Oswaldo Cruz Institute, Fiocruz, Rio de Janeiro, Rio de Janeiro, Brazil.
Lilian Rose
LR
Pratt-Riccio
Laboratory of Clinical Immunology, Oswaldo Cruz Institute, Fiocruz, Rio de Janeiro, Rio de Janeiro, Brazil.
Dalma Maria
DM
Banic
Laboratory of Immunoparasitology, Oswaldo Cruz Institute, Fiocruz, Rio de Janeiro, Rio de Janeiro, Brazil.
Josué da Costa
0000-0002-5848-404X
JD
Lima-Junior
D001938:Brazil; D017124:Conserved Sequence; D000939:Epitopes / Q000235:genetics* / Q000276:immunology*; D014644:Genetic Variation; D020125:Mutation, Missense; D010966:Plasmodium vivax / Q000235:genetics* / Q000276:immunology*; D020641:Polymorphism, Single Nucleotide; D015800:Protozoan Proteins / Q000235:genetics* / Q000276:immunology*; D017422:Sequence Analysis, DNA
D000939:Epitopes; D015800:Protozoan Proteins