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

• Published in: PLoS neglected tropical diseases Vol. 11; no. 2; p. e0005344
• Main Authors: Bitencourt Chaves, Lana, Perce-da-Silva, Daiana de Souza, Rodrigues-da-Silva, Rodrigo Nunes, Martins da Silva, João Hermínio, Cassiano, Gustavo Capatti, Machado, Ricardo Luiz Dantas, Pratt-Riccio, Lilian Rose, Banic, Dalma Maria, Lima-Junior, Josué da Costa
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 01-02-2017; Public Library of Science (PLoS)
• Subjects: Analysis; Antigenic determinants; Biology and Life Sciences; Brazil; Cellular proteins; Conserved Sequence; Epitopes - genetics; Epitopes - immunology; Genes; Genetic aspects; Genetic diversity; Genetic Variation; Immunology; Laboratories; Malaria; Medicine and Health Sciences; Mutation; Mutation, Missense; Parasitic diseases; Physiological aspects; Plasmodium vivax - genetics; Plasmodium vivax - immunology; Polymorphism, Single Nucleotide; Proteins; Protozoan Proteins - genetics; Protozoan Proteins - immunology; Research and Analysis Methods; Sequence Analysis, DNA; Single nucleotide polymorphisms; Tropical diseases; Brazil; Rio de Janeiro Brazil
• ISSN: 1935-2735; 1935-2727; 1935-2735
• DOI: 10.1371/journal.pntd.0005344

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.