Dados do Trabalho

Título

GLYCOSYLPHOSPHATIDYLINOSITOL AS A THERANOSTIC TARGET AGAINST INTRACELLULAR PARASITIC DISEASES

Introdução

Continuous transmission of malaria has been reported worldwide, especially in Americas and Africa, where 90% of the total world cases and 92% of deaths from malaria are observed. Protozoa of the genus Plasmodium, belonging to the phylum Apicomplexa are the causative agents of malaria in humans. Glycosylphosphatidylinositol (GPI) is a glycolipid complex that anchors several proteins and glycoproteins to the cell membrane, considered an essential molecule for the interaction of several protozoa with their hosts. Parasite resistance is attributed to individuals with high anti-GPI antibody titers.

Objetivo (s)

The objectives of this study were to develop antibodies of single-chain variable fragments (scFv) selected by Phage Display against GPI of Plasmodium falciparum and to evaluate their ability to decrease the mortality of mice with cerebral malaria, as well as to neutralize parasitic cell invasion of broad intracellular protozoa.

Material e Métodos

The selection of P. falciparum GPI-binding scFv was performed from a Antibody Phage Display library. The expression and specificity of clones were analyzed by ELISA. The DNA extracted from the highest reactivity clone was subjected to sequencing and analysis of bioinformatics, with molecular modeling to predict the three-dimensional structure, as well as the complementarity determining regions (CDRs) and frameworks (FWRs). C57BL / 6 mice infected with P. berghei-ANKA were treated with the scFv clone and analyzes of parasitemia and mortality curve of the animals were performed. The reactivity of scFv with extracts of P. falciparum, Toxoplasma gondii and Trypanosoma cruzi was also evaluated, as well as its ability to prevent cell invasion.

Resultados e Conclusão

Among selected scFv clones, eight (G1-G8) presented different sequences, and the expressed scFv G7 had the highest affinity to the P. falciparum GPI. GPI scFv G7 antibody presents great potential as a promising immunobiological drug that may be applied to the treatment of parasitic diseases, such as malaria, toxoplasmosis and Chagas disease. In addition, its binding peptides, mimetic to GPI, may also have theranostic potential, by acting in the future both in diagnosis and as vaccine antigens.

Palavras-chave

Glycosylphosphatidylinositol, scFv, P. falciparum, T. gondii, T. cruzi.

Agradecimentos

This research was funded by National Institute of Science and Technology in Theranostics and Nanobiotechnology – INCT-Teranano (CNPq/CAPES/FAPEMIG, CNPq-403193/2022-2, FAPEMIG APQ-03613-17), FAPEMIG APQ-00660-21.