Caracterização molecular e imunológica da proteína de membrana Sm29 do Schistosoma mansoni.

Abstract

Cardoso FC. 2006 Thesis (Doctoral) Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais.Schistosomiasis affects more than 200 million people in developing and under developed countries. Chemotherapy, along with other control strategies, has high cost and is unable to eradicate the disease. Due to a clear necessity of elaborating a vaccine against schistosomiasis, various antigens have been investigated as vaccine candidates. In the past years, sequencing of the S. mansoni transcriptome has generated a great deal of very useful information for the identification of new vaccine candidates and for the study of its biological characteristics. Proteins associated with the parasite surface are potential vaccine candidates due to their exposed position for recognition by the host immune system. In the present work, we identified potentially exposed proteins on the surface of the parasite through mining the data bank generated by the Minas Gerais Genome Network, S. mansoni transcriptome Project. One of the selected antigens, denominated Sm29, after immunization of mice was capable of producing a reduction of 56.7% in the number of worms, 61.6% in the number of liver granuloma and 60% in the number of intestine eggs in the murine model of schistosomiasis. Gene expression analysis demonstrated that this transcript is expressed at the schistosomula and adult worm stages. Immunolocalization assays demonstrated that Sm29 is present on the surface of the schistosomula and the female and male adult worms. Finally, humoral analysis of individuals from schistosomiasis endemic areas demonstrated that this antigen was highly recognized by the sera of the patients with a resistant profile against infection and reinfection of the disease. According to these data, we can conclude that the in silico selection, followed by the in vivo evaluation of the protective potential using recombinant proteins is a efficient strategy in selecting vaccine candidates from genome and transcriptome projects of pathogenic organisms.