Peptide microarray applied to identification of B cell epitopes on Rhipicephalus microplus (Acari: Ixodidae) salivary antigens for the elaboration of an anti-tick vaccine

• Grant number: 18/22700-8
• Support Opportunities: Scholarships in Brazil - Master
• Effective date (Start): July 01, 2019
• Effective date (End): August 31, 2020
• Field of knowledge: Biological Sciences - Immunology - Applied Immunology
• Principal Investigator: Beatriz Rossetti Ferreira
• Grantee: Alexsander de Moraes
• Host Institution: Escola de Enfermagem de Ribeirão Preto (EERP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated research grant: 15/09683-9 - Development of a recombinant multicomponent chimeric vaccine based in protein epitopes from Rhipicephalus microplus ticks, AP.TEM

Abstract

Ticks are obligate hematophagous arthropods, vectors of lethal diseases that affect several animals, among them cattle. Thus, this parasite has a negative impact on livestock activity worldwide. As a control method, commonly acaricides have been used, however its indiscriminate use has produced resistant ticks. In addition, such compounds leave hazardous waste disposal in the environment that have the potential to cause harm to animals, and contaminate livestock products such as meat and milk. As being so, a vaccine strategy against Rhipicephalus microplus, the main tick species that parasite cattle in Brazil, is needed. Our research group targets tick salivary proteins, in order to block hematophagy and impair tick feeding and reproduction. Until now, experimental immunizations performed with a combination of recombinant antigens have shown vaccine potential, since they generated a protective response around 75%. Hence, the present project aim to identify the specific regions of the antigens, which possibly trigger such immunity (epitopes), specifically B cell linear epitopes that are relevant to produce the humoral immune response. Thus, we will use the immune sera of the bovines protected by our vaccine to screen a peptide microarray assembled with amino acid sequences present in the antigens of the experimental vaccine. Further immunization of animals with the recognized epitopes will allow analyzing the ones responsible for protection, as well as subsequent artificial feeding of ticks with its blood may indicate its probable effect on the tick organism. The results will assist future elaboration of a chimeric antigen (protein) containing the major protective epitopes. We expected to obtain a potentially protective chimeric antigen to use as a novel anti-tick vaccine formulation. (AU)