Evaluation of the vaccine-induced immunity of a formulation based on multiple epitopes of salivary gland proteins of ticks Rhipicephalus microplus

• Grant number: 21/11245-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: August 01, 2022
• End date: August 31, 2024
• Field of knowledge: Biological Sciences - Immunology - Applied Immunology
• Principal Investigator: Isabel Kinney Ferreira de Miranda Santos
• Grantee: Thales Eduardo Galdino Andrade
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated scholarship(s): 22/13778-9 - Elucidating mechanisms of action of multicomponent anti-tick vaccines with different efficacies, BE.EP.DR

Abstract

In livestock, we can highlight the tick in cattle as one of the main problems affecting health and productivity. To control these parasites, acaricides are widely used which, in addition to directly killing ticks, also affect the environment and contaminate meat and milk. In this context, vaccines to combat infestation by ticks emerged, however, limitations and variations in effectiveness were observed, requiring continuous revaccinations and combined use of acaricides, which discourages their use by the producer. In the search for a more protective vaccine, our research group selected and tested pooled salivary antigens, which allowed us to observe an efficacy greater than 70% in all experiments. However, the fermentation of so many recombinant proteins separately makes the manufacture and use of the vaccine impossible in practice, making it impossible for this biotechnological product to be taken beyond the walls of the university. The objective of this project is to obtain a vaccine based on epitopes of salivary antigens from Rhipicephalus microplus ticks that generate protection, immunological memory, and manufacturing potential. For this, antigens used in previous works by our research group will be selected, in which we will carry out mappings of B and T cell epitopes, to guarantee the capture, processing, and induction of humoral immune response. We will physicochemically evaluate the binding peptides individually and together, and then elaborate the construction of a plasmid that allows us to express a multi-epitope recombinant protein. Finally, we will immunize and challenge cattle in the field to assess vaccine efficacy and induce a systemic and local immune response. We believe that this project has the potential to generate several publications and at least two patents, an MHC II-binding TagHTL molecule that provides broad coverage of the most frequent BoLA DRB3 alleles in commercial cattle breeds, and a multi-epitope vaccine construct against ticks. (AU)