Development of an artificial tick feeding system for Rhipicephalus sp. for in vitro screening of vaccine antigens

• Grant number: 18/18395-5
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Effective date (Start): September 30, 2018
• Effective date (End): November 07, 2018
• Field of knowledge: Biological Sciences - Parasitology
• Principal Investigator: Beatriz Rossetti Ferreira
• Grantee: Isabela Pazotti Daher
• Supervisor: Theo Schetters
• Host Institution: Escola de Enfermagem de Ribeirão Preto (EERP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Research place: Clinvet Research Innovation, South Africa
• Associated to the scholarship: 17/26759-4 - Mapping of epitopes of r. microplus tick salivary antigens using in silico and phage display techniques for the development of a multicomponent anti-tick vaccine, BP.MS

Abstract

Ticks are hematophagous arthropods that parasitize vertebrate hosts and transmit diseases to animals. The main form of control of this parasite has been done with acaricides. However, the use of acaricides has presented enormous disadvantages such as contamination of the environment and animal products, and selection of acaricide-resistant ticks. The formulation of anti-tick vaccines emerges as a form of control, safe and sustainable. The currently available anti-tick vaccines contain single antigens, that induce different protection profiles, which limits their use. Due to complexity of the tick-host interaction, studies have suggested that an efficient vaccine may need to be composed of more than one antigen (multicomponent), and several studies are currently being performed in the search for tick salivary antigens that can be used as good vaccine targets. The project that underlies this Brazilian fellowship (Masters Scholarship FAPESP 2017/26759-4) aims do identify conformational B cell epitopes in tick salivary antigens using a phage display approach and further evaluate their anti-tick protective activity in vivo. Previous results of our group indicate that a high number of conformational epitopes are present in some candidate antigens selected by us, that could be related with protection to ticks. Therefore, the next step foreseen in this project is the validation of the anti-tick activity of these sequences using in vivo immunization and a challenge infestation on animal models. However, the great number of candidate antigen sequences makes it difficult to perform this process efficiently, since we would need a large number of animals for immunization/challenge. An alternative to the in vivo model of feeding is the artificial feeding of ticks. The membrane feeding system can be used to mimic the natural feeding process, and uses a synthetic membrane or animal skin through which the ticks feed on a provided blood source. This technique is not limited to adult ticks, and can also be used to feed larval-phase ticks, helping to screen the best antigens for the vaccine. In this project, we propose to learn how to build the artificial membrane feeding system to evaluate the effectiveness of sera obtained from hosts that were vaccinated against ticks. (AU)