Recombinant multicomponent vaccine based on antigens secreted by Rhipicephalus microplus induces protective immunity against ticks in cattle and dogs

Author(s)

Andressa Fisch

• Document type: Doctoral Thesis
• Press: Ribeirão Preto.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina de Ribeirão Preto (PCARP/BC)
• Defense date: 2018-10-17

Examining board members

Beatriz Rossetti Ferreira; Odir Antônio Dellagostin; Luciana Cezar de Cerqueira Leite; Celio Lopes Silva

• Advisor: Beatriz Rossetti Ferreira

Abstract

Ticks are hematophagous parasites which transmit diseases to humans and animals, and are responsible for billions of dollars of damage to the world\'s livestock systems. The emergence of ticks resistant to multiple acaricides makes urgent the development of effective vaccines against this parasite. In this work, we used data from the R. microplus tick sialotranscriptome to select antigens secreted by the parasite to be tested as a multicomponent vaccine. Recombinant antigens expressed in E. coli were used as antigens in tick\'s susceptible hosts to evaluate it efficacy in protect animals against R. microplus and R. sanguineus infestations. In the first assay, bovines immunized with eight recombinant antigens adjuvanted with a synthetic polymer presented the induction of serum IgG reactive for five antigens, and reduction of R. microplus infestation in 22%. In the second trial, immunization of cattle with nine antigens adjuvanted with aluminum salts generated serum IgG against all antigens, and vaccine protection against R. microplus parasitism was calculated in 70% and 75% for each infestation. In the third trial, the immunization of dogs with recombinant antigens adjuvanted with aluminum hydroxide induced IgG seroconversion against all antigens, and a 36% of protection against infestation by R. sanguineus ticks in immunized animals. All formulations reduced mainly the number of engorged females recovered from infestation. The cross reactive protection induced by R. microplus derived antigens R. sanguineus tick infestation indicate that it is possible to develop a unique multicomponent vaccine against the two parasites. (AU)

• FAPESP's process: 14/11010-0 - Development of a recombinant multicomponent chimeric vaccine based in proteins epitopes from Rhipicephalus microplus ticks
• Grantee: Andressa Fisch
• Support Opportunities: Scholarships in Brazil - Doctorate