title: Protective immunity against tick infestation in cattle vaccinated with recombinant trypsin inhibitor of Rhipicephalus microplus.
abstract: The cattle tick, Rhipicephalus microplus, is regarded as the most economically important ectoparasite of livestock globally. Control is achieved primarily through the use of acaricides. This approach is hampered by the development of resistance to commercial acaricides among cattle tick populations. Vaccination against R. microplus infestation is another technology that can be integrated for effective cattle tick control. Proteins belonging to the Kunitz-BPTI family are abundant in cattle tick salivary glands, midgut, and ovaries. These organs are attractive targets for the development of a novel cattle tick vaccine. Efficacy assessment against cattle tick infestation in bovines using a vaccine containing the recombinant form of a member of the Kunitz family from R. microplus produced in a yeast expression system is reported for the first time here. The yeast Pichia pastoris was bioengineered to produce the recombinant version of a trypsin inhibitor that is expressed in cattle tick larvae (rRmLTI). Immunization with rRmLTI afforded 32% efficacy against R. microplus. The estimated molecular weight of rRmLTI was 46 kDa. Structural homology to the native form of the larval trypsin inhibitor was documented by recognition of rRmLTI in Western-blots using polyclonal antibodies from mice immunized with cattle tick larval extract or rRmLTI. Bioinformatics analysis of the partial nucleotide and deduced amino acid sequences indicated that the rRmLTI closely resembles BmTI-6, which is a three-headed Kunitz protein present in cattle tick ovary and fat tissue.
authors.affiliation: EMBRAPA Beef Cattle, Avenida Rádio Maia, 830 - Vila Popular - Caixa Postal 154, CEP 79106-550 - Campo Grande, MS, Brazil. andreott@cnpgc.embrapa.br
authors.forename: Renato
authors.initials: R
authors.lastname: Andreotti
authors.forename: Rodrigo Casquero
authors.initials: RC
authors.lastname: Cunha
authors.forename: Mariana Aparecida
authors.initials: MA
authors.lastname: Soares
authors.forename: Felix D
authors.initials: FD
authors.lastname: Guerrero
authors.forename: Fábio P Leivas
authors.initials: FP
authors.lastname: Leite
authors.forename: Adalberto A Pérez
authors.initials: AA
authors.lastname: de León
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002418:Cattle Diseases / Q000469:parasitology / Q000517:prevention & control*; D005260:Female; D056724:Immunity, Humoral; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D010843:Pichia / Q000378:metabolism; D011994:Recombinant Proteins / Q000276:immunology; D048494:Rhipicephalus / Q000276:immunology*; D013984:Tick Infestations / Q000517:prevention & control / Q000662:veterinary*; D014361:Trypsin Inhibitors / Q000276:immunology*; D014611:Vaccination / Q000662:veterinary; D014612:Vaccines / Q000276:immunology*
chemical_list: D011994:Recombinant Proteins; D014361:Trypsin Inhibitors; D014612:Vaccines