title: Rhipicephalus (Boophilus) microplus aquaporin as an effective vaccine antigen to protect against cattle tick infestations.
abstract: BACKGROUND
  Vaccination as a control method against the cattle tick, Rhipicephalus (Boophilus) microplus has been practiced since the introduction of two products in the mid-1990s. There is a need for a vaccine that could provide effective control of R. microplus in a more consistent fashion than existing products. During our transcriptome studies of R. microplus, several gene coding regions were discovered to encode proteins with significant amino acid similarity to aquaporins.
  
  
  METHODS
  A cDNA encoding an aquaporin from the cattle tick, Rhipicephalus microplus, was isolated from transcriptomic studies conducted on gut tissues dissected from fully engorged adult female R. microplus.
  
  
  RESULTS
  Bioinformatic analysis indicates this aquaporin, designated RmAQP1, shows greatest amino acid similarity to the human aquaporin 7 family. Members of this family of water-conducting channels can also facilitate the transport of glycerol in addition to water. The efficacy of this aquaporin as an antigen against the cattle tick was explored in cattle vaccine trials conducted in Brazil. A cDNA encoding a significant portion of RmAQP1 was expressed as a recombinant protein in Pichia pastoris, purified under native conditions using a polyhistidine C-terminus tag and nickel affinity chromatography, emulsified with Montanide adjuvant, and cattle vaccinated intramuscularly. The recombinant protein provided 75% and 68% efficacy in two cattle pen trials conducted in Campo Grande, Brazil on groups of 6 one year old Holstein calves.
  
  
  CONCLUSIONS
  The effectiveness of this vaccine in reducing the numbers of adult female ticks shows this aquaporin antigen holds promise as an active ingredient in cattle vaccines targeted against infestations of R. microplus.
authors.affiliation: USDA-ARS Knipling Bushland US Livestock Insect Research Laboratory, 2700 Fredericksburg Rd., Kerrville, TX, 78028, USA. Felix.Guerrero@ars.usda.gov.
authors.forename: Felix D
authors.initials: FD
authors.lastname: Guerrero
authors.affiliation: EMBRAPA Beef Cattle, Avenida Radio Maia, 830-Vila Popular, Caixa postal n. 154, CEP79106-550, Campo Grande, MS, Brazil. renato.andreotti@embrapa.br.
authors.forename: Renato
authors.initials: R
authors.lastname: Andreotti
authors.affiliation: USDA-ARS Knipling Bushland US Livestock Insect Research Laboratory, 2700 Fredericksburg Rd., Kerrville, TX, 78028, USA. Kylie.Bendele@ars.usda.gov.
authors.forename: Kylie G
authors.initials: KG
authors.lastname: Bendele
authors.affiliation: EMBRAPA Beef Cattle, Avenida Radio Maia, 830-Vila Popular, Caixa postal n. 154, CEP79106-550, Campo Grande, MS, Brazil. Rodrigocunha_vet@hotmail.com.
authors.forename: Rodrigo C
authors.initials: RC
authors.lastname: Cunha
authors.affiliation: USDA-ARS Cattle Fever Tick Research Laboratory, 22675 North Moorefield Rd., Edinburg, TX, 78541, USA. Robert.Miller@ars.usda.gov.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Miller
authors.affiliation: USDA-ARS Southern Plains Area Office, 1001 Holleman Drive East, College Station, TX, 77845, USA. kathleen.yeater@ars.usda.gov.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Yeater
authors.affiliation: USDA-ARS Knipling Bushland US Livestock Insect Research Laboratory, 2700 Fredericksburg Rd., Kerrville, TX, 78028, USA. Beto.PerezdeLeon@ars.usda.gov.
authors.forename: Adalberto A
authors.initials: AA
authors.lastname: Pérez de León
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000941:Antigens / Q000276:immunology*; D020346:Aquaporins / Q000276:immunology*; D001483:Base Sequence; D001938:Brazil / Q000453:epidemiology; D002417:Cattle; D019295:Computational Biology; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D048494:Rhipicephalus / Q000276:immunology / Q000378:metabolism*; D014612:Vaccines / Q000008:administration & dosage / Q000276:immunology*
chemical_list: D000941:Antigens; D020346:Aquaporins; D014612:Vaccines