title: Subolesin: a candidate vaccine antigen for the control of cattle tick infestations in Indian situation.
abstract: Identification of cross-protective tick vaccine antigens is a challenging area of veterinary research. To address this challenge, a recently identified candidate tick protective antigen, Subolesin (SUB), was targeted in this research. The conservation of subolesin ortholog of Hyalomma anatolicum and Rhipicephalus (Boophilus) microplus across different Indian strains was 98.1-99.4% (within species), while at the amino acid level SUB sequence homology was ≥53.2% (between tick species). Recombinant R. (B.) microplus SUB (rBmSu) was produced in Escherichia coli and characterized. Cross-bred cattle male calves (N=10) were immunized with three doses of 100 μg each of the rBmSu emulsified in 10% Montanide 888 at monthly intervals on days 0, 30 and 60. The control group was injected with PBS in 10% Montanide 888. For the first tick challenge, calves were infested with larvae of R. (B.) microplus generated from 100mg eggs 2 weeks after last immunization (day 75). The immunization resulted in 16.3%, 8.0%, 9.4%, and 26.1% reduction in female tick numbers (DT), weight (DW), oviposition (DO) and egg fertility (DF), respectively, when compared to controls. In the subsequent challenge on day 105, DT, DW, DO and DF were reduced by 9.0%, 4.1%, 8.6%, and 24.2%, respectively, when compared to controls. The vaccine efficacy (E) was equal to 44.0% and 37.2% after the first and second challenges, respectively. The results showed a positive correlation between antibody titers for both total IgG and IgG1 and E in the second but not in the first tick challenge. These results suggested the possibility of developing a SUB-based vaccine for control of cattle tick infestations under Indian conditions.
authors.affiliation: Division of Parasitology, Indian Veterinary Research Institute, Izatnagar 243122, India.
authors.forename: Mukesh
authors.initials: M
authors.lastname: Shakya
authors.affiliation: Division of Parasitology, Indian Veterinary Research Institute, Izatnagar 243122, India.
authors.forename: Binod
authors.initials: B
authors.lastname: Kumar
authors.affiliation: Division of Parasitology, Indian Veterinary Research Institute, Izatnagar 243122, India.
authors.forename: Gaurav
authors.initials: G
authors.lastname: Nagar
authors.affiliation: SaBio, Instituto de Investigación en Recursos Cinegéticos IREC-CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13005 Ciudad Real, Spain; Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078, USA.
authors.forename: José
authors.initials: J
authors.lastname: de la Fuente
authors.affiliation: Division of Parasitology, Indian Veterinary Research Institute, Izatnagar 243122, India. Electronic address: sghoshtick@gmail.com.
authors.forename: Srikanta
authors.initials: S
authors.lastname: Ghosh
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000917:Antibody Formation; D000941:Antigens / Q000276:immunology*; D060829:Arthropod Proteins / Q000276:immunology*; D002417:Cattle; D002418:Cattle Diseases / Q000517:prevention & control*; D005260:Female; D007074:Immunoglobulin G / Q000097:blood; D007194:India; D026863:Ixodidae / Q000145:classification; D008297:Male; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000276:immunology; D048494:Rhipicephalus / Q000145:classification; D013984:Tick Infestations / Q000517:prevention & control*; D014612:Vaccines / Q000276:immunology*
chemical_list: D000941:Antigens; D060829:Arthropod Proteins; D007074:Immunoglobulin G; D011994:Recombinant Proteins; D014612:Vaccines; C550207:subolesin, tick
keywords: Anti-tick vaccine; Rhipicephalus (Boophilus) microplus; Subolesin