Progress 02/01/08 to 01/31/11
Outputs
OUTPUTS: The Lone Star tick (LST) (Amblyomma americanum) is the major tick pest of cattle, humans and animals, especially white tailed deer, in Oklahoma and other areas of the United States. The LST greatly impacts cattle production and vectors several emerging human pathogens and their associated diseases. This research represents the first attempt to develop a vaccine for control of the LST. We identified four key tick protective antigens in the LST by RNA interference (RNAi) screening. These four tick protective clones were characterized by sequence analysis and by RT-PCR to confirm their role in tick development stages and selected tissues. We then identified protective gene homologues in other Amblyomma sp. which have or may have impact on cattle production and pathogen transmission, including A. americanum OSU, A. americanum OSU 2, A. americanum Athens (Georgia, Sussan Little), A. americanum Hans (Barnsfall, Osage Co., OK), A. americanum Springfield (MO), A. cajenense (Mexico), A. variegatum (Guadeloupe, Ard), A. hebraeum (R. Kaufmann), and A. maculatum OK, USA. The four key genes were tested individually as a vaccine antigen in a preliminary vaccine trials in cattle. Each gene was cloned, expressed and prepared as vaccine antigen. In vaccinated cattle, an overall efficacy (E) > 30% was obtained when considering the vaccine effect on both nymphs and adults, but only 2D10, 2G7 and subolesin affected both tick stages. The highest efficacy of control for adult ticks (E > 55%) was obtained in cattle vaccinated with recombinant 2G7 or subolesin. In a second cattle/tick vaccine trial, a prototype multivalent vaccine was tested that include recombinant 2G7 and subolesin. These two antigens were used to immunize cattle which were subsequently challenge-exposed with adult ticks. The prototype vaccine did not impact tick feeding and therefore did not show promise for further testing. While the use of RNAi for identification of tick protective antigens proved to be a rapid and cost-effective tool for discovery of candidate vaccine antigens, further studies are needed to evaluate the response of cattle to immunization with recombinant antigens. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Veterinarians, Animal Health Scientists Regulations Officials PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
: The LST is a major arthropod pest of cattle. All stages feed on white-tailed deer. The LST has long mouthparts allow the ticks to feed for long periods and results in large skin lesions that are susceptible to secondary bacterial infection. Current control of ticks is through the application of acaricides. Development of a vaccine for control of the LST could greatly reduce tick infestations on cattle, thus preventing economic loss to cattle production. Tick vaccines offer a cost-effective control measure, with the important advantages of reducing environmental contamination and preventing the selection of drug resistant ticks that result from repeated acaricide application. In addition, development of vaccines against the LST could likely allow for inclusion of multiple antigens that could target a broad range of Amblyomma species. Key pathogen antigens may also reduce the vector capacity of the LST ticks for A. phagocytophilum, the causative agent of granulocytic ehrlichiosis and also other pathogens that impact human health. In this research we identified tick protective antigens by use of an RNA interference screening method. When key tick protective antigens were used individually in vaccine trials, the immunization of cattle with three antigens resulted in partial control of tick infestations. However, when multiple antigens were used in a prototype vaccine to simultaneously immunize cattle, the tick protective effect was not observe. Future research will focus on the characterization of the bovine response against tick protective antigens. The ultimate goal of this research is to develop a dual target vaccine designed to protect cattle against tick infestations and also prevent the development and transmission of tick-borne pathogens. This approach could be applied to any tick/pathogen/vertebrate host of interest and would greatly reduce the need to use acaricides for tick control and thus avoid the undesirable effects of acaricide application. In addition, tick vaccines may have a dual effect by decreasing tick infestations and reducing the vector capacity of ticks for transmission of pathogens.
Publications
- Villar M, Ayllon N, Busby AT, Galindo RC, Blouin EF, Kocan KM, Bonzon-Kulichenko E, Zivkovic Z, Almazan C, Torina A, Vazquez J, de la Fuente J.2010. Expression of heat shock and other stress response proteins in ticks and cultured tick cells in response to Anaplasma spp. infection and heat shock. International Journal of Proteomics, Volume 2010, Article ID 657261, 11 pages, doi:10.1155/2010/657261.
- Jaworski DC, Zou Z,C. Bowen J, Madden R, Wang Y, Kocan KM, Dillwith JW, Jiang H. 2010. Pyrosequencing and characterization of immune response genes from the tick, Dermacentor variabilis (L.). Insect Molecular Biology, 19(5): 617-630.
- Kocan KM, Blouin EF, de la Fuente J. 2011. RNA interference in ticks. Journal of Visualized Experiments 47(http://www.jove.com/details.phpid=2474 ).
- Merino O, Almazan C, Canales M, Villar M, Moreno-Cid JA, Estrada-Pena A, Kocan KM, de la Fuente J. 2011. Control of Rhipicephalus (Boophilus) microplus infestations by the combination of subolesin vaccination and tick autocidal control after subolesin gene knockdown in ticks fed on cattle. Vaccine, 29: 2248-2254.
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Progress 02/01/09 to 01/31/10
Outputs
OUTPUTS: The Lone Star tick (LST) (Amblyomma americanum) is the major tick pest of cattle, humans and animals, especially white tailed deer, in Oklahoma and other areas of the United States. The LST greatly impacts cattle production and vectors several emerging human pathogens and their associated diseases. This research represents the first attempt to develop a vaccine for control of the LST. We identified four key tick protective antigens in the LST by RNA interference (RNAi) screening. These four tick protective clones were characterized by sequence analysis and by RT-PCR to confirm their role in tick development stages and selected tissues. We then identified protective gene homologues in other Amblyomma sp. which have or may have impact on cattle production and pathogen transmission, including A. americanum OSU, A. americanum OSU 2, A. americanum Athens (Georgia, Sussan Little), A. americanum Hans (Barnsfall, Osage Co., OK), A. americanum Springfield (MO), A. cajenense (Mexico), A. variegatum (Guadeloupe, Ard), A. hebraeum (R. Kaufmann), and A. maculatum OK, USA. The four key genes were tested individually as a vaccine antigen in a preliminary vaccine trials in cattle. Each gene was cloned, expressed and prepared as vaccine antigen. In vaccinated cattle, an overall efficacy (E) > 30% was obtained when considering the vaccine effect on both nymphs and adults, but only 2D10, 2G7 and subolesin affected both tick stages. The highest efficacy of control for adult ticks (E > 55%) was obtained in cattle vaccinated with recombinant 2G7 or subolesin. These collective results demonstrated the feasibility of developing vaccines for the control of lone star tick infestations. The use of RNAi for identification of tick protective antigens proved to be a rapid and cost-effective tool for discovery of candidate vaccine antigens, and this approach could likely be applied to other parasites of veterinary and medical importance. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Veterinarians, Animal Health Scientist Regulations Officials PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Development of a vaccine for control of the LST will likely greatly reduce tick infestations on cattle, thus preventing economic loss to cattle production. Tick vaccines offer a cost-effective control measure, with the important advantages of reducing environmental contamination and preventing the selection of drug resistant ticks that result from repeated acaricide application. In addition, development of vaccines against the LST will likely allow for inclusion of multiple antigens that could target a broad range of Amblyomma species and key pathogen antigens that collectively would reduce the vector capacity of the LST ticks for A. phagocytophilum, the causative agent of granulocytic ehrlichiosis and also other pathogens that impact human health. Future research will focus on the characterization of these key tick antigens and the development of an dual target vaccine designed to protect cattle against tick infestations and also prevent the development and transmission of tick-borne pathogens. This approach could be applied to any tick/pathogen/vertebrate host of interest.
Publications
- de la Fuente J, Manzano-Roman R, Naranjo V, Kocan KM, Zivkovic Z, Blouin EF, Canales M, Almazan C, Galindo RC, Step DL, Villar M. 2010. Identification of protective antigens by RNA interference for control of the lone star tick, Amblyomma americanum. Vaccine, 28:1786-1795.
- Canales M, Naranjo, V, Almazan C, Molina R, Tsuruta SA, Szabo MPJ, Manzano-Roman R, Perez de la Lastra JM, Kocan KM, Jimenez MI, Lucientes J, Villar M, de la Fuente J. 2009. Conservation and immunogenicity of the mosquito ortholog of the tick protective antigen, subolesin. Parasitology Research, 105:97-111.
- Zivkovic Z, Torina A, Mitra R, Alongi A, Scimeca S, Kocan KM, Naranjo V, Galindo RC, Almazan C, Blouin EF, Villar M, Nijhof AM, Mani R, Caracappa S, Jongejan F, de la Fuente J. 2009. Subolesin expression in response to pathogen infection in ticks. BMC Immunology, 11:7.
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Progress 02/01/08 to 01/31/09
Outputs
OUTPUTS: The Lone Star tick (LST) (Amblyomma americanum) is the major tick pest of cattle, humans and animals, especially white tailed deer, in Oklahoma and other areas of the United States. The LST greatly impacts cattle production and vectors several emerging human pathogens and their associated diseases. This research represents the first attempt to develop a vaccine for control of the LST. We identified four key tick protective antigens in the LST by RNA interference (RNAi) screening. These four tick protective clones were characterized by sequence analysis and by RT-PCR to confirm their role in tick development stages and selected tissues. We then identified protective gene homologues in other Amblyomma sp. which have or may have impact on cattle production and pathogen transmission, including A. americanum OSU, A. americanum OSU 2, A. americanum Athens (Georgia, Sussan Little), A. americanum Hans (Barnsfall, Osage Co., OK), A. americanum Springfield (MO), A. cajenense (Mexico), A. variegatum (Guadeloupe, Ard), A. hebraeum (R. Kaufmann), and A. maculatum OK, USA. The four key genes are currently being tested individually as a vaccine antigen in a preliminary vaccine trials in cattle. Each gene was cloned, expressed and prepared as vaccine antigen. In this preliminary trial, 3 cattle are being used per group, including 4 LST antigens, subolesin positive control and saline/adjuvant-injected controls. Immunized and control cattle will be challenge-exposed with nymphal and adult ticks in order to assess the impact of vaccination on tick survival, feeding and reproduction. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Veterinarians, Animal Health Scientists Regulations Officials PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Development of a vaccine for control of the LST will likely greatly reduce tick infestations on cattle, thus preventing economic loss to cattle production. Tick vaccines offer a cost-effective control measure, with the important advantages of reducing environmental contamination and preventing the selection of drug resistant ticks that result from repeated acaricide application. In addition, development of vaccines against the LST will likely allow for inclusion of multiple antigens that could target a broad range of Amblyomma species and key pathogen antigens that collectively would reduce the vector capacity of the LST ticks for A. phagocytophilum, the causative agent of granulocytic ehrlichiosis and also other pathogens that impact human health. Future research will focus on the characterization of these key tick antigens and the development of an dual target vaccine designed to protect cattle against tick infestations and also prevent the development and transmission of tick-borne pathogens. This approach could be applied to any tick/pathogen/vertebrate host of interest.
Publications
- de la Fuente J, Kocan KM, Almazan C, Blouin EF. 2008. Targeting the tick tick-pathogen interface for novel control strategies. Frontiers in Bioscience, 13:6947-6956.
- de la Fuente J, Estrada-Pena A, Venzal JM, Kocan KM, Sonenshine DE. 2008. Overview: Ticks as vectors of pathogens that cause disease in humans and animals. Frontiers in Bioscience 13:6938-6946.
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