Location: Livestock Arthropod Pest Research Unit
Title: Identification of Amblyomma americanum antigens after vaccination with tick extracellular vesicles in white-tailed deerAuthor
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OLIVA-CHAVEZ, ADELA - University Of Wisconsin |
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GONZALEZ-GONZALEZ, JULIA - Texas A&M University |
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HARVEY, CHRISTINA - Texas A&M University |
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RIBIERO-SILVA, CARITA - Federal University Of Goias |
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LEAL-GALVAN, BRENDA - Texas A&M University |
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PERSINGER, KELLY - Texas A&M Agrilife |
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DURSKI, SARAH - University Of Wisconsin |
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Olafson, Pia |
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JOHNSON, TAMMI - Texas A&M Agrilife |
Submitted to: Vaccines
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 3/19/2025 Publication Date: 3/27/2025 Citation: Oliva-Chavez, A., Gonzalez-Gonzalez, J., Harvey, C., Ribiero-Silva, C., Leal-Galvan, B., Persinger, K.A., Durski, S., Olafson, P.U., Johnson, T.L. 2025. Identification of Amblyomma americanum antigens after vaccination with tick extracellular vesicles in white-tailed deer. Vaccines. https://doi.org/10.3390/vaccines13040355. DOI: https://doi.org/10.3390/vaccines13040355 Interpretive Summary: Anti-tick vaccines represent a promising alternative to pesticides for the management of ticks on wildlife; however little progress has been made to produce an effective vaccine targeting wild hosts on which ticks reproduce, such as the white-tailed deer. To date, most anti-tick vaccine targets have been tested using laboratory models (i.e. rabbits); however, their expression in wild hosts has not been confirmed. We recently tested salivary (SG) and midgut (MG) extracellular vesicles (EVs) from the lone star tick for their potential as vaccine candidates targeting ticks on white-tailed deer; this resulted in on-host female tick mortality. Here, using a proteomic approach, we show that these SG- and MG-EVs contain a “core-cargo” enriched in proteins that can serve as anti-tick vaccine targets, as well as other proteins previously reported in small EVs. Quantitative proteomics showed significant differences in protein cargo between MG and SG-EVs (333 proteins out of 516). Serum from white-tailed deer prior to vaccination and at day 57 post-injection were used to isolate antigenic proteins from SG- and MG-EV preparations. Proteomic analysis of these isolated proteins identified seven that were considered high priority. Additionally, two MG-EVs and 21 SG-EV proteins show antigenic potential. These proteins represent promising candidates for anti-tick vaccine design targeting ticks on white-tailed deer and other wildlife. Technical Abstract: Anti-tick vaccines represent a promising alternative to chemical acaricides for the management of ticks on wildlife; however little progress has been made to produce a vaccine effective in reproductively relevant wild hosts, such as the white-tailed deer (Odocoileus virginianus; WTD). To date, most of tick antigens have been tested using laboratory models (i.e. rabbits); however, their expression in wild hosts has not been confirmed. We recently tested Amblyomma americanum salivary (SG) and midgut (MG) extracellular vesicles (EVs) as vaccine candidates in WTD, which resulted in on-host female tick mortality. Using a proteomic approach, we show that these SG- and MG-EVs contain a “core-cargo” enriched in chaperones, small GTPases, actin and actin-related proteins, and other proteins previously reported in small EVs. Label-free quantitative proteomics showed significant differences in protein cargo between MG and SG-EVs (333 proteins out of 516). Pre-vaccinated and day 57 post-injection serum samples from three vaccinated and one control WTD were used to immunoprecipitate antigenic proteins from SG- and MG-EV preparations. Proteomic analysis of immune-precipitated proteins identified seven antigenic proteins that were considered as high priority for further testing. Additionally, two MG-EVs and 21 SG-EV proteins show antigenic potential. These proteins represent promising candidates for anti-tick vaccine design in WTD and other wildlife. |