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Adela Oliva Chavez

Assistant Professor

740 Russell Labs
1630 Linden Dr.
Madison, WI 53706

Lab website – https://www.tickchavezlab.com/

Research interests: Extracellular vesicles, tick feeding, skin immune responses, epigenetics, tick management, diagnostics

Education:

  • Ph.D. University of Minnesota. Department of Entomology. Saint Paul, MN. (March 2008 – December 2013).  
  • M.Sc. University of Minnesota. Department of Entomology. Saint Paul, MN. (August 2005 – March 2008).  
  • B.Sc. Pan-American School of Agriculture “Zamorano”. Agricultural Engineer. Honduras. (January 2000 – December 2003)

Research Focus:

Understanding the molecular and cellular interactions between ticks, their hosts, and the pathogens they transmit. Hard ticks, unlike other hematophagous arthropods, feed for long period of time (days to weeks). Thus, they have developed intricate mechanisms to manipulate their host immune and wound healing responses. This allows tick to feed uninterrupted and provides a safe haven to the pathogens they transmit. Using intracellular bacteria within the Anaplasmataceae family, we study the effect of tick-borne pathogen transmission in the skin responses and are characterizing how inflammatory and delayed wound healing aids in the establishment of infection in the skin. We utilize molecular, immunological, and microbiology techniques to define the role of extracellular vesicles in the modulation of host responses, how ticks regulate the content (proteins and miRNAs) within these extracellular, and what effect pathogens have on tick extracellular vesicle cargo.

Epigenetic drivers of tick adaptation and pathogen transmission. Tick-borne diseases are gaining relevance in the US. Interestingly, 80% of the cases are concentrated in the Northeastern and Midwestern, US. Several factors play a role in an arthropod’s ability to vector pathogens, which may impact pathogen distribution. Behavioral and biological differences between tick populations may be driven by epigenetics. Epigenetic variations correlate with global transcriptional changes that result in phenotypic plasticity. In bees, caste differentiation is influenced by variations in DNA methylation in response to environmental and nutritional clues. We will investigate the role of epigenetics in tick biology by looking at the methylation of Ixodes scapularis DNA to determine epigenetic variations between tick populations in the South (Texas), Midwest (Minnesota), and Northeast (Pennsylvania), US. By establishing the link between epigenetics and vector competence, we can develop novel approaches to reduce the capacity of ticks to vector pathogens.

Development of novel tick management strategies. Ticks and tick-borne disease significantly affect livestock worldwide. Tick feeding can reduce milk production, reduced weight gain, damage to hides, anemia, and even death. Current tick control measures are focused on the use of synthetic acaricides.  Nevertheless, the emergence of resistance to several acaricides in tick populations has become a source of concern. Thus, increased interest has emerged in finding alternative approaches for the control of tick populations. One of such approaches is the development of anti-tick vaccines. Although some subunit vaccines have shown partial protection, polymorphism in protein sequence between tick populations and tick species reduces their efficiency. This project aims to examine the potential use of tick salivary glands- and midgut-derived extracellular vesicles as vaccine candidates against ticks. Effective tick vaccines will decrease the impact that ticks have on cattle and lessen the tick-borne disease burden. This knowledge can then be applied to other systems, potentially impacting animal and human health.

Tick-borne disease biomarker identification for diagnostics. Tick-borne diseases are the most significant vector-borne diseases in the U.S. Lyme disease alone affects around 400,000 people per year according to insurance estimates. Although serological and molecular diagnostics, such as ELISA and PCR, are used in clinical settings, these techniques sometimes result in undesirable rates of false negatives or false positives. This is particularly true during the early phases of infection, when pathogen numbers are low and pathogen-specific antibodies have not been mounted or antibodies mounted cross-react with antigens present in other tick-borne pathogens. We are characterizing the content of circulating extracellular vesicles to identify potential biomarkers that can be exploited for the development of new diagnostic approaches.

These novel techniques will potentially permit the early accurate diagnosis of these illnesses and coinfections with tick-borne pathogens to allow for prompt treatment.

Research Category: Basic and Applied

About me: I am a 6-time marathon runner, scuba diver, and cat enthusiast

Online profiles: Google Scholar | ResearchGate

Selected publications:

Butler LR, Gonzalez J, Pedra JHF, Oliva Chavez AS. Tick extracellular vesicles in host skin immunity and pathogen transmission. Trends Parasitol. 2023 Oct;39(10):873-885. doi: 10.1016/j.pt.2023.07.009. Epub 2023 Aug 16. Review. PubMed PMID: 37591719.

Oliva Chávez AS, Guzman Valencia S, Lynn GE, Rosario CA, Thomas DB, Johnson TL. Evaluation of the in vitro acaricidal effect of five organic compounds on the cattle fever tick Rhipicephalus (Boophilus) microplus (Acari: Ixodidae). Exp Appl Acarol. 2023 Apr;89(3-4):447-460. doi: 10.1007/s10493-023-00780-9. Epub 2023 Apr 13. PubMed PMID: 37052726; PubMed Central PMCID: PMC10167096.

Gordon JL, Oliva Chavez AS, Martinez D, Vachiery N, Meyer DF. Possible biased virulence attenuation in the Senegal strain of Ehrlichia ruminantium by ntrX gene conversion from an inverted segmental duplication. PLoS One. 2023;18(2):e0266234. doi: 10.1371/journal.pone.0266234. eCollection 2023. PubMed PMID: 36800354; PubMed Central PMCID: PMC9937504.

Underwood J, Harvey C, Lohstroh E, Pierce B, Chambers C, Guzman Valencia S, Oliva Chávez AS. Anaplasma phagocytophilum Transmission Activates Immune Pathways While Repressing Wound Healing in the Skin. Life (Basel). 2022 Nov 24;12(12). doi: 10.3390/life12121965. PubMed PMID: 36556330; PubMed Central PMCID: PMC9781593.

Leal-Galvan B, Harvey C, Thomas D, Saelao P, Oliva Chavez AS. Isolation of microRNAs from Tick Ex Vivo Salivary Gland Cultures and Extracellular Vesicles. J Vis Exp. 2022 Apr 6;(182). doi: 10.3791/63618. PubMed PMID: 35467650.

Skinner KM, Underwood J, Ghosh A, Oliva Chavez AS, Brelsfoard CL. Wolbachia Impacts Anaplasma Infection in Ixodes scapularis Tick Cells. Int J Environ Res Public Health. 2022 Jan 18;19(3). doi: 10.3390/ijerph19031051. PubMed PMID: 35162074; PubMed Central PMCID: PMC8834366.

Park JM, Oliva Chávez AS, Shaw DK. Ticks: More Than Just a Pathogen Delivery Service. Front Cell Infect Microbiol. 2021;11:739419. doi: 10.3389/fcimb.2021.739419. eCollection 2021. PubMed PMID: 34540723; PubMed Central PMCID: PMC8440996.

Oliva Chávez AS, Wang X, Marnin L, Archer NK, Hammond HL, Carroll EEM, Shaw DK, Tully BG, Buskirk AD, Ford SL, Butler LR, Shahi P, Morozova K, Clement CC, Lawres L, Neal AJO, Mamoun CB, Mason KL, Hobbs BE, Scoles GA, Barry EM, Sonenshine DE, Pal U, Valenzuela JG, Sztein MB, Pasetti MF, Levin ML, Kotsyfakis M, Jay SM, Huntley JF, Miller LS, Santambrogio L, Pedra JHF. Tick extracellular vesicles enable arthropod feeding and promote distinct outcomes of bacterial infection. Nat Commun. 2021 Jun 17;12(1):3696. doi: 10.1038/s41467-021-23900-8. PubMed PMID: 34140472; PubMed Central PMCID: PMC8211691.

Ante VM, Farris LC, Saputra EP, Hall AJ, O’Bier NS, Oliva Chávez AS, Marconi RT, Lybecker MC, Hyde JA. The Borrelia burgdorferi Adenylate Cyclase, CyaB, Is Important for Virulence Factor Production and Mammalian Infection. Front Microbiol. 2021;12:676192. doi: 10.3389/fmicb.2021.676192. eCollection 2021. PubMed PMID: 34113333; PubMed Central PMCID: PMC8186283.

Pham M, Underwood J, Oliva Chávez AS. Changing the Recipe: Pathogen Directed Changes in Tick Saliva Components. Int J Environ Res Public Health. 2021 Feb 12;18(4). doi: 10.3390/ijerph18041806. Review. PubMed PMID: 33673273; PubMed Central PMCID: PMC7918122.

Quadros DG, Johnson TL, Whitney TR, Oliver JD, Oliva Chávez AS. Plant-Derived Natural Compounds for Tick Pest Control in Livestock and Wildlife: Pragmatism or Utopia?. Insects. 2020 Aug 1;11(8). doi: 10.3390/insects11080490. Review. PubMed PMID: 32752256; PubMed Central PMCID: PMC7469192.

Chávez ASO, O’Neal AJ, Santambrogio L, Kotsyfakis M, Pedra JHF. Message in a vesicle – trans-kingdom intercommunication at the vector-host interface. J Cell Sci. 2019 Mar 18;132(6). doi: 10.1242/jcs.224212. Review. PubMed PMID: 30886004; PubMed Central PMCID: PMC6451414.

Oliva Chávez AS, Herron MJ, Nelson CM, Felsheim RF, Oliver JD, Burkhardt NY, Kurtti TJ, Munderloh UG. Mutational analysis of gene function in the Anaplasmataceae: Challenges and perspectives. Ticks Tick Borne Dis. 2019 Feb;10(2):482-494. doi: 10.1016/j.ttbdis.2018.11.006. Epub 2018 Nov 15. PubMed PMID: 30466964; PubMed Central PMCID: PMC6342664.

McClure Carroll EE, Wang X, Shaw DK, O’Neal AJ, Oliva Chávez AS, Brown LJ, Boradia VM, Hammond HL, Pedra JHF. p47 licenses activation of the immune deficiency pathway in the tick Ixodes scapularis. Proc Natl Acad Sci U S A. 2019 Jan 2;116(1):205-210. doi: 10.1073/pnas.1808905116. Epub 2018 Dec 17. PubMed PMID: 30559180; PubMed Central PMCID: PMC6320499.

McClure EE, Chávez ASO, Shaw DK, Carlyon JA, Ganta RR, Noh SM, Wood DO, Bavoil PM, Brayton KA, Martinez JJ, McBride JW, Valdivia RH, Munderloh UG, Pedra JHF. Engineering of obligate intracellular bacteria: progress, challenges and paradigms. Nat Rev Microbiol. 2017 Sep;15(9):544-558. doi: 10.1038/nrmicro.2017.59. Epub 2017 Jun 19. Review. PubMed PMID: 28626230; PubMed Central PMCID: PMC5557331.

Oliva Chávez AS, Shaw DK, Munderloh UG, Pedra JH. Tick Humoral Responses: Marching to the Beat of a Different Drummer. Front Microbiol. 2017;8:223. doi: 10.3389/fmicb.2017.00223. eCollection 2017. Review. PubMed PMID: 28261180; PubMed Central PMCID: PMC5306392.

Shaw DK, Wang X, Brown LJ, Chávez AS, Reif KE, Smith AA, Scott AJ, McClure EE, Boradia VM, Hammond HL, Sundberg EJ, Snyder GA, Liu L, DePonte K, Villar M, Ueti MW, de la Fuente J, Ernst RK, Pal U, Fikrig E, Pedra JH. Infection-derived lipids elicit an immune deficiency circuit in arthropods. Nat Commun. 2017 Feb 14;8:14401. doi: 10.1038/ncomms14401. PubMed PMID: 28195158; PubMed Central PMCID: PMC5316886.

Oliva Chávez AS, Fairman JW, Felsheim RF, Nelson CM, Herron MJ, Higgins L, Burkhardt NY, Oliver JD, Markowski TW, Kurtti TJ, Edwards TE, Munderloh UG. An O-Methyltransferase Is Required for Infection of Tick Cells by Anaplasma phagocytophilum. PLoS Pathog. 2015;11(11):e1005248. doi: 10.1371/journal.ppat.1005248. eCollection 2015. PubMed PMID: 26544981; PubMed Central PMCID: PMC4636158.

Oliver JD, Chávez AS, Felsheim RF, Kurtti TJ, Munderloh UG. An Ixodes scapularis cell line with a predominantly neuron-like phenotype. Exp Appl Acarol. 2015 Jul;66(3):427-42. doi: 10.1007/s10493-015-9908-1. Epub 2015 Apr 17. PubMed PMID: 25894426; PubMed Central PMCID: PMC4449809.

Chávez AS, Felsheim RF, Kurtti TJ, Ku PS, Brayton KA, Munderloh UG. Expression patterns of Anaplasma marginale Msp2 variants change in response to growth in cattle, and tick cells versus mammalian cells. PLoS One. 2012;7(4):e36012. doi: 10.1371/journal.pone.0036012. Epub 2012 Apr 25. PubMed PMID: 22558307; PubMed Central PMCID: PMC3338850.

Felsheim RF, Chávez AS, Palmer GH, Crosby L, Barbet AF, Kurtti TJ, Munderloh UG. Transformation of Anaplasma marginale. Vet Parasitol. 2010 Feb 10;167(2-4):167-74. doi: 10.1016/j.vetpar.2009.09.018. Epub 2009 Sep 20. PubMed PMID: 19837516; PubMed Central PMCID: PMC2817780.

Baldridge GD, Burkhardt NY, Oliva AS, Kurtti TJ, Munderloh UG. Rickettsial ompB promoter regulated expression of GFPuv in transformed Rickettsia montanensis. PLoS One. 2010 Jan 29;5(1):e8965. doi: 10.1371/journal.pone.0008965. PubMed PMID: 20126457; PubMed Central PMCID: PMC2813287.

Nelson CM, Herron MJ, Felsheim RF, Schloeder BR, Grindle SM, Chavez AO, Kurtti TJ, Munderloh UG. Whole genome transcription profiling of Anaplasma phagocytophilum in human and tick host cells by tiling array analysis. BMC Genomics. 2008 Jul 31;9:364. doi: 10.1186/1471-2164-9-364. PubMed PMID: 18671858; PubMed Central PMCID: PMC2527338.

Baldridge GD, Kurtti TJ, Burkhardt N, Baldridge AS, Nelson CM, Oliva AS, Munderloh UG. Infection of Ixodes scapularis ticks with Rickettsia monacensis expressing green fluorescent protein: a model system. J Invertebr Pathol. 2007 Mar;94(3):163-74. doi: 10.1016/j.jip.2006.10.003. Epub 2006 Nov 27. PubMed PMID: 17125789; PubMed Central PMCID: PMC1868488.

I will be teaching the following courses:

  • Medical Entomology
  • One-Health Entomology

Professional affiliations:

  • Frontiers in Cellular and Infection Microbiology – Veterinary and Zoonotic Infection, Associate Editor (2023-present)
  • American Society for Rickettsiology, Diversity Ambassador (2022-present)
  • Frontiers in Cellular and Infection Microbiology, Guest Editor (2021-2023)
  • Zoonoses and public health, Editorial Board (2020-present)
  • International journal of Environmental Research and Public Health, Guest Editor and Topics Board (2020-2023)

Selected honors and awards:

  1. College of Agriculture and Life Sciences Dean’s Outstanding Achievement Award for Early Career Research. Texas A&M University. 2023
  2. USDA E. Kika De La Garza Science Fellow. USDA. 2023.
  3. Scialog Fellow: Mitigating Zoonotic Threats (MZT). Research Corporation for Science Advancement. 2021-2022.
  4. Young Scientist Ticks & Tick-borne Pathogens Award. International Ticks & Tick-borne Pathogens Meeting. 2014.
  5. Most Valuable PhD Student. Department of Entomology. University of Minnesota. 2009.
  6. Distinguished Master Thesis. Graduate School. University of Minnesota. 2009.
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