Washington State University researcher Dana Shaw has been awarded a $420,750 grant to investigate how ticks suppress the bacteria they carry, work that may open the door to new, more effective ways to limit the spread of tick-borne illnesses like Lyme disease.
The two-year project, funded through a National Institutes of Health R21 award from the National Institute of Allergy and Infectious Diseases, will study how tick immune systems work and how that affects their ability to carry and spread disease-causing pathogens. The research could help lay the groundwork for strategies that stop tick-borne diseases in ticks before they reach people or animals.
"A tick's immune system can restrict pathogens like the bacteria that cause Lyme disease, but we still don't know how that works at a molecular level," said Shaw, an associate professor and Caroline Engle Distinguished Professor of Infectious Disease in the College of Veterinary Medicine's Department of Veterinary Microbiology and Pathology. "If we can identify those mechanisms, it could open the door to stopping transmission at the source."
Shaw's lab has spent years investigating vector competency, or a tick's ability to harbor and transmit pathogens. Her team has focused on an immune pathway known as the immune deficiency, or IMD, pathway. While this pathway has been well studied in insects, far less is known about how it works in ticks, including how it suppresses pathogens such as Borrelia burgdorferi, which causes Lyme disease, and Anaplasma phagocytophilum, which causes anaplasmosis.
Previous research from Shaw's group showed that cellular stress responses can activate this pathway in ticks, but the question of what molecules the pathway produces to kill or control invading microbes remains. The new project is designed to answer that question.
Using a computational tool developed by Shaw's lab called ArthroQuest, researchers will scan the tick genome for genes controlled by key immune signals. Early results point to a promising candidate called Tachylectin-5, a protein linked to immune defense in horseshoe crabs that may help ticks recognize and neutralize bacteria.
"No one has looked at this in ticks before," Shaw said. "It could represent an entirely different mechanism of killing pathogens than what we see in insects."
The team will also use new genetic tools to study tick cells in the lab, allowing them to turn the pathway on and see which genes respond, helping researchers to better understand how ticks mount their immune defense against pathogens.
The findings could lead to new approaches to fighting tick-borne disease. Most current strategies focus on treating infections after they occur or preventing them through vaccines and public health measures. Shaw's research may allow infections to be targeted in ticks before transmission.
"If we understand what ticks are doing to control these pathogens, we can potentially enhance those processes," she said. "That could mean designing new interventions that stop transmission before it ever reaches humans or animals."
The grant will support a postdoctoral researcher and a graduate student working in Shaw's lab.
NIH NIAID R21 grants support high-risk, early-stage research with the potential to generate new insights into infectious disease and immunity.
