Below is a list and description of the ongoing projects in the Petersen Lab. If you are interested in learning more about any of these projects, you can contact Dr. Petersen directly at christine-petersen@uiowa.edu, and/or one of the other lead researchers of the project listed below. 

Studying how foxhound nutrition, important vitamins and minerals, and measures of stress impact ability to combat infections

One of the most important inputs for canine health and performance is optimal nutrition. Recent discoveries in nutrition and immunology have tied the quality of caloric intake to its impacts on vitamins like A and D, and biological metals like iron and magnesium, shown to alter immunity. Different inflammatory responses are critical to eliminating infection with agents like Borrelia burgdorferi and Leishmania infantum, the causative agents of Lyme disease and canine leishmaniosis, respectively. Infectious diseases have an oversized impact on the hunting hound population, due to their outdoor exposure to ticks, their cohousing and breeding susceptibility to Leishmania. Although there is a growing body of work indicating that what we eat can alter how we fight off infection, there is very limited experimental work demonstrating this in a genetically similar, cohoused group of animals, like kennels of Foxhounds. We are uniquely qualified to do this work as Dr. Petersen and her group has worked collaboratively with the MFHA to evaluate immune responses of hunting hounds to various infectious challenges for the last fifteen years, setting the cutting edge of canine immunology work, for which she was recently nominated to the National Academy of Medicine. To this we add Dr. Jessica Hite, a mathematical modeler at the University of Wisconsin, Department of Pathobiology, College of Veterinary Medicine, whose research focus is the impacts of nutrition and fasting on infection in many different biological and ecological systems.

In this study, we will assess the quality and quantity of hound nutrition on both a hunt and individual dog level, using radio-frequency ID (RFID) technology, measure key nutritional markers including different forms of Vitamin D and iron, measures of inflammation and stress via C-reactive protein and cortisol, and assess body condition score changes over a year of hunting, as well as huntsman or master based evaluation of overall effort and effort of a key group of dogs fit with RVID per hunt.

If you are interested in learning more about this project, please contact:
Dr. Christine Petersen (christine-petersen@uiowa.edu)

Studying the Dermal Immune Environment in Progressive Canine Leishmaniosis and its Influence on Transmissibility

Canine Leishmaniosis (CanL) is a fatal disease in dogs. Additionally, Leishmania infantum, the causative agent, is zoonotic – capable of moving from infected dogs to humans through a sand fly vector. The skin of infected dogs is a significant deposit for L. infantum parasites and the site of interactions between the local immune response, the parasites, and feeding sand fly vectors. Understanding how progressive infection alters both the skin environment and transmission of Leishmania is critical to develop transmission-blocking interventions that prevent further infection of both dogs and humans.

In dogs infected with L. infantum, the systemic immune response plays a central role in the progression of clinical disease. These findings brought up questions about the dermal immune environment and the effects on transmissibility to feeding sand fly vectors. In this project, we investigate:

1. When during disease progression, and by what inflammatory mechanisms, is Leishmania transmission to sand flies augmented?
2. How do immune/inflammatory changes over the course of Leishmania infection modify the immune modulatory action of sand fly salivary proteins?
3. Can manipulation of host skin inflammation alter host infectiousness to sand flies at different stages of disease?

The results of this work will provide valuable, foundational information on the sand fly-skin-parasite immune interface, an interaction that influences parasite transmission from skin to feeding sand flies. Additionally, this work will give valuable insight into how pro-inflammatory and anti-inflammatory signaling acts in skin after sand fly bites to impact both the skin immune environment and transmission to sand flies. Characterizing host factors that influence parasite transmission will enable identification of novel strategies to block L. infantum transmission from host skin to feeding sand flies.

If you are interested in learning more about this project, please contact:
Dr. Christine Petersen (christine-petersen@uiowa.edu)
Dr. Max Waugh (max-waugh@uiowa.edu)

Lyme Transmission-Blocking Vaccine Project

Estimates from the CDC indicate that over 300,000 people are diagnosed each year with LD. Ecological approaches to decrease B. burgdorferi burden in Ixodes ticks, and transmission to other hosts, are highly desired tools for use instead of the current ‘check for ticks’ approach. It is well established that after a vertebrate host is immunized with B. burgdorferi’ OspA they produce antibody that, upon bloodmeal ingestion by a feeding tick, kills B. burgdorferi within that tick. These are known as transmission-blocking vaccines (TBV). These tools, including TBV, have not been proven to decrease B. burgdorferi exposure in critical intermediate incidental host(s). In North America, both humans and dogs are incidental hosts of B. burgdorferi. We and others have demonstrated that dogs can serve as stand-in/proxies for human exposure to infected ticks. Hunting dogs are a robust model for this trial because they serve both as a proxy of an active outdoors incidental host (like people at high-risk of contracting LD) and are a conduit of ticks into domestic habitats, increasing human exposure. The goal of this work is to demonstrate that a commercial-grade reservoir targeted TBV alters B. burgdorferi infection prevalence in questing ticks, in endemic areas (MD) geographically distinct from the first field trial (NY).

To show proof-of-principle for an ecological disruption of Borrelia transmission, we propose to:
1) Establish the efficacy of a commercial-grade reservoir targeted transmission blocking vaccine (TBV) in reducing prevalence of B. burgdorferi in the tick vector and how it affects clinical disease in incidental hosts (dogs) in a five-year field study.
2) Use a Bayesian hierarchical statistical model to estimate how TBV treatment of infected ecosystems will alter human B. burgdorferi exposure.

These proposed studies are highly significant to public health as a field trial demonstration of a TBV that disrupts the enzootic transmission cycle of B. burgdorferi to incidental hosts. Furthermore, demonstration of reduced human (incidental host) Lyme disease will be performed through a stochastic Bayesian model that will provide critical evidence for a new tool to decrease environmental exposure to Lyme disease. This work innovates as a demonstration of an efficacious, easily distributable and inexpensive TBV that reduces B. burgdorferi prevalence in nymphal and adult ticks, as well as B. burgdorferi transmission from ticks to incidental hosts. Reduction of transmission of B. burgdorferi to incidental hosts as a result of TBV distribution will prove to be a paradigm-shifting strategy to reduce the burden of Lyme disease in veterinary and human populations. Findings from experiments proposed in this study will advance translational knowledge of B. burgdorferi vaccinology and will provide strong evidence regarding the possibility of TBV reducing the human health risk of exposure to Lyme disease across the United States.

If you are interested in learning more about this project, please contact:
Dr. Christine Petersen (christine-petersen@uiowa.edu)

Here is a list of other ongoing projects that are still being developed, close to being finished, or are done in collaboration with another laboratory.

• India Non-Human Reservoir Study
• US Leishmania Genetics Study / Leishmania Proteomics Project
• Canine L. braziliensis Treatment Project
• Brazil Anaplasma Project
• Leishmania Canine Spleen Pathology Project
• Leishmania Sarolaner Project (recently completed)
• Canine Lyme Disease NK/T cell Project (recently completed)