Recipient Organization
UNIVERSITY OF MISSOURI
(N/A)
COLUMBIA,MO 65211
Performing Department
Veterinary Medicine & Surgery
Non Technical Summary
Cytauxzoon felis is a parasite that causes severe illness and often death in infected cats. Death from cytauxzoonosis comes quickly, and cats often develop respiratory distress, cry out as if in pain, and seizure before they succumb. Although once thought to be uniformly fatal in domestic cats, some cats do survive initial infection either after aggressive medical care, or occasionally without any overt illness. Why some cats do not develop illness despite infection with the parasite is completely unknown. Once infected, cats become immune to re-infection and illness. There have been no scientific studies of the immunological response to Cytuaxzoon felis that might both contribute to the disease presentation, or provide protection from a second infection. An understanding of the cat's immune response to the parasite could guide the development of treatment and vaccination protocols. In an unrelated study of Cytauxzoon felis, three cats were experimentally infected with Cytauxzoon felis via the bite of a tick (the method of transmission in natural infection). Blood was collected every other day from before infection to the time that the cats became ill. This blood was stored and is available for further testing. In the current study, we will measure the amount of different cytokines in each of the blood samples. Cytokines are small molecules that permit signaling between different cells of the immune system. It is expected that there will be a relative increase in some of the measured cytokines over the time course of infection. By understanding which of these cytokines increase with infection, a more targeted and efficient evaluation of the immune response will be possible in future studies.
Animal Health Component
(N/A)
Research Effort Categories
Basic
(N/A)
Applied
(N/A)
Developmental
(N/A)
Goals / Objectives
Cytauxzoon felis is an apicomplexan hemoprotozoan parasite that can cause severe morbidity and mortality in domestic cats. While the pathology associated with the disease is very well described, the immune response has not been reported. We hypothesize that domestic cats experimentally infected with C. felis via the bite of a tick vector will produce increased amounts of some of the proinflammatory cytokines TNF, IL-1Beta, IL-2, IL-6, and IFN gamma from the time of tick feeding through the onset of clinical illness. By understanding which of these cytokines is increased, a more targeted and efficient evaluation of the immune response will be possible. The aims of this study are to determine whether there is an increase in serum concentration of each of the aforementioned cytokines in three naive cats that were experimentally infected via tick bite and subsequently developed clinical signs of disease.
Project Methods
A feline specific bead based immunoassay (EMD Millipore) previously validated for use in cats will be used to determine TNF, IL-1Beta, IL-2, IL-6 and IFN gamma serum concentrations. The unique feature of this assay is the ability to measure multiple different cytokines on extraordinarily small volumes of plasma or serum. The assay will be performed in duplicate following the manufacturer's instructions, with optimization in our laboratory. Feline recombinant TNF, IL-1Beta, IL-2, IL-6 and IFN-gamma diluted in a plasma/serum matrix background to control for protein matrix effects will be used to construct standard curves. Median fluorescence intensity of the test wells will be compared to the median fluorescence intensity of wells containing known concentrations of each cytokine for quantification. The assay will be completed on each of the serum samples. Following quantification, cytokine concentrations will be compared temporally for an individual cat using a Friedman Repeated Measures Analysis of Variance of Ranks and Dunnett's test for post-hoc analysis to compare to baseline. Significance will be p less than 0.05.