2007 Miller Trust Grant Awards
January 7, 2008 (published)
Winn Feline Health Foundation

EveryCat Health Foundation
(formerly Winn Feline Health Foundation)

George and Phyllis Miller Trust
San Francisco Foundation
Six studies funded for a total of $99,909

RNA interference of feline herpesvirus by synthetic siRNAs in corneal epithelial cells.
Rebecca P. Wilkes, DVM and Stephen A. Kania, PhD; University of Tennessee. $15,000 (Continuation of previously funded project)

Feline herpesvirus 1 (FHV-1) is a DNA virus that produces the most clinically significant respiratory disease of cats. Vaccines only confer partial protection from clinical disease, and antiviral medications approved for treatment of HSV-1 in humans are minimally effective for treatment of chronic herpesvirus cases in cats. Therefore, we evaluated RNA interference (RNAi), a RNA-guided gene regulatory mechanism that is found in a variety of eukaryotic organisms and provides anti-viral immunity in plants as a therapeutic method for suppression of FHV-1 infection in feline cells. We discovered that RNAi can be used to dramatically reduce FHV-1 replication in an immortalized cell line by targeting essential viral genes, including the viral DNA polymerase and glycoprotein D, an envelope protein apparently involved in viral attachment and/or cell penetration. Therefore, RNAi is a potential therapeutic agent for FHV-1. The purpose of this study is to evaluate RNAi for FHV-1 in primary corneal epithelial cells and determine which concentration and combinations of small interfering RNAs will produce the most dramatic reduction in FHV-1 replication in this cell line. Use of corneal epithelial cells as an in vitro model more closely resembles the in vivo environment preferred by the virus.

Association of vaccine administration with systemic disease in cats.
Michael Lappin, DVM, PhD, DACVIM, and Jacqueline C. Whittemore, DVM., PhD, DACVIM; Colorado State University. $25,000

Widespread vaccination of feline patients has been associated with dramatic decreases in morbidity and mortality from a variety of diseases. The vaccine against feline herpesvirus, calicivirus, and panleukopenia virus (FVRCP) remains one of the most commonly administered feline vaccinations. The viruses included in this vaccine are frequently cultivated using the Crandell Rees Feline Kidney (CRFK) cell line, a cell line grown from naïve feline kidney tissue. Previous work has documented CRFK antibody development post-vaccination and has suggested an association with interstitial nephritis in hyperinoculated cats. The immunodominant CRFK antigens have been identified as α-enolase, annexin A2, and cap G/macrophage capping protein (MCP). Autoantibody development against α-enolase and annexin A2 is associated with autoimmune disease in other species. Given these proteins are highly conserved among species it is possible that FVRCP vaccination may be associated with feline immune-mediated disease in both renal and non-renal tissues through induction of anti-α-enolase and anti-annexin A2 antibodies. In this project, we will use commercially available human and murine α-enolase, α-enolase-HE, and annexin A2 to develop protein-specific ELISAs. To assess potential associations between antibody levels and common diseases of cats, these ELISAs will be applied to banked sera from 5 populations of cats: 1,477 privately-owned cats with complete biochemical profile data; pair-matched samples from cats with and without suspected idiopathic uveitis, azotemia, and stomatitis; and sera from 500 cats with varying results in the pancreatic lipase immunoreactivity assay (PLI) as a marker of pancreatitis.

Adrenocortical function in cats with feline interstitial cystitis.
C. A. Tony Buffington, DVM. PhD, DACVN and Linda Lord, DVM, PhD; The Ohio State University. $25,920

The purpose of this study is to test the hypothesis that adrenocortical dysfunction plays a role in feline interstitial cystitis (FIC). This syndrome is the most common cause of lower urinary tract signs in domestic cats, occurring in approximately 1% of client owned cats. Millions of cats are euthanized as a result of inappropriate elimination, making this a major veterinary problem. Our laboratory has identified both anatomical and functional adrenocortical abnormalities in cats with FIC that may be important in treatment. Based on preliminary data, we propose to compare adrenocortical steroid hormones (ACSH) concentrations in 32 neutered healthy and FIC cats of both sexes housed in our research colony. The presence of both healthy and affected cats in our colony assures that all cats will be kept under the same housing and environmental conditions, reducing some common sources of variability. We will use these data to design ASCH replacement therapy to test the effects of repair of identified abnormalities on physiological responses of 32 male and female cats with FIC using a prospective, blinded, placebo controlled design. We expect these experiments to confirm and extend our preliminary results of ASCH abnormalities in cats with FIC, and that replacement therapy will result in statistically and clinically positive outcome on relevant physiological parameters. These studies are intended to lead to development of an appropriate hormone replacement mixture that could be administered by pellet (comparable in size to a microchip) for long term therapy.

A novel heritable progressive retinal atrophy in the Bengal cat breed.
Leslie A. Lyons, PhD; University of California, Davis. $7,260

Inherited progressive retinal atrophies (PRA) are recognized in humans, cats and other species. An early-onset, autosomal recessive PRA has been documented in Persians and two forms of PRA, one autosomal dominant form with early onset and one autosomal recessive form with late onset are known in Abyssinians. A potentially novel form of PRA has been identified in cats of the Bengal breed. A 9-month intact Bengal male (proband) was presented to the U.C. Davis Veterinary Medicine Teaching Hospital with the presenting complaint of tapetal hyperreflectivity. Fundic examinations identified bilateral retinal vessel attenuation, slowed pupillary and dazzle reflexes and tapetal hyperreflectivity. Behavioral examinations suggested compromised vision. A second male Bengal of 5 months of age was identified as part of an ophthalmic evaluation of a litter of related kittens. Pedigree analyses and interactions with breeders have identified 9 Bengals that form an extended family of Bengal cats with a mid-onset form of PRA. Pedigree evaluations and controlled breedings suggest an autosomal recessive disease. A repeat breeding has been performed by the breeders to produce cats for the Bengal PRA project. The proband male has been donated to U.C. Davis for breeding studies. The proband has been bred to a PRA-affected Persian and a PRA-affected Somali to test if the diseases are within the same genes, but different mutations (complementation tests). This project proposes the clinical and genetic evaluation of a novel PRA in Bengal cats. The complementation tests may suggest genes for mutation screening and the breedings will produce kittens for clinical characterization.

Are differences in feline calicivirus (FCV) tissue tropism and virulence determined by changes in virus interactions with cell surface glycans?
John S. L. Parker, DVM, PhD; Baker Institute for Animal Health, Cornell University. $15,750

New isolates of feline calicivirus (FCV) cause severe life-threatening virulent systemic (VS) disease. VS-FCV isolates differ from non-VS isolates in their tissue and cell tropism, infecting epithelial and endothelial cells in several different organs. Expanded cell and tissue tropism is often a consequence of changes in virus-receptor interactions. We have shown that VS-FCV isolates spread more rapidly in tissue culture than non-VS FCV isolates. Our long-term goals are to understand the relationship between FCV-receptor interactions and viral tropism, and to identify what role these interactions play in FCV virulence. Our central hypothesis is that increased rate of spread in tissue culture and altered tropism of VS-FCV isolates are partly determined by specific virus-receptor interactions. Recently, two cell surface molecules were identified as receptors for FCV - feline junctional adhesion molecule and a2,6-linked sialic acid. Glycans (carbohydrates, e.g. sialic acid) are common receptor molecules for viruses and are often major determinants of tropism. The goals of this project are to determine the role that glycans play in determining the cell tropism of different FCV isolates and to identify the range of different glycans that FCV isolates can bind. We expect one outcome of these studies will be greater understanding of the role of glycans in FCV tropism and virulence. Studies of the basic biology of FCV are essential for rational development of new methods of diagnosis, treatment and prevention of FCV disease.

Oxidative stress and antioxidant therapy in cats with renal failure.
Craig B. Webb, PhD, DVM; Colorado State University. $10,979

Oxidative stress is an important component in the progression of chronic renal failure. Reactive oxygen species increase vascular resistance and promote hypertension, alter NF-kappaB expression, and both perpetuate as well as mediate many of the deleterious effects of chronic renal inflammation. The superoxide anion is a short-lived but critical free radical, and levels of the enzymatic antioxidant superoxide dismutase are reduced in human patients with chronic renal failure. This study is designed to determine the level of oxidative stress in cats with chronic renal failure compared to healthy control cats. Measures of oxidative stress as well as neutrophil function will be obtained in two groups of 10 cats. Samples will be collected for a biochemical profile, complete blood count, urinalysis, urine culture, blood pressure, whole blood levels of superoxide dismutase enzyme, glutathione peroxidase enzyme, malondialdehyde, and neutrophil phagocytosis and oxidative burst production. Statistical comparisons will be made among groups. It is hypothesized that oxidative stress in cats with chronic renal failure is significantly greater than in healthy cats, and identification of those parameters of oxidative stress that are most elevated will help direct future efforts at appropriate antioxidant supplementation in this common clinical condition of felines.