Feline Foamy Virus Infection: Characterization of Experimental Infection and Prevalence of Natural Infection in Domestic Cats with and without Chronic Kidney Disease.

Carmen Ledesma-Feliciano,Ryan M Troyer,Craig Miller,Martin Löchelt,Matteo Bordicchia,Xin Zheng,Sue Vandewoude,Nicholas Dannemiller,Rachel Cianciolo,Roderick Gagne,Jessica Quimby,Julia Beatty

doi:10.3390/v11070662

Abstract

Foamy viruses (FVs) are globally prevalent retroviruses that establish apparently apathogenic lifelong infections. Feline FV (FFV) has been isolated from domestic cats with concurrent diseases, including urinary syndromes. We experimentally infected five cats with FFV to study viral kinetics and tropism, peripheral blood mononuclear cell (PBMC) phenotype, urinary parameters, and histopathology. A persistent infection of primarily lymphoid tropism was detected with no evidence of immunological or hematologic perturbations. One cat with a significant negative correlation between lymphocytes and PBMC proviral load displayed an expanded FFV tissue tropism. Significantly increased blood urea nitrogen and ultrastructural kidney changes were noted in all experimentally infected cats, though chemistry parameters were not outside of normal ranges. Histopathological changes were observed in the brain, large intestine, and other tissues. In order to determine if there is an association of FFV with Chronic Kidney Disease, we additionally screened 125 Australian pet cats with and without CKD for FFV infection and found that FFV is highly prevalent in older cats, particularly in males with CKD, though this difference was not statistically significant compared to controls. Acute FFV infection was clinically silent, and while some measures indicated mild changes, there was no overt association of FFV infection with renal disease.

Highlights

Feline foamy virus (FFV) is a retrovirus belonging to the ancient Spumaretrovirinae subfamily that infects domestic cats (Felis catus) and was originally discovered following development of cytopathic effects (CPEs) in feline cell lines [1,2]
We found that while FFV is highly prevalent in AU, there was no direct association between FFV infection and Chronic kidney disease (CKD) pathology in our sampled population
Provirus was primarily isolated from in renal tissues during acute FFV infection (Figure 6A and Table 4), we investigated the potential association of FFV with CKD in Australian client-owned cats following natural FFV infection

Summary

Introduction

Feline foamy virus (FFV) is a retrovirus belonging to the ancient Spumaretrovirinae subfamily that infects domestic cats (Felis catus) and was originally discovered following development of cytopathic effects (CPEs) in feline cell lines [1,2]. In naturally-occurring and experimental infections of the domestic cat, FFV infection does not cause obvious disease, and has not been definitively associated with pathology despite establishing a persistent, life-long infection with a wide tissue tropism [3,6,7,8,9,10,11]. It is believed the apathogenicity of FVs in general is due to long periods of co-evolution with their hosts that has led to a disease-free or highly-attenuated infection [2,12,13]. In cats, biting and amicable prolonged contact, such as grooming, have been suggested as routes of transmission [7,15,16]

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Conclusion