HSV-1-based amplicon particles are able to transduce cells of feline origin with genes encoding biologically functional feline IL-10 or IL-6

The most common viral disease of cats worldwide is the infection with feline herpesvirus 1 (FeHV-1). This infection may be followed by Herpetic stromal keratitis (HSK), which is supposed to have an immunopathological basis. Experiments using herpes simplex viruses (HSV) in mouse models indicated that HSK may be treated by topical application of the interleukin 10 (IL-10) gene. The objective of this study was the construction of human herpes simplex virus type 1 (HSV-1)-based amplicon vectors expressing feline interleukin genes and delivery of these genes into cells of feline origin. HSV-1-based amplicon vectors encoding either the enhanced green fluorescent protein, the feline IL-6 or the feline IL-10 under control of the HSV-1 immediate-early 4/5 promotor were constructed, packaged into amplicon particles, transduced into feline cells, and tested for RNA synthesis and biological activity. Feline cells were successfully transduced by HSV-1-based amplicon particles and RNA specific for the transgene was detected already at 2h post transduction, with a maximum at 24h. The recombinant feline IL-10 was functionally active as demonstrated by the reduction of both IL-12 p40 and interferon-gamma-mRNA production in Pansorbin stimulated feline peripheral mononuclear cells. Similarly, the recombinant feline IL-6, which was secreted into the supernatant of transduced cells, was able to support the growth of the IL-6-dependent murine B cell hybridoma 7TD1. HSV-1-based amplicon particles are able to transduce cells of feline origin with genes encoding biologically functional feline IL-10 or IL-6. It will be of high interest to study the effects of these tools in vivo.