Felis catus papillomavirus type-2 but not type-1 is detectable and transcriptionally active in the blood of healthy cats

Abstract

Papillomaviruses (PVs) are small DNA viruses that induce benign and/or malignant epithelial tumours in different species, including the domestic cat (Felis catus). To date, five F. catus papillomavirus genotypes have been identified (FcaPV-1 to FcaPV-5). FcaPV-1 is associated with skin and oral benign lesions, while FcaPV-2 infection is widely associated with feline squamous cell carcinomas. Several human and animal PVs have been found in body fluids such as peripheral blood; however, the presence of FcaPVs in non-epithelial tissues has not previously been investigated. The aim of this study was to assess the presence and gene expression of FcaPV-1 and FcaPV-2 in the blood of healthy cats. We detected FcaPV-2 DNA in 26 of 103 (25%) blood samples. Importantly, FcaPV-2 L1, E2, E6 and E7 genes were found to be expressed in 3 (25%), 11 (92%), 6 (50%) and 5 (42%) of the samples available for mRNA analysis, respectively. FcaPV-1 was not detected in any of the blood samples analysed here. The data obtained in this work suggest active and eventually productive infection of FcaPV-2 in the blood of healthy cats, implying a possible role in intra-individual spreading as well as in vertical and horizontal transmission.

Detection of bovine Deltapapillomavirus DNA in peripheral blood of healthy sheep (Ovis aries )

“…This supports the earlier study that detected human alpha, beta or gamma papillomavirus DNA in the blood of 8.3% of healthy male blood donors (Chen et al., ). Furthermore, Felis catus papillomavirus type 2 belonging to Dyothetapapillomavirus genus (dyoθFcaPV) was recently detected in the blood of healthy cats (Altamura, Jebara, Cardeti, & Borzacchiello, ). Overall, there is increasing evidence that PVs can infect blood cells and the presence of PV DNA in the blood may more common than has historically been recognized.…”

Felis catus papillomavirus type-2 E6 binds to E6AP, promotes E6AP/p53 binding and enhances p53 proteasomal degradation

“…DNA from formalin-fixed paraffin embedded (FFPE) tissues and cultured cells was extracted by using the DNA Blood and Tissue kit (Qiagen #69504) following the manufacturer recommendations. Real-time PCR for amplification of a specific fragment of FcaPV-2 E6 from SCCF2 and SCCF3 cell lines was performed by using iTaq Universal SYBR Green Supermix (Bio-Rad Laboratories #1725121) according to the brand instructions, by using the primers described elsewhere 18 . DNA from CRFKpCEFL and CRFKE6 were run concomitantly as negative and positive controls, respectively.…”

“…In tissue samples, Real- time PCR for detection of viral DNA was performed as previously described 19 . Feline β-globin was amplified as previously reported to ensure the presence of amplifiable DNA in each cell and tissue sample 18 .…”

“…RT was performed on 1 µg of RNA using iScript cDNA Synthesis Kit (Bio-Rad Laboratories #1708890); RT without the addition of reverse transcriptase enzyme was also performed on each RNA sample as control. For each sample, 50 ng of cDNA were subjected to Real-time qPCR as described above to amplify a segment of FcaPV-2 E6 and p53 transcript employing the primers detailed elsewhere 18 . Amplification of feline β-2-microglobulin (β2MG) was performed in parallel to allow normalization of the results as previously reported 20 .…”

Telomerase Reverse Transcriptase (TERT) Expression, Telomerase Activity, and Expression of Matrix Metalloproteinases (MMP)-1/-2/-9 in Feline Oral Squamous Cell Carcinoma Cell Lines Associated With Felis catus Papillomavirus Type-2 Infection

“…For each sample, 1 µg of RNA was subjected to RT by using iScript cDNA Synthesis Kit (Bio-Rad Laboratories, #1708890); RT without the addition of reverse transcriptase enzyme was also performed on each RNA sample as control. Real-time qPCR was performed on 50 ng of the obtained cDNAs by using iTaq Universal SYBR Green Supermix (Bio-Rad Laboratories, #1725121) according to the brand instructions, employing the primers for feline TERT and FcaPV-2 E6 detailed elsewhere (31,32). The following primers for feline cMyc were designed based on the gene sequence previously published: cMyc-FW: 5 ′ -CAAAAGGTCGGAATCGGGGT-3 ′ , cMyc-REV: 5 ′ -CGTGGCATCTCTTAAGGACCA-3 ′ (33).…”