TY - JOUR

T1 - Further evidence of Chelonid herpesvirus 5 (ChHV5) latency

T2 - high levels of ChHV5 DNA detected in clinically healthy marine turtles

AU - Alfaro Nuñez, Luis Alonso

AU - Bojesen, Anders Miki

AU - Bertelsen, Mads Frost

AU - Wales, Nathan

AU - Balazs, George H.

AU - Gilbert, Tom

PY - 2016/7/27

Y1 - 2016/7/27

N2 - The Chelonid herpesvirus 5 (ChHV5) has been consistently associated with fibropapillomatosis (FP), a transmissible neoplastic disease of marine turtles. Whether ChHV5 plays a causal role remains debated, partly because while FP tumours have been clearly documented to contain high concentrations of ChHV5 DNA, recent PCR-based studies have demonstrated that large proportions of asymptomatic marine turtles are also carriers of ChHV5. We used a real-time PCR assay to quantify the levels of ChHV5 Glycoprotein B (gB) DNA in both tumour and non-tumour skin tissues, from clinically affected and healthy turtles drawn from distant ocean basins across four species. In agreement with previous studies, higher ratios of viral to host DNA were consistently observed in tumour versus non-tumour tissues in turtles with FP. Unexpectedly however, the levels of ChHV5 gB DNA in clinically healthy turtles were significantly higher than in non-tumour tissues from FP positive turtles. Thus, a large proportion of clinically healthy sea turtle populations worldwide across species carry ChHV5 gB DNA presumably through persistent latent infections. ChHV5 appears to be ubiquitous regardless of the animals' clinical conditions. Hence, these results support the theory that ChHV5 is a near ubiquitous virus with latency characteristics requiring co-factors, possibly environmental or immune related, to induce FP.

AB - The Chelonid herpesvirus 5 (ChHV5) has been consistently associated with fibropapillomatosis (FP), a transmissible neoplastic disease of marine turtles. Whether ChHV5 plays a causal role remains debated, partly because while FP tumours have been clearly documented to contain high concentrations of ChHV5 DNA, recent PCR-based studies have demonstrated that large proportions of asymptomatic marine turtles are also carriers of ChHV5. We used a real-time PCR assay to quantify the levels of ChHV5 Glycoprotein B (gB) DNA in both tumour and non-tumour skin tissues, from clinically affected and healthy turtles drawn from distant ocean basins across four species. In agreement with previous studies, higher ratios of viral to host DNA were consistently observed in tumour versus non-tumour tissues in turtles with FP. Unexpectedly however, the levels of ChHV5 gB DNA in clinically healthy turtles were significantly higher than in non-tumour tissues from FP positive turtles. Thus, a large proportion of clinically healthy sea turtle populations worldwide across species carry ChHV5 gB DNA presumably through persistent latent infections. ChHV5 appears to be ubiquitous regardless of the animals' clinical conditions. Hence, these results support the theory that ChHV5 is a near ubiquitous virus with latency characteristics requiring co-factors, possibly environmental or immune related, to induce FP.

KW - Chelonid herpesvirus 5 (ChHV5)

KW - Fibropapillomatosis (FP)

KW - Glycoprotein B

KW - Clinically healthy

KW - Quantitative PCR

KW - Viral loads

KW - Ubiquitous

KW - Asymptomatic

U2 - 10.7717/peerj.2274

DO - 10.7717/peerj.2274

M3 - Journal article

C2 - 27547576

VL - 4

JO - PeerJ

JF - PeerJ

SN - 2167-8359

M1 - e2274

ER -