Replication kinetics of bovine gammaherpesvirus 4 in the presence of platelet rich plasma in vitro

Abstract

Diseases of the reproductive tract are a frequent problem in dairy herds. Herpesviruses cause several syndromes including uterine diseases. The role of bovine gammaherpesvirus 4 (BoGHV-4) in the development of endometritis has not been clearly described. Platelet-rich plasma (PRP) is an emerging therapeutic in tissue regeneration due to its enrichment in growth factors with mitogenic and anti-inflammatory potential. This study analysed the replication kinetics of BoGHV-4 in the presence of 5% and 10% PRP, compared to 10% fetal bovine serum. For this, Madin-Darby Bovine Kidney (MDBK) and primary culture-derived endometrial bovine (BEC) cells and the field BoGHV4 strain 07/435 were used. Supernatants and cells were collected at 12, 24, and 48 hours post infection (hpi) for virus titration using the endpoint titration method. A factorial model, as a function of time and treatment, testing hypotheses of absence of interaction was used. Viral titers (VT) were fitted to polynomial regression models. The extracellular VT in BEC cells were not affected by the treatment at any time-points. However, intracellular titers at 24 hpi were significantly higher with 5% PRP and decreased with 10% PRP. At 72 hpi, the VT with PRP significantly decreased compared to earlier time-points. Extracellular BoGHV-4 titers in MDBK, were significantly higher with 5%PRP at all times. Conversely, with 10%PRP, the VT decreased at 48 hpi. However, a significant increase was observed at 72 hpi. This study demonstrates that PRP has strong effects on the replication kinetics of BoGHV4, being highly dependent on the host cell.