Comparative study on the in vitro replication and genomic variability of Argentinean field isolates of bovine herpesvirus type 4 (BoHV-4)

Abstract

Bovine herpesvirus 4 (BoHV-4) is a gammaherpesvirus, belonging to the Rhadinovirus genus, which is increasingly associated with various problems of the reproductive tract of cattle. In Argentina, analysis of BoHV-4 strains isolated from cervico-vaginal mucus of aborted cows revealed a high genetic divergence among strains, which could be classified in three different groups: Genotype 1 comprises Movar-like strains (European prototype), Genotype 2 includes DN599-like strains (American prototype) and Genotype 3 corresponds to a novel genotype group. Understanding the replication behavior in cell cultures and the molecular characteristics of this pathogen of cattle is critical for the rational design of in vitro experiments. The aim of this work was to quantitatively evaluate the replication properties of different Argentinean BoHV-4 strains and to characterize their phylogenetic relationships. Significant differences were evident among the virus titers of the different BoHV-4 isolates in vitro. The most conserved gene was the major capsid protein (ORF25). The glycoprotein B (gB), glycoprotein H (gH), and thymidine kinsase (TK) genes displayed both synonymous and non-synonymous substitutions, with the highest diversity observed for gB, which displayed amino acid substitutions in 24 out of the 178 positions examined. Strains 09/759, 12/512, and 07/568 presented a deletion encompassing amino acid position 27 to 35, whereas strains 07/435 and 09/227 had a deletion from position 28 to 35. Two strains, 07/435 and 09/227, also displayed the highest divergence compared to the other strains analyzed. This study provides information about the in vitro replication and behavior of nine field isolates of BoHV-4. These findings are relevant since available information on the in vitro growth characteristics of BoHV-4 strains is scarce. The results from this study may also be useful for establishing comparisons with other related viruses.

Comparative analysis of replicative properties of phylogenetically divergent, Argentinean BoHV-4 strains in cell lines from different origins

“…coincidently, a significant variation in the kinetics of replication of different BoHV4 local isolates has been previously reported by our research group [35].…”

“…highlights the significance of studying the role of this virus. Furthermore, although the genomic characterization of these strains is currently being expanded, in previous studies, synonymous and non-synonymous substitutions have been observed in the gB, gH and Tk genes of the strains analyzed in this work [26,35].…”

“…Determining the kinetics of viral replication is relevant for the in vitro characterization of viruses. Although information on the susceptibility of several cell lines to the infection by BoHV4 is available [20], the in vitro behaviour of some Argentinean strains has been only analyzed on one cell lines from bovine origin [35]. Therefore, the aim of the present study was to comparatively evaluate the biological characteristics of six Argentinean BoHV4 field isolates in four cell lines from different origins.…”

Whole Genome Sequencing of a Canadian Bovine Gammaherpesvirus 4 Strain and the Possible Link between the Viral Infection and Respiratory and Reproductive Clinical Manifestations in Dairy Cattle

“…Notably, virus genomic differences can potentially lead to different pathogenic potential. This was recently demonstrated in vitro when replication kinetics and virus titers of different BoHV-4 strains were compared (46). Most of the divergences between BoHV-4 genomes were in the Bo genes and in the repeat regions (Figure 2).…”

Tissular Distribution of Argentinean Strains of Bovine Herpesvirus Type 4 (BoHV-4) in Experimentally-Infected Calves

“…Nevertheless, the findings of this study provide an initial step to understand the biology of the Argentinean isolates of BoHV-4. The high variability among strains isolated in Argentina (Verna et al 2012(Verna et al , 2016 highlights the significance of research on the role of this virus as an infectious agent capable of causing reproductive disease in cattle. This is the first report in Argentina on histopathological findings and tissue distribution of BoHV-4 in its natural host after an experimental infection…”