Deletion of the thymidine kinase gene attenuates Caprine alphaherpesvirus type 1 in goats

Publication date: Available online 19 August 2019Source: Veterinary MicrobiologyAuthor(s): Jéssica Caroline Gomes Noll, Lok Raj Joshi, Gabriela Mansano do Nascimento, Maureen Hoch Vieira Fernandes, Bishwas Sharma, Eduardo Furtado Flores, Diego Gustavo DielAbstractCaprine alphaherpesvirus 1 (CpHV-1) is a pathogen associated with systemic infection and respiratory disease in kids and subclinical infection or reproductive failure and abortions in adult goats. The enzyme thymidine kinase (TK) is an important viral product involved in nucleotide synthesis necessary for virus replication. Therefore, it is a common target for herpesvirus attenuation. Here we deleted the tk gene of a CpHV-1 isolate and characterized the recombinant CpHV-1ΔTK in vitro and in vivo. In vitro characterization revealed that the recombinant CpHV-1ΔTK replicated to similar titers and produced plaques of similar size to the parental CpHV-1 strain in BT and CRIB cell lines. Upon intranasal inoculation, of young goats, the parental virus replicated more efficiently and for a longer period than the recombinant virus. In addition, infection with the parental virus resulted in mild systemic and respiratory signs whereas the kids inoculated with the recombinant CpHV-1ΔTK virus remained healthy. Goats inoculated with the parental virus also developed higher neutralizing antibody titers when compared to CpHV-1ΔTK inoculated animals. Dexamethasone (Dx) administration on days 35 to 39 post-inoculation did not res...
Source: Veterinary Microbiology - Category: Veterinary Research Source Type: research