Critical assessment of an in vitro bovine respiratory organ culture system: A model of bovine herpesvirus-1 infection

A bovine in vitro organ culture (BIVOC) system was evaluated as a model to study host and pathogen events during the course of bovine herpesvirus-1 infection. Upper respiratory tract epithelium, from slaughtered animals, was cultured in an air–liquid interface system and integrity, viability, and TNF-α gene expression of tissue explants were monitored over 72 h in the presence or absence of infection by bovine herpesvirus type 1 (BHV-1). Uninfected explants maintained viability and integrity over the 72 h time course although histological signs of degeneration were first visible from 24 h of culture. Explants were productively infected with BHV-1 and typical, dose dependent, cytopathic changes were observed in response to infection. Regulation of TNF-α gene expression in uninfected explants varied over time and was region-specific but there was significant down-regulation of TNF-α gene expression at 2 h post-infection when compared to uninfected controls at the same time point. Taking caveats into consideration the BIVOC system shows promise as a tool for analysis of immediate or early events in host–pathogen interaction.