We evaluated whether a bovine intestinal epithelial (BIE) cell line could serve as a useful in vitro model
system for studying antiviral immune responses in bovine intestinal epithelial cells (IECs) and for the primary
screening of immunobiotic microorganisms with antiviral protective capabilities. Immunofluorescent
analyses revealed that toll-like receptor 3 (TLR3) was expressed in BIE cells, and the results of realtime
quantitative PCR showed that these cells respond to stimulation with poly(I:C) by up-regulating
pro-inflammatory cytokines and type I interferons. In addition, we demonstrated that BIE cells are useful
for the primary screening of immunobiotic lactic acid bacteria strains which are able to beneficially modulate
antiviral immune responses triggered by TLR3 activation in bovine IECs. The characterization of BIE
cells performed in the present study represents an important step towards the establishment of a valuable
bovine in vitro system that could be used for the development of immunomodulatory feed for bovine
hosts.