TLR3 and infection: Although other pattern recognition receptors (PRR), such as retinoic acid-inducible gene protein I (RIG-I) and melanoma differentiation-associated protein 5 (MDA-5), belong to the RIG-I-like receptor (RLR) family and might also be involved in the innate immune response against EIAV infection, our results indicate that enhancing TLR3 expression alone effectively improved the ability of macrophages to resist to EIAVUK3 infection.