Torovirus Pathogenesis and Immune Responses

Abstract

Toroviruses are pleomorphic viruses with a peplomer-bearing envelope containing an elongated tubular nucleocapsid with helical symmetry. They contain a linear, nonsegmented, positive- and single-stranded polyadenylated RNA genome. Currently only four species are recognized as members of the Torovirus genus in the Coronaviridae family: equine torovirus (EToV), initially known as Berne virus; bovine torovirus (BToV), originally known as Breda virus; human torovirus (HToV); and porcine torovirus. Torovirus-like (TVL) particles have been detected in feces from other animal species, such as turkeys, dogs, and cats. In addition, antibodies against toroviruses are frequently detected in ungulates such as horses, sheep, goats, and pigs. This chapter provides a comprehensive review of torovirus pathogenesis and immune responses. A brief epidemiological background highlighting HToVs is also provided.