RNA silencing serves as the primary antiviral immune system in plants, fungi, and invertebrates. Upon virus invasion, its replication intermediates act as pathogen-associated molecular patterns (PAMPs), promptly recognized and processed by Dicer into siRNAs. These virus-derived small interfering RNAs (vsiRNAs) then guide specific cleavage of the viral genome. In mammalian cells, the presence of vsiRNAs has been difficult to detect. However, recent studies indicate that vsiRNA expression can be detected when viruses infect undifferentiated mammalian cells. These findings complement new antiviral mechanisms in mammalian cells, but also face several controversies. Therefore, we will briefly discuss the current research status of vsiRNAs in mammals and analyze the controversies existing in this field.
virus-derived small interfering RNAs; antiviral immunity; mammal