Distinct Antiviral Responses in Pluripotent versus Differentiated Cells
Figure 1
The dichotomy of antiviral responses in differentiated versus undifferentiated cells.
In most differentiated cells, PRRs (e.g., RIG-I, OAS-1/RNaseL, PKR) recognize pathogen-associated molecular patterns and stimulate the protein-based interferon response. The RNAi pathway functions, through miRNAs, to temper the expression of cytotoxic transcripts, but is inhibited in response to stress and antiviral signaling pathway activation. In undifferentiated/pluripotent cells, the interferon response is attenuated through reduced expression and activity of numerous components. In these cells, the RNAi pathway can function directly as an antiviral defense, using longer, virally derived dsRNA to generate siRNAs that target and silence viral transcripts.