Mechanism of Nucleic Acid Sensing in Retinal Pigment Epithelium (RPE): RIG-I Mediates Type I Interferon Response in Human RPE

Figure 3

ARPE-19 cannot sense nucleic acids in RIG-I-deficient cells. The ARPE-19 RIG-I KO cell line was generated and validated using an ARPE-19-Cas9 line (see Supplementary Figure 3). Cells were stimulated with indicated inducers at 0.25 μg/mL, and the release of IFN-β or IL-6 was measured by ELISA 24 h after stimulation. (a) The IFN response was abolished in RIG-I KO ARPE-19 cells. Similar to ARPE-19, Cas9-expressing ARPE-19 cells respond to RNA but not DNA. Interestingly, ARPE-19 RIG-I KO cells did not respond to any tested nucleic acids, further validating RIG-I as the major sensor in RPE cells. (b) The nucleic acid-induced release of IL-6 was also reduced in ARPE-19 RIG-I KO cells. Note that unlike other stimuli, the poly(I:C)-induced release of IL-6 was only partly reduced in RIG-I KO cells, suggesting the potential involvement of other sensors. compared with corresponded vehicle-treated groups. compared with same inducers in control gRNA-transduced cells.

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