Fig. 3.

Free ISG15 induces PDL-1 expression on pancreatic cancer cells. a PDL-1 mRNA levels were determined by quantitative PCR in Panc02 wild type, ISG15 knockdown, and UbcH8 knockdown cells. b Wild type Panc02 and ISG15 knockdown cells were cultured for 3 days and the culture media were collected and used as conditioned media. ISG15 knockdown cells were then cultured in the conditioned media for 3 days and quantitative PCR analysis was performed for PDL-1 expression. c IRF-1 quantitative PCR was performed on the same samples as in part b