Immunopotentiator Aikejia improves the therapeutic efficacy of PD-1/PD-L1 immunosuppressive pathway in CT26.WT cancer cell

Tumors can escape immunosurveillance through immunocheckpoint such as the PD-1/PD-L1 pathway. Aikejia comes from Nocardia rubra cell-wall skeleton and can increase the number of inflammatory factors and immune cells. In this work, we showed that the levels of PD-L1 increase in CT26.WT xenograft after subcutaneous injection of Aikejia in mice, but Aikejia did not induce the expression of PD-L1 in vitro. When we treated the mice with Aikejia and blocked PD-1/PD-L1 pathway in vivo at the same time, the CT26.WT xenografts were significantly inhibited or eliminated, which was better than single treatment alone. Our results suggested that Aikejia may be an effective adjuvant for PD-1/PD-L1 immunotherapy.