mTOR inhibitor, gemcitabine and PD-L1 antibody blockade combination therapy suppresses pancreatic cancer progression via metabolic reprogramming and immune microenvironment remodeling in Trp53flox/+LSL-KrasG12D/+Pdx-1-Cre murine models

•SPG decreased tumor growth in Trp53flox/+LSL-KrasG12D/+Pdx-1-Cre murine models.•The combination therapy changed the immune microenvironment of PC.•Change of immune microenvironment was related to metabolic reprogramming.•Sirolimus-induced metabolic reprogramming affected macrophages' anti-tumor activity.