Meanwhile, Met@Man-MPs-reset macrophages efficiently reconstructed antitumor immune microenvironment to improve anti-PD-1 therapy by decreasing the numbers of Tregs and MDSCs and increasing the recruitment of CD8+ T cells in tumor tissues, as evidenced by the fact that macrophage depletion using clodronates liposomes significantly abrogated the improved tumor immune microenvironment induced by Met@Man-MPs. Here, PDCD1 is linked to neoplasm.