Adoptive transfer of anti-nucleolin T cells combined with PD-L1 inhibition against triple-negative breast cancer

Mol Cancer Ther. 2022 Mar 21:molcanther.0823.2021. doi: 10.1158/1535-7163.MCT-21-0823. Online ahead of print.

ABSTRACT

Dendritic cell (DC)-based T cell activation is an alternative immunotherapy in breast cancer. The anti-programmed death ligand 1 (PD-L1) can enhance T cell function. Nucleolin (NCL) is overexpressed in triple-negative breast cancer (TNBC). The regulation of PD-L1 expression through autophagy and the anti-PD-L1 peptide to help sensitize T cells for NCL-positive TNBC cell killing has not been evaluated. Results showed the worst clinical outcome in patients with high NCL and PD-L1. Self-differentiated myeloid-derived antigen-presenting-cells reactive against tumors presenting NCL or SmartDCs-NCL producing GM-CSF and IL-4, could activate NCL-specific T cells. SmartDCs-NCL plus recombinant human ribosomal protein substrate 3 (RPS3) successfully induced maturation and activation of DCs characterized by the reduction of CD14 and the induction of CD11c, CD40, CD80, CD83, CD86 and HLA-DR. Interestingly, SmartDCs-NCL plus RPS3 in combination with anti-PD-L1 peptide revealed significant killing activity of the effector NCL-specific T cells against NCLHigh/PD-L1High MDA-MB-231 and NCLHigh/PD-L1High HCC70 TNBC cells at the effector: a target ratio of 5 : 1 in 2-D and 10 : 1 in the 3-D culture system; and increments of IFN-γ by the ELISpot assay. No killing effect was revealed in MCF-10A normal mammary cells. Mechanistically, NCL-specific T cell-mediated TNBC cell killing was through both apoptotic and autophagic pathways. Induction of autophagy by curcumin, an autophagic stimulator, inhibited the expression of PD-L1 and enhanced cytolytic activity of NCL-specific T cells. These findings provide the potential clinical approaches targeting NCLHigh/PD-L1High TNBC cells with NCL-specific T cells in combination with a PD-L1 inhibitor or autophagic stimulator.

PMID:35313339 | DOI:10.1158/1535-7163.MCT-21-0823