Tumor-Derived Exosomal CCT6A Serves as a Matchmaker Introducing Chemokines to Tumor-Associated Macrophages in Pancreatic Ductal Adenocarcinoma [mouse RNA-seq]

M2-polarized tumor-associated macrophages (TAMs) are a key factor contributing to the poor prognosis of pancreatic ductal adenocarcinoma (PDAC). While various factors within the tumor microenvironment drive their formation, the role of PDAC-derived exosomes in this process remains unclear. We aim to clarify the regulatory impacts of tumor-derived exosomes to TAMs. Through multi-Omics analysis, we identified CCT6A as a novel tumor-derived exosomal protein, bridging TAMs M2 polarization and PDAC prognosis. Co-culture with exosomes derived from CCT6Ahigh PDAC leads to greater M2 phenotype of TAMs via PI3K-AKT signaling. According to proteomics data, chemokines’ abundance reduces over tenfold once exosomal CCT6A absence, including CXCL1, CXCL3, CXCL20 and CCL5, whose interaction with CCT6A in PDAC cells was confirmed by interactomics data. Morever, we found CCT6A clearance abrogated the antagonism effects of CD47 antibody immunotherapy. The subunit of the T-complex protein Ring Complex (TRiC) CCT6A serves as a matchmaker, during exosomes-mediated chemokines transfer from PDAC to TAMs. Subcutaneous mouse models of pancreatic cancer were established using KPC cells. The mice were then treated with either KPC-derived exosomes or PBS, and tumor tissues were subsequently harvested for RNA sequencing and transcriptome analysis.