IFNγ treatment restores TAP-dependent presentation competence of PD-L1 sensitive PDAC cells
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ABSTRACT: For immunotherapy, there is an urgent need to restore presentation-competence of cancer cells with defects in MHC-I processing/presentation. We identified two tumor-specific antigens expressed in the ER of pancreatic ductal adenocarcinoma cells (PDACCs) that induced effector CD8 T cells either independent (Cripto-1-Kb/Cr16-24) or dependent (gp70-Kb/p15E) on TAP-mediated antigen processing/presentation by DNA immunization. In systematic analyses, we showed that transplantation into syngeneic C57BL/6J mice or IFNγ-treatment in vitro upregulated MHC-I but also co-inhibitory PD-L1 molecules on PDACCs. IFNγ-treated PDACCs efficiently formed solid tumors in transplanted C57BL/6J and PD-L1-/- but were rejected in PD-1-/- mice. PDACCs induced a prophylactic immunity against tumor transplants in C57BL/6J mice when irradiated at day 2-3 post IFNγ-treatment, thereby silencing the tumor-initiated immune-suppressive PD-L1/PD-1-signaling axis. Immune-protection correlated with a significant enhanced induction of CD8 T cells against the TAP- but not the TAP-dependent antigen/epitope.
ORGANISM(S): Mus musculus
PROVIDER: GSE140397 | GEO | 2020/08/06
REPOSITORIES: GEO
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