PD-1 Blockade Induces Reactivation of Nonproductive T-Cell Responses Characterized by NF-κB Signaling in Patients with Pancreatic Cancer

Abstract

Purpose: Pancreatic ductal adenocarcinoma (PDAC) trials have evaluated CTLA-4 and/or PD-(L)1 blockade in patients with advanced disease where bulky tumor burden and limited time to develop anti-tumor T cells may have contributed to poor clinical efficacy. Here we evaluated peripheral blood and tumor T cells from patients with PDAC receiving neoadjuvant chemoradiation plus anti-PD-1 (pembrolizumab) versus chemoradiation alone. We analyzed whether PD-1 blockade successfully reactivated T cells in the blood and/or tumor to determine whether lack of clinical benefit could be explained by lack of reactivated T cells versus other factors. Experimental Design: We used single cell transcriptional profiling and TCR clonotype tracking to identify TCR clonotypes from blood that match clonotypes in the tumor. Results: PD-1 blockade increases the flux of TCR clonotypes entering cell cycle and induces an IFNγ signature like that seen in patients with other GI malignancies who respond to PD-1 blockade. However, these reactivated T cells have a robust signature of NF-κB signaling not seen in cases of PD-1 antibody response. Among paired samples between blood and tumor, several of the newly cycling clonotypes matched activated T cell clonotypes observed in the tumor. Conclusions: Cytotoxic T cells in the blood of PDAC patients remain sensitive to reinvigoration by PD-1 blockade and some have tumor-recognizing potential. Although these T cells proliferate and have a signature of IFN exposure, they also upregulate NF-κB signaling, which potentially counteracts the beneficial effects of anti-PD-1 reinvigoration and marks these T cells as non-productive contributors to anti-tumor immunity.

Enhanced Complement Expression in the Tumor Microenvironment Following Neoadjuvant Therapy: Implications for Immunomodulation and Survival in Pancreatic Ductal Adenocarcinoma

“…Next, we investigated the impact of NAT on carcinoma cells in more detail by utilizing the recently defined gene signatures for the seven malignant cell programs representing the lineages of carcinoma cells and the seven malignant cell states 19 . Signature scores for each of these malignant programs and cell states were calculated for all carcinoma AOIs based on the geometric mean of expression levels for their respective signature genes set.…”

“…There was no statistically significant change of signature scores for most types of immune cells in the TIME of the NAT group compared to the naïve group, except for mast cells which were increased with a marginal statistical significance (p=0.09) (Figure 4A). Next, we studied the effect of NAT on the cancer-associated fibroblasts (CAFs) within PDAC TME using the expanded CAF classification system recently defined by Hwang et al in 2022 19 , in which CAFs are categorized into 4 specific programs based their gene expression profiles, including myofibroblastic CAFs, adhesive CAFs, immunomodulatory CAFs, and neurotrophic CAFs. We computed signature scores for all four programs of CAFs within each TME AOI and analyzed the association with NAT treatment while controlling for age, gender, carcinoma grade and stage.…”

“…Single-cell RNA sequencing (scRNA-seq) is a valuable tool for characterizing TME as it provides insights into cellular heterogeneity and molecular subtypes (17,18). Several scRNA-seq studies have explored the PDAC TME, offering valuable insights into this complex ecosystem (19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35). However, scRNA-seq techniques lack spatial context, and are susceptible to cell dissociation-associated artifacts.…”

Enhanced Complement Expression in the Tumor Microenvironment Following Neoadjuvant Therapy: Implications for Immunomodulation and Survival in Pancreatic Ductal Adenocarcinoma

“…Single-cell RNA sequencing (scRNA-seq) is a valuable tool for characterizing TME as it provides insights into cellular heterogeneity and molecular subtypes 18,19 . Several scRNA-seq studies have explored the PDAC TME, offering valuable insights into this complex ecosystem [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] . However, scRNAseq techniques lack spatial context, and are susceptible to cell dissociation-associated artifacts.…”