Dataset Information

Gastrin vaccine improves response to immune checkpoint antibody in murine pancreatic cancer by altering the tumor microenvironment.

ABSTRACT: Pancreatic cancer has been termed a 'recalcitrant cancer' due to its relative resistance to chemotherapy and immunotherapy. This resistance is thought to be due in part to the dense fibrotic tumor microenvironment and lack of tumor infiltrating CD8?+?T cells. The gastrointestinal peptide, gastrin, has been shown to stimulate growth of pancreatic cancer by both a paracrine and autocrine mechanism. Interruption of gastrin at the CCK receptor may reduce tumor-associated fibrosis and alter tumor immune cells. Polyclonal Ab Stimulator (PAS) is a vaccine that targets gastrin and has been shown to prolong survival of patients with pancreatic cancer. Here, we report that PAS vaccination monotherapy elicits both a humoral and cellular immune response when used in immune competent mice-bearing pancreatic tumors and that PAS monotherapy produced a marked T-cell activation and influx of CD8?+?lymphocytes into pancreatic tumors. Isolated peripheral lymphocytes elicited cytokine release upon re-stimulation with gastrin in vitro demonstrating specificity of immune activation for the target peptide. Combination therapy with PAS and PD-1 Ab activated CD4 -/CD8 - TEMRA cells important in T-cell-mediated tumor death and memory. Tumors of mice treated with PAS (250 ?g) or PAS (100 and 250 ?g) in combination with a PD-1 Ab were significantly smaller compared to tumors from PBS or PD-1 Ab-treated mice. When PAS was given in combination with PD-1 Ab, tumors had less fibrosis, fewer inhibitory Treg lymphocytes, and fewer tumor-associated macrophages. These findings reveal a novel approach to improve treatment strategies for pancreatic cancer.

SUBMITTER: Osborne N

PROVIDER: S-EPMC6814262 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Gastrin vaccine improves response to immune checkpoint antibody in murine pancreatic cancer by altering the tumor microenvironment.

Osborne Nicholas N Sundseth Rebecca R Burks Julian J Cao Hong H Liu Xunxian X Kroemer Alexander H AH Sutton Lynda L Cato Allen A Smith Jill P JP

Cancer immunology, immunotherapy : CII 20190924 10

Pancreatic cancer has been termed a 'recalcitrant cancer' due to its relative resistance to chemotherapy and immunotherapy. This resistance is thought to be due in part to the dense fibrotic tumor microenvironment and lack of tumor infiltrating CD8 + T cells. The gastrointestinal peptide, gastrin, has been shown to stimulate growth of pancreatic cancer by both a paracrine and autocrine mechanism. Interruption of gastrin at the CCK receptor may reduce tumor-associated fibrosis and alter tumor imm ...[more]

PMID: 31549214

Similar Datasets

Project description:Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer that has proven refractory to immunotherapy. Previously, treatment with the DNA hypomethylating drug decitabine (5-aza-dC; DAC) extended survival in the KPC-Brca1 mouse model of PDAC. Here we investigated the effects of DAC in the original KPC model and tested combination therapy with DAC followed by immune checkpoint inhibitors (ICI). Four protocols were tested: PBS vehicle, DAC, ICI (anti-PD-1 or anti-VISTA), and DAC followed by ICI. For each single-agent and combination treatment, tumor growth was measured by serial ultrasound, tumor-infiltrating lymphoid and myeloid cells were characterized, and overall survival was assessed. Single-agent DAC led to increased CD4+ and CD8+ tumor-infiltrating lymphocytes (TIL), PD1 expression, and tumor necrosis while slowing tumor growth and modestly increasing mouse survival without systemic toxicity. RNA-sequencing of DAC-treated tumors revealed increased expression of Chi3l3 (Ym1), reflecting an increase in a subset of tumor-infiltrating M2-polarized macrophages. While ICI alone had modest effects, DAC followed by either of ICI therapies additively inhibited tumor growth and prolonged mouse survival. The best results were obtained using DAC followed by anti-PD-1, which extended mean survival from 26 to 54 days (P < 0.0001). In summary, low-dose DAC inhibits tumor growth and increases both TILs and a subset of tumor-infiltrating M2-polarized macrophages in the KPC model of PDAC, and DAC followed by anti-PD-1 substantially prolongs survival. Because M2-polarized macrophages are predicted to antagonize antitumor effects, targeting these cells may be important to enhance the efficacy of combination therapy with DAC plus ICI. SIGNIFICANCE: In a pancreatic cancer model, a DNA hypomethylating drug increases tumor-infiltrating effector T cells, increases a subset of M2 macrophages, and significantly prolongs survival in combination with immune checkpoint inhibitors.See related commentary by Nephew, p. 4610.

Dataset Information

Gastrin vaccine improves response to immune checkpoint antibody in murine pancreatic cancer by altering the tumor microenvironment.

Publications

Gastrin vaccine improves response to immune checkpoint antibody in murine pancreatic cancer by altering the tumor microenvironment.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets