A novel target for combination immunotherapy in pancreatic cancer: IL-1β mediates immunosuppression in the tumour microenvironment

TiSe2-mediated sonodynamic and checkpoint blockade combined immunotherapy in hypoxic pancreatic cancer

Background

Pancreatic cancer remains among the most prevalent and aggressive forms of cancer. While immunotherapeutic treatment strategies have shown some promise in affected patients, the benefits of these interventions have been limited by insufficient tumor infiltration by activated T cells.

Results

Here, Titanium diselenide (TiSe₂) nanosheets were synthesized with good stability. When exposed to ultrasound (US), the TiSe₂ nanosheets served as a reliable nano-sensitizer capable of inducing large amounts of reactive oxygen species (ROS) mediating sonodynamic therapy (SDT) under hypoxic and normoxic conditions. The tumor-released TAAs induced by TiSe₂ nanosheet-mediated SDT promoted immunogenic cell death (ICD) conducive to the maturation of dendritic cells (DCs), and cytokine secretion and the subsequent activation and infiltration of T cells into the tumor. Combining TiSe₂-mediated SDT with anti-PD-1 immune checkpoint blockade treatment led to the efficient suppression of the growth of both primary tumor and distant tumor, while simultaneously preventing lung metastasis. These improved immunotherapeutic and anti-metastatic outcomes were associated with activated systematic antitumor immune responses, including the higher levels of DC maturation and cytokine secretion, the increased levels of CD8⁺ T cells and the decreased levels of T_reg cells infiltrated in tumors.

Conclusion

TiSe₂ can be used as a sonosensitizer with good efficacy and high safety to mediate efficient SDT. The combination treatment strategy comprised of TiSe₂-mediated SDT and PD-1 blockade activate anti-tumor immune responses effectively thorough inducing ICD, resulting in the inhibition the growth and metastasis of tumor. The combination therapy holds promise as a novel immunotherapy-based intervention strategy for pancreatic cancer patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01659-4.

Combination immunotherapy for pancreatic cancer: challenges and future considerations

INTRODUCTION

: Immune checkpoint inhibitors (ICI) have not yielded significant efficacy in pancreatic ductal adenocarcinoma (PDA), despite the role of the innate and adaptive immune systems on progression and survival. However, recently identified pathways have identified new targets and generated promising clinical investigations into promoting an effective immune-mediated antitumor response in PDA.

AREAS COVERED

: We review biological mechanisms associated with immunotherapy resistance and outline strategies for therapeutic combinations with established and novel therapies in PDA.

EXPERT OPINION

: Pancreatic cancers rarely benefits from treatment with ICI due to an immunosuppressive tumor microenvironment (TME). New understandings of factors associated with the suppressive TME, include low and poor quality neoantigens, constrained effector T cells infiltration, and the presence of a dense, suppressive myeloid cell population. These findings have been translated into new clinical investigations evaluating novel therapies in combination with ICI and/or standard systemic chemotherapy and radiotherapy. The epithelial, immune, and stromal compartments are intricately related in PDA, and the framework for successful targeting of this disease requires a comprehensive and personalized approach.

Single-cell transcriptomics reveals shared immunosuppressive landscapes of mouse and human neuroblastoma

BACKGROUND

High-risk neuroblastoma is a pediatric cancer with still a dismal prognosis, despite multimodal and intensive therapies. Tumor microenvironment represents a key component of the tumor ecosystem the complexity of which has to be accurately understood to define selective targeting opportunities, including immune-based therapies.

METHODS

We combined various approaches including single-cell transcriptomics to dissect the tumor microenvironment of both a transgenic mouse neuroblastoma model and a cohort of 10 biopsies from neuroblastoma patients, either at diagnosis or at relapse. Features of related cells were validated by multicolor flow cytometry and functional assays.

RESULTS

We show that the immune microenvironment of MYCN-driven mouse neuroblastoma is characterized by a low content of T cells, several phenotypes of macrophages and a population of cells expressing signatures of myeloid-derived suppressor cells (MDSCs) that are molecularly distinct from the various macrophage subsets. We document two cancer-associated fibroblasts (CAFs) subsets, one of which corresponding to CAF-S1, known to have immunosuppressive functions. Our data unravel a complex content in myeloid cells in patient tumors and further document a striking correspondence of the microenvironment populations between both mouse and human tumors. We show that mouse intratumor T cells exhibit increased expression of inhibitory receptors at the protein level. Consistently, T cells from patients are characterized by features of exhaustion, expressing inhibitory receptors and showing low expression of effector cytokines. We further functionally demonstrate that MDSCs isolated from mouse neuroblastoma have immunosuppressive properties, impairing the proliferation of T lymphocytes.

CONCLUSIONS

Our study demonstrates that neuroblastoma tumors have an immunocompromised microenvironment characterized by dysfunctional T cells and accumulation of immunosuppressive cells. Our work provides a new and precious data resource to better understand the neuroblastoma ecosystem and suggest novel therapeutic strategies, targeting both tumor cells and components of the microenvironment.

First-in-human phase 1 dose-escalation study of CAN04, a first-in-class interleukin-1 receptor accessory protein (IL1RAP) antibody in patients with solid tumours

BACKGROUND

Interleukin-1 (IL-1) signalling is involved in various protumoural processes including proliferation, immune evasion, metastasis and chemoresistance. CAN04 is a first-in-class monoclonal antibody that binds IL-1 receptor accessory protein (IL1RAP), required for IL-1 signalling. In this first-in-human phase 1 study, we assessed safety, recommended phase 2 dose (RP2D), pharmacokinetics, pharmacodynamics and preliminary anti-tumour activity of CAN04 monotherapy.

METHODS

Patients with advanced solid tumours known to express IL1RAP and refractory to standard treatments were enrolled in a dose-escalation study with 5 dose levels (1.0-10.0 mg/kg) of weekly CAN04.

RESULTS

Twenty-two patients were enrolled. Most common adverse events were infusion-related reactions (41%), fatigue (32%), constipation (27%), diarrhoea (27%), decreased appetite (23%), nausea (23%) and vomiting (23%). One dose limiting toxicity was reported. No maximum tolerated dose was identified. Pharmacokinetics analyses indicate higher exposures and slower elimination with increasing doses. Decreases in serum IL-6 and CRP were observed in most patients. Twenty-one patients were evaluable for response, 43% had stable disease per immune-related response criteria with no partial/complete responses.

CONCLUSIONS

The IL1RAP targeting antibody CAN04 can be safely administered to patients up to 10.0 mg/kg weekly, which was defined as the RP2D. Serum biomarkers supported target engagement and IL-1 pathway inhibition.

CLINICAL TRIAL REGISTRATION

NCT03267316.

Pancreatic Ductal Adenocarcinoma (PDAC) circulating tumor cells influence myeloid cell differentiation to support their survival and immunoresistance in portal vein circulation

The portal venous circulation provides a conduit for pancreatic ductal adenocarcinoma (PDAC) tumor cells to the liver parenchyma sinusoids, a frequent site of metastasis. Turbulent flow in the portal circulation promotes retention of PDAC shed circulating tumor cells (CTC) and myeloid-derived immunosuppressor cells (MDSC). Excessive colony stimulating factor-1 receptor (CSF1R) signaling can induce myeloid differentiation to MDSC and transformation of MDSC to myeloid-derived fibroblasts (M-FB). Interactions between PDAC CTC and M-FB in the portal blood promotes the formation of immunoresistant clusters that enhance CTC proliferation, migration, and survival. Analysis of portal and peripheral blood samples collected intraoperatively from 30 PDAC patients undergoing pancreatico-duodenectomy showed that PDAC patient plasma contained high levels of macrophage colony stimulating factor (M-CSF/CSF1), granulocyte-macrophage colony stimulating factor (GM-CSF/CSF2), interleukin-8 (IL-8), and interleukin-34 (IL-34) compared to healthy control levels. Moreover, the level of M-CSF in portal blood was significantly higher than that detected in the peripheral blood of PDAC patients. PDAC CTC aseptically isolated by fluorescence activated cell sorting (FACS) out of freshly collected patient portal blood mononuclear cells (PortalBMC) had elevated RNA expression of IL34 (IL-34 gene) and CSF1 (M-CSF/CSF1 gene) which both signal through CSF1R. PDAC CTC also had high levels of RNA expression for CXCL8, the gene encoding chemokine interleukin-8 (IL-8) which can attract myeloid cells through their CXCR2 receptors. FACS-isolated portal PDAC CTC and M-FB co-cultured ex vivo had increased CTC proliferation, motility, and cluster formation compared to CTC cultured alone. CSF1R and CXCR2 cell surface expression were found on PDAC portal blood CTC and M-FB, suggesting that both cell types may respond to M-CSF, IL-34, and IL-8-mediated signaling. Portal PDAC CTC displayed enhanced RNA expression of CSF1 and IL34, while CTC+M-FB+ clusters formed in vivo had increased RNA expression of CSF2 and IL34. Portal M-FB were found to have high CSF1R RNA expression. CTC isolated from ex vivo 7-day cultures of PDAC patient portal blood mononuclear cells (PortalBMC) expressed elevated CSF1, IL34, and IL8 RNA, and CSF1 expression was elevated in M-FB. Treatment with rabbit anti-CSF1R antibodies decreased CTC proliferation. Treatment of PortalBMC cultures with humanized anti-CSF1R, humanized anti-IL-8, or anti-IL-34 antibodies disrupted CTC cluster formation and increased CTC apoptosis. U937 myeloid precursor cell line cultures treated with conditioned media from PortalBMC ex vivo cultures without treatment or treated with anti-IL-8 and/or anti-CSF1R did not prevent myeloid differentiation in the myeloid precursor cell line U937 to macrophage, dendritic cell, MDSC, and M-FB phenotypes; whereas, U937 cultures treated with conditioned media from PortalBMC ex vivo cultures exposed to anti-IL-34 were significantly inhibited in their myeloid differentiation to all but the M-FB phenotype. PDAC patient T cells that were found phenotypically anergic (CD3+CD25+CTLA4+PD1L1+) in PortalBMC could be re-activated (CD3+CD25+CTLA4-PD1L1-), and displayed increased interferon gamma (IFNγ) production when PortalBMC ex vivo cultures were treated with anti-CSF1R, anti-IL-8, and anti-IL-34 antibodies alone or in combination. These findings suggest that PDAC CTC have the potential to influence myeloid differentiation and/or antigen presenting cell activation in the PDAC portal blood microenvironment, and that disruption of CTC/M-FB interactions may be potential targets for reversing the immunosuppression supporting CTC survival in the portal blood.

Effects of Forkhead box O1 on lipopolysaccharide-induced mitochondrial dysfunction in human cervical squamous carcinoma SiHa cells

Persistent infection and chronic inflammation play important roles in the development of cervical squamous cell carcinoma. Forkhead box O1 (FOXO1) is a notable regulator of mitochondrial metabolism, which is involved in the occurrence and development of tumors. The present study explored the effects of FOXO1 in human cervical squamous carcinoma SiHa cells. The expression of FOXO1 was examined using reverse transcription-quantitative PCR, western blotting and immunohistochemical staining. SiHa cell migration and proliferation were detected using Transwell and ³H-TdR assays. Mitochondrial functions were assessed based on reactive oxygen species (ROS) generation and changes in the mitochondrial membrane potential (ΔΨm). The present study revealed that lipopolysaccharide (LPS) stimulation significantly inhibited the expression of FOXO1 in cervical squamous carcinoma SiHa cells; while silencing FOXO1 resulted in the accumulation of mitochondrial ROS, a decrease in the ΔΨm and abnormal morphology of mitochondria. Accordingly, enhancing FOXO1 expression or treatment with metformin, which protects mitochondrial function, reversed LPS-induced mitochondrial dysfunction, cell pyroptosis, migration and proliferation of cervical squamous carcinoma SiHa cells. Overall, the current study indicated that treatment with FOXO1 could potentially be used as therapeutic strategy to prevent LPS-induced cervical squamous cell carcinoma-related dysfunction in a mitochondria-dependent manner.