scholarly journals Interactions between Cancer-Associated Fibroblasts and T Cells in the Pancreatic Tumor Microenvironment and the Role of Chemokines

Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2995
Author(s):  
Laia Gorchs ◽  
Helen Kaipe

Less than 10% of patients diagnosed with pancreatic ductal adenocarcinoma (PDAC) survive 5 years or more, making it one of the most fatal cancers. Accumulation of T cells in pancreatic tumors is associated with better prognosis, but immunotherapies to enhance the anti-tumor activity of infiltrating T cells are failing in this devastating disease. Pancreatic tumors are characterized by a desmoplastic stroma, which mainly consists of activated cancer-associated fibroblasts (CAFs). Pancreatic CAFs have emerged as important regulators of the tumor microenvironment by contributing to immune evasion through the release of chemokines, cytokines, and growth factors, which alters T-cell migration, differentiation and cytotoxic activity. However, recent discoveries have also revealed that subsets of CAFs with diverse functions can either restrain or promote tumor progression. Here, we discuss our current knowledge about the interactions between CAFs and T cells in PDAC and summarize different therapy strategies targeting the CAF–T cell axis with focus on CAF-derived soluble immunosuppressive factors and chemokines. Identifying the functions of different CAF subsets and understanding their roles in T-cell trafficking within the tumor may be fundamental for the development of an effective combinational treatment for PDAC.

2019 ◽  
Vol 8 (11) ◽  
pp. 1989 ◽  
Author(s):  
Tom J. Harryvan ◽  
Els M. E. Verdegaal ◽  
James C. H. Hardwick ◽  
Lukas J. A. C. Hawinkels ◽  
Sjoerd H. van der Burg

The introduction of a wide range of immunotherapies in clinical practice has revolutionized the treatment of cancer in the last decade. The majority of these therapeutic modalities are centered on reinvigorating a tumor-reactive cytotoxic T-cell response. While impressive clinical successes are obtained, the majority of cancer patients still fail to show a clinical response, despite the fact that their tumors express antigens that can be recognized by the immune system. This is due to a series of other cellular actors, present in or attracted towards the tumor microenvironment, including regulatory T-cells, myeloid-derived suppressor cells and cancer-associated fibroblasts (CAFs). As the main cellular constituent of the tumor-associated stroma, CAFs form a heterogeneous group of cells which can drive cancer cell invasion but can also impair the migration and activation of T-cells through direct and indirect mechanisms. This singles CAFs out as an important next target for further optimization of T-cell based immunotherapies. Here, we review the recent literature on the role of CAFs in orchestrating T-cell activation and migration within the tumor microenvironment and discuss potential avenues for targeting the interactions between fibroblasts and T-cells.


2019 ◽  
Vol 37 (8_suppl) ◽  
pp. 55-55
Author(s):  
Gregory P. Botta ◽  
Tatiana Hurtado De Mendoza ◽  
Harri Jarvelainen ◽  
Erkki Ruoslahti

55 Background: Fibrotic solid tumors have lagged in immunotherapy efficacy. Although breast cancer (BC) shows modest single-agent activity, pancreatic ductal adenocarcinoma (PDAC) immunotherapy has repeatedly failed in clinical trials. A protective desmoplastic, inflammatory reaction encapsulates BC and PDAC where it can make up to 80% of the tumor microenvironment (TME). Reports in BC and PDAC patients and mouse models suggest that tumoricidal effector CD8+ T-cells are indeed present, yet suppressed by regulatory CD4+/CD25+/FoxP3+ T-cells (Tregs) and myeloid cells. Long-term PDAC and BC survivors harbor CD8+ T-cells by immunohistochemistry (IHC), and although inactivated (CD107a-), they are not terminally exhausted (PD-1low). Further, when CD8+ T-cells were found in large quantities within a treatment-naïve biopsy, that patient had an increased overall survival. We hypothesize that low doses of the T-cell proliferative cytokine IL-2 can class switch the TME T-cells if specifically concentrated within the tumor by the stroma-penetrating peptide iRGD. Methods: Subcutaneous BC tumors (4T1) and PDAC (KPC ) tumors were formed in immunocompetent mouse models. Mice were treated with either vehicle, iRGD, IL-2, or both in combination. Tumors were preserved for IHC or enzymatically digested for FACS. CD45+ live cells were fluorescently labeled for effector T-cells (CD4+/CD44+ or CD8+/CD44+), Tregs (CD4+/CD25+/FoxP3+), or cytotoxic T-cells (CD8+/CD44+/Granzyme B+/IL-2+). Results: Versus normal controls, tumors from BC and PDAC both showed a subsequent increase in bulk CD3+ T-cells within the tumor microenvironment (14.3% ± 5 vs. 27.6% ± 8). A significant increase in CD3+ T-cells within all tumors (10%) occured with iRGD only, IL-2 only, or iRGD + IL-2 treatment. Whereas sub-populations of T-cells in the iRGD only and IL-2 only treatment groups was overwhelming composed of Tregs (5%) at CD4/Treg and CD8/Treg ratios of 1.75 and 0.5 respectively, the combination of iRGD + IL-2 shifted the T-cell sub-populations away from Tregs (1.5%) and towards increased CD4/Treg and CD8/Treg ratios (4 and 12 respectively). Conclusions: The combination of iRGD + IL-2 is capable of reprogramming the immunosuppressive Treg tumor microenvironment, increasing effector CD4+ and CD8+ T-cells.


Cells ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1070 ◽  
Author(s):  
Yazdanifar ◽  
Zhou ◽  
Grover ◽  
Williams ◽  
Bose ◽  
...  

Chimeric antigen receptor (CAR) T cells have shown remarkable success in treating hematologic cancers. However, this efficacy has yet to translate to treatment in solid tumors. Pancreatic ductal adenocarcinoma (PDA) is a fatal malignancy with poor prognosis and limited treatment options. We have developed a second generation CAR T cell using the variable fragments of a novel monoclonal antibody, TAB004, which specifically binds the tumor-associated-MUC1 (tMUC1). tMUC1 is overexpressed on ~85% of all human PDA. We present data showing that TAB004-derived CAR T cells specifically bind to tMUC1 on PDA cells and show robust killing activity; however, they do not bind or kill normal epithelial cells. We further demonstrated that the tMUC1-CAR T cells control the growth of orthotopic pancreatic tumors in vivo. We witnessed that some PDA cells (HPAFII and CFPAC) were refractory to CAR T cell treatment. qPCR analysis of several genes revealed overexpression of indoleamine 2, 3-dioxygenases-1 (IDO1), cyclooxygenase 1 and 2 (COX1/2), and galectin-9 (Gal-9) in resistant PDA cells. We showed that combination of CAR T cells and biological inhibitors of IDO1, COX1/2, and Gal-9 resulted in significant enhancement of CAR T cell cytotoxicity against PDA cells. Overcoming PDA resistance is a significant advancement in the field.


2021 ◽  
Vol 11 ◽  
Author(s):  
Zoe C. Schmiechen ◽  
Ingunn M. Stromnes

Pancreatic ductal adenocarcinoma (PDA) is a lethal malignancy with an overall 5-year survival rate of 10%. Disease lethality is due to late diagnosis, early metastasis and resistance to therapy, including immunotherapy. PDA creates a robust fibroinflammatory tumor microenvironment that contributes to immunotherapy resistance. While previously considered an immune privileged site, evidence demonstrates that in some cases tumor antigen-specific T cells infiltrate and preferentially accumulate in PDA and are central to tumor cell clearance and long-term remission. Nonetheless, PDA can rapidly evade an adaptive immune response using a myriad of mechanisms. Mounting evidence indicates PDA interferes with T cell differentiation into potent cytolytic effector T cells via deficiencies in naive T cell priming, inducing T cell suppression or promoting T cell exhaustion. Mechanistic research indicates that immunotherapy combinations that change the suppressive tumor microenvironment while engaging antigen-specific T cells is required for treatment of advanced disease. This review focuses on recent advances in understanding mechanisms limiting T cell function and current strategies to overcome immunotherapy resistance in PDA.


2020 ◽  
Vol 8 (2) ◽  
pp. e001100
Author(s):  
Michael Brandon Ware ◽  
Bassel F El-Rayes ◽  
Gregory B Lesinski

Pancreatic ductal adenocarcinoma (PDAC) is plagued by a dismal 5-year survival rate, early onset of metastasis and limited efficacy of systemic therapies. This scenario highlights the need to fervently pursue novel therapeutic strategies to treat this disease. Recent research has uncovered complicated dynamics within the tumor microenvironment (TME) of PDAC. An abundant stroma provides a framework for interactions between cancer-associated fibroblasts, suppressive myeloid cells and regulatory lymphocytes, which together create an inhospitable environment for adaptive immune responses. This accounts for the poor infiltration and exhausted phenotypes of effector T cells within pancreatic tumors. Innovative studies in genetically engineered mouse models have established that with appropriate pharmacological modulation of suppressive elements in the TME, T cells can be prompted to regress pancreatic tumors. In light of this knowledge, innovative combinatorial strategies involving immunotherapy and targeted therapies working in concert are rapidly emerging. This review will highlight recent advances in the field related to immune suppression in PDAC, emerging preclinical data and rationale for ongoing immunotherapy clinical trials. In particular, we draw attention to foundational findings involving T-cell activity in PDAC and encourage development of novel therapeutics to improve T-cell responses in this challenging disease.


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