scholarly journals Stromal HIF2 Regulates Immune Suppression in the Pancreatic Cancer Microenvironment

2021 ◽  
Author(s):  
Yanqing Huang ◽  
Carolina J. Garcia Garcia ◽  
Daniel Lin ◽  
Nicholas D. Nguyen ◽  
Tara N. Fujimoto ◽  
...  

Background & Aims. Pancreatic ductal adenocarcinoma (PDAC) has a hypoxic, immunosuppressive stroma, which contributes to its resistance to immune checkpoint blockade therapies. The hypoxia-inducible factors (HIFs) mediate the cellular response to hypoxia, but their role within the PDAC tumor microenvironment remains unknown. Methods. We used a dual recombinase mouse model to delete Hif1α or Hif2α in α-smooth muscle actin (αSMA)-expressing cancer-associated fibroblasts (CAFs) arising within spontaneous pancreatic tumors. The effects of CAF-Hif2α expression on tumor progression and composition of the tumor microenvironment were evaluated by Kaplan-Meier analysis, quantitative real-time polymerase chain reaction, histology, immunostaining, and by both bulk and single-cell RNA sequencing. CAF-macrophage crosstalk was modeled ex vivo using conditioned media from CAFs after treatment with hypoxia and PT2399, a HIF2 inhibitor currently in clinical trials. Syngeneic flank and orthotopic PDAC models were used to assess whether HIF2 inhibition improves response to immune checkpoint blockade. Results. CAF-specific deletion of HIF2, but not HIF1, suppressed PDAC tumor progression and growth, and improved survival of mice by 50% (n = 21-23 mice/group, Log-rank P = 0.0009). Deletion of CAF-HIF2 modestly reduced tumor fibrosis and significantly decreased the intratumoral recruitment of immunosuppressive M2 macrophages and regulatory T cells. Treatment with the clinical HIF2 inhibitor PT2399 significantly reduced in vitro macrophage chemotaxis and M2 polarization, and improved tumor responses to immunotherapy in both syngeneic PDAC mouse models. Conclusions. Together, these data suggest that stromal HIF2 is an essential component of PDAC pathobiology and is a druggable therapeutic target that could relieve tumor microenvironment immunosuppression and enhance immune responses in this disease.

2021 ◽  
Vol 9 (1) ◽  
pp. e001136
Author(s):  
Moran Yang ◽  
Jiaqi Lu ◽  
Guodong Zhang ◽  
Yiying Wang ◽  
Mengdi He ◽  
...  

BackgroundMost patients with high-grade serous ovarian cancer (HGSC) lack an effective response to immune checkpoint blockade, highlighting the need for more knowledge about what is required for successful treatment. As follicular cytotoxic CXCR5+CD8+ T cells are maintained by reinvigoration by immune checkpoint blockade in tumors, we attempted to reveal the relationship between CXCR5+CD8+ T cells and the tumor microenvironment to predict immunotherapy responses in HGSC.Methods264 patients with HGSC from two cohorts and 340 HGSC cases from The Cancer Genome Atlas cohort were enrolled. Ex vivo and in vivo studies were conducted with human HGSC tumors and murine tumor models. The spatial correlation between CXC-chemokine ligand 13 (CXCL13), CXCR5, CD8, and CD20 was evaluated by immunohistochemistry and immunofluorescence. Survival was compared between different subsets of patients using Kaplan-Meier analysis. The therapeutic effect of CXCL13 and programmed cell death-1 (PD-1) blockade was validated using human HGSC tumors and murine models.ResultsHigh CXCL13 expression was associated with prolonged survival. Tumors with high CXCL13 expression exhibited increased infiltration of activated and CXCR5-expressing CD8+ T cells. Incubation with CXCL13 facilitated expansion and activation of CXCR5+CD8+ T cells ex vivo. CXCR5+CD8+ T cells appeared in closer proximity to CXCL13 in tumors and chemotaxis towards CXCL13 in vitro. The combination of CXCL13, CXCR5, and CD8+ T cells was an independent predictor for survival. In addition, CXCL13 was associated with clusters of CD20+ B cells. CD20+ B cells predicted better patient survival in the presence of CXCL13. Histological evaluation highlighted colocalization of CXCL13 with tertiary lymphoid structures (TLSs). TLSs carried prognostic benefit only in the presence of CXCL13. CXCL13 in combination with anti-PD-1 therapy retarded tumor growth in a CD8+ T-cell-dependent manner, resulting in increased infiltration of cytotoxic CD8+ T cells and CXCR5+CD8+ T cells.ConclusionsThese data define a critical role of CXCL13 in shaping antitumor microenvironment by facilitating the maintenance of CXCR5+CD8+ T cells in TLSs and support a clinical investigation for a combination of CXCL13 and PD-1 blockade therapy in HGSC.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. Farias ◽  
A. Soto ◽  
F. Puttur ◽  
C. J. Goldin ◽  
S. Sosa ◽  
...  

AbstractBrucella lumazine synthase (BLS) is a homodecameric protein that activates dendritic cells via toll like receptor 4, inducing the secretion of pro-inflammatory cytokines and chemokines. We have previously shown that BLS has a therapeutic effect in B16 melanoma-bearing mice only when administered at early stages of tumor growth. In this work, we study the mechanisms underlying the therapeutic effect of BLS, by analyzing the tumor microenvironment. Administration of BLS at early stages of tumor growth induces high levels of serum IFN-γ, as well as an increment of hematopoietic immune cells within the tumor. Moreover, BLS-treatment increases the ratio of effector to regulatory cells. However, all treated mice eventually succumb to the tumors. Therefore, we combined BLS administration with anti-PD-1 treatment. Combined treatment increases the outcome of both monotherapies. In conclusion, we show that the absence of the therapeutic effect at late stages of tumor growth correlates with low levels of serum IFN-γ and lower infiltration of immune cells in the tumor, both of which are essential to delay tumor growth. Furthermore, the combined treatment of BLS and PD-1 blockade shows that BLS could be exploited as an essential immunomodulator in combination therapy with an immune checkpoint blockade to treat skin cancer.


2020 ◽  
Vol 220 ◽  
pp. 88-96 ◽  
Author(s):  
Yaqi Li ◽  
Jing Liu ◽  
Long Gao ◽  
Yuan Liu ◽  
Fang Meng ◽  
...  

2019 ◽  
Vol 11 (501) ◽  
pp. eaav7816 ◽  
Author(s):  
Rachael M. Zemek ◽  
Emma De Jong ◽  
Wee Loong Chin ◽  
Iona S. Schuster ◽  
Vanessa S. Fear ◽  
...  

Cancer immunotherapy using antibodies that target immune checkpoints has delivered outstanding results. However, responses only occur in a subset of patients, and it is not fully understood what biological processes determine an effective outcome. This lack of understanding hinders the development of rational combination treatments. We set out to define the pretreatment microenvironment associated with an effective outcome by using the fact that inbred mouse strains bearing monoclonal cancer cell line–derived tumors respond in a dichotomous manner to immune checkpoint blockade (ICB). We compared the cellular composition and gene expression profiles of responsive and nonresponsive tumors from mice before ICB and validated the findings in cohorts of patients with cancer treated with ICB antibodies. We found that responsive tumors were characterized by an inflammatory gene expression signature consistent with up-regulation of signal transducer and activator of transcription 1 (STAT1) and Toll-like receptor 3 (TLR3) signaling and down-regulation of interleukin-10 (IL-10) signaling. In addition, responsive tumors had more infiltrating-activated natural killer (NK) cells, which were necessary for response. Pretreatment of mice with large established tumors using the STAT1-activating cytokine interferon-γ (IFNγ), the TLR3 ligand poly(I:C), and an anti–IL-10 antibody sensitized tumors to ICB by attracting IFNγ-producing NK cells into the tumor, resulting in increased cure rates. Our results identify a pretreatment tumor microenvironment that predicts response to ICB, which can be therapeutically attained. These data suggest a biomarker-driven approach to patient management to establish whether a patient would benefit from treatment with sensitizing therapeutics before ICB.


2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e20512-e20512
Author(s):  
Paul R. Walker ◽  
Nitika Sharma ◽  
Chipman Robert Geoffrey Stroud ◽  
Mahvish Muzaffar ◽  
Cynthia R. Cherry ◽  
...  

e20512 Background: Veristrat (Biodesix, Boulder, CO) is a blood based proteomic assay that is dominated by inflammatory proteins and is prognostic and predictive in metastatic NSCLC after treatment with platinum based chemotherapy (Gregorc et al, Lancet 2014). Smoldering inflammation in the tumor microenvironment regulates and escalates cancer invasion, angiogenesis and immune surveillance escape (Balkwill and Mantovani, Lancet 2001). There is preclinical evidence to suggest that the tumor microenvironment can be altered with immunomodulatory interventions (Martino et al, 2016). While immune checkpoint blockade has shown durable benefit in metastatic NSCLC, the response rates still hover around 20%. As a result, identification of predictive biomarkers are of critical importance. The predictive value of the Veristrat assay with respect to ICB is poorly defined. Methods: At our institution, 83 pts with metastatic lung cancer pts were treated with nivolumab between 6/2015 to 12/2016. The following clinicopathologic characteristics were abstracted from medical records: tumor histology, Veristrat status, no. of doses of nivolumab, irAEs and overall survival. Results: Of the 83 pts, 65 pts were found to have NSCLC. Veristrat status was available for 17/65 of these pts. Nine pts were identified to have “Veristrat good” and seven pts were “Veristrat poor”. Median number of nivolumab doses was 4. Median survival for all patients was 30 weeks. Median survival was 20 weeks for “Veristrat poor” and 26 weeks for “Veristrat good”(p = 0.68). Grade 3-4 irAEs were noted in 5/9 patients with “Veristrat good” and 5/7 patients with “Veristrat poor”. Conclusions: “Veristrat poor” pts treated with ICB have a lower median survival as compared to “Veristrat good” pts. Our study did not meet statistically significant end point due to limited sample size. Further studies are needed to identify poorly immunogenic tumors and develop novel treatment approaches to optimize outcomes. [Table: see text]


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