Abstract B032: The PI3K-γ inhibitor, IPI-549, increases antitumor immunity by targeting tumor-associated myeloid cells and remodeling the immune-suppressive tumor microenvironment

2016 ◽  
Author(s):  
Matthew Rausch ◽  
Jeremy Tchaicha ◽  
Thomas Tibbitts ◽  
Olivier De Henau ◽  
Sujata Sharma ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Antitumor Immunity ◽  
Myeloid Cells

scholarly journals Activation of GM-CSF and TLR2 signaling synergistically enhances antigen-specific antitumor immunity and modulates the tumor microenvironment

2021 ◽  
Vol 9 (10) ◽  
pp. e002758
Author(s):  
Wan-Lun Yan ◽  
Chiao-Chieh Wu ◽  
Kuan-Yin Shen ◽  
Shih-Jen Liu
Keyword(s):  
T Cells ◽  
Tumor Microenvironment ◽  
Tumor Growth ◽  
Antitumor Immunity ◽  
Synergistic Effects ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Toll Like Receptor ◽  
Tlr2 Agonist ◽  
Gm Csf

BackgroundThe major challenge of antitumor immunotherapy is dealing with the immunosuppressive tumor microenvironment, which involves immature myeloid cell accumulation that results in T cell dysfunction. Myeloid cell activation is induced by Toll-like receptor agonists. Additionally, granulocyte/macrophage colony stimulating factor (GM-CSF) promotes myelopoiesis and recruits myeloid cells. Here, we combined the Toll-like receptor 2 (TLR2) agonist lipoprotein and GM-CSF to assess whether this bifunctional immunotherapy has synergistic effects on myeloid cells and could be further developed as a therapeutic intervention that enhances the antitumor response.MethodsWe investigated the synergistic effects of biadjuvanted tumor antigen on antigen-presenting cell (APC) activation in bone marrow-derived dendritic cells. Furthermore, therapeutic efficacy was monitored in different tumor models treated via intratumoral or subcutaneous administration routes. The immune effects of the bifunctional fusion protein on myeloid cells in the tumor mass and draining lymph nodes were analyzed by flow cytometry. The induction of cytotoxic T lymphocytes was evaluated via intracellular cytokine levels, perforin/granzyme B staining and an in vivo killing assay.ResultsThe TLR2 agonist lipoprotein combined with GM-CSF synergistically induced DC maturation, which subsequently enhanced antitumor immunity. In addition, rlipoE7m-MoGM modulated tumor-infiltrating myeloid cell populations. Vaccination with rlipoE7m-MoGM therapy increased the number of CCR7+CD103+ cDC1s, whereas the number of suppressive tumor-associated macrophages was reduced in the tumor lesions. Consistent with this observation, proliferating antigen-specific CD8+ T cells are highly infiltrated within the tumor, and the expression of IFN-r and perforin was most pronounced within antigen-specific CD8+ T cells in mice administered rlipoE7m-MoGM therapy. This finding corresponded with observation that the combination of a TLR2 agonist and GM-CSF provides increased antitumor activity by inhibiting established tumor outgrowth and protecting against metastatic cancer compared with a TLR2 agonist alone. Importantly, tumor growth inhibition was not due to the direct effects of the TLR2 agonist or GM-CSF but was instead due to the induction of antigen-specific immunity.ConclusionsThe combination of a TLR2 agonist and GM-CSF has synergistic effects that inhibit tumor growth and modulate tumor-infiltrating APCs. This therapeutic approach could be applied to other tumor antigens to treat different cancers.

scholarly journals Macrophages/Microglia in the Glioblastoma Tumor Microenvironment

2021 ◽  
Vol 22 (11) ◽  
pp. 5775
Author(s):  
Jun Ma ◽  
Clark C. Chen ◽  
Ming Li
Keyword(s):  
Tumor Microenvironment ◽  
Myeloid Cells ◽  
Complex Interaction ◽  
Key Factors ◽  
Cell Markers ◽  
Tumor Associated Macrophage ◽  
Recent Advances ◽  
Definition Of

The complex interaction between glioblastoma and its microenvironment has been recognized for decades. Among various immune profiles, the major population is tumor-associated macrophage, with microglia as its localized homolog. The present definition of such myeloid cells is based on a series of cell markers. These good sentinel cells experience significant changes, facilitating glioblastoma development and protecting it from therapeutic treatments. Huge, complicated mechanisms are involved during the overall processes. A lot of effort has been dedicated to crack the mysterious codes in macrophage/microglia recruiting, activating, reprogramming, and functioning. We have made our path. With more and more key factors identified, a lot of new therapeutic methods could be explored to break the ominous loop, to enhance tumor sensitivity to treatments, and to improve the prognosis of glioblastoma patients. However, it might be a synergistic system rather than a series of clear, stepwise events. There are still significant challenges before the light of truth can shine onto the field. Here, we summarize recent advances in this field, reviewing the path we have been on and where we are now.

Tumor Microenvironment-Regulating Immunosenescence-Independent Nanostimulant Synergizing with Near-Infrared Light Irradiation for Antitumor Immunity

2021 ◽  
Vol 13 (4) ◽  
pp. 4844-4852
Author(s):  
Saji Uthaman ◽  
Shameer Pillarisetti ◽  
Hye Suk Hwang ◽  
Ansuja Pulickal Mathew ◽  
Kang Moo Huh ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Antitumor Immunity ◽  
Near Infrared ◽  
Light Irradiation ◽  
Infrared Light ◽  
Near Infrared Light

scholarly journals Inflammation and Cancer: Extra- and Intracellular Determinants of Tumor-Associated Macrophages as Tumor Promoters

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Gabor J. Szebeni ◽  
Csaba Vizler ◽  
Klara Kitajka ◽  
Laszlo G. Puskas
Keyword(s):  
Tumor Microenvironment ◽  
Macrophage Polarization ◽  
Myeloid Cells ◽  
Therapeutic Interventions ◽  
Tumor Associated Macrophages ◽  
Poor Survival ◽  
Cell Functions ◽  
Intracellular Signals ◽  
Ontogenetic Diversity ◽  
Cell Dissemination

One of the hallmarks of cancer-related inflammation is the recruitment of monocyte-macrophage lineage cells to the tumor microenvironment. These tumor infiltrating myeloid cells are educated by the tumor milieu, rich in cancer cells and stroma components, to exert functions such as promotion of tumor growth, immunosuppression, angiogenesis, and cancer cell dissemination. Our review highlights the ontogenetic diversity of tumor-associated macrophages (TAMs) and describes their main phenotypic markers. We cover fundamental molecular players in the tumor microenvironment including extra- (CCL2, CSF-1, CXCL12, IL-4, IL-13, semaphorins, WNT5A, and WNT7B) and intracellular signals. We discuss how these factors converge on intracellular determinants (STAT3, STAT6, STAT1, NF-κB, RORC1, and HIF-1α) of cell functions and drive the recruitment and polarization of TAMs. Since microRNAs (miRNAs) modulate macrophage polarization key miRNAs (miR-146a, miR-155, miR-125a, miR-511, and miR-223) are also discussed in the context of the inflammatory myeloid tumor compartment. Accumulating evidence suggests that high TAM infiltration correlates with disease progression and overall poor survival of cancer patients. Identification of molecular targets to develop new therapeutic interventions targeting these harmful tumor infiltrating myeloid cells is emerging nowadays.

scholarly journals Aberrant PGE2 metabolism in bladder tumor microenvironment promotes immunosuppressive phenotype of tumor-infiltrating myeloid cells

2011 ◽  
Vol 11 (7) ◽  
pp. 848-855 ◽  
Author(s):  
Evgeniy Eruslanov ◽  
Irina Daurkin ◽  
Johannes Vieweg ◽  
Yehia Daaka ◽  
Sergei Kusmartsev
Keyword(s):  
Tumor Microenvironment ◽  
Bladder Tumor ◽  
Myeloid Cells

scholarly journals Dendritic cell targeting with Fc-enhanced CD40 antibody agonists induces durable antitumor immunity in humanized mouse models of bladder cancer

2021 ◽  
Vol 13 (594) ◽  
pp. eabd1346
Author(s):  
Christopher S. Garris ◽  
Jeffrey L. Wong ◽  
Jeffrey V. Ravetch ◽  
David A. Knorr
Keyword(s):  
Bladder Cancer ◽  
T Cells ◽  
Tumor Microenvironment ◽  
Mouse Models ◽  
Antitumor Immunity ◽  
Bladder Tumor ◽  
Immune Surveillance ◽  
Disease Recurrence ◽  
Bcg Therapy ◽  
Agonist Antibody

Intravesical immunotherapy using Bacille Calmette-Guérin (BCG) attenuated bacteria delivered transurethrally to the bladder has been the standard of care for patients with high-risk non–muscle-invasive bladder cancer (NMIBC) for several decades. BCG therapy continues to be limited by high rates of disease recurrence and progression, and patients with BCG-unresponsive disease have few effective salvage therapy options besides radical cystectomy, highlighting a need for new therapies. We report that the immune-stimulatory receptor CD40 is highly expressed on dendritic cells (DCs) within the bladder tumor microenvironment of orthotopic bladder cancer mouse models, recapitulating CD40 expression by DCs found in human disease. We demonstrate that local CD40 agonism in mice with orthotopic bladder cancer through intravesical delivery of anti-CD40 agonist antibodies drives potent antitumor immunity and induces pharmacodynamic effects in the bladder tumor microenvironment, including a reduction in CD8+ T cells with an exhausted phenotype. We further show that type 1 conventional DCs (cDC1) and CD8+ T cells are required for both bladder cancer immune surveillance and anti-CD40 agonist antibody responses. Using orthotopic murine models humanized for CD40 and Fcγ receptors, we demonstrate that intravesical treatment with a fully human, Fc-enhanced anti-CD40 agonist antibody (2141-V11) induces robust antitumor activity in both treatment-naïve and treatment-refractory settings, driving long-term systemic antitumor immunity with no evidence of systemic toxicity. These findings support targeting CD40-expressing DCs in the bladder cancer microenvironment through an intravesical agonistic antibody approach for the treatment of NMIBC.

NIMG-48. TLR7/8-AGONIST-LOADED NANOPARTICLES REPROGRAM TUMOR-ASSOCIATED MYELOID CELLS FOR EFFECTIVE IMMUNOTHERAPY OF EXPERIMENTAL GLIOMA AND MRI-BASED TREATMENT MONITORING

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi139-vi140
Author(s):  
Kira Pfleiderer ◽  
Verena Turco ◽  
Natalie K Horvat ◽  
Jessica Hunger ◽  
Kianush Karimian-Jazi ◽  
...  
Keyword(s):  
T Cells ◽  
Tumor Microenvironment ◽  
Progressive Disease ◽  
Tumor Regression ◽  
Myeloid Cells ◽  
Complete Response ◽  
New Approach ◽  
Splenic Macrophages ◽  
Selective Depletion ◽  
Immunosuppressive Tumor Microenvironment

Abstract Drivers of glioblastoma progression include the immunosuppressive tumor microenvironment (TME), dominated by tumor-associated myeloid cells. Therefore, we investigated a new approach targeting the myeloid compartment to reprogram myeloid cells in the TME using a β-cyclodextrin nanoparticle (CDNP) formulation encapsulating the toll-like receptor 7 and 8 (TLR7/8) agonist R848. Biodistribution confirmed specific targeting of CDNP-R848 to tumor-associated macrophages (TAMs) (labeling efficiency: 34.0% ± 22.2%), whereas tumor microglia (5.4% ± 4.4%) and splenic macrophages (13.2% ± 0.7%) revealed less uptake. Interestingly, intravenous application of CDNP-R848 induced strong tumor regression with an overall response rate of 80% (2.5% complete response, 52.5% partial response and 25% stable disease, n=40 mice) in Gl261 syngeneic experimental gliomas, while CDNP vehicle treated animals showed exponential tumor growth (100% progressive disease, n=12 mice). As advanced imaging is essential to monitor intracranial disease and possibly predict response and resistance, we performed high resolution magnetic resonance imaging using ultrasmall iron oxide nanoparticles (USPIO) for macrophage tracking. Increased levels of USPIO uptake in vehicle treated animals compared to CDNP-R848 treated animals were found as an early marker of responding mice (ΔT2*: -11.7 ± 4.2 vs -4.0 ± 2.8 ms, p=0.01). This correlated with an increased influx of myeloid cells into the TME of vehicle treated animals and showed a strong correlation of macrophage recruitment and USPIO uptake (R2: 0.78, p=0.004). Mechanistically, phenotyping of macrophages (CD45high/CD11b+) indicated a pro-inflammatory shift of TAMs with an increased infiltration of pro-inflammatory F4/80+/MHCII+ macrophages during CDNP-R848 treatment. Surprisingly, the anti-tumor effect of CDNP-R848 was independent of CD8+ T cells, CD4+ T cells or NK cells during selective depletion experiments. In summary, this work demonstrates the ability of myeloid-targeted therapies to re-shape the tumor microenvironment for an effective immunotherapy of glioma.

IMMU-14. REVEALING THE MANY MYELOID STATES IN HUMAN BRAIN TUMORS AND WAYS TO PERTURB THEM

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi94-vi95
Author(s):  
Tyler Miller ◽  
Chadi El Farran ◽  
Julia Verga ◽  
Charles Couturier ◽  
Zeyu Chen ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Tumor Microenvironment ◽  
Immune Cells ◽  
Ex Vivo ◽  
Myeloid Cells ◽  
Human Tumor ◽  
Myeloid Cell ◽  
Low Grade ◽  
Tumor Patients ◽  
The Many

Abstract Recent breakthroughs in immunotherapy have revolutionized treatment for many types of cancer, but unfortunately trials of these therapies have failed to provide meaningful life-prolonging benefit for brain tumor patients, potentially due to abundant immunosuppressive myeloid cells in the tumor. Our ultimate goal is to reprogram immunosuppressive tumor associated myeloid cells to an antitumor state to enable effective immunotherapy. Towards this goal, we have deeply characterized the immune microenvironment of more than 50 primary high and low grade gliomas using high-throughput single-cell RNA-sequencing to reveal recurrent myeloid cell states and immunosuppressive programs across IDH1 wild-type and mutant tumors. We have also established a brain tumor organoid model from primary patient tissue that maintains all of the tumor microenvironment, including myeloid and other immune cells. We utilize the this model to functionally test data-driven reprogramming strategies and understand how they impact the states of tumor and immune cells in the ex vivo human tumor microenvironment.

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