Multifunctional Immunoliposomes Enhance the Immunotherapeutic Effects of PD‐L1 Antibodies against Melanoma by Reprogramming Immunosuppressive Tumor Microenvironment

Small ◽  
2021 ◽  
pp. 2105118
Author(s):  
Yu Hei ◽  
Yang Chen ◽  
Qian Li ◽  
Zi Mei ◽  
Jijia Pan ◽  
...  
2021 ◽  
Author(s):  
Wyatt M. Becicka ◽  
Peter Bielecki ◽  
Morgan Lorkowski ◽  
Taylor J. Moon ◽  
Yahan Zhang ◽  
...  

The efficacy of immunotherapies is often limited by the immunosuppressive tumor microenvironment, which is populated with dysfunctional innate immune cells. To reprogram the tumor-resident innate immune cells, we developed an...


Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1020
Author(s):  
Stefan Grote ◽  
Guillermo Ureña-Bailén ◽  
Kenneth Chun-Ho Chan ◽  
Caroline Baden ◽  
Markus Mezger ◽  
...  

Background: Melanoma is the most lethal of all skin-related cancers with incidences continuously rising. Novel therapeutic approaches are urgently needed, especially for the treatment of metastasizing or therapy-resistant melanoma. CAR-modified immune cells have shown excellent results in treating hematological malignancies and might represent a new treatment strategy for refractory melanoma. However, solid tumors pose some obstacles for cellular immunotherapy, including the identification of tumor-specific target antigens, insufficient homing and infiltration of immune cells as well as immune cell dysfunction in the immunosuppressive tumor microenvironment (TME). Methods: In order to investigate whether CAR NK cell-based immunotherapy can overcome the obstacles posed by the TME in melanoma, we generated CAR NK-92 cells targeting CD276 (B7-H3) which is abundantly expressed in solid tumors, including melanoma, and tested their effectivity in vitro in the presence of low pH, hypoxia and other known factors of the TME influencing anti-tumor responses. Moreover, the CRISPR/Cas9-induced disruption of the inhibitory receptor NKG2A was assessed for its potential enhancement of NK-92-mediated anti-tumor activity. Results: CD276-CAR NK-92 cells induced specific cytolysis of melanoma cell lines while being able to overcome a variety of the immunosuppressive effects normally exerted by the TME. NKG2A knock-out did not further improve CAR NK-92 cell-mediated cytotoxicity. Conclusions: The strong cytotoxic effect of a CD276-specific CAR in combination with an “off-the-shelf” NK-92 cell line not being impaired by some of the most prominent negative factors of the TME make CD276-CAR NK-92 cells a promising cellular product for the treatment of melanoma and beyond.


2021 ◽  
Author(s):  
Yadan Zheng ◽  
Zhanzhan Zhang ◽  
Qi Liu ◽  
Ying Wang ◽  
Jialei Hao ◽  
...  

Photodynamic therapy has great potential for tumor ablation and the activation of antitumor immune responses. However, its overall therapeutic efficiency is often limited by the immunosuppressive tumor microenvironment. We developed...


Nanoscale ◽  
2021 ◽  
Author(s):  
Simeng Liu ◽  
Huimin Liu ◽  
Xiaoshuang Song ◽  
Ailing Jiang ◽  
Yuchuan Deng ◽  
...  

Efficient tumor-targeting delivery of CpG or BMS-202 by adoptive T-cells coupled with drug loaded liposomes reversed the immunosuppressive tumor microenvironment, restoring T cell viability and effectively inhibiting the growth of melanoma.


2020 ◽  
Vol 6 (3) ◽  
pp. eaax5032 ◽  
Author(s):  
Kuan-Wei Huang ◽  
Fu-Fei Hsu ◽  
Jiantai Timothy Qiu ◽  
Guann-Jen Chern ◽  
Yi-An Lee ◽  
...  

While immunotherapy holds great promise for combating cancer, the limited efficacy due to an immunosuppressive tumor microenvironment and systemic toxicity hinder the broader application of cancer immunotherapy. Here, we report a combinatorial immunotherapy approach that uses a highly efficient and tumor-selective gene carrier to improve anticancer efficacy and circumvent the systemic toxicity. In this study, we engineered tumor-targeted lipid-dendrimer-calcium-phosphate (TT-LDCP) nanoparticles (NPs) with thymine-functionalized dendrimers that exhibit not only enhanced gene delivery capacity but also immune adjuvant properties by activating the stimulator of interferon genes (STING)–cGAS pathway. TT-LDCP NPs delivered siRNA against immune checkpoint ligand PD-L1 and immunostimulatory IL-2–encoding plasmid DNA to hepatocellular carcinoma (HCC), increased tumoral infiltration and activation of CD8+ T cells, augmented the efficacy of cancer vaccine immunotherapy, and suppressed HCC progression. Our work presents nanotechnology-enabled dual delivery of siRNA and plasmid DNA that selectively targets and reprograms the immunosuppressive tumor microenvironment to improve cancer immunotherapy.


2021 ◽  
Author(s):  
SANJAY MISHRA ◽  
Manish Charan ◽  
Rajni Kant Shukla ◽  
Pranay Agarwal ◽  
Swati Misri ◽  
...  

Abstract Background: Metastasis is the major cause of mortality in breast cancer; however, the molecular mechanisms remain elusive. In our previous study, we demonstrated that S100A7/RAGE mediates breast cancer growth and metastasis by recruitment of tumor-associated macrophages. However, the downstream S100A7-mediated inflammatory oncogenic signaling cascade that enhances breast tumor growth and metastasis by generating the immunosuppressive tumor microenvironment (iTME) has not been studied. In this present study, we aimed to investigate the S100A7 and cPLA2 cross-talk in enhancing tumor growth and metastasis through enhancing the iTME.Methods: Human breast cancer tissue and plasma samples were used to analyze the expression of S100A7, cPLA2, and PGE2 titer. S100A7-overexpressing or downregulated human metastatic breast cancer cells were used to evaluate the S100A7-mediated downstream signaling mechanisms. Bi-transgenic mS100a7a15 overexpression, TNBC C3(1)/Tag transgenic, and humanized patient-derived xenograft mouse models and cPLA2 inhibitor (AACOCF3) were used to investigate the role of S100A7/cPLA2/PGE2 signaling in tumor growth and metastasis. Additionally, CODEX, a highly advanced multiplexed imaging was employed to delineate the effect of S100A7/cPLA2 inhibition on the recruitment of various immune cells.Results: S100A7 and cPLA2 are highly expressed and positively correlated in malignant breast cancer patients. S100A7/RAGE upregulates cPLA2/PGE2 axis in aggressive breast cancer cells. Furthermore, S100A7 is positively correlated with PGE2 in breast cancer patients. Moreover, cPLA2 pharmacological inhibition suppressed S100A7-mediated tumor growth and metastasis in multiple pre-clinical models. Mechanistically, S100A7-mediated activation of cPLA2 enhances the recruitment of immunosuppressive myeloid cells by increasing PGE2 to fuel breast cancer growth and its secondary spread. We revealed that cPLA2 inhibitor mitigates S100A7-mediated breast tumorigenicity by suppressing the iTME. Furthermore, CODEX imaging data showed that cPLA2 inhibition increased the infiltration of CD4+/CD8+ T cells in the TME. Analysis of metastatic breast cancer samples revealed a positive correlation between S100A7/cPLA2 with CD163+ tumor-associated M2-macrophages.Conclusions: Our study shows that cross-talk between S100A7 and cPLA2 plays an important role in enhancing breast tumor growth and metastasis by generating an immunosuppressive tumor microenvironment and reducing infiltration of T cells. Furthermore, S100A7 could be used as a novel non-invasive prognostic marker and cPLA2 inhibitors as promising drugs against S100A7-overexpressing metastatic breast cancer.


2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi139-vi140
Author(s):  
Kira Pfleiderer ◽  
Verena Turco ◽  
Natalie K Horvat ◽  
Jessica Hunger ◽  
Kianush Karimian-Jazi ◽  
...  

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.


2019 ◽  
Vol 8 (9) ◽  
pp. 1472 ◽  
Author(s):  
Sireesha Upadhrasta ◽  
Lei Zheng

With the advent of cancer immunotherapies, significant advances have been made in the treatment of many tumor types including melanoma, lung cancer, squamous cell carcinoma of the head and neck, renal cell carcinoma, bladder cancer, etc. However, similar success has not been observed with the treatment of pancreatic cancer and all other immunogenic “cold” tumors. This prompts the need for a better understanding of the complexity of the cold tumor microenvironment (TME) of pancreatic cancer and what are truly the “defects” in the TME making the cancer unresponsive to immune checkpoint inhibitors. Here we discuss four major immune defects that can be recognized in pancreatic cancer, including lack of high-quality effector intratumoral T cells, heterogeneous dense stroma as a barrier to effector immune cells infiltrating into the tumor, immunosuppressive tumor microenvironment, and failure of the T cells to accomplish tumor elimination. We also discuss potential strategies for pancreatic cancer treatment that work by correcting these immune defects.


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