Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Tumor hypoxia represses γδ T cell-mediated antitumor immunity against brain tumors

ABSTRACT: The anatomic location and immunologic characteristics of brain tumors result in strong lymphocyte suppression. Consequently, conventional immunotherapies targeting CD8 T-cells are ineffective against brain tumors. Tumor cells escape immunosurveillance by various mechanisms, and tumor cell metabolism can affect the metabolic states and functions of tumor-infiltrating lymphocytes. Oxygen tension is one important factor influencing immune responses. Here, we discovered that brain tumor cells had a particularly high demand for oxygen, which affected γδ T-cell-mediated antitumor immune responses but not those of conventional T-cells. Specifically, tumor hypoxia activated the γδ T-cell protein kinase A (PKA) pathway at a transcriptional level, resulting in repression of NKG2D expression. Alleviating tumor hypoxia reinvigorated NKG2D expression and the antitumor function of γδ T-cells. These results reveal a hypoxia-mediated mechanism by which brain tumors and γδ T-cells interact and emphasize the importance of γδ T-cells for antitumor immunity against brain tumors.

ORGANISM(S): Mus musculus

PROVIDER: GSE159542 | GEO | 2020/12/04

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Tumor hypoxia represses γδ T cell-mediated antitumor immunity against brain tumors

Project description:Tumor hypoxia represses γδ T cell-mediated antitumor immunity against brain tumors

| PRJNA670005 | ENA

Obesity enhances antiviral immunity in the genital mucosa through a microbiota-mediated effect on γδ T cells

Project description:Obesity is detrimental to the immune system. It impairs lymphatics, T cell development, and lymphopoiesis; induces dysfunction of antitumor immunity; and also promotes tumor progression. However, direct evidence of the impact of obesity on viral infection is lacking. We found an unexpected protective role of obesity against herpes simplex virus 2 infection of the genital mucosa in mice. Although conventional antiviral immunity was comparable between obese mice and lean mice, obesity enhanced the cytotoxic subset of γδ T cells. This effect was mediated by L-arginine produced by commensal microbiota in the genital mucosa, which induced “pseudonormoxia” of γδ T cells, resulting in increased NKG2D expression of γδ T cells through the downregulation of HIF1A by inducing NO production, thereby protecting mice from lethal genital herpes. Thus, our work illuminates one mechanism by which obesity-induced compositional changes in the vaginal microbiota can affect mucosal immune responses against viral infection.

2023-07-12 | GSE201274 | GEO

Hypoxic tumors are sensitive to FLASH radiotherapy

Project description:Purpose: Tumor hypoxia is a major cause of treatment resistance, especially to radiation therapy at conventional dose rate (CONV), and we wanted to assess whether hypoxia does alter tumor sensitivity to FLASH. Methods and materials: We engrafted several tumor types (glioblastoma [GBM], head and neck cancer, and lung adenocarcinoma) subcutaneously in mice to provide a reliable and rigorous way to modulate oxygen supply via vascular clamping or carbogen breathing. We irradiated tumors using a single 20-Gy fraction at either CONV or FLASH, measured oxygen tension, monitored tumor growth, and sampled tumors for bulk RNAseq and pimonidazole analysis. Next, we inhibited glycolysis with trametinib in GBM tumors to enhance FLASH efficacy. Results: Using various subcutaneous tumor models, and in contrast to CONV, FLASH retained antitumor efficacy under acute hypoxia. These findings show that in addition to normal tissue sparing, FLASH could overcome hypoxia-mediated tumor resistance. Follow-up molecular analysis using RNAseq profiling uncovered a FLASH-specific profile in human GBM that involved cell-cycle arrest, decreased ribosomal biogenesis, and a switch from oxidative phosphorylation to glycolysis. Glycolysis inhibition by trametinib enhanced FLASH efficacy in both normal and clamped conditions. Conclusions: These data provide new and specific insights showing the efficacy of FLASH in a radiation-resistant context, proving an additional benefit of FLASH over CONV.

2024-01-24 | GSE223607 | GEO

Breast cancer stem cell-derived tumors escape from γδ T cell immunosurveillance in vivo by modulating γδ T cell ligands

Project description:Triple negative breast cancer (TNBC) lacks targeted therapy options. TNBC is enriched in breast cancer stem cells (BCSCs), which play a key role in metastasis, chemoresistance, relapse and mortality. γδ T cells hold great potential in immunotherapy against cancer, and might be an alternative to target TNBC. γδ T cells are commonly observed to infiltrate solid tumors and have an extensive repertoire of tumor sensing, recognizing stress-induced molecules and phosphoantigens (pAgs) on transformed cells. We show that patient derived triple negative BCSCs are efficiently recognized and killed by ex vivo expanded γδ T cells from healthy donors. Orthotopically xenografted BCSCs, however, were refractory to γδ T cell immunotherapy. Mechanistically, we unraveled concerted differentiation and immune escape: xenografted BCSCs lost stemness, expression of γδ T cell ligands, adhesion molecules and pAgs, thereby evading immune recognition by γδ T cells. Indeed, neither pro-migratory engineered γδ T cells, nor anti-PD 1 checkpoint blockade significantly prolonged overall survival of tumor-bearing mice. BCSC immune escape was independent of the immune pressure exerted by the γδ T cells, and could be pharmacologically reverted by Zoledronate or IFN-α treatment. These results pave the way for novel combinatorial immunotherapies for TNBC.

2023-07-20 | PXD039463 | Pride

Nano-hijacked myeloid cells potentiate antitumor immunity and radiotherapy for glioblastoma

Project description:Abstract: Radiation therapy is a key component of the standard of care for glioblastoma (GBM). Although this treatment is known to trigger pro-inflammatory immune responses, it also results in several immune resistance mechanisms such as the upregulation of CD47 by tumors leading to avoidance of phagocytosis and the overexpression of PD-L1 in tumor-associated myeloid cells (TAMCs). Leveraging these RT-elicited processes, we generated a bispecific-lipid nanoparticle (B-LNP) that engaged TAMCs to glioma cells via anti-CD47/PD-L1 dual-ligation. We show that B-LNP blocked these two vital immune checkpoint molecules and promoted the phagocytic activity of TAMCs. In order to boost subsequent T cell recruitment and antitumor activity after tumor engulfment, the B-LNP was encapsulated with diABZI, a non-nucleotidyl agonist for stimulator of interferon genes (STING). In vivo treatment with the diABZI-loaded B-LNP induced a transcriptomic and metabolic switch in TAMCs, transforming them into potent antitumor effector cells, which induced T cell infiltration and activation of in the brain tumors. In preclinical murine glioma models, B-LNP therapy significantly potentiated the antitumor effects of radiotherapy, promoted brain tumor regression, and induced immunological memory against gliomas. The nano37 therapy was efficacious through both intra-tumoral and systemic delivery routes. In summary, our study shows a unique nanotechnology-based approach that hijacks multiple immune checkpoints to boost potent and long-lasting antitumor immunity against GBM.

2023-02-06 | ST002467 | MetabolomicsWorkbench

Hypoxia-responsive gene expression profile of U87 MG glioblastoma cells and their exosomes.

Project description:How cancer cells adapt to hypoxia during tumor development remains an important question. The hypothesis tested in the present study was that tumor cell-derived exosome vesicles (also known as microvesicles or extracellular vesicles) are mediators of hypoxia-dependent intercellular signaling in glioblastoma (GBM), i.e. highly aggressive brain tumors characterized by hypoxia and a vascular density that is among the highest of all human malignancies. In vitro hypoxia experiments and studies with patient materials reveal the enrichment in exosomes of hypoxia-regulated mRNAs and proteins, several of which were associated with poor patient prognosis. We show that cancer cell exosomes mediate hypoxia-dependent, phenotypic modulation of stromal cells in vitro and ex vivo, resulting in accelerated GBM tumor angiogenesis and growth in mice. These data suggest that exosomes constitute potent mediators of hypoxia-driven tumor development, and circulating multiparameter biomarkers of tumor hypoxia. U87 MG glioblastoma cells were grown at normoxic (21% oxygen) or hypoxic (1% oxygen) conditions for 48 hours. Conditioned media from normoxic and hypoxic cells were then used to isolate exosomes by differential centrifugation. Both cells and exosomes were lysed in Trizol reagent, and RNA was isolated.Total RNA from all samples (four types of samples in three biological repilicates) was subjected to genome-wide transcriptional analysis with Illumina HumanHT-12 V3.0 expression beadchip. Gene expression profile obtained from hypoxic U87 MG glioblastoma cells was compared to the profile of normoxic control cells. Analogically, gene expression profile obtained from hypoxic U87 MG cells was compared to the profile of exosomes secreted by normoxic U87 MG cells.

2013-03-20 | E-GEOD-45301 | biostudies-arrayexpress

Antibody-Mediated Inhibition of MICA/B Shedding Promotes NK Cell-Driven Tumor Immunity

Project description:MICA and MICB (MICA/B) are expressed by many human cancers due to cellular stress and tag cells for elimination by cytotoxic lymphocytes through NKG2D receptor activation. However, tumors evade this immune recognition pathway through proteolytic shedding of MICA/B proteins. We rationally designed antibodies targeting the MICA α3 domain, the site of proteolytic shedding, and found that these antibodies prevented loss of cell surface MICA/B by human cancer cells. These antibodies inhibited tumor growth in multiple fully immuno-competent mouse models and also reduced human melanoma metastases in a humanized mouse model. Anti-tumor immunity was mediated mainly by NK cells through activation of NKG2D and CD16 Fc receptors. This novel approach prevents the loss of important immunostimulatory ligands by human cancers and reactivates antitumor immunity.

2018-02-01 | GSE109542 | GEO

The Impact of Cycling Hypoxia on the Phenotype of HPV-Positive Cervical Cancer Cells

Project description:Tumor hypoxia affects the aggressiveness and therapy response in solid tumors, including HPV-positive cancers. Cycling hypoxia, characterized by recurrent fluctuations in oxygen supply, is a prevalent, but much less investigated form of tumor hypoxia, and has been associated with a particularly therapy-resistant cancer cell subpopulation. Using mass spectrometry-based quantitative proteome analyses, we compare SiHa cells cultivated under normoxia (21% O2), physoxia (5.5% O2), chronic hypoxia (1% O2) and cycH (repeated cycles of 1 h at 1% O2 and 1 h at 5.5% O2) and assess distinct effects of cycH on the phenotype of HPV-positive cervical cancer cells.

2023-12-07 | PXD044908 | Pride

Tumor hypoxia causes DNA hypermethylation by reducing TET activity (DIP-Seq)

Project description:Hypermethylation of tumor suppressor gene (TSG) promoters confers growth advantages to cancer cells, but how these changes arise is poorly understood. Here, we report that tumor hypoxia reduces the activity of oxygen-dependent TET enzymes, which catalyze DNA de-methylation through 5-methylcytosine oxidation. This occurs independently of hypoxia-associated alterations in TET gene expression, basal metabolism, HIF activity or nuclear reactive oxygen species, but directly depends on oxygen shortage. Hypoxia-induced loss of TET activity increases hypermethylation at gene promoters in vitro, while also in patients, gene promoters are markedly more methylated in hypoxic than normoxic tumors. Affected genes are frequently involved in DNA repair, cell cycle regulation, angiogenesis and metastasis, indicating cellular selection of hypermethylation events. Overall, up to 50% of the tumor-associated hypermethylation is ascribable to hypoxia across various cancer types. Accordingly, spontaneous murine breast tumors become hypermethylated when rendered hypoxic through vessel pruning, whereas vessel normalisation rescues this effect. Tumor hypoxia thus acts as a novel regulator underlying DNA methylation.

2016-09-01 | GSE71400 | GEO