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Updated: Jun 7, 2025
Measuring Mitochondrial Function of Naïve and Effector CD8 T Cells
Published on: March 28, 2025
Glycolysis regulated exosomal LINC01214 inhibited CD8+ T cell function and induced anti-PD1 resistance in melanoma
Zhi Ding1, Baojin Wu1, Junyi Yang1
1Department of Plastic Surgery, Huashan Hospital, Fudan University, Shanghai, China.
Background:
Long non-coding RNAs (lncRNAs) can be incorporated into exosomes to mediate the intercellular communication, regulating the occurrence, development, and immunosuppression of cancers. T cell dysfunction has been a hallmark of many cancers, including melanoma, which enables cancer cells escape from host immune surveillance. However, the molecular mechanism of exosome-transmitted lncRNAs in CD8+ T cell dysfunction in melanoma remains largely unclear.
Method:
The expression of circulating LINC01214 (cirLINC01214) was detected by quantitative real-time polymerase chain reaction (RT-qPCR). Exosomes were isolation from the culture medium and plasma of melanoma patients via ultracentrifugation and characterized by transmission electronic microscopy. The regulation of exosomal LINC01214 on CD8+ T cell function was determined by ELISA. The molecular mechanism of exosomal LINC01214 in CD8+ T cells were assessed by the RNA immunoprecipitation and pull-down assay. A mouse model with reconstituted human immune system was used to explore the role of exosomal LINC01214 in the resistance to anti-PD1 therapy.
Results:
LINC01214 was highly expressed in melanoma tissues compared with matched adjacent normal tissues. Increased levels of circulating LINC01214 (cirLINC01214) was observed in melanoma patient plasma and correlated with poor PD-1 immunotherapy response. The cirLINC01214 was predominantly released by melanoma cells in an exosome manner. Melanoma cell-derived exosomal LINC01214 inhibits the production of IFN-γ, TNF-α, Granzyme-B and Perforin by CD8+ T cells. Further mechanism study found that cirLINC01214 delivered by exosomes suppressed CD8+ T cell function by up-regulating the expression of Protein Phosphatase 1 Regulatory Inhibitor Subunit 11 (PPP1R11) through sponging miR-4492. CirLINC01214 conferred resistance to PD-1 immunotherapy in melanoma xenograft mouse model. Melanoma patients with poor prognosis after PD-1 treatment carried high levels of exosomal LINC01214. Additionally, the secretion of exosomal cirLINC01214 was enhanced by the Warburg effect, which was consistent with the reprogrammed glucose metabolism of melanoma.
Conclusions:
Our results demonstrated that exosomal LINC01214 released by melanoma cells promoted immunotherapy resistance by inducing CD8+ T cell dysfunction via the miR-4492/PPP1R11 regulatory loop. Targeting cirLINC01214 might be a potential therapeutic strategy to enhance the outcome of immunotherapy in melanoma.
Insights
Exosomal LINC01214 from melanoma cells impairs CD8+ T cell function, leading to resistance against PD-1 immunotherapy. Targeting this molecule may improve melanoma treatment outcomes.
Area of Science:
- Oncology
- Immunology
- Molecular Biology
Background:
- Long non-coding RNAs (lncRNAs) within exosomes mediate intercellular communication in cancer, influencing tumor development and immune evasion.
- CD8+ T cell dysfunction is a key feature of melanoma, allowing cancer cells to escape immune surveillance.
- The precise mechanisms by which exosome-transmitted lncRNAs contribute to CD8+ T cell dysfunction in melanoma are not fully understood.
Purpose of the Study:
- To investigate the role of exosomal LINC01214 in melanoma.
- To elucidate the molecular mechanisms by which exosomal LINC01214 affects CD8+ T cell function.
- To evaluate the potential of exosomal LINC01214 as a therapeutic target for enhancing anti-PD-1 immunotherapy in melanoma.
Main Methods:
- Quantitative real-time PCR (RT-qPCR) to measure LINC01214 expression.
- Exosome isolation (ultracentrifugation) and characterization (transmission electron microscopy) from melanoma cell cultures and patient plasma.
- ELISA to assess CD8+ T cell function (IFN-γ, TNF-α, Granzyme-B, Perforin production).
- RNA immunoprecipitation and pull-down assays to determine molecular interactions (miR-4492/PPP1R11 axis).
- Mouse models with human immune system reconstitution to evaluate anti-PD-1 therapy resistance.
Main Results:
- LINC01214 expression is elevated in melanoma tissues and patient plasma, correlating with poor PD-1 immunotherapy response.
- Melanoma cell-derived exosomes carry LINC01214, which suppresses CD8+ T cell function by downregulating key cytokines and cytotoxic molecules.
- Exosomal LINC01214 upregulates PPP1R11 by sponging miR-4492, thereby inhibiting CD8+ T cell activity.
- High levels of exosomal LINC01214 are associated with resistance to PD-1 immunotherapy in a melanoma mouse model.
- The Warburg effect in melanoma enhances the secretion of exosomal LINC01214.
Conclusions:
- Exosomal LINC01214 secreted by melanoma cells promotes immunotherapy resistance by inducing CD8+ T cell dysfunction through the miR-4492/PPP1R11 pathway.
- Targeting exosomal LINC01214 presents a potential therapeutic strategy to improve the efficacy of immunotherapy in melanoma patients.
