scholarly journals Clinical Implications of Exosomal PD-L1 in Cancer Immunotherapy

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Sergio Ayala-Mar ◽  
Javier Donoso-Quezada ◽  
José González-Valdez
Keyword(s):  
Cell Death ◽  
T Cell ◽  
Programmed Cell Death ◽  
Cancer Immunotherapy ◽  
Cell Function ◽  
Immune Escape ◽  
Transmembrane Protein ◽  
Clinical Implications ◽  
Tumor Immune Escape ◽  
Immunological Mechanisms

Inhibiting the programmed cell death ligand-1 (PD-L1)/programmed cell death receptor-1 (PD-1) signaling axis reinvigorates the antitumor immune response with remarkable clinical efficacy. Yet, low response rates limit the benefits of immunotherapy to a minority of patients. Recent studies have explored the importance of PD-L1 as a transmembrane protein in exosomes and have revealed exosomal PD-L1 as a mechanism of tumor immune escape and immunotherapy resistance. Exosomal PD-L1 suppresses T cell effector function, induces systemic immunosuppression, and transfers functional PD-L1 across the tumor microenvironment (TME). Because of its significant contribution to immune escape, exosomal PD-L1 has been proposed as a biomarker to predict immunotherapy response and to assess therapeutic efficacy. In this review, we summarize the immunological mechanisms of exosomal PD-L1, focusing on the factors that lead to exosome biogenesis and release. Next, we review the effect of exosomal PD-L1 on T cell function and its role across the TME. In addition, we discuss the latest findings on the use of exosomal PD-L1 as a biomarker for cancer immunotherapy. Throughout this review, we propose exosomal PD-L1 as a critical mediator of tumor progression and highlight the clinical implications that follow for immuno-oncology, discussing the potential to target exosomes to advance cancer treatment.

scholarly journals Serum-derived exosomes promote CD8+ T cells to overexpress PD-1, affecting the prognosis of hypopharyngeal carcinoma

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Qian Gao ◽  
Hui-Ting Liu ◽  
Yu-Qin Xu ◽  
Lin Zhang ◽  
Yuan-Ru Liu ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
Programmed Cell Death ◽  
Cd8 T Cells ◽  
Poor Prognosis ◽  
Cell Function ◽  
Immune Escape ◽  
Cd8 T Cell ◽  
Serum Exosomes

Abstract Background Hypopharyngeal cancer (HPC) is associated with a poor prognosis and a high recurrence rate. Immune escape is one of the reasons for the poor prognosis of malignant tumors. Programmed cell death ligand 1 (PD-L1) and programmed cell death-1 (PD-1) have been shown to play important roles in immune escape. However, the role of PD-1/PD-L1 in HPC remains unclear. In this experiment, we investigated the effect of exosomes from HPC patient serum on CD8+ T cell function and PD-1/PD-L1 expression and, thus, on prognosis. We hope to provide guidance for the identification of new targets for HPC immunotherapy. Methods PD-1 and CD8 expression in 71 HPC tissues and 16 paracarcinoma tissues was detected by immunohistochemistry. Concurrently, the clinicopathological data of the patients were obtained to conduct correlation analysis. Exosomes were isolated from serum and then identified by Western blotting (WB), transmission electron microscopy (TEM), and nanoparticle tracking analysis (NTA). Flow cytometry was used to assess the activity of CD8+ T cells after exosome stimulation. The effects of exosomes on the ability of CD8+ T cells to kill FaDu cells were assessed by CCK-8 assay. The expression of IL-10 and TGF-β1 was measured by enzyme-linked immunosorbent assay (ELISA). PD-L1 expression in HPC tissue samples was evaluated by immunohistochemistry, and the relationship between PD-1/PD-L1 expression and prognosis was investigated with patient specimens. Results PD-1 expression was significantly upregulated on CD8+ T cells in tumor tissues compared with those in normal tissues. The overall survival (OS) and disease-free survival (DFS) of PD-1-overexpressing patients were decreased. Serum exosomes from patients can elevate PD-1 expression on CD8+ T cells and suppress their killing capacity and secretory function. The rate of positive PD-L1 expression was increased in HPC tissues compared with paracancerous tissues. The DFS and OS of the PD-1(+)-PD-L1(+) group were significantly lower than those of the PD-1(−)-PD-L1(−) group. Conclusion Our findings indicate that serum exosomes from HPC patients can inhibit CD8+ T cell function and that the PD-1-PD-L1 pathway plays an important role in the immune escape of HPC. Exosomes combined with immunotherapy may guide the treatment of patients with advanced disease in the future.

scholarly journals Research Progresses in Immunological Checkpoint Inhibitors for Breast Cancer Immunotherapy

2021 ◽  
Vol 11 ◽  
Author(s):  
Wenxiang Zhang ◽  
Xiangyi Kong ◽  
Bolun Ai ◽  
Zhongzhao Wang ◽  
Xiangyu Wang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Cancer Immunotherapy ◽  
Immune Checkpoint ◽  
Immune Escape ◽  
Checkpoint Inhibitors ◽  
Immune Checkpoints ◽  
Tumor Immune Escape ◽  
Cell Death Protein

Tumor immune escape refers to the phenomenon in which tumor cells escape the recognition and attack of the body’s immune system through various mechanisms so that they can survive and proliferate in vivo. The imbalance of immune checkpoint protein expression is the primary mechanism for breast cancer to achieve immune escape. Cytotoxic T lymphocyte antigen 4 (CTLA4) and programmed cell death protein 1 (PD-1)/programmed cell death protein-ligand 1 (PD-L1) are critical immune checkpoints for breast cancer. Immune checkpoint inhibitors block the checkpoint and relieve its inhibition effect on immune cells, reactivate T-cells and destroy cancer cells and restore the body’s ability to resist tumors. At present, immunological checkpoint inhibitors have made significant progress in breast cancer immunotherapy, and it is expected to become a new treatment for breast cancer.

Combination cancer immunotherapy targeting PD-1 and GITR can rescue CD8+T cell dysfunction and maintain memory phenotype

2018 ◽  
Vol 3 (29) ◽  
pp. eaat7061 ◽  
Author(s):  
Bei Wang ◽  
Wen Zhang ◽  
Vladimir Jankovic ◽  
Jacquelynn Golubov ◽  
Patrick Poon ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
Programmed Cell Death ◽  
Cancer Immunotherapy ◽  
Effector Memory ◽  
Cell Phenotype ◽  
Checkpoint Inhibition ◽  
Cell Dysfunction ◽  
T Cell Dysfunction

Most patients with cancer do not develop durable antitumor responses after programmed cell death protein 1 (PD-1) or programmed cell death ligand 1(PD-L1) checkpoint inhibition monotherapy because of an ephemeral reversal of T cell dysfunction and failure to promote long-lasting immunological T cell memory. Activating costimulatory pathways to induce stronger T cell activation may improve the efficacy of checkpoint inhibition and lead to durable antitumor responses. We performed single-cell RNA sequencing of more than 2000 tumor-infiltrating CD8+T cells in mice receiving both PD-1 and GITR (glucocorticoid-induced tumor necrosis factor receptor–related protein) antibodies and found that this combination synergistically enhanced the effector function of expanded CD8+T cells by restoring the balance of key homeostatic regulators CD226 and T cell immunoreceptor with Ig and ITIM domains (TIGIT), leading to a robust survival benefit. Combination therapy decreased CD8+T cell dysfunction and induced a highly proliferative precursor effector memory T cell phenotype in a CD226-dependent manner. PD-1 inhibition rescued CD226 activity by preventing PD-1–Src homology region 2 (SHP2) dephosphophorylation of the CD226 intracellular domain, whereas GITR agonism decreased TIGIT expression. Unmasking the molecular pathways driving durable antitumor responses will be essential to the development of rational approaches to optimizing cancer immunotherapy.

scholarly journals Unveiling the immune infiltrate modulation in cancer and response to immunotherapy by MIXTURE—an enhanced deconvolution method

2020 ◽  
Author(s):  
Elmer A Fernández ◽  
Yamil D Mahmoud ◽  
Florencia Veigas ◽  
Darío Rocha ◽  
Matías Miranda ◽  
...  
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Immune Cells ◽  
Immune Cell ◽  
Immune Escape ◽  
Intratumor Heterogeneity ◽  
Support Vector ◽  
Tumor Immune Escape ◽  
Immune Infiltrate ◽  
Tumor Biopsies

Abstract The accurate quantification of tumor-infiltrating immune cells turns crucial to uncover their role in tumor immune escape, to determine patient prognosis and to predict response to immune checkpoint blockade. Current state-of-the-art methods that quantify immune cells from tumor biopsies using gene expression data apply computational deconvolution methods that present multicollinearity and estimation errors resulting in the overestimation or underestimation of the diversity of infiltrating immune cells and their quantity. To overcome such limitations, we developed MIXTURE, a new ν-support vector regression-based noise constrained recursive feature selection algorithm based on validated immune cell molecular signatures. MIXTURE provides increased robustness to cell type identification and proportion estimation, outperforms the current methods, and is available to the wider scientific community. We applied MIXTURE to transcriptomic data from tumor biopsies and found relevant novel associations between the components of the immune infiltrate and molecular subtypes, tumor driver biomarkers, tumor mutational burden, microsatellite instability, intratumor heterogeneity, cytolytic score, programmed cell death ligand 1 expression, patients’ survival and response to anti-cytotoxic T-lymphocyte-associated antigen 4 and anti-programmed cell death protein 1 immunotherapy.

scholarly journals Finding and characterizing a catalytic antibody light chain, H34, capable of degrading the PD-1 molecule

2021 ◽  
Author(s):  
Emi Hifumi ◽  
Hiroaki Taguchi ◽  
Tamami Nonaka ◽  
Takunori Harada ◽  
Taizo Uda
Keyword(s):  
Cell Death ◽  
T Cell ◽  
Programmed Cell Death ◽  
Light Chain ◽  
Immune Checkpoint ◽  
Cell Function ◽  
Catalytic Antibody ◽  
T Cell Function ◽  
Programmed Cell Death 1

Programmed cell death 1 (PD-1) is an immune checkpoint regulating T-cell function. A catalytic antibody light chain, H34, could enzymatically degrade the PD-1 molecule. In addition, it inhibited the binding of PD-1 with PD-L1.

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