Related Experiment Video
Updated: Feb 23, 2026
Co-immunoprecipitation Assay for Studying Functional Interactions Between Receptors and Enzymes
Published on: September 28, 2018
Functional Expression of Programmed Death-Ligand 1 (B7-H1) by Immune Cells and Tumor Cells
Rachel M Gibbons Johnson1, Haidong Dong2,3
1Biology Discipline, University of Minnesota Morris, Morris, MN, United States.
Abstract:
The programmed death-1 (PD-1) and its ligand PD-L1 (B7-H1) signaling pathway has been the focus of much enthusiasm in the fields of tumor immunology and oncology with recent FDA approval of the anti-PD-1 antibodies pembrolizumab and nivolumab and the anti-PD-L1 antibodies durvalumab, atezolimuab, and avelumab. These therapies, referred to here as PD-L1/PD-1 checkpoint blockade therapies, are designed to block the interaction between PD-L1, expressed by tumor cells, and PD-1, expressed by tumor-infiltrating CD8+ T cells, leading to enhanced antitumor CD8+ T cell responses and tumor regression. The influence of PD-L1 expressed by tumor cells on antitumor CD8+ T cell responses is well characterized, but the impact of PD-L1 expressed by immune cells has not been well defined for antitumor CD8+ T cell responses. Although PD-L1 expression by tumor cells has been used as a biomarker in selection of patients for PD-L1/PD-1 checkpoint blockade therapies, patients whose tumor cells lack PD-L1 expression often respond positively to PD-L1/PD-1 checkpoint blockade therapies. This suggests that PD-L1 expressed by non-malignant cells may also contribute to antitumor immunity. Here, we review the functions of PD-L1 expressed by immune cells in the context of CD8+ T cell priming, contraction, and differentiation into memory populations, as well as the role of PD-L1 expressed by tumor cells in regulating antitumor CD8+ T cell responses.
Insights
The programmed death-1 (PD-1) and programmed death-ligand 1 (PD-L1) pathway is crucial in cancer immunotherapy. This review explores PD-L1
Area of Science:
- Oncology
- Immunology
- Cancer Immunotherapy
Background:
- The PD-1/PD-L1 pathway is a key target in cancer treatment, with approved checkpoint blockade therapies.
- Tumor cell PD-L1 expression is a known factor influencing T cell responses, but its role is not fully understood.
- Some patients respond to PD-L1/PD-1 blockade despite lacking PD-L1 expression on tumor cells, suggesting other factors are involved.
Purpose of the Study:
- To review the functions of PD-L1 expressed by immune cells in CD8+ T cell responses.
- To examine the role of tumor cell PD-L1 in regulating antitumor CD8+ T cell activity.
- To highlight the importance of non-malignant cell PD-L1 in antitumor immunity.
Main Methods:
- Literature review of studies on PD-1/PD-L1 pathway in cancer immunology.
- Analysis of the impact of PD-L1 on immune cells, specifically CD8+ T cells.
- Examination of PD-L1 expression in both tumor cells and non-malignant cells.
Main Results:
- PD-L1 on tumor cells influences CD8+ T cell responses.
- PD-L1 on immune cells plays a role in T cell priming, contraction, and memory differentiation.
- PD-L1 expression by non-malignant cells may contribute to antitumor immunity.
Conclusions:
- Understanding PD-L1 expression on both tumor and immune cells is critical for optimizing cancer immunotherapy.
- PD-L1 on immune cells significantly impacts CD8+ T cell dynamics and antitumor responses.
- Further research into the multifaceted roles of PD-L1 is essential for advancing checkpoint blockade therapies.
More Related Videos
05:24Two Flow Cytometric Approaches of NKG2D Ligand Surface Detection to Distinguish Stem Cells from Bulk Subpopulations in Acute Myeloid Leukemia
Published on: February 21, 2021
09:06Development of a 68Gallium-Labeled D-Peptide PET Tracer for Imaging Programmed Death-Ligand 1 Expression
Published on: February 3, 2023
Related Concept Videos
01:17The Extrinsic Apoptotic Pathway
01:30Overview of Cell Death
Cell death was observed in the early 19th century, but there was no experimental evidence to prove it. In 1842, Carl Vogt first discovered cell death in a metamorphic toad; however, it was not termed ‘cell death.’ Scientists discovered different cell death pathways only in the...
02:23Abnormal Proliferation
01:27Cytotoxic T Cells-mediated Immune Response
Immunological surveillance is the ability of immune cells to monitor and eliminate infected cells with intracellular pathogens, neoplastically transformed cells, and cells with non-self antigens. Cytotoxic T cells and NK...
01:31The Intrinsic Apoptotic Pathway
01:28Cells of the Innate Immune Response
Phagocytes
Phagocytes police the peripheral tissues by removing cellular debris and responding to the invasion of foreign substances or pathogens. Many phagocytes attack and remove microorganisms even before lymphocytes detect them. The human body has two general...