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Updated: Mar 26, 2026
Monitoring PD-1-Blocking Antibodies Bound to T Cells Derived from a Drop of Peripheral Blood
Published on: February 5, 2020
Basics of PD-1 in self-tolerance, infection, and cancer immunity
1Department of Microbiology and Immunology, Keio University School of Medicine, 35 Shinanomachi, East Lecture Hall 4F, Shinjuku-ku, Tokyo, 160-8582, Japan. schikuma@keio.jp.
Abstract:
Successful cancer treatment requires understanding host immune response against tumor cells. PD-1 belongs to the CD28 superfamily of receptors that work as "checkpoints" of immune activation. PD-1 maintains immune self-tolerance to prevent autoimmunity and controls T-cell reaction during infection to prevent excessive tissue damage. Tumor cells that arise from normal tissue acquire mutations that can be targeted by lymphocytes. Accumulating lines of evidence suggest that tumor cells evade host immune attack by expressing physiological PD-1 ligands and stimulating PD-1 on the lymphocytes. Based on this idea, researchers have successfully demonstrated that systemic administration of monoclonal antibodies that inhibit the binding of PD-1 to the ligands reactivated T cells and augmented the anti-cancer immune response. In this review, I summarize the basics of T-cell biology and its regulation by PD-1 and discuss the current understanding and questions about this multifaceted molecule.
Insights
Cancer cells evade immune attack by activating PD-1 checkpoints. Blocking PD-1 ligands with antibodies reactivates T cells, enhancing the anti-cancer immune response for successful cancer treatment.
Area of Science:
- Immunology
- Oncology
- Cell Biology
Background:
- The host immune response is crucial for cancer treatment.
- Programmed cell death protein 1 (PD-1) acts as an immune checkpoint, regulating T-cell activation and self-tolerance.
- Tumor cells can evade immune surveillance by exploiting the PD-1 pathway.
Purpose of the Study:
- To review the fundamental aspects of T-cell biology and PD-1 regulation.
- To discuss the current understanding of how tumor cells utilize PD-1 to evade immune attack.
- To explore the therapeutic potential of targeting the PD-1 pathway in cancer treatment.
Main Methods:
- Review of existing literature on T-cell biology, PD-1 function, and cancer immunology.
- Analysis of studies demonstrating the efficacy of PD-1/PD-1 ligand inhibitors in preclinical and clinical settings.
Main Results:
- PD-1 pathway engagement by tumor cells suppresses anti-tumor T-cell responses.
- Systemic administration of monoclonal antibodies targeting PD-1 ligands reactivates T cells.
- Inhibition of the PD-1 pathway has shown promise in augmenting anti-cancer immune responses.
Conclusions:
- Understanding PD-1-mediated immune regulation is key to developing effective cancer therapies.
- Targeting the PD-1 pathway represents a promising strategy for enhancing anti-cancer immunity.
- Further research is needed to fully elucidate the complexities of PD-1 in cancer and autoimmunity.
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