PD-L1 Regulation in Tumor Immunology

Programmed death-ligand 1 (PD-L1) is a key immune checkpoint molecule expressed on tumour cells and various stromal and immune cells. Engagement of PD-L1 with its receptor PD-1 on T lymphocytes dampens effector functions, enabling tumours to evade immune destruction. Regulation of PD-L1 expression is multifaceted. At the transcriptional level, inflammatory cytokines such as interferon-γ and oncogenic pathways including JAK/STAT, RAS/MAPK and PI3K/AKT drive CD274 gene transcription. Post-transcriptional mechanisms involve mRNA stabilisation, alternative splicing and control by microRNAs. Post-translational modifications—glycosylation, phosphorylation, ubiquitination and lysosomal trafficking—determine PD-L1 surface abundance and turnover. The tumour microenvironment, characterised by hypoxia, metabolic by-products and cell–cell interactions, further modulates these pathways. Deciphering PD-L1 regulation informs patient stratification for immune checkpoint blockade, guides the development of combination regimens and suggests novel targets to overcome primary and acquired resistance. Advances in this field carry global significance, promising more durable responses across a spectrum of malignancies.

Research from Nature Portfolio

One foundational study revealed that microRNA miR-424(322) directly binds to the 3′ untranslated region of PD-L1, suppressing its expression in chemoresistant ovarian cancer models. Restoration of miR-424(322) led to decreased PD-L1 and CD80 on tumour cells, reinvigoration of CD8+ T-cell cytotoxicity and reduction of immunosuppressive myeloid-derived suppressor cells. This work highlights the therapeutic potential of targeting post-transcriptional regulation of PD-L1 to enhance the efficacy of combined chemo-immunotherapy strategies.

PD-L1 Regulation in Tumor Immunology publication trend

The graph below shows the total number of articles in pd-l1 regulation in tumor immunology across all publications each year (not limited to Nature Index journals).

Technical terms

PD-L1: A transmembrane ligand that engages PD-1 on T cells to inhibit immune responses.

Immune checkpoint: A regulatory pathway that restrains immune activation to maintain self-tolerance and prevent tissue damage.

Tumour microenvironment: The complex milieu of cancer cells, stromal elements, immune infiltrates and biochemical factors surrounding a tumour.

MicroRNA: A small non-coding RNA species that binds target mRNAs to repress translation or promote degradation.

Post-translational modification: Covalent chemical changes to proteins (e.g. glycosylation, ubiquitination) that influence stability, localisation and function.

References

1. Macrophages facilitate tumor cell PD‐L1 expression via an IL‐1β‐centered loop to attenuate immune checkpoint blockade. MedComm (2023).
2. The opportunities and challenges in immunotherapy: Insights from the regulation of PD-L1 in cancer cells. Cancer Letters (2023).
3. Role of the tumor microenvironment in PD-L1/PD-1-mediated tumor immune escape. Molecular Cancer (2019).
4. Genetic, transcriptional and post-translational regulation of the programmed death protein ligand 1 in cancer: biology and clinical correlations. Oncogene (2018).
5. miR-424(322) reverses chemoresistance via T-cell immune response activation by blocking the PD-L1 immune checkpoint. Nature Communications (2016).