Interferon regulatory factor-responsive elements in the Programmed death-ligand 1 promoter (IRF-REs (PD-L1))

The IRF-responsive DNA elements in the PD-L1 promoter are specific genomic sequences located within the regulatory region of the CD274 gene, which encodes the Programmed death-ligand 1 (PD-L1) protein. These elements, primarily consisting of two Interferon-Stimulated Response Elements (ISREs) termed IRF-E1 and IRF-E2, serve as critical docking sites for transcription factors such as IRF1 and IRF3 (Garcia-Diaz et al., 2017, Cell Reports). In the tumor microenvironment, the production of interferon-gamma by T cells triggers the JAK/STAT signaling pathway, leading to the upregulation of IRF1, which then binds to these DNA elements to drive PD-L1 transcription (Bellucci et al., 2015, Oncoimmunology). This mechanism, known as adaptive immune resistance, allows cancer cells to suppress anti-tumor immune responses by engaging the PD-1 receptor on T cells. While these DNA elements are not traditional protein targets, they represent a pivotal node in immune checkpoint regulation. Therapeutic strategies aimed at disrupting the interaction between IRFs and these promoter elements, such as decoy oligonucleotides or inhibitors of upstream signaling (e.g., JAK inhibitors), are areas of active research to overcome resistance to immunotherapy (Lu et al., 2017, Cancer Letters).

Other names

ISRE in CD274 promoterIRF-binding sites in PD-L1 promoterInterferon-stimulated response elements of PD-L1IRF-E1 and IRF-E2

Acts as a transcriptional regulatory site where Interferon Regulatory Factors (primarily IRF1) bind to induce the expression of the CD274 (PD-L1) gene in response to interferon signaling.