{
  "id": 10480531,
  "title": "A Novel PD-L1 Splice Isoform Modulates β Cell Communication in Response to Interferon Signaling",
  "url": "https://urgent.news/2026/09/28/a-novel-pd-l1-splice-isoform-modulates-cell-communication-in-response",
  "topic": "culture",
  "section": "Culture",
  "published": "2026-09-28T00:00:00.000Z",
  "source": {
    "name": "bioRxiv",
    "slug": "biorxiv",
    "url": "https://www.biorxiv.org/content/10.64898/2026.09.25.754099v1?rss=1"
  },
  "original_language": "en",
  "account": "A novel splice isoform of PD-L1, called PD-L1Δ3, has been discovered in human beta cells and islets. This isoform arises from an alternative splicing process, triggered by interferon (IFN) signaling or viral infections. Unlike the full-length PD-L1 protein, PD-L1Δ3 is not found on the cell surface but remains intracellular. This intracellular localization prevents PD-L1Δ3 from interacting with PD-1, a receptor that helps regulate immune cell activity.\n\nThe research team found that PD-L1Δ3 is present in higher amounts in islets from individuals with single autoantibody positivity (AAB+) and those diagnosed with type 1 diabetes (T1D). Unlike the protein encoded by the full-length PD-L1 gene, PD-L1Δ3 does not bind to PD-1, thereby losing its ability to suppress the activity of CD8+ and CD4+ T cells. These T cells play a crucial role in the immune response against the beta cells in T1D patients. Additionally, PD-L1Δ3 is not efficiently incorporated into extracellular vesicles (EVs), which are small particles released by cells that can carry various biomolecules, including proteins.\n\nInterestingly, the researchers also identified a specific genetic variant in the splicing site of the PD-L1 gene. This germline variant, found in siblings with neonatal T1D, leads to the production of PD-L1Δ3. This variant shares the same intracellular retention, reduced PD-1 binding, and impaired EV PD-L1 expression as PD-L1Δ3. The findings suggest that PD-L1Δ3 is an IFN-induced splice variant that diverts PD-L1 from its immunoregulatory, EV-competent form. This discovery highlights a post-transcriptional mechanism that influences beta cell immune communication, potentially contributing to the development and progression of T1D.",
  "summary": "{beta} cell expression of the immune checkpoint ligand PD-L1 (encoded by CD274) limits autoimmune {beta} cell destruction in type 1 diabetes (T1D). {beta} cell display PD-L1 not only at the cell surface but also secreted on extracellular vesicles (EVs), which bind PD-1 and restrain CD8+ T cell activation. {beta} cell IFN signaling is an early driver of T1D pathogenesis, yet the mechanisms linking…",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}