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    "headline": "The Embryo Had an Earlier Rejection Gate",
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    "dek": "Primitive macrophages ate living donor cells across species; blocking the signal improved rat-pancreas generation in mice.",
    "summary": "Primitive macrophages ate living donor cells across species; blocking the signal improved rat-pancreas generation in mice.",
    "body_text": "Science Tokyo and Stanford researchers describe xenophagocytosis, in which stressed donor cells expose phosphatidylserine and embryonic macrophages recognize it through Axl before adaptive immunity exists. Depleting host macrophages, disrupting Axl, adding the CD47 'don't eat me' signal or boosting ATP11C improved donor-cell survival. Suppression increased rat-pancreas generation in mice and human-cell survival in mouse chimeras. This remains embryo and animal research, far from transplantable human organs.",
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      "Suppression increased rat-pancreas generation in mice and human-cell survival in mouse chimeras."
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    "tags": [
      "regenerative medicine",
      "chimeras",
      "macrophages",
      "organ transplantation"
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      "source_id": "source-2026-08-02-012",
      "title": "Cell: xenophagocytosis blockade enhances interspecies chimerism",
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