"Nucleocytosis" Discovered: Immune Cells Found Extracting DNA from the Nuclei of Dying Cells

University of Tokyo researchers identify "nucleocytosis," a new cellular process where immune cells extract DNA from dying nuclei to trigger immune responses.

By: AXL Media

Published: Feb 25, 2026, 7:41 AM EST

Source: The information in this article was sourced from The Institute of Medical Science, The University of Tokyo

Challenging the Barrier Theory of the Nucleus In classical biology, the nuclear envelope is viewed as a strict, impenetrable barrier that keeps genetic material isolated from the rest of the cell, only breaking down during cell division (mitosis) or total cell death. The discovery of nucleocytosis by Professor Ken J. Ishii and his team proves that this barrier can be bypassed in a controlled, regulated manner. This allows immune cells to "reach in" and pull out DNA from a dying cell to use as a signaling molecule.

A Regulated Immune "Messenger" System The study utilized advanced fluorescence microscopy to track the movement of DNA. The researchers observed that nucleocytosis is not a random result of cellular damage but a deliberate, repeatable function. By extracting this DNA, immune cells can activate specific pathways—such as the cGAS-IFN-I response—which alerts the body to infection or cellular stress. This suggests that "self-DNA" acts as a potent molecular messenger, shaping how our body handles inflammation.

Implications for Autoimmune Disease and Cancer Because the immune system’s recognition of its own DNA is a central factor in many diseases, this discovery has massive clinical potential:

Autoimmune Diseases: In conditions like Lupus, the body attacks its own DNA. Nucleocytosis may be the "leak" that triggers this overactive response.

Cancer Immunotherapy: Understanding how DNA is extracted from dying tumor cells could help scientists design drugs that better alert the immune system to the presence of cancer.

Antiviral Research: The study was partially inspired by the need to understand how antiviral drugs work at a cellular level, particularly following the COVID-19 pandemic.