Tissue-Resident T Cells Retain 'Inflammatory Memory' and Spread Systemically: A Beacon of Hope for Developing New Treatments for Systemic Allergic Diseases

Key facts

  • Tissue-Resident T Cells Retain 'Inflammatory Memory' and Spread Systemically: A Beacon of Hope for Developing New Treatments for Systemic Allergic Diseases
  • A research group at Chiba University discovered that tissue-resident memory CD4⁺ T cells, which carry 'inflammatory memory', can leave organs, enter the bloodstream, and spread inflammation systemically. This finding opens new pathways for chronic allergy treatments.
  • Source: PR Times
  • Date: April 9, 2026

Direct answer

A research group at Chiba University discovered that tissue-resident memory CD4⁺ T cells, which carry 'inflammatory memory', can leave organs, enter the bloodstream, and spread inflammation systemically. This finding opens new pathways for chronic allergy treatments.

Citation
Tissue-Resident T Cells Retain 'Inflammatory Memory' and Spread Systemically: A Beacon of Hope for Developing New Treatments for Systemic Allergic Diseases (April 9, 2026), PR Times
Source
PR Times
Date
April 9, 2026
A research group at Chiba University discovered that tissue-resident memory CD4⁺ T cells, which carry 'inflammatory memory', can leave organs, enter the bloodstream, and spread inflammation systemically. This finding opens new pathways for chronic allergy treatments.
調査NQ 84/100出典：PR Times

📋 Article Processing Timeline

  • 📰 Published: April 9, 2026 at 19:10
  • 🔍 Collected: April 9, 2026 at 10:30
  • 🤖 AI Analyzed: April 20, 2026 at 12:50 (266h 20m after Collected)
A research group led by Project Associate Professor Chiaki Iwamura, Professor Kiyoshi Hirahara, Project Assistant Professor Rui Hirasawa, and Professor Seiji Ohtori of the Graduate School of Medicine, Chiba University, has revealed that the mechanism by which tissue-resident memory CD4⁺ T cells (CD4⁺ TRM cells) (Note 1) remain in organs is controlled by a cell surface molecule called CD69 (Note 2). Furthermore, CD4⁺ TRM cells that reside in organs acquire an "inflammation-prone property" within the inflamed tissue and retain this property even after migrating into the bloodstream. This suggests that organ-specific chronic allergic inflammation, such as asthma, may be the cause of inflammation in other parts of the body, and it is expected to lead to the development of new therapeutic strategies for chronic inflammatory diseases.

This research finding will be published in the international scientific journal Science Advances on April 8, 2026 (Eastern Standard Time).

(Paper available here: 10.1126/sciadv.adw1038)

[Figure: Immune cells that were in the lungs circulate in the blood and spread inflammation elsewhere]

■ Research Background
In our bodies, there are immune cells called "memory T cells" that "remember" invading pathogens and react quickly when they invade again. Among them, "tissue-resident memory T cells (TRM cells)" that remain in peripheral organs such as the skin, lungs, and intestines for a long time play an important role in infection defense; however, in allergies and autoimmune diseases, they prolong organ-specific inflammation and make diseases difficult to treat. However, the dynamics and properties of these cells after they once settle in a tissue have not been fully elucidated.

■ Key Points of the Research Findings
In this study, through analysis using asthma model mice and human patient specimens, the following points were clarified:

1. CD69 is a crucial regulatory molecule that retains CD4⁺ TRM cells in tissues by suppressing the function of S1PR1 (Note 3).
2. When the expression of CD69 decreases, TRM cells move from the tissue into the blood and circulate as "ex-TRM cells" (TRM cells that have migrated from tissue to blood).
3. These ex-TRM cells retain the "inflammation-prone property" acquired in the tissue where they resided as cellular memory, and cause strong inflammatory reactions in other tissues to which they migrate.
4. Identified ex-TRM cells (cells characterized by surface molecules GPR183 and CD161) circulating in the blood of patients with chronic inflammation.

[From left: Professor Kiyoshi Hirahara, Project Associate Professor Chiaki Iwamura, Project Assistant Professor Rui Hirasawa]

■ Future Prospects (Researcher's Comment)
The findings of this study provide insights into new therapeutic strategies...

FAQ

Who led the research team at Chiba University that studied tissue-resident memory CD4⁺ T cells and their role in systemic inflammation?

The research team was led by Project Associate Professor Chiaki Iwamura, Professor Kiyoshi Hirahara, Project Assistant Professor Rui Hirasawa, and Professor Seiji Ohtori of the Graduate School of Medicine at Chiba University.

What cell surface molecule controls the retention of CD4⁺ TRM cells in organs according to the Chiba University study?

The cell surface molecule CD69 controls the mechanism by which tissue-resident memory CD4⁺ T cells remain in organs, as discovered by the research group at Chiba University.

What property do CD4⁺ TRM cells acquire in inflamed tissues, and do they retain it after leaving the organ?

CD4⁺ TRM cells acquire an 'inflammation-prone property' within inflamed tissues and retain this property even after they migrate from the organ into the bloodstream.

When will the research findings from Chiba University be published in Science Advances, and what is the publication's DOI?

The research findings will be published in Science Advances on April 8, 2026 (Eastern Standard Time), and the paper's DOI is 10.1126/sciadv.adw1038.

What potential impact could this discovery have on the treatment of chronic inflammatory diseases such as asthma?

This discovery may lead to new therapeutic strategies for chronic inflammatory diseases like asthma by explaining how organ-specific inflammation can trigger systemic allergic responses through circulating CD4⁺ TRM cells.

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