The cells that keep the body from attacking itself

In plain terms

1940s

At Oak Ridge, Tennessee, in a laboratory studying radiation for the Manhattan Project, male mice are born with flaky skin and swollen glands and live only a few weeks. The strain is named scurfy.

1982

Sakaguchi and Yasuaki Nishizuka show that a fraction of immune cells from normal mice can stop the autoimmune disease that follows removal of the thymus.

1995

After more than a decade’s work, Sakaguchi defines regulatory T cells by the marker CD25. Many colleagues remain sceptical.

2001

Brunkow and Ramsdell find the scurfy mutation in a new gene, Foxp3, and show that mutations in the human gene cause IPEX.

2003

Sakaguchi shows that Foxp3 governs the development of regulatory T cells. Ramsdell’s group and Alexander Rudensky’s publish supporting results the same year.

2025

The prize. Brunkow saw a Swedish number at night, took it for spam, and went back to sleep. Ramsdell, on a three-week hike with his phone in airplane mode, heard the news from his wife when they came back into signal in Montana.

2026

In June the FDA approves Orca-T, a transplant product containing purified regulatory T cells, to reduce graft-versus-host disease in adults with blood cancers. Treatments for autoimmune disease are still in early trials.

Say it accurately

“They discovered how the body learns not to attack itself.”

Immune tolerance itself was recognised long before: Burnet and Medawar won the 1960 prize for it, and the weeding out of self-attacking T cells in the thymus, called central tolerance, was worked out in the 1980s. This prize is for a second safeguard that works out in the body’s tissues, the regulatory T cell. The committee’s background paper names others who contributed, among them Nishizuka, Fiona Powrie, Ethan Shevach and Alexander Rudensky.

“A cure for autoimmune disease is coming.”

The committee speaks of hope and of treatments now being tested in clinical trials. The one approval so far, in June 2026, is for transplant patients with blood cancers, where purified regulatory T cells lower the risk that donor cells attack the patient. For autoimmune disease the work is early. A trial in rheumatoid arthritis run by Ramsdell’s company, for instance, reported its first results from a phase 1 study in six patients.

“Autoimmune disease is the body sinning against itself,” or “the immune system attacking the body is like sin.”

An immune cell has no will. The boys with IPEX are ill because a gene is damaged, not because anyone has done wrong, and the same goes for anyone living with an autoimmune disease. The image may be borrowed for a sermon on how Christians treat one another. It must not be turned back on the sick.

“The science shows that tolerance is always good.”

In immunology tolerance means not attacking one’s own tissues. It is not the virtue of bearing with people who differ. And immune restraint can do harm: tumours draw in large numbers of regulatory T cells to shield themselves, and some cancer treatments under test aim to remove them. Health is the right attack on the right target, not the least attack.

“They found the gene for autoimmune disease.”

Foxp3 is the gene a regulatory T cell needs in order to be one. When it is broken, as in the rare inherited disease IPEX, the whole system breaks down. That shows how much depends on these cells. It does not mean that common autoimmune diseases come from a faulty Foxp3.

For preaching

• “Ours, at least, can explain what we saw” Instance

  1 Thessalonians 5:21 · Proverbs 18:17

  When the evidence for “suppressor T cells” partly proved false, the field abandoned the whole idea. Sakaguchi kept to a result he had seen himself, that normal T cells could stop a disease. Each time a new theory appeared, he said, “we checked which one is better, our idea or theirs.” He neither clung to the idea blindly nor dropped it because it was out of fashion. Paul is speaking of prophecy, but his rule is general: “Test all things, and hold firmly that which is good” (1 Thessalonians 5:21, WEB).

• The twentieth gene Instance

  Ecclesiastes 9:10 · Galatians 6:9

  Brunkow and Ramsdell narrowed the scurfy mutation to a stretch of DNA holding about twenty genes, and checked them one by one. It was the last of the twenty. Brunkow called it “a molecular slog.” She has since left the field, and called the work “an amazing team effort.” “Whatever your hand finds to do, do it with your might” (Ecclesiastes 9:10, WEB).

• If you bite and devour one another Likeness

  Galatians 5:13–15 · 1 Corinthians 12:21–26

  Without its regulatory T cells, a body’s defences turn on its own organs, and the scurfy mice lived only a few weeks. Paul warns a church of the same outcome: “if you bite and devour one another, be careful that you don’t consume one another” (Galatians 5:15, WEB). The picture proves nothing about churches. It also fails at a point a preacher must state aloud: the immune system has no choice, and the people of Galatia did.

• Strength held in check Likeness

  Proverbs 16:32 · Galatians 5:22–23 · James 1:19–20

  Regulatory T cells do not weaken the immune system. They hold it back from the wrong target, and calm it once an invader is gone, so that a strong defence does not become a danger. “One who is slow to anger is better than the mighty; one who rules his spirit, than he who takes a city” (Proverbs 16:32, WEB). Use it as a picture of self-control. The cells exercise no virtue, and the fruit of the Spirit is not a mechanism.

On the Wesleyan shelf

• On Zeal (sermon on Galatians 4:18)

  Wesley takes a force that is good and needed and asks what keeps it from doing harm. Zeal, he says, is “not properly religious or Christian zeal, if it be not joined with charity” (§I.2); it is “no other than the flame of love” (§I.3). So “every sort of bitterness toward them that oppose us” is “directly opposite to it” (§III.1), and as for those “who call their anger by that name,” they “put darkness for light, and light for darkness” (§III.3). His subject is the soul, not the body. But a sermon on this prize can borrow the shape of his argument: the defender that will not be governed becomes the attacker.

• A Caution against Bigotry (sermon on Mark 9:38–39)

  The committee notes that harmful microbes “do not wear a uniform,” so the immune system must judge friend from foe some other way. Wesley’s sermon is about the same mistake among Christians: forbidding one who does Christ’s work “because he followeth not us.” He warns how “unwilling men are to allow anything good in those who do not in all things agree with themselves” (§III.2), and defines the bigot as one so attached to his own “party, opinion, church, and religion” that he forbids such a man (§IV.1). His test is the fruit, not the badge. The parallel is a likeness only; Wesley argues from Scripture and from what can be seen, not from the body.

• On the Fall of Man (sermon on Genesis 3:19)

  Wesley marvels at the body as “fearfully and wonderfully wrought”, its parts mixed “in the most exact proportion; so that while the body is in health, no one of them predominates” (§II.1). In the present state of things, though, the embodied mind misjudges: “I mistake, and possibly cannot avoid mistaking the character of this or that man. I suppose him to be what he is not” (§II.2), a mistake “occasioned by the defect of my bodily organs.” His physiology of elements is long gone. His sense that health is a balance, and that an embodied creature can take a friend for an enemy and “possibly cannot avoid” it, sits well beside this prize. The immune system is a picture of his point, not a proof of it.