Page 115 - Binder2

Most T cells in the immune system are built to respond.
Cytotoxic T cells kill infected cells. Helper T cells amplify
inflammation. Memory T cells store information for future
encounters. These are the troops of immune defense—
designed for speed, power, and escalation.

But Tregs are different.

They’re not built for war.
They’re built for restraint.

Tregs function as moderators within the immune system.
Their job is not to attack, but to prevent unnecessary
attacks—especially against harmless or self-derived
antigens. They maintain the balance between defense and
overreaction. Between surveillance and tolerance. They are,
quite literally, the immune system’s brakes.

What makes them unique isn’t just their role—but their
behavior:

• Tregs suppress the activation of other T cells and
antigen-presenting cells through the secretion of
anti-inflammatory cytokines like IL-10 and TGF-β.
• They disrupt co-stimulatory signaling, depriving
conventional T cells of the secondary signals they
need to activate.
• They consume IL-2, a growth factor necessary for
effector T cell proliferation—starving inflammatory
responses before they can take hold.
• And critically, they are antigen-specific. Once
induced, a Treg trained on a particular antigen can
suppress immune responses to that antigen only,
without globally suppressing immunity elsewhere.

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