How Do Immune Cells Fight Together?
7 月 27, 2026Core Framework & Diagram How Does the Immune System Stop Attacking?
7 月 27, 2026
1 minuete Read
How Does the Immune System Stop Attacking?
How does the immune system stand down after a battle? This matters more than you'd think
编辑部精选 · 一分钟理解
Many people think about how the immune system launches attacks, but very few wonder: how does it stop?
This stopping process is just as important as the launching process. If the immune system can't apply the brakes at the right time, inflammation persists, tissue gets damaged, and autoimmune disease develops.
The immune system uses several methods to end the battle: effector cells actively undergo apoptosis, Treg cells issue ceasefire signals, anti-inflammatory cytokines are released, immune checkpoint molecules engage. This termination system is as precise as the initiation system — and can fail just as badly. When it fails, the result is chronic inflammation and autoimmune disease.
核心要点
01
Immune response shutdown and initiation are equally important and equally precise. Shutdown failure consequences — chronic inflammation, autoimmune disease, cytokine storm — are no less harmful than 'insufficient immunity.'
02
First mechanism: after antigen and IL-2 decrease, effector T cells actively undergo AICD (activation-induced cell death), with 90–95% of effector cells dying in an orderly fashion within 2–3 weeks after infection resolves.
03
Second mechanism: Treg cells actively issue ceasefire signals by secreting IL-10 and TGF-β. IL-10 is the most important inflammation brake molecule; chronic inflammation partly comes from insufficient IL-10 signaling.
04
Third mechanism: SPMs (resolvins/protectins, from omega-3 fatty acids) actively sweep the battlefield, stop reinforcement recruitment, and launch repair — inflammation resolution is an active process, not passive depletion.
05
Checkpoint inhibitors' (PD-1/CTLA-4 inhibitors) anti-tumor effects come from releasing T cell brakes; immune-related side effects (dermatitis/colitis) come from simultaneously releasing brakes on self-tissue attacks — balance is key.
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