Regulatory T cells

Definition

Regulatory T cells, also known as Tregs, are a specialized subset of T cells that play a crucial role in maintaining immune system homeostasis and preventing autoimmune responses. They achieve this by suppressing the activity of other immune cells, thereby preventing excessive immune responses that could harm the body's own tissues. Tregs are essential for maintaining tolerance to self-antigens and modulating the overall immune response during infection or inflammation.

5 Must Know Facts For Your Next Test

1. Regulatory T cells express specific surface markers such as CD4, CD25, and the transcription factor FoxP3, which are critical for their development and function.
2. Tregs can suppress the activation and proliferation of various immune cells, including T helper cells and B cells, thereby controlling inflammation and autoimmunity.
3. They play a vital role in peripheral tolerance, preventing unwanted immune responses against harmless antigens like food proteins or gut microbiota.
4. Dysfunction or deficiency of regulatory T cells is associated with increased susceptibility to autoimmune diseases, indicating their importance in self-tolerance.
5. Therapeutic strategies targeting Tregs are being explored for enhancing immune responses in cancer treatments or dampening them in autoimmune disorders.

Review Questions

• How do regulatory T cells contribute to the prevention of autoimmune diseases?
  • Regulatory T cells help prevent autoimmune diseases by maintaining self-tolerance and suppressing overactive immune responses. By inhibiting the activation and proliferation of effector T cells, they ensure that the immune system does not mistakenly target the body’s own tissues. This suppression is vital for protecting against autoimmune conditions where the body would otherwise attack itself.
• Discuss the mechanisms through which regulatory T cells exert their suppressive effects on other immune cells.
  • Regulatory T cells utilize several mechanisms to exert their suppressive effects on other immune cells. They can produce inhibitory cytokines like IL-10 and TGF-β that dampen the activity of effector T cells and B cells. Additionally, they may engage in direct cell-cell interactions that inhibit the activation signals needed for other immune cells to respond effectively. By employing these strategies, Tregs maintain immune balance and prevent excessive responses.
• Evaluate the potential therapeutic applications of manipulating regulatory T cell functions in treating diseases such as cancer and autoimmunity.
  • Manipulating regulatory T cell functions presents promising therapeutic opportunities in treating diseases like cancer and autoimmunity. In cancer therapy, enhancing Treg activity could suppress anti-tumor immunity to protect normal tissues during treatment; however, this could also allow tumors to evade immune detection. Conversely, reducing Treg activity in autoimmune diseases may boost the immune response against harmful self-antigens. Careful modulation is essential to strike a balance between promoting effective immunity against malignancies while preventing damaging autoimmunity.

Related terms

T helper cells: A subset of T cells that help activate and regulate other immune cells, playing a pivotal role in the adaptive immune response.

Cytokines: Signaling molecules produced by immune cells that mediate and regulate immunity, inflammation, and hematopoiesis.

Autoimmunity:

A condition where the immune system mistakenly attacks the body's own tissues, often due to a failure in regulatory mechanisms like those provided by Tregs.