What is the primary function of regulatory T cells (Tregs) in the immune system?

• A. To stimulate excessive immune responses
• B. To attack infected cells directly
• C. To maintain tolerance to self-antigens
• D. To enhance inflammation

Answer: (C)

Regulatory T cells (Tregs) play a crucial role in maintaining immune tolerance to self-antigens, which is essential for preventing autoimmune diseases. Their primary function is to suppress the immune response, ensuring that the body does not launch an attack against its own tissues. Tregs are involved in modulating the activity of other immune cells and can inhibit the proliferation and activation of effector T cells as well as other immune cells that may contribute to inflammation and potential autoimmunity.

The regulation of immune responses by Tregs is vital for distinguishing between harmful pathogens and the body’s own cells, thereby preventing unnecessary and potentially damaging immune reactions. By maintaining this balance, Tregs help promote stability within the immune system and protect against uncontrolled inflammation. This is why the correct answer highlights their role in maintaining tolerance to self-antigens, a foundational aspect of effective immune functioning.