Regulatory T Cells - Online Tutor, Practice Problems & Exam Prep

Regulatory T cells, or Tregs, are a specialized subset of helper T cells that inhibit immune responses, preventing autoimmune reactions by stopping self-reacting T cells from attacking healthy cells. Unlike cytotoxic and helper T cells that promote immune activity, Tregs maintain immune tolerance and prevent overreactions to harmless substances. Their role is crucial in ensuring the immune system does not target the body’s own tissues, and ongoing research continues to uncover their detailed functions in immune regulation.

Regulatory T Cells

In this video, we're going to briefly talk about regulatory T cells. These regulatory T cells are commonly abbreviated as Tregs. Regulatory T cells or Tregs are unlike the other T cells that we've talked about so far. The other T cells, including the cytotoxic T cells and the helper T cells, are all about stimulating and generating an immune response. However, the regulatory T cells or Tregs are all about inhibiting and preventing an immune response. These regulatory T cells or Tregs are really a subset of the helper T cells that are going to once again inhibit self-reacting T cells ultimately involved with preventing autoimmune reactions, preventing our own immune system from attacking our own healthy cells. These Tregs play an important role. They help to make sure that our immune system does not target our own cells. Once again, these Tregs are unlike the other types of T cells because the other types of T cells are promoting and initiating immune responses. However, the Tregs are all about stopping the immune system response. They stop the immune system response from overreacting and responding to harmless substances. That's a good thing; we do not want our immune system to overreact and to respond to harmless substances. So these Tregs have an important role. However, the detailed role of the Tregs is still being studied and still being revealed today. It's undergoing research as we speak. More and more information will become available about these regulatory T cells. Now, these regulatory T cells, again, what they can do is they can inhibit the activity of other T cells via peripheral tolerance mechanisms during development. Again, helping to prevent immune system responses from overreacting and targeting self cells.

If we take a look at this cartoon that we have down below of these regulatory T cells we can get a little bit of a better understanding of what they are involved with. Notice over here on the left-hand side, what we have are some immune system cells, here represented as a SWAT team. We have a CD8+ cell over here or a cytotoxic T cell, and perhaps some neutrophils and things like that. Notice that these T cells over here are self-reacting because they're saying we need to destroy that cell over there. But notice that this cell over here is a normal cell, that is displaying normal cytoplasmic proteins on its MHCs. Because this is a normal cell, we do not want our immune system targeting this normal healthy cell. These, right here in the middle, represent our regulatory T cell or, in other words, our Treg cell. The Treg cell is all about stopping and inhibiting the immune system response from overreacting and targeting self cells. Notice here our regulatory T cell is saying stop, this cell is perfectly healthy, do not attack it. These regulatory T cells help to inhibit the immune response, whereas the other types of T cells that we've talked about are all about promoting and generating immune responses. This concludes our brief lesson on regulatory T cells, and we'll be able to get some practice applying these concepts as we move forward. So I'll see you all in our next video.

Which of the following is NOT a function of regulatory T cells?

• A. Regulatory T cells contain receptors that remove cytokines required for the growth and proliferation of effector cells.
• B. Regulatory T cells induce apoptosis of effector cells via perforin and granzyme.
• C. Regulatory T cells secret cytokines that reduce the signaling activity of effector T cells.
• D. Regulatory T cells interact with MHC class I APCs and inhibit their maturation.

What does it mean when TReg cells control lymphocyte functions via peripheral tolerance?

• A. T_Reg cells show T and B lymphocytes in the peripheral lymphoid organs which antigens to attack.
• B. T_Reg cells inhibit T and B lymphocytes that have exited the primary lymphoid organs from attacking self-antigens.
• C. T_Reg cells control the production of T and B lymphocytes and ensure only cells with immune tolerance proliferate.
• D. T_Reg cells inhibit T and B lymphocytes that are maturing within the primary lymphoid organs.

Here’s what students ask on this topic:

What are regulatory T cells (Tregs) and what is their primary function?

Regulatory T cells, commonly known as Tregs, are a specialized subset of helper T cells. Their primary function is to inhibit immune responses, thereby preventing autoimmune reactions. Unlike cytotoxic and helper T cells that promote immune activity, Tregs stop self-reacting T cells from attacking healthy cells. This inhibition is crucial for maintaining immune tolerance and ensuring that the immune system does not overreact to harmless substances or target the body’s own tissues. Ongoing research continues to uncover the detailed mechanisms by which Tregs regulate immune responses.

How do regulatory T cells (Tregs) prevent autoimmune reactions?

Regulatory T cells (Tregs) prevent autoimmune reactions by inhibiting the activity of self-reacting T cells. They achieve this through peripheral tolerance mechanisms, which occur during the development of the immune system. By stopping self-reacting T cells from attacking the body's own healthy cells, Tregs maintain immune tolerance. This inhibition ensures that the immune system does not overreact to harmless substances or target normal tissues, thereby preventing autoimmune diseases. Tregs play a crucial role in maintaining the balance and proper functioning of the immune system.

What distinguishes regulatory T cells (Tregs) from other types of T cells?

Regulatory T cells (Tregs) are distinct from other types of T cells, such as cytotoxic T cells and helper T cells, in their function. While cytotoxic and helper T cells are involved in stimulating and generating immune responses, Tregs are specialized in inhibiting and preventing immune responses. Tregs stop self-reacting T cells from attacking healthy cells, thereby preventing autoimmune reactions. This unique role of Tregs in maintaining immune tolerance and preventing overreactions to harmless substances sets them apart from other T cell types.

Why is ongoing research important for understanding the role of regulatory T cells (Tregs)?

Ongoing research is crucial for understanding the role of regulatory T cells (Tregs) because their detailed functions in immune regulation are still being uncovered. While it is known that Tregs inhibit immune responses and prevent autoimmune reactions, the specific mechanisms and pathways involved are not fully understood. Continued research can provide deeper insights into how Tregs maintain immune tolerance, how they interact with other immune cells, and how they can be manipulated for therapeutic purposes. This knowledge is essential for developing new treatments for autoimmune diseases and improving immune system regulation.

How do regulatory T cells (Tregs) contribute to immune tolerance?

Regulatory T cells (Tregs) contribute to immune tolerance by inhibiting the activity of self-reacting T cells, thereby preventing them from attacking the body's own healthy cells. This inhibition is achieved through peripheral tolerance mechanisms, which occur during the development of the immune system. By stopping self-reacting T cells, Tregs ensure that the immune system does not overreact to harmless substances or target normal tissues. This maintenance of immune tolerance is crucial for preventing autoimmune diseases and ensuring the proper functioning of the immune system.