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T Regulatory Cells and Their Immune-Suppressive Role

Description: T Regulatory Cells and Their Immune-Suppressive Role Quiz
Number of Questions: 15
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Tags: immunology t cells immune suppression
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What is the primary function of T regulatory cells (Tregs)?

  1. To activate immune responses

  2. To suppress immune responses

  3. To produce antibodies

  4. To phagocytose pathogens


Correct Option: B
Explanation:

Tregs are a specialized subset of T cells that play a crucial role in maintaining immune homeostasis by suppressing excessive immune responses and preventing autoimmune disorders.

Which cytokine is primarily responsible for the suppressive function of Tregs?

  1. Interferon-gamma (IFN-γ)

  2. Interleukin-2 (IL-2)

  3. Interleukin-10 (IL-10)

  4. Tumor necrosis factor-alpha (TNF-α)


Correct Option: C
Explanation:

Tregs produce high levels of IL-10, which is a potent anti-inflammatory cytokine that inhibits the activation and proliferation of other immune cells, thereby suppressing immune responses.

What is the main mechanism by which Tregs suppress immune responses?

  1. By releasing cytotoxic molecules

  2. By inducing apoptosis in immune cells

  3. By inhibiting the production of pro-inflammatory cytokines

  4. By promoting the differentiation of Th2 cells


Correct Option: C
Explanation:

Tregs suppress immune responses primarily by inhibiting the production of pro-inflammatory cytokines, such as IFN-γ and TNF-α, which are key mediators of inflammation and immune activation.

Which transcription factor is essential for the development and function of Tregs?

  1. T-bet

  2. RORγt

  3. Foxp3

  4. GATA-3


Correct Option: C
Explanation:

Foxp3 is a critical transcription factor that plays a central role in the development, differentiation, and function of Tregs. It is essential for the suppressive activity of Tregs and mutations in the Foxp3 gene can lead to autoimmune disorders.

What is the role of Tregs in preventing autoimmune diseases?

  1. They activate immune responses against self-antigens

  2. They suppress immune responses against self-antigens

  3. They produce antibodies against self-antigens

  4. They promote the differentiation of Th1 cells


Correct Option: B
Explanation:

Tregs play a crucial role in preventing autoimmune diseases by suppressing immune responses against self-antigens. They maintain immune tolerance and prevent the development of autoimmune reactions that can damage healthy tissues.

Which cell surface marker is commonly used to identify Tregs?

  1. CD4

  2. CD8

  3. CD25

  4. CD19


Correct Option: C
Explanation:

Tregs are typically identified by the expression of CD25, which is the alpha chain of the interleukin-2 receptor (IL-2Rα). CD25 is a marker associated with regulatory T cell function and is commonly used to distinguish Tregs from other T cell subsets.

What is the role of Tregs in immune responses to pathogens?

  1. They enhance immune responses against pathogens

  2. They suppress immune responses against pathogens

  3. They produce antibodies against pathogens

  4. They promote the differentiation of Th17 cells


Correct Option:
Explanation:

Tregs play a role in modulating immune responses against pathogens. They can suppress excessive immune responses that could lead to tissue damage, while also maintaining immune surveillance to prevent infections.

Which type of T cell is most commonly associated with the development of Tregs?

  1. Th1 cells

  2. Th2 cells

  3. Th17 cells

  4. Th9 cells


Correct Option: B
Explanation:

Tregs are often generated from naive T cells under the influence of Th2 cytokines, such as interleukin-4 (IL-4) and interleukin-10 (IL-10). These cytokines promote the differentiation of naive T cells into Tregs.

What is the role of Tregs in transplantation tolerance?

  1. They promote graft rejection

  2. They suppress graft rejection

  3. They produce antibodies against the graft

  4. They promote the differentiation of Th1 cells


Correct Option: B
Explanation:

Tregs play a crucial role in promoting transplantation tolerance by suppressing immune responses against the transplanted organ or tissue. They prevent the development of graft rejection and contribute to the long-term acceptance of the graft.

Which signaling pathway is involved in the suppressive function of Tregs?

  1. Wnt signaling pathway

  2. TGF-β signaling pathway

  3. NF-κB signaling pathway

  4. MAPK signaling pathway


Correct Option: B
Explanation:

The TGF-β signaling pathway is a key regulator of Treg function. TGF-β promotes the differentiation and expansion of Tregs and is involved in their suppressive activity. It plays a crucial role in maintaining immune homeostasis and preventing excessive immune responses.

What is the role of Tregs in immune responses to tumors?

  1. They promote tumor growth

  2. They suppress tumor growth

  3. They produce antibodies against tumor cells

  4. They promote the differentiation of Th17 cells


Correct Option:
Explanation:

The role of Tregs in immune responses to tumors is complex and can vary depending on the tumor type and context. Tregs can suppress anti-tumor immune responses, allowing tumors to evade immune surveillance and grow. However, in some cases, Tregs can also contribute to tumor regression by suppressing excessive immune responses that could lead to tissue damage.

Which cell type is a major target of Treg-mediated suppression?

  1. B cells

  2. Macrophages

  3. Neutrophils

  4. Dendritic cells


Correct Option: D
Explanation:

Dendritic cells (DCs) are a major target of Treg-mediated suppression. Tregs can suppress the activation and maturation of DCs, thereby inhibiting the initiation of immune responses and promoting immune tolerance.

What is the role of Tregs in regulating immune responses to allergens?

  1. They promote allergic responses

  2. They suppress allergic responses

  3. They produce antibodies against allergens

  4. They promote the differentiation of Th1 cells


Correct Option: B
Explanation:

Tregs play a role in regulating immune responses to allergens by suppressing excessive allergic reactions. They can prevent the development of allergies and asthma by maintaining immune tolerance to harmless environmental antigens.

Which cytokine is produced by Tregs that can inhibit the proliferation of other T cells?

  1. Interferon-gamma (IFN-γ)

  2. Interleukin-2 (IL-2)

  3. Interleukin-10 (IL-10)

  4. Tumor necrosis factor-alpha (TNF-α)


Correct Option: C
Explanation:

Tregs produce interleukin-10 (IL-10), which is a potent anti-inflammatory cytokine that can inhibit the proliferation of other T cells. IL-10 plays a crucial role in the suppressive function of Tregs and contributes to the maintenance of immune homeostasis.

What is the role of Tregs in immune responses to chronic infections?

  1. They promote the clearance of pathogens

  2. They suppress the clearance of pathogens

  3. They produce antibodies against pathogens

  4. They promote the differentiation of Th17 cells


Correct Option:
Explanation:

The role of Tregs in immune responses to chronic infections is complex and can vary depending on the specific pathogen and the stage of infection. Tregs can suppress excessive immune responses that could lead to tissue damage, but they can also contribute to the control of chronic infections by preventing immune exhaustion and maintaining immune memory.

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