Immunological Tolerance: Mechanisms and Clinical Significance

Question 1

In central tolerance, which mechanism is primarily responsible for eliminating autoreactive T cells?

Accepted Answer

Clonal deletion

Answer

Clonal anergy

Answer

T cell receptor modification

Question 2

In the periphery, which cell type plays a key role in immune suppression and maintains self-tolerance?

Accepted Answer

Regulatory T cells

Answer

T helper cells

Answer

Cytotoxic T cells

Question 3

What is the main function of regulatory T cells?

Accepted Answer

Immune response suppression

Answer

Pro-inflammatory cytokine secretion

Question 4

Type 1 diabetes is linked to a defect in which type of tolerance?

Accepted Answer

Central tolerance

Answer

Peripheral tolerance

Question 5

What is Foxp3's role in regulatory T cell development and function?

Accepted Answer

Suppression of immune responses

Answer

Activation of cytotoxic T cells

Question 6

Which of the following is NOT a mechanism by which the immune system achieves immunological tolerance?

Accepted Answer

Competitive inhibition

Answer

Clonal anergy

Answer

Central tolerance

Answer

Peripheral tolerance

Question 7

Which type of immune cell plays a key role in maintaining peripheral tolerance?

Accepted Answer

Regulatory T cells

Answer

Helper T cells

Answer

Cytotoxic T cells

Answer

B cells

Question 8

What is the primary function of regulatory T cells in immunological tolerance?

Accepted Answer

To suppress immune responses directed against self-antigens

Answer

To activate immune responses against pathogens

Answer

To differentiate into effector T cells

Answer

To produce antibodies

Question 9

What is the term for the failure of the immune system to distinguish between self and non-self?

Accepted Answer

Autoimmunity

Answer

Immunodeficiency

Answer

Hypersensitivity

Answer

Tolerance

Question 10

Which of the following therapeutic approaches aims to induce immune tolerance in clinical settings?

Accepted Answer

Administration of immunosuppressive drugs

Answer

Blood transfusions

Answer

Radiation therapy

Answer

Vaccination

Question 11

What is the key role of the thymus in the development of immunological tolerance?

Accepted Answer

It provides a site for the maturation and selection of T cells

Answer

It produces regulatory T cells

Answer

It suppresses the production of autoreactive antibodies

Answer

It is the primary site of B cell development

Question 12

What is the ultimate goal of immunological tolerance?

Accepted Answer

To protect the body from harmful immune responses

Answer

To eliminate all pathogens from the body

Answer

To promote the production of antibodies against foreign antigens

Answer

To optimize the function of immune cells

Question 13

Regulatory T cells (Tregs) contribute to immune tolerance primarily by:

Accepted Answer

Suppressing the activation of T effector cells

Answer

Inducing apoptosis in activated T cells

Answer

Promoting the differentiation of Th2 cells

Answer

Inhibiting the production of pro-inflammatory cytokines

Question 14

Which of the following is a mechanism of peripheral tolerance that involves the functional inactivation of T cells?

Accepted Answer

Clonal anergy

Answer

Clonal deletion

Answer

Immune ignorance

Answer

Suppression by regulatory T cells

Question 15

Checkpoint inhibitors have shown promise in cancer treatment. Which of the following mechanisms of action is commonly associated with checkpoint inhibitors?

Accepted Answer

Blocking co-stimulatory molecules on T cells

Answer

Inducing apoptosis in T cells

Answer

Stimulating the differentiation of regulatory T cells

Answer

Increasing the production of pro-inflammatory cytokines

Question 16

Which of the following diseases is NOT caused by a malfunction in immunological tolerance?

Accepted Answer

Sickle Cell Anemia

Answer

Type 1 Diabetes

Answer

Multiple Sclerosis

Question 17

Regulatory T cells primarily maintain immune balance by:

Accepted Answer

Suppressing the activation of autoreactive T cells

Answer

Promoting the differentiation of B cells into plasma cells

Answer

Enhancing the immune response to foreign antigens

Answer

Inducing the production of antibodies against self-antigens

Question 18

Which of the following molecules is essential for the negative selection of thymocytes?

Accepted Answer

MHC-I

Answer

MHC-II

Answer

CD3

Answer

TCR

Question 19

A defining characteristic of autoimmune diseases is:

Accepted Answer

Loss of immune tolerance to self-antigens

Answer

Increased production of antibodies against foreign antigens

Answer

Impaired phagocytosis by macrophages

Answer

Reduced activity of natural killer cells

Question 20

Regulatory T cells can mediate immune suppression through:

Accepted Answer

Production of inhibitory cytokines

Answer

Expression of cytotoxic molecules

Answer

Activation of B cells to produce antibodies

Answer

Inducing the maturation of dendritic cells

Question 21

Clonal deletion primarily occurs during:

Accepted Answer

Central tolerance

Answer

Peripheral tolerance

Answer

Both central and peripheral tolerance

Answer

Neither central nor peripheral tolerance

Question 22

Regulatory T cells are essential for maintaining immune homeostasis by:

Accepted Answer

Preventing excessive immune responses to self-antigens

Answer

Promoting the development of autoimmune diseases

Answer

Amplifying the immune response to foreign antigens

Answer

Stimulating the production of natural killer cells