Immunological Tolerance: Mechanisms and Clinical Significance

Question 1

Which type of cell death is induced in developing thymocytes to eliminate autoreactive T cells?

Accepted Answer

Apoptosis

Answer

Necrosis

Answer

Pyroptosis

Answer

Ferroptosis

Question 2

Which cell type plays a pivotal role in the initiation of central tolerance in the thymus?

Accepted Answer

Immature T cells

Answer

Mature T cells

Answer

Regulatory T cells

Answer

B cells

Question 3

During negative selection in the thymus, self-reactive T cells are eliminated by which mechanism?

Accepted Answer

Fas-mediated apoptosis

Answer

Clonal anergy

Answer

Immune checkpoint blockade

Answer

Suppression by regulatory T cells

Question 4

Which of the following is NOT a recognized mechanism of peripheral tolerance?

Accepted Answer

Positive selection

Answer

Antigenic ignorance

Answer

Clonal deletion

Answer

Infectious tolerance

Question 5

Regulatory T cells primarily suppress immune responses through:

Accepted Answer

Releasing inhibitory cytokines

Answer

Expressing cytotoxic molecules

Answer

Activating T helper cells

Answer

Promoting B cell differentiation

Question 6

Autoimmune diseases primarily result from a breakdown in:

Accepted Answer

Immune tolerance

Answer

Excessive immune activation

Answer

Immunodeficiency

Answer

Malfunction of regulatory T cells

Question 7

Which of the following best describes a characteristic of clonal anergy?

Accepted Answer

T cells become unresponsive to specific antigens

Answer

T cells remain fully functional

Answer

T cells undergo apoptosis

Answer

T cells differentiate into effector cells

Question 8

Infectious tolerance is achieved by:

Accepted Answer

Administering antigen in a tolerogenic form

Answer

Inducing clonal deletion of T cells

Answer

Activating regulatory T cells

Answer

Blocking immune checkpoints

Question 9

Which cell type is responsible for presenting self-antigens to T cells in the thymus?

Accepted Answer

Thymic epithelial cells

Answer

Macrophages

Answer

B cells

Answer

Epithelial cells

Question 10

The primary function of immune checkpoints is to:

Accepted Answer

Inhibit immune responses

Answer

Enhance immune responses

Answer

Regulate B cell activity

Answer

Differentiate T cells

Question 11

Within the thymus, which cell type undergoes clonal deletion to ensure central tolerance?

Accepted Answer

CD8+T cells

Answer

Naïve B cells

Answer

CD4+T cells

Answer

Regulatory T cells

Question 12

Which of the following is the primary mechanism involved in peripheral tolerance?

Accepted Answer

Anergy

Answer

Clonal deletion

Answer

T cell exhaustion

Answer

Fas-mediated apoptosis

Question 13

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

Accepted Answer

Suppression of immune responses

Answer

Activation of B cells

Answer

Cytotoxic killing of infected cells

Answer

Antigen presentation to T cells

Question 14

Which of the following statements accurately describes clonal deletion?

Accepted Answer

Elimination of self-reactive T cells in the thymus

Answer

Permanent state of immune tolerance

Answer

Destruction of self-reactive B cells

Answer

Reversible process under certain conditions

Question 15

What is the role of anergy in establishing immunological tolerance?

Accepted Answer

Inhibition of T cell activation

Answer

Induction of T cell apoptosis

Answer

Enhancement of T cell function

Answer

Promotion of T cell differentiation

Question 16

Which of these is NOT classified as a type of regulatory checkpoint molecule?

Accepted Answer

Fas

Answer

PD-1

Answer

CTLA-4

Answer

ICOS

Question 17

How do regulatory T cells contribute to the maintenance of immune tolerance?

Accepted Answer

Regulatory T cells suppress autoreactive T cells, preventing autoimmune responses.

Answer

Regulatory T cells promote the differentiation of effector T cells, enhancing immune responses.

Answer

Regulatory T cells produce antibodies that neutralize self-antigens, preventing immune reactions against the body's own tissues.

Answer

Regulatory T cells enhance the phagocytic activity of macrophages, improving the body's ability to clear pathogens.

Question 18

Which of the following is a mechanism of central tolerance?

Accepted Answer

Deletion of self-reactive thymocytes

Answer

Anergy of self-reactive B cells

Answer

Suppression by regulatory T cells

Answer

Clonal exhaustion

Question 19

Which autoimmune disease results from a breakdown in immune tolerance to thyroid tissue?

Accepted Answer

Graves' disease

Answer

Multiple sclerosis

Answer

Rheumatoid arthritis

Answer

Systemic lupus erythematosus

Question 20

Which type of tolerance is established during T cell development in the thymus?

Accepted Answer

Central tolerance

Answer

Peripheral tolerance

Answer

Clonal deletion

Answer

Anergy

Question 21

What is the mechanism of action of CTLA-4, an immune checkpoint receptor?

Accepted Answer

Inhibition of T cell activation by competing for binding to CD28

Answer

Activation of T cell apoptosis

Answer

Induction of regulatory T cells

Answer

Stimulation of B cell responses

Question 22

How does clonal exhaustion contribute to immune tolerance?

Accepted Answer

It inhibits T cell proliferation and effector function

Answer

It promotes the development of regulatory T cells

Answer

It triggers apoptosis in antigen-specific T cells

Answer

It enhances antibody production by B cells

Question 23

In cancer immunotherapy, the primary reason for manipulating immune checkpoints is to:

Accepted Answer

Relieve the inhibitory signals on T cells that restrain their ability to target cancer cells

Answer

Enhance the suppressive activity of regulatory T cells

Answer

Upregulate the expression of immune checkpoint molecules on tumor cells

Answer

Stimulate the development of novel tumor-specific cytotoxic T cells

Question 24

Which type of regulatory T cell is primarily responsible for suppressing immune responses and maintaining self-tolerance in the periphery?

Accepted Answer

Regulatory T cells (Tregs)

Answer

Th1 cells

Answer

Th2 cells

Answer

Th17 cells

Question 25

What is the primary function of immune checkpoint molecules?

Accepted Answer

To inhibit immune responses and prevent excessive immune activation

Answer

To enhance immune responses and promote antigen presentation

Answer

To activate immune cells and facilitate antibody production

Answer

To suppress regulatory T cells and induce immune tolerance

Question 26

Why is it crucial to maintain immunological tolerance within the body?

Accepted Answer

To prevent autoimmune diseases and protect against excessive immune responses

Answer

To ensure efficient immune responses against foreign pathogens

Answer

To promote allergic reactions and hypersensitivity

Answer

To facilitate tissue regeneration and repair processes

Question 27

Which factors are believed to contribute to the development of autoimmune diseases?

Accepted Answer

Genetic predisposition, environmental triggers, and hormonal imbalances

Answer

Age and gender alone

Answer

Dietary habits and stress

Answer

Exposure to infectious agents only

Question 28

What is the primary mechanism by which regulatory T cells contribute to immune tolerance?

Accepted Answer

Suppressing immune responses and preventing excessive activation

Answer

Inducing clonal deletion of autoreactive immune cells

Answer

Promoting antibody production and enhanced immune responses

Answer

Activating immune cells and facilitating antigen presentation

Question 29

Which therapeutic approach aims to restore or enhance immunological tolerance in autoimmune diseases?

Accepted Answer

Administering immunosuppressive drugs to dampen immune activity

Answer

Stimulating immune responses with vaccines and adjuvants

Answer

Using antibiotics to eliminate pathogenic bacteria

Answer

Applying radiation therapy to target affected tissues

Question 30

What is the key distinction between central and peripheral tolerance?

Accepted Answer

Central tolerance involves the deletion of autoreactive T cells, while peripheral tolerance involves the suppression of autoreactive T cells.

Answer

Central tolerance is induced in the thymus, while peripheral tolerance occurs in the bone marrow.

Answer

Central tolerance is permanent, while peripheral tolerance is transient.

Question 31

Which immune checkpoint protein has emerged as a promising target in cancer immunotherapy due to its role in suppressing anti-tumor immune responses?

Accepted Answer

PD-1

Answer

MHC-I

Answer

CD80

Answer

ICOS

Question 32

Which of the following is a mechanism of central tolerance that involves the elimination of self-reactive thymocytes?

Accepted Answer

Deletion of self-reactive thymocytes

Answer

Suppression by regulatory T cells

Answer

Clonal expansion of self-reactive B cells

Answer

Induction of anergy in self-reactive thymocytes

Question 33

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

Accepted Answer

Suppressing the activation and proliferation of other T cells

Answer

Stimulating the production of antibodies against self-antigens

Answer

Activating complement to destroy self-tissues

Question 34

Immune checkpoints are molecular pathways that function to:

Accepted Answer

Downregulate immune responses to prevent excessive tissue damage

Answer

Select for high-affinity B cells during antibody production

Answer

Upregulate immune responses to enhance pathogen clearance

Question 35

Central tolerance, a process that eliminates self-reactive lymphocytes, primarily occurs in the:

Accepted Answer

Thymus

Answer

Lymph nodes

Answer

Spleen

Question 36

Anergy refers to a state of:

Accepted Answer

Functional unresponsiveness in T cells

Answer

Increased production of inflammatory cytokines

Answer

Enhanced sensitivity to antigen stimulation

Answer

Immunological memory formation

Question 37

Immune checkpoint inhibitors, a class of therapeutic agents, are designed to:

Accepted Answer

Block immune checkpoint molecules to enhance anti-tumor responses

Answer

Suppress T cell activation to prevent autoimmune diseases

Answer

Promote B cell differentiation into plasma cells

Question 38

Clonal deletion, a mechanism of central tolerance, involves the:

Accepted Answer

Apoptosis of self-reactive lymphocytes

Answer

Activation of regulatory T cells

Answer

Formation of anergic lymphocytes

Answer

Production of anti-inflammatory cytokines

Question 39

Which of the following accurately describes the main function of immunological tolerance?

Accepted Answer

Preventing the immune system from reacting against the body's own tissues

Answer

Supporting the production of antibodies against foreign invaders

Answer

Controlling the magnitude of immune responses to external threats

Question 40

Central tolerance primarily involves which specific mechanism?

Accepted Answer

Negative selection within the thymus

Answer

Clonal deletion in the bone marrow

Answer

Suppression by regulatory T cells

Answer

Anergy in the spleen

Question 41

Which type of immune cell is central to the mechanisms of peripheral tolerance?

Accepted Answer

Regulatory T cells (Tregs)

Answer

Neutrophils

Answer

B cells

Answer

Dendritic cells

Question 42

What is the primary function of immune checkpoints in the regulation of immune responses?

Accepted Answer

Inhibiting immune responses to prevent excessive activation and potential tissue damage

Answer

Distinguishing between self and non-self antigens

Answer

Activating immune responses to enhance the clearance of pathogens

Question 43

Which of the following health conditions is strongly associated with a breakdown in immunological tolerance?

Accepted Answer

Autoimmune disease

Answer

Graft-versus-host disease

Answer

Allergic reaction

Answer

Immunodeficiency

Question 44

Which of the following factors are known to influence the development and maintenance of immunological tolerance?

Accepted Answer

Genetic predisposition, environmental exposures, and nutritional status

Answer

Age and gender alone

Answer

Microbiome composition alone

Answer

Lifestyle choices alone

Question 45

Immunosuppressive drugs used to prevent transplant rejection primarily act by:

Accepted Answer

Inhibiting the activation and proliferation of T cells

Answer

Enhancing immune surveillance

Answer

Depleting immune cells

Answer

Stimulating the production of antibodies

Question 46

Why is an understanding of immunological tolerance crucial in the design and development of vaccines?

Accepted Answer

To prevent immune responses against the vaccine itself and ensure long-lasting immunity

Answer

To enhance the speed of the immune response

Answer

To reduce the cost of vaccine production

Question 47

Define the primary function of Regulatory T cells (Tregs) in the context of immunological tolerance.

Accepted Answer

Suppressing immune responses directed against self-antigens

Answer

Activating cytotoxic T cells

Answer

Promoting antibody production

Answer

Eliminating foreign pathogens

Question 48

Which of the following molecules is an example of an immune checkpoint involved in immunological tolerance?

Accepted Answer

Programmed cell death protein 1 (PD-1)

Answer

Immunoglobulin M (IgM)

Answer

T cell receptor (TCR)

Answer

Major histocompatibility complex class II (MHC II)

Question 49

Describe the potential consequences of a breakdown in immunological tolerance.

Accepted Answer

Development of autoimmune disorders

Answer

Allergic reactions

Answer

Reduced ability to fight cancer

Answer

Increased susceptibility to infections

Question 50

Which characteristic accurately describes peripheral tolerance?

Accepted Answer

Occurs in the secondary lymphoid tissues and organs

Answer

Involves the deletion of immature T cells in the thymus

Answer

Relies exclusively on regulatory T cells for its mechanisms

Answer

Functions independently of antigen-presenting cells

Question 51

Identify the most likely clinical outcome in a patient with a defect in central tolerance.

Accepted Answer

Autoimmune disorders

Answer

Immunodeficiency

Answer

Severe allergies

Answer

Increased cancer risk

Question 52

Which of the following factors is NOT involved in the establishment of immunological tolerance?

Accepted Answer

Major histocompatibility complex (MHC) restriction

Answer

Clonal deletion

Answer

Negative selection

Answer

Clonal anergy

Question 53

Classify immunological tolerance into its two major categories.

Accepted Answer

Central tolerance and peripheral tolerance

Answer

Active tolerance and passive tolerance

Answer

Innate tolerance and adaptive tolerance

Answer

Humoral tolerance and cell-mediated tolerance

Question 54

Identify the experimental technique commonly employed to evaluate immunological tolerance.

Accepted Answer

Mixed lymphocyte reaction (MLR)

Answer

Western blotting

Answer

Polymerase chain reaction (PCR)

Answer

Enzyme-linked immunosorbent assay (ELISA)

Question 55

Explain the primary role of immune checkpoints in immunological tolerance.

Accepted Answer

Regulating immune responses and preventing excessive immune activation

Answer

Activating immune cells

Answer

Inducing apoptosis

Answer

Promoting antibody production