Autoimmune Disease & Hypersensitivity

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What is the primary mechanism that prevents autoimmune cells from entering the periphery?

Peripheral tolerance
Immunological tolerance to self
Central tolerance (correct)
Molecular mimicry

What happens to self-reactive T cells in the absence of signal 2?

They differentiate into regulator T cells
They undergo apoptosis
They become anergic and fail to proliferate (correct)
They recognize self-antigens and attack healthy tissues

What is the result of a breakdown in peripheral tolerance?

Generation of regulator T cells
Central tolerance
Induction of anergic T cells
Autoimmune disease (correct)

What is the function of regulator T cells in peripheral tolerance?

To suppress through actions of cytokines (C) Signup and view all the answers

What is the purpose of negative selection in central tolerance?

To remove T cells that strongly recognize self MHC and peptide (C) Signup and view all the answers

What is the result of molecular mimicry in autoimmune disease?

Loss of immunological tolerance to self (C) Signup and view all the answers

What is the primary result of P. gingivalis in the gingiva?

Citrullination by PAD (A) Signup and view all the answers

What is the purpose of CD40 and CD40L in B cell activation?

To deliver the 2nd signal to Th cells (B) Signup and view all the answers

What is the primary characteristic of a hypersensitivity reaction?

An exaggerated immune response that damages tissue (B) Signup and view all the answers

What is required for a hypersensitivity reaction to occur?

Previous exposure to antigens (C) Signup and view all the answers

What is the time frame for a Type I hypersensitivity reaction?

0-2 hours (C) Signup and view all the answers

What is the treatment for anaphylaxis?

All of the above (D) Signup and view all the answers

What is the primary symptom of anaphylaxis?

Difficulty breathing (D) Signup and view all the answers

What is the purpose of adrenaline in anaphylaxis treatment?

To reduce symptoms (C) Signup and view all the answers

What is the primary result of IgG binding to antigen on the cell surface?

Opsonisation and activation of phagocytic cells (D) Signup and view all the answers

What is the primary purpose of TLR7/9 in B cell activation?

To trigger production of type I interferon (D) Signup and view all the answers

What is the mechanism by which activated T cells are eliminated to prevent accumulation of self-reactive cells?

Interactions between Fas and FasL (B) Signup and view all the answers

What is the primary reason for the higher prevalence of autoimmune diseases in females?

Incomplete X chromosome inactivation leads to an increased expression of immune response genes (C) Signup and view all the answers

What is the primary function of regulatory T cells in preventing autoimmune diseases?

To inhibit the immune response against self-antigens (A) Signup and view all the answers

What is the term for the process by which microbial antigens mimic self-antigens, leading to the activation of self-reactive T cells?

Molecular mimicry (C) Signup and view all the answers

What is the name of the enzyme associated with Rheumatoid Arthritis?

Protein-arginine deaminase (PAD) (C) Signup and view all the answers

What is the term for the process by which the immune system prevents self-reactive B and T cells from forming?

Random generation of cell surface antigens (C) Signup and view all the answers

What is the primary mechanism by which Treg cells inhibit the immune response against self-antigens?

By secreting inhibitory cytokines (A) Signup and view all the answers

What is the term for the studies that implicate multiple genes in immune activation and antigen presentation?

Genome-wide association studies (GWAS) (D) Signup and view all the answers

What is the primary mechanism by which innate immune response can lead to autoimmune disease?

By bypassing the regulatory T cell response (B) Signup and view all the answers

What is the disease that occurs when there is a mutation in the Treg cell?

IPEX (Immunodysregation, Polyendocrinopathy, Enteropathy, X-linked syndrome) (D) Signup and view all the answers

What is the mechanism of a Type II hypersensitivity reaction?

Antibody-mediated response to organ-specific autoimmune disease (C) Signup and view all the answers

What is the timescale for a Type III hypersensitivity reaction?

Hours-days (D) Signup and view all the answers

What is the mechanism of a Type IV hypersensitivity reaction?

T cells secrete chemokines, cytokines to recruit and activate macrophages (D) Signup and view all the answers

What is the characteristic of antigens in Type III hypersensitivity reactions?

Not bound to cell surfaces (C) Signup and view all the answers

What is the result of immune complexes being deposited in joints and blood vessels?

Tissue damage and inflammation (D) Signup and view all the answers

What is the role of Fcgamma receptors in Type III hypersensitivity reactions?

Binding to mast cells and increasing vascular permeability (B) Signup and view all the answers

What is the function of granulomas in Type IV hypersensitivity reactions?

To contain the toxic products and prevent tissue damage (A) Signup and view all the answers

What is the result of multiple granulomas forming in autoimmune disease?

Tissue damage (C) Signup and view all the answers

Which of the following is NOT a characteristic of Type III hypersensitivity reactions?

Antigens are bound to cell surfaces (A) Signup and view all the answers

What is the effect of mutated Aire and Fez2f transcription factors?

Severe autoimmune disease (A) Signup and view all the answers