Exam 3: Dr. Pinchuk Autoimmune Diseases Flashcards Preview

Immunology - DVM year 1 > Exam 3: Dr. Pinchuk Autoimmune Diseases > Flashcards

Flashcards in Exam 3: Dr. Pinchuk Autoimmune Diseases Deck (29)
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1
Q

In healthy individuals, what is the immune system tolerant?

A

Self antigens

2
Q

What are autoimmune diseases cause by?

A

The loss of tolerance

3
Q

What are the central tolerance mechanisms that contribute to immunological self-tolerance?

A

Negative selection in the bone marrow and thymus

Expression of tissue specific proteins in the thymus

4
Q

What are the peripheral tolerance mechanisms that contribute to immunological self-tolerance?

A

No lymphocyte access to some tissues
Suppression of autoimmune responses by regulatory T cells
Induction of anergy in auto reactive B and T cells

5
Q

What do the effector mechanisms of autoimmunity resemble?

A

Those causing hypersensitivity reactions

6
Q

What are the auto antigens for lupus?

A
DNA
Histones
Ribosomes
snRNP
scRNP
7
Q

What are the consequences for lupus?

A

Glomerulonephritis
Vasculitis
Arthritis

8
Q

What are the 3 mechanisms that destroy erythrocytes in autoimmune hemolytic anemia?

A

FcR+ cells in spleen
Complement activation and CR1+ cells in spleen
Complement activation and intravascular hemolysis

9
Q

What do FcR+ cells in spleen cause?

A

Phagocytosis and erthyrocyte destruction

10
Q

What does complement activation and CR1+ cells in spleen cause?

A

Phagocytosis and erthyrocyte destruction

11
Q

What does complement activation and intravascular hemolysis cause?

A

Lysis and erythrocyte destruction

12
Q

What can autoantibodies against cell-surface receptors do?

A

Either stimulate or inhibit the receptor’s function

13
Q

What causes myasthenia gravis?

A

Signaling from nerve to muscle across the neuromuscular junction is impaired

14
Q

What is major example of rheumatic diseases caused by autoimmunity?

A

Systemic lupus erythematosus

15
Q

What are the pathogenic mechanisms for lupus?

A

Type III hypersensitivity
A large amount of small immune complexes are formed due to the availability of autoantigen and autoantibody. Immune complexes deposit in the capillaries if various tissues. Immune complexes can either enter through the fenestrations of glomerular capillaries and become trapped in the basement membrane

16
Q

What is the mechanism of autoantigen accumulation for lupus?

A

Possible defect in the clearance of apoptotic cells:

Macrophages from lupus patients have a reduced capacity to engulf apoptotic cells in vitro

17
Q

Describe type I diabetes

A

T cell responses and antibodies are made against insulin and other specialized proteins of the pancreatic β cell islets of Langerhan’s

18
Q

What can the two recently developed therapies that target different aspects of the rheumatoid arthritis do?

A

Eliminate B cells in a patient, which is okay because in theses patients most B cells are auto-reactive

19
Q

What happens with ADCC in rheumatoid arthritis?

A

Lysis of B cells by NK cells and the therapeutic anti-CD20 antibody rituximab

20
Q

What are the causes of rheumatoid arthritis?

A

Effector CD4 T cells and antibody

21
Q

What is a feature of all autoimmune diseases?

A

Breaking T cell tolerance

22
Q

Describe what happens in breaking T cell tolerance

A

Incomplete deletion of self-reactive T cells in the thymus, APECED
Insufficient control of T cell co-stimulation (CTLA-4 deficiency)
Lack of Treg cells, deficiency in FoxP3 is called immune dysregulation, polyendocrynopathy, enterophathy, and C-linked syndrome (IPEX)

23
Q

What is HLA?

A

The dominant genetic factor affecting susceptibility to autoimmune disease

24
Q

What is the HLA allotrope for ankylosing spondylitis?

A

B27 (MHC class I)

25
Q

What is autoimmunity initiated by?

A

Disease-associate HLA allotypes presenting antigens to autoimmune T cells

26
Q

What do animal models of autoimmune disease demonstrate?

A

That autoreactive T cell clones can transfer disease

27
Q

What is an example of an infection as environmental facotrs that can trigger autoimmune disease?

A

Streptococcal cell wall stimulates antibody response

Some antibodies cross-react with hear tissue, causing rheumatic fever

28
Q

How can autoimmune T cells be activated?

A

In a pathogen-specifc of non-specific manner by infection

29
Q

What can predispose to autoimmune disease?

A

Genetic and environmental factors

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