Module 9 Flashcards
(41 cards)
What is central tolerance?
The negative selection of self-reactive B and T cells
What is peripheral tolerance?
Tolerance mechanisms that happen outside the bone marrow and thymus gland
What are the three subcategories of peripheral tolerance?
Immune privilege
Suppression
Anergy
What is AIRE?
An autoimmune regulator that eliminates self-reactive T cells that would otherwise cause autoimmune disease
What is the consequence of AIRE deficiency?
APECED, a multiorgan immune syndrome
How are autoreactive B cells in the periphery managed through T cells?
B cell reliance on Th cells provide a safeguard from rouge B cells
What does the peripheral tolerance mechanism of immune privilege consist of?
Certain tissues such as the nervous system, the eyes, testes and uterus are shielded from the immune system
What does the peripheral tolerance mechanism of suppression consist of?
Suppressive cytokines and TReg cells keep immune responses in check
What does the peripheral tolerance mechanism of anergy consist of?
When autoreactive B and T cells go into a frozen state for protection
What are some mechanisms and symptoms of Grave’s disease?
Type 2 hypersensitivity
Agonistic autoantibodies
Overproduction of thyroid hormones
What are some of the mechanisms and symptoms of Hashimoto’s disease?
Type 2 and 3 hypersensitivity
B and T cells destroy thyroid tissue
Reduction of thyroid hormones
What are some of the mechanisms and symptoms of insulin dependent diabetes myelitis (IDDM)?
Type 1 diabetes onset in childhood
Type 2 and 4 hypersensitivity
Organ specific
Loss of ability to produce insulin and metabolize glucose
What are some of the mechanisms and symptoms of systemic lupus erythematosus (SLE)?
Type 3 hypersensitivity Systemic Nuclear antigens and other common target Facial rash More likely in African/Asian women
What are some of the mechanisms and symptoms of rheumatoid arthritis (RA)?
Type 3 and 4 hypersensitivity
Systemic
Anti-IgG antibodies
Chronic inflammation in joints
What are some of the mechanisms and symptoms of myasthenia gravis?
Type 2 hypersensitivity Neuro-muscular system Anti-acetylcholine receptor antibodies Block muscle stimulation Progressive muscular weaknesses
What are some of the mechanisms and symptoms of multiple sclerosis?
Type 4 hypersensitivity
Destruction of insulating myelin sheath of CNS
Progressive paralysis
What are some of the genetic factors associated with autoimmune disease?
Gender
Defects if immunoregulatory proteins
HLA alleles
What are some of the environmental factors associated with autoimmune disease?
Altered self exposure
Molecular mimicry
Exposure to sequestered Ags
Hygiene hypothesis
Why is HLA associated with certain autoimmune disease?
Some alleles may present self antigens to autoreactive T cells better than others
What is molecular mimicry?
When exposure to an infectious microorganism induces memory B and T cells to react with self antigens
How does exposure to sequestered self Ags happen?
When trauma to tissues expose immune system to privileged sites
What are some additional risk factors of autoimmune disease?
Inflammation induced HLA expression
Aging
Hygiene hypothesis
TReg
How are autoimmune diseases treated?
Immunosuppressive and anti-inflammatory agents
Some novel therapies -
Humanized monoclonal antibodies
What is an autograft?
Self to self transplant
