Autoimmunity Flashcards
1
Q
Mechanisms of tolerance
A
- Clonal deletion
- Clonal anergy
- Clonal ignorance
- Regulation
2
Q
Clonal deletion
A
- Deletion of self reactive lymphocytes
- Apoptosis
3
Q
Clonal anergy
A
- Silencing of self reactive lymphocytes
- Clone present but unable to respond
- Because, no co-stimulatory molecules, or a lower binding specificity- doesn’t bind properly
4
Q
Clonal ignorance
A
- Self reactive lymphocytes don;t have the opportunity to see/respond to antigen
- Antigen segregation
- eg, we may have T cell receptors for brain antigens, but its on an issue because immune cells don’t go into the brain unless there’s an injury
5
Q
Regulation
A
-Active suppression of antigen-specific lymphocytes
6
Q
Genes that predispose to autoimmunity- affect immune regulation and self tolerance
A
- Autoantigen availability and clearance
- Apoptosis (if we expose antigens that are usually inside the cells)
- Control of lymphocyte activation
- AIRE (autoimmune regulator), responsible for presentation of peripheral tissue antigens in the thymus
- Some associated with HLA locus
7
Q
General features of autoimmune diseases
A
- Tend to be chronic- relapses and remissions, damage often progressive. Intrinsic amplificatoin loops- when directed against self tissues, they exacerbate and prolong the injury or epitope spreading- immune response against one self antigen causes tissue damage
- Clinical and pathology determined by nature of the underlying immune response
8
Q
Organ specific autoimmune disease
A
Confined to particular organs or cell types -Thyroid Ovary -Islet cells (T1 diabetes) -Gastric parietal cell -Neurologicakk
9
Q
Systemic autoimmune disease
A
-Multiple organs and systems
10
Q
Pathogenic autoantibodies
A
- Key autoantibodies assocaiated with autoimmune diseases
- Non-organ specific
- Ani-DNA antibodies: SLE
- Anti-cytoskeleton antibodies
- Organ-specific
- Anti-glomerular basement membrane: SLE, Goodpasture’s syndrome
- Anti-thyroglobulin antibodies: thyoiditis
- Anti-myelin basic protein: MS
- Anti-mitochondrial antibodies: primary biliary cirrhosis
- anti- beta cell molecules: type 1 diabetes
11
Q
Pathogenic autoantibodies
A
- Key autoantibodies assocaiated with autoimmune diseases
- Non-organ specific
- Ani-DNA antibodies: SLE
- Anti-cytoskeleton antibodies
- Organ-specific
- Anti-glomerular basement membrane: SLE, Goodpasture’s syndrome
- Anti-thyroglobulin antibodies: thyoiditis
- Anti-myelin basic protein: MS
- Anti-mitochondrial antibodies: primary biliary cirrhosis
- anti- beta cell molecules: type 1 diabetes