Autoimmune Disease Flashcards
What is immunologically acted on in Graves’ disease?
TSH receptors in thyroid
What is immunologically acted on in type 1 diabetes?
Beta islet cells of the pancreas
What are some examples of autoimmune diseases of HLA B27-associated apondyloarthropathies?
Reactive arthritis
Psoriatic arthritis
Urethritis
Iritis
What is systemic lupus erythematosus characterised by?
Autoantibodies binding to nuclear antigens
What is autoimmunity?
Failure of regulatory controls to attacking host components
What is immune tolerance?
Knowing what to attack/what not to attack
What is central tolerance?
Destruction of self-reacting T or B cells before they enter circulation
What happens in central tolerance ?
Immature B cells in bone marrow encounters antigen in a form which can cross-link their IgM, triggering apoptosis
What is peripheral tolerance?
Destruction or control of any self-reactive T or B cell which do not enter circulation
What are the types of peripheral tolerance?
Ignorance
Anergy
Regulation
When does ignorant peripheral tolerance happen?
Antigen present in too low a concentration to reach the threshold for T cell receptor trigger
Immunologically privileged sites means there are T cells but they cant get to the sites
What causes anergic peripheral tolerance?
Naive T cell seeing its MHC without appropriate costimulatory protein
What is Anergy?
Naive T cells need costimulation to become activated
If they dont, they’re less likely to be stimulated in future even if costimulation is present
Which cells inhibit T cells?
Treg cells
Which disease has defective treg cells been observed in?
Multiple sclerosis
How does treg regulation happen?
Expresses transcription factor FOXP3