Immunology 2 Flashcards
What is a hapten?
An antigen that needs covalent linkage to a carrier to stimulate an immune response eg penicillin
What is a superantigen?
Bind Vbeta chain of the TCR, bypassing the need for MHC to present the antigen–>large number polyclonal T lymphocytes activated
How does adrenaline work?
Act on beta and alpha receptors to cause vasoconstriction and bronchodilation
Downregulate histamine and tryptase release
MOA sodium chromoglycate
stabilise mast cell
prevent degranulation by blocking calcium influx
What has to be done before skin prick testing?
hold antihistamines 4-7 days
RAST can be done on antihistamines
Of T reg cells, IL-10 does what?
Promote IgG4
Of T reg cells, TGF beta does what?
promotes IgA
What are the three sets of things that bind between APC and T cell?
TCR binds to MHC on APC
CD40L on T cell binds CD40 on APC
CD28 on T cell binds B7 AKA CD80/86 on APC
Note CTLA4 on T cell can also bind CD80/86
MHC1 made up of what molecules?
3 alpha chains
and
beta 2 microglobulin
MHC2 made up of what molecules?
2 alpha
2 beta
Which cells express MCH class 2?
Macrophages dendritic cells B lymphocytes Thymic epithelia Activated T cells
The most common autoimmune disease?
Coeliac then Graves
What does GAD actually do?
Involved in glutamate metabolism
Increase age of onset of type 1 DM….
reducing incidence of multiple antibodies being positive
Later onset DM- more GAD, less anti insulin
ie LADA often only GAD positive with intermediate risk HLA
Breast feeding does what to celiac risk?
Lowers
Too much early gluten increases risk
Chronic atrophic gastritis- antral vs corpus
antral gastritis- H pylori
Corpus gastritis- autoimmune