Immunology Revision Flashcards
What are the 3 complement pathways?
alternative, classical and lectin
How is the classical pathway activated?
immune complexes
What is the outcome of the complement pathway?
inflammation, opsonisation, phagocytosis, activation of adaptive immunity
What does C1 esterase deficiency lead to?
hereditary angioedema
What is the pathogenesis of hereditary angioedema?
C1 esterase deficiency means that kallikrein releases more bradykinin which causes increased vascular permeability which leads to angioedema
What complement deficiency causes aHUS?
factor I and factor H
What complement deficiency causes leukocyte adhesion deficiency?
CR3/CR4
What complement deficiency causes paroxysmal nocturnal haematuria?
CD59/CD55
How is CRP made?
TLR are bound which causes release of IL-6 which stimulates the liver to produce acute phase reactants including CRP
What is anakinra?
An IL1 receptor antagonist
What is caused by a mutation in AIRE?
autoimmune polyendocrinopathy syndrome
Which T cells do MHC-II present to?
CD4
Which T cells do MHC-I present to?
CD8
Which cells have MHC-II?
antigen presenting cells
Which cells have MHC-I?
all nucleated cells
What happens when when a MHC-I activates a cytotoxic lymphocyte?
release of granzymes and perforins, binding of FAS and FAS ligand, release of cytokines driving inflammation
What 3 signals are required for T cell differentiation?
antigen presentation, cytokine millieu, co-stimulation
What is the role of CTLA4?
to down regulate T cell activation
What is the result of CTLA-4 absence?
autoimmunity and immunodeficiency
What is the role of PD1?
inhibits TCR signalling leading to T cell anergy
Where does B cell maturation occur?
in the bone marrow
What causes B cell class switching?
binding to T cells
What causes hyper IgM syndrome?
lack of CD40-CD40 ligand binding so there is no B cell class switching
