Hypersensitivity 2 Flashcards
What is the antibody type that mediates type 1 rxns? What is the time line
IgE
Immediate response
What types of cells can mediate type 1 rxns _
Cells with granules (Mast cells, basophils, eosinophils)
Are type 1 mediators preformed of newly formed?
Both preformed and newly formed
The most common immunity disorder are _
Allergic response
What is the role of genetics in allergic response?
Genetic predisposition to allergies
Low - medium MW, stable, glycosylated and highly soluble in body fluids. These are all characteristics of _
Allergens
2 major contributors to the development of allergic disease are _ and _
Genetic susceptibility and environment
What subtype of CD4 cell mediates type 1 hypersensitivity? What are the associated cytokines
TH2 cells
IL4 and IL13
Cytokines IL4 and IL13 function in hypersensitivity reactions by _
Inducing isotype switching in IgE producing B cells
The role of IL13 during the first exposure to antigen in type 1 hypersensitivity is _
Recruit eosinophils
The immediate reaction upon exposure to antigen during type 1 hypersensitivity is _
Crosslinking of IgE on mast cells, leading to degranulation. Effects on vasculature and smooth muscle
What is the late phase reaction? What is the time line?
Inflammation
2-4 hrs after exposure
What is the name of the mast cell receptor targeted by IgE? What is the time line of activation?
FC-epsilon-R1
Seconds
The 3 major cell types involved in immediate hypersensitivity are _
Mast cells
Basophils
Eosinophils
What are the preformed components of the Type 1 rxn (2)? Where are they stored?
Biogenic amines
Enzymes
Cytoplasmic granules
What are the components of the type 1 rxn that are produced following activation?
Lipid mediators
Cytokines
The major biogenic amine mediate to Type 1 rxns is _. It binds to what receptors _. It causes _
Histamine
H1, H2 and H3
Wheal and flare
Arachidonic acid, COX, prostaglandins, thromboxanes, Lipoxigenase, Leukotrienes are all _
Lipid mediators of type 1 rxns
The mediators of vasoconstrictors and broncho-constriction are _
Leukotrienes (B4, C4, D4, E4)
Vasodialation and vascular leak are mediated by _
Biogenic amines
CD4 T cells mediate allergic reactions. How do T-cell independent antigens cause hypersensitivity reactions?
They can’t, unless they become attached to protein
Penicilin is a drug (chemical, non-protein) that can mediate hypersensitivity. How is this accomplished?
By becoming attached to AAs on self proteins, i.e. becomes a hapten. A chemical that modifies protein
Where is IgE found in the body? What is its function?
Bound to mast cells, constitutively
Mediate recognition of antigens
Which antibody-Fc receptor combination has the highest antibody affinity?
IgE - Fc-epsilon R1
