Allergy and IgE-Dependent Responses Flashcards
what immune cells characterize the late-phase reaction of allergic response?
neutrophils, eosinophils, macrophages and CD4+ Th2 cells accumulate
what does atopy mean?
allergy
what percentage of the population has allergy
20% of the U.S. population has allergies
the actions of what cells characterize immediate hypersensitivity?
mast cells, basophils and eosinophils
describe the sequence of events in immediate hypersensitivity
exposure to antigen, activation of Th2 cells and B cells specific to the antigen, production of IgE, binding of IgE to Fc receptors of mast cells, degranulation of mast cells releasing pro-inflammatory mediators
how are mast cells sensitized?
When mast cells are bound by IgE they are stimulated to degranulate and release pro-inflammatory mediators. This is called sensitization.
which cells generally cause immediate vs. delayed-type hypersensitivity
Th2 cells cause immediate hypersensitivity while Th1 cells cause delayed-type hypersensitivity
IL-12 secreted from APCs induce which T helper cell type?
Th1 (which promotes the cell-mediated response instead of antibody response)
which cytokine secreted from APCs causes differentiation towards Th2 cells?
IL-4
what cytokines does Th2 secrete?
IL-4 and IL-13
how does Th2 promote antibody production?
Th2 produces IL-4 and IL-13 which trigger B cells to isotype switch to IgE and produce high levels of IgE
what does IgE promote (for a Th2 response)
degranulation of mast cells and basophils
true or false: sensitization causes production of memory B and T cells
true
