how RAST works
Patient serum applied to disc coated with potential allergen. If IgE to allergen is present it will stick to allergen on disc. Radiolabeled anti-human IgE added. After washing, presence of radiolabeled Ab indicates allergy
how bee allergy works
Bees have multi-antigen venom
When an allergic individual is stung, anti-bee venom IgE bearing mast cells bind to venom and degranulate.
Degranulation: Vasoactive and pro-inflammatory cytokines are released.
Anaplylactic reaction can be blocked by epinephrine
mechanism of peanut allergy
certain MHC II presentation leads to Th2 response and formation if IgE instead of IgG
anti peanut allergy vaccine mechanism
Unsensitized mice given DNA for peanut allergen Arah-2 encapsulated in carbohydrate to allow it to get to stomach. DNA vaccine increases IgA levels, Th1 response. Vaccinated mice now do not produce IgE antibody to allergen!
small molecule that can elicit an immune response when attached to a large carrier (e.g. protein)
desensitization to allergy happens via...
Can happen due to expansion of Tregs that reroute immune response to Th2 T cells that produced IgG instead of IgE.
May occur after repeated exposure.
allergy to "lucky" bracelet is due to...
Nickel ion leaching out of bracelet, diffusing through epidermis, combining will proteins and taken up by DC and presented as antigen.
TMMI response occurs.
Ouchterlony - Agar gel immunoprecipitin assay
Agar gel immunoprecipitin assay used to analyze antigen-antibody precipitation. Antigens and antibodies (known or unknown) are placed in wells in a gel. # and pattern of precipitin bands give info. on # of specific antigen/antibody systems present and isotype of antibody
See page 6 of notes!
Why worm infection can help Crohn's and ulcerative colitis
Helps "reset" CD4, 25 FoxP3 Tregs.
Essentially Th1/Th2 balance is reset.
This is the reason underdeveloped countries have lower rates of asthma and Crohn's disease.