Class Notes (836,126)
Canada (509,644)
Biology (529)
BLG 307 (38)
Clare Chua (38)
Lecture

allergies

3 Pages
114 Views
Unlock Document

Department
Biology
Course
BLG 307
Professor
Clare Chua
Semester
Fall

Description
IMMEDIATE HYPERSENSITIVTY REACTIONS Type I Hypersensitivity/ Allergic Reactions Nomenclature: Allergen = antibody that elicits an IgE (REAGIN) response - can be inhaled, ingested, or injected - small proteins or chemicals bound to proteins - very soluble - they display SENSITIZATION (previous exposure elicits a reaction) Allergy = clinical manifestations of reaction ATOPY = genetic predisposition to make IgE’s Immediate Skin Response = WHEAL and FLARE IgER’s (FcER’s) RI – high affinity binding (mast cells, basophils) tetramer (abg2); beta and gamma domains have ITAM motifs trimeric version (no beta) – found in monocytes and DC’s UPREGULATED BY IgE PRESENCE RII – low affinity binding; also called CD23 2 isoforms; neither is homologous to FcERI CONTROL OF IgE SYNTHESIS: 2 SIGNAL HYPOTHESIS 2 SIGNALS work on B – cells 1. IL4/IL13 from Th2 cells, Basophils, and Mast Cells **activates E gene transcription** occurs via JAK/STAT6 pathway 2. CD40/CD40L binding between B and Th2 Cells **activates switch recombination** Secreted IgE’s bind to Mast Cells Crosslinking by allergen causes degranulation, tyrosine kinase activity EARLY PHASE (minutes) skin (wheal, flare, itchiness) airway (sneezing) mediated by histamine/heparin DEGRANULATION leukotriene/prostaglandin synthesis from MEMRANE LIPIDS LATE PHASE (hours) recurrent airway/skin problems mediated by cytokines/chemokines (IL4/IL13) expression and secretion involves other cells’ migration (eosinophils, basophils, lymphocytes) Mediators from mast cells/ basophils (summarized) - granule products (heparin, histamine, tryptase) histamine’s effects: nerve activation (for sneezing/pruritis) vasodilation (tissue swelling/hypotension) gland secretion (musocal) smooth muscle contraction (bronchocontriction, diarrhea) - membrane lipids (leukotriene/prostaglandin) LKT synth. involves PHOSPHOLIPASE A cleavage of membrane
More Less

Related notes for BLG 307

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit