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28 Cards in this Set
- Front
- Back
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What causes classical Type IV hypersensitivity?
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CD4(TH1) cells-->macro activation-->damage
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What do CD4(TH2) cells do in hypersensitivity?
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chronic allergy and asthma, produce IgE and activate eosinophils-->damage
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What do CD8 cells do in hypersensitivity
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direct cell killing, contact dermatitis, transplant rejection
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Can you get both delayed and immediate hypersensitivity to same Ag
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Yes
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Delayed Type Hypersensitivity?
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Ag: proteins(insect venom, mycobacterial proteins)-->local skin swelling, erythema, induration, cellular infiltrate, dermatitis
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Contact Hypersensitivity?
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Ag: Haptens(pentadecacatechol[poison ivy], DNFB, small metal ions[peptide interactions]-->local epidermal rxn, erythema, cellular infiltrate, vesicles, intraepidermal abcesses
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Gluten Sensitive enteropathy aka Celiac Disease
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Ag: Gliadin-->villous atrophy in small bowel-->malabsorption
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What must be doen to small molecules before hypersesnsitivity reaction occurs?
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must bind to larger molecule so immune system can see it
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What is the timeframe of delayed type hypersensitivity?
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Sensitization phase due to T cell proliferation(1-2 weeks) Effector Phase(1-3 days after reexposure) and longer if single exposure
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Can delayed type hypersensitivity be transferred in T cells? Serum?
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Yes, NO
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what type of cell usually mediates Delayed Type Hypersensitivity?
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TH1 cells
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what happens in effector phase?
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TH1 cells secrete cytokines(IFN-Gamma, TNF-Beta, IL2, IL3, GM-CSF) and chemokines(IL8, MCAF, MIF)
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what are the effects of macrophage activation?
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increased Class II MHC molecules increased TNF receptors, increased oxygen radicals, increased NO
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What is Macrophage Migration Inhibitory Factor(MIF) for?
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secreted by T cells, adenohypophysis, skin, & liver macros localizes macros and activates them MIF and TNFalpha enhance each other counters Cortisol's inhibition effects
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What is cortisol?
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principal stress hormone antiinflammatory glucocorticoid inhibits immune system
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How to give TB test
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inject .1 mL of % TU PPD TB produce wheal 6mm to 10mm in diameter, be careful with needle, read 48-72 hours later
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What Ag causes poison ivy?
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Pentadecacatechol
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What Ag cause contact dermatitis
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Nickel, hair dyes, poison ivy, formaldehyde, late gloves
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How do metals and small molecules stimulate T cells
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complex with skin proteins to make hapten-->MHCI or MHCII
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What causes Nickel allergy?
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nickel complexed with peptide recognized by CDR3(Vbeta17 arginine-95)
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Contact Dermatitis Progression
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Ag penetrates skin-->langerhans cells-->haplenated and presented by Langerhans-->keratinocytes secrete IL1, TNF-alpha, IL8, IP9 and MIG-->macro activation-->inflammation
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What does sun damaged skin do?
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makes this contact dermatitis reaction more severe
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Celiac Disease progression
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Gluten Ag transglutaminated via Tissue Transglutaminase-->MHCII presentation-->CD4 T cell activation-->killing of mucosal cells
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psoriasis
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gets lots of T cells involved with shortened cell cycle in keratinocytes
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Why is Tb hard to treat?
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STUPID Patients don't listen and take their pills due to side effects
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TB containment
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aided by 4 types of T cells to make granulomas CD4 TH1 cells, CD8 CTLs, gammadelta T cells, T cells recognizing lipind on CD1
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What promotes phagosomal maturation?
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Interferon-Gamma
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What is most important in controlling TB? What else helps?
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IFN-GAMMA THF-alpha and lymphotoxin-3 help
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