lecture 9 hypersensativity and autoimmunity Flashcards Preview

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Flashcards in lecture 9 hypersensativity and autoimmunity Deck (45)
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1
Q

can T cells undergo affinity maturation?

A

no

2
Q

when to T cells get variation in the hypervariable loops?

A

during recombination (rag 1 and rag 2)

3
Q

what do TdT cells do to antibodies?

A

add random nucleotides

4
Q

what are the four mechanisms driving an abnormal immune response?

A

type 1 type 2 type 3 and type 4

5
Q

what mediates type 1 hypersensitivity?

A

IgE antibodies

6
Q

where do IgE antibodies bind to?(type1)

A

mast cells and basophils

7
Q

on mast cells and basophils what do antibodies act as?(type1)

A

receptors for allergens

8
Q

what induces cellular deregulation from mast cells?(type1)

A

cross linking of r or more IgE receptors

9
Q

what is released during degranulation of mast cells?(type1)

A

histamine, leukotrienes and protoglandins

10
Q

what does histamine do upon degranulation?(type1)

A

dilates blood vessels, increases permeability of blood vessels, increases mucus secretion and smooth muscle contraction

11
Q

what do prostoglandins do upon degranulation?(type1)

A

contract smooth muscle and increase msucus secretion

12
Q

what do leukotrienes do upon degranulation?(type1)

A

bronchial spasms

13
Q

what happens to blood pressure during anaphylaxis?(type1)

A

drops

14
Q

what is IgE released by?(type1)

A

B cells that have class switched by cytokines

15
Q

on mast cells where do IgE bind to?(type1)

A

Fc epsilon receptors

16
Q

what does mast cell activation and degranulation cause in the GI tract?(type1)

A

increase in peristalsis, increased fluid, vomitting and diaoreah

17
Q

what happens during mast cell degranulation in the eyes, nasal cavity and airways?(type1)

A

increased diameter and increased musuc secretion leading to congestion and blockage of airways

18
Q

mast cell activation in blood vessels causes what?(type1)

A

inc fluid in tissues, increased flow of lymph to lymph nodes, increased effector response in tissues and hypotension

19
Q

what is released in immediate degranulation?(type1)

A

histamine, TNFalph, proteses and heparin

20
Q

what do leukotrienes do?(type1)

A

recruit neutrophils, cause bronchio constriction, increase vascular permeability, cause mucus secretion and chemotaxis

21
Q

what does TNFa do?(type1)

A

causes tissue injury and cell recruitment

22
Q

what do proteases do in the context of mast cell release?(type1)

A

tissue injury and mucus production

23
Q

what are the characteristic symptoms of allergic disease?(type1)(type1)

A

rhinnorrohea, itching and nasopharyngeal congestion

24
Q

what is the treatment in type 1 hypersensitivity?(type1)

A

anti IgE

25
Q

what are bronchio dilators?(type1)

A

short acting B2 andrenergic receptor agonists

26
Q

what does an epipen do?(type1)

A

causes vaso constrction and relaxation of smooth muscle

27
Q

in atopic dermatitis what does a break in the skin result in?(type1)

A

neutraphil influx

28
Q

physiology of itching in atopic dermatitis? (type1)

A

skin gets damaged and releases TSPL which binds to the itch neuron causing you to itch and so the cylce repeats

29
Q

what can be used to stop the itchiness cycle? (type1)

A

emolliants

30
Q

what is type 4 hypersensitivity response mediated by? (type4)

A

cell mediated response

31
Q

why is there a slow reactiuon?(type4)

A

cells need to migrate

32
Q

which type of T cell is involved in a contact hypersensitivity response? (type4)

A

CD8T cells

33
Q

what is the treatment in contact hypersensitivity?(type4)

A

contact avoidance

34
Q

what cells educate T cells?(type4)

A

education of T cell is done by thymic epithelial

35
Q

what is the process of removing T cells called?(type4)

A

negative selection

36
Q

what are T cells removed during negative selection?(type4)

A

bind too strong

37
Q

what regulates normal immune homeostasis?`

A

co-stimulation and T regulator cells

38
Q

what is type 2 hypersensitivity characterised by?

A

characterised by IgM and IgE binding to cells and causing lysis by complement activation

39
Q

what happens when antibodies bind to the complement cascade?(type 2)

A

pores are created in the compliment cascade

40
Q

what can induce haemolytic anaemia? (type 2)

A

drugs

41
Q

what happens in drug induces anaemia? (type 2)

A

drugs bind to the red cells making the body recognise them as foreign and induces the production of antibodies causeing the red blood cells to by lysed or phagocytosed

42
Q

what happens in myasthenia gravis? (type 2)

A

autoantibodies block acetylcholine transmisson

43
Q

what is the treatment in myasthenia gravis?(type 2)

A

antibody removal, thymus removal

44
Q

what is type three hypersensativity characterised by?

A

characterised by IgG antibodies against soluble anigens

45
Q

what causes the inflammation in type 3 hypersensitivity?

A

antibody antigen complexes deposited actiavting the complement system and therefor infalmmation damage