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Flashcards in HOST DEFENCE Deck (29)
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1

what are the non-immune host defence mechanisms in the lungs?

mucociliary clearance
coughing - some voluntary control
sneezing - involuntary
multipotent basal cell population - can differentiate into different cell types if damage occurs

2

what system is used to classify hypersensitivity?

gell and coombs hypersensitivity classification

3

what is type 1 hypersensitivity?

allergy, anaphylaxis and atopy
IgE causes release of histamines from mast cells by activating FceR1 receptors
causes vasodilation and opening of gap junctions

4

how is type 1 hypersensitivity diagnosed?

via skin prick test
radio-immunosorbent assay (RAST)

5

how is type 1 hypersensitivity treated?

avoiding trigger
antihistamines
steroids

6

what is type 2 hypersensitivity?

IgG binding to self antigens (autoimmune)
cytotoxic
attacks own body's cells

7

give an example of type 2 hypersensitivity?

goodpastures syndrome
IgG is raised due to type IV collagen
this leads to glomerulonephritis and pulmonary haemorrhage

8

what is type 3 hypersensitivity?

immune complex diseases
large scale immune response leading to complexes of IgG precipitating - are unable to be cleared by macrophages

9

give examples of type 3 hypersensitivity

pigeon fanciers lung
farmers lung
malt worker's lung

10

give an example of type 1 hypersensitivity?

hayfever
asthma
eczema

11

what is type 4 hypersensitivity?

delayed type hypersensitivity reaction
T-helper cells form granulomas around pathogens with macrophages in a cell mediated response
does not involve antibodies

12

give examples of type 4 hypersensitivity

tuberculosis
sarcoidosis
contact dermatitis

13

what is the innate immune system?

the immune system you are born with
comprised of specialist macrophages and neutrophils

14

what are the specialist macrophages of the innate immune system?

dendritic cells
kupffer cells
alveoalr macrophages
they initate acute inflammation via cytokines and antigen presenting via MHC II

15

what are primary granules found in neutrophils?

contain myeloperoxidase, elastase, cathespins, defensins

16

what are the secondary granules found in neutrophils?

receptors, lysozymes and collagenase

17

how do neutrophils work?

they carry out bacterial killing through enzyme release and generation of ROS by NADPH oxidase complex

18

what is the adaptive immune system mediated by?

B and T lymphocytes

19

how are lymphocytes activated?

through receptor binding to epitopes of antigens on pathogen surface, free antigens in plasma or through peptides presented via MHCs

20

how is the variable region of antibody receptors generated?

by VDJ gene recombination

21

what is affinity maturation?

it is the process by which antibodies with a higher affinity for antigen are more favourably selected

22

what is the role of Treg cells?

they are responsible for removal of cells that have receptors capable of binding self-antigens - immune tolerance

23

how does immune memory work?

primary immune response is low level, but further exposure produces larger responses as more memory cells are produced which have higher affinity receptors and antibodies

24

what is the role of B cells?

they mature into plasma cells which produce antibodies M-G

25

what happens in B-2 integrin deficiency?

CD18 marker not expressed on neutrophil surface
it is unable to move out of endothelium to infected tissue
this causes deep recurrent infections

26

what happens in acutre respiratory distress syndrome (ARDS)?

respiratory distress due to widespread inflammation
leads to respiratory failure, non-cardiogenic oedema and multi-organ failure

27

what happens in goblet cell metaplasia?

pathogenic plasticity of airways in smokers due to basal cell differentiation

28

what is anti-neutrophil cytoplasmic antibodies?

an autoimmune reaction causing vasculitis

29

what happens as a result of failure of T cell response?

opportunistic infections