49-Barriers and Pathogen Recognition Flashcards Preview

Immunology > 49-Barriers and Pathogen Recognition > Flashcards

Flashcards in 49-Barriers and Pathogen Recognition Deck (48)
1

physical barrier of skin

multiple layers with tight junctions

2

mechanical barrier of skin

shedding every 28 days and perspiration

3

chemical barrier of skin

dry, cool, salty, acidic pH 5, lysozyme to degrade peptidoglycan, sebum

4

physical barrier of mucous membrane

goblet cells creating slime layer, epiglottis blocking respiratory tract

5

mechanical barrier of mucous membrane

cilia in lower respiratory
tears, blinking, urination, defecation, sneezing, coughing, vomiting

6

chemical barrier of mucous membrane

low pH in stomach and vagina, release of antibodies, lysozyme in tears and saliva

7

what is normal microbial flora

commensal bacteria found all over body, different species at each site of colonization

8

how does normal flora inhibit pathogens

compete for nutrients, compete for space, produce toxins, alter growing conditions

9

how do barriers fail

wounds, defective barrier, chronic disease, malnutrition, insect bite, pathogenicity

10

what happens when barriers fail

innate immune response starts quickly

11

what does it mean that the innate is constitutive

does not change over your life

12

what does it mean that the innate is conserved

responds to conserved features of pathogens like cell wall, peptidoglycan

13

what are the goals of the innate response?

detect and kill pathogen, sound alarm to bring in more cells, activate the adaptive response

14

what are pattern recognition receptors

recognize infection in coming by recognizing pathogens

15

what are the types of pattern recognition receptors

Toll like (TLR)
Nod like (NLR)
RIG-I

16

what do TLR recognize

PAMPs-conserved features of pathogens essential for viability
DAMPs- human derived signals which start inflammation

17

what are Pathogen Associated Molecular Patterns

PAMPs, conserved features of pathogens essential for viability

18

What are Danger Associated Molecular Patterns

DAMPs, human derived signals, drive non infectious inflammation and start inflammation caused by infection

19

Where are TLRs found

cell surface and intracellularly (phagolysosome or endosome)

20

what do cell surface TLRs recognize

bacterial and fungal cell wall

21

what do intracellular TLRs recognize

nucleic acid

22

what happens with inappropriate TLR activation

chronic inflammation and human disease

23

what activates TLR

dimerization with leucine ligands
intracellular region has Toll/IL-1 (TIR) domain

24

what drives intracellular signaling of TLR

dimerization if TIR domain
all TLR except TLR3 interact with MyD88 drive activation of NF-kB for inflammation

25

what do TLR4 and TLR3 bind to

TRIF to activate NF-kB and IRF3 to produce type 1 interferons for antiviral

26

where are NLR found

cytoplasm of multicellular eukaryotes

27

what facilitates oligomerization of NLR

NACHT domain

28

what facilitates ligand sensing and regulate NLR

leucine rich repeats

29

what drives intracellular signaling of NLR

N terminal domain

30

what activates NLR

many things: bacterial, viral, fungal, ion efflux, ATP, human protiens

31

Explain how NLRs drive expression of inflammatory cytokine

1-oligomerization of NLR using NLR ligand
2- recruitment of intracellular signaling molecules to activate NF-kB and MAP
3-NF-kB and MAP induce inflammation and chemokines

32

altered activation of NLR leads to what

autoimmune disease
1- Loss of function-prevent NF-kB activation, Crohn's disease
2-gain of function- constitutive NF-kB activation, autoinflammatory

33

what induces inflammasome

NLRP1, 3, 4, 6

34

how do NLRs induce inflammasome

1-priming induces production of pro IL-1B and pro IL-18
2-presence of ROS, PAMP, DAMP, ion efflux result in the formation of inflammasome
3-inflammasome (caspase 1) cleaves to IL-1B and IL-18

35

what activates NLRP3

potassium efflux, ROS, phagolysosomal release

36

polymorphisms in inflammasome lead to what

autoimmunity, gain of function and chronic inflammation

37

what has anakinra been approved for

RA as a IL-1 receptor antagonist

38

how do pathogens influence inflammasome

inhibit it to enhance pathogenesis

39

what are the RIG-I family members

RIG-I, MDA5, and LGP2

40

what does the helicase domain/DExD/H do in RIG-I family

bind viral RNA ligand

41

what does the regulatory domain in RIG-I family do

control receptor funciton

42

what does the CARD domain do in the RIG-I family

intracellular signaling in RIG-I and MDA5
regulates RIG-I and MDA5 in LGP2

43

RIG-I binds to what

short viral RNA on terminal 5' triphosphate

44

MDA5 binds to what

large RNA molecules internally and results in oligomerization

45

what activates the CARD domains

binding of viral RNA to RIG-I or MDA5

46

activated RIG-I and MDA do what

bind to adaptor protein IPS-1 (found on mitochondria)

47

activation of IPS-1 does what

NF-kB and IRF3 activation to produce interferons and antiviral

48

how do viruses suppress function of RIG-I and what does it lead to

inhibit RIG-I signaling
chronic viral infections