Induced Immunity: Cellular responses and Cytokines Flashcards Preview

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Flashcards in Induced Immunity: Cellular responses and Cytokines Deck (71)
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1
Q

Induced immunity effector functions

A
phagocytosis
targeted killing
antimicrobial peptides
cytokine release
inflammation
cellular recruitment
B and T cell activation
2
Q

What is the timeline for induced innate repsonse

A

hours to days

usually 4 hours to 4 days

3
Q

What are the cells of the innate immune system

A
monocyte which leads to Macs and Dendritic
mast cells
eosinophils
NK cell
Neutrophil
Basophil
4
Q

what cells are already in the tissues

A

macs
dendritic cells
mast cells
Specialized T cells

5
Q

what are 4 ways the induced immune response can be initiated

A
  • tissue resident immune cells
  • complement
  • pro-inflammatory signaling
  • interferon response and altered MHC expression
6
Q

what are the four pro inflammatory signaling systems

A

cytokines
eicosanoids
acute phase response
interferons

7
Q

what are the four different tissue resident Macs

A

brain: microglia
bone: osteoclast
liver: kupffer cells
skin: langerhans cells

8
Q

what are the four effector mechanisms of macrophages

A
phagocytosis
cytokine release
degranulation
antigen presentation 
*activate the adaptive immune system
9
Q

innate immune cells recognize what?

A

patterns on the surface of cells

10
Q

macrophage receptors recognize the cell-surface carbohydrates of bacterial cells but not those of?

A

human cells

11
Q

what cells recognize human cells that are infected?

A

NK cells

12
Q

what is the purpose of Toll Like Receptors?

A

induce the release of cytokines

13
Q

what is the purpose of mannose, complement, dectin, scavenger receptors A and B, and Lipopolysaccharaide receptors?

A

the induce phagocytosis

14
Q

what are the 3 innate phagocytic cells

A

macs
neutrophils
dendritic cells

15
Q

what is the process of phagocytosis

A
  • bacterium becomes attached to membrane envaginations called pseudopodia
  • bacterium ingested forming phagosome
  • phagosome fuses with lysosome
  • bacterium is killed
  • digestion products are released(PMNs) and Macs and dendritic cells present
16
Q

agents in phagolysosomes and granules that kill pathogens

A
acidification
toxic oxygen products
toxic nitrogen oxides
antimicrobial peptides
enzymes
competitiors
17
Q

what are the external TLRs?

A

1,2,4,5,6

18
Q

what are the internal TLRs?

A

3,7,8,9

19
Q

what must TLRs do the send signal?

A

dimerize

20
Q

what does TLR 9 recognize

A

CpG DNA bacteria

21
Q

what does TLR 7 recognize

A

ssRNA virus

22
Q

what does TLR 8 recognize

A

ssRNA virus

23
Q

what does TLR 3 recognize

A

dsRNA virus

24
Q

what does TLR 5 recognize

A

flagellin

*also only external to recognize a protein not a lipid

25
Q

what does TLR 4 recognize

A

LPS

26
Q

what does TLR 1-2 recognize

A

triacyle lipopeptides

27
Q

what does TLR 2-6 recognize

A

diacyle lipopeptides

28
Q

what are the two heterodimer TLRs

A

TLR 1:TLR2

TLR2: TLR6

29
Q

TLR signals cytokine production through what?

A

NF-kB which is a transcription factor

30
Q

what is the process of cytokine production through NFkB?

A

IRAK4->TRAF6->IKK phosphorylates inhibitor of kB which releases the inhibition of NFkB and allows cytokine production which are made in the cytoplasm and secreted via the ER

31
Q

what do nucleotide-binding oligomerization domain NOD receptors detect?

A

degraded antigens

32
Q

what is the process of activating NFkB via NOD receptors

A

intracellular toxins, viruses, cell stress proteins are detected to phosphorlyate inhibitor of kB to allow NFkB to be released and to make cytokines

  • also forms and inflammasome
  • cooperate with TLRs
33
Q

what is an inflammasome?

A

activates and promotes cytokine release by proteolytic activity (caspase 1), enhancing other pro-inflammatory signals and is a CHECKPOINT FUNCTION

34
Q

what are cytokines

A

signaling molecules of the immune system

  • paracrine and autocrine
  • other names interleukins, chemokines
35
Q

what are the six families of cytokines based on?

A

receptor morphology

  • class I
  • class II
  • interleukin 1
  • interleukin 17
  • TNF
  • chemokines
36
Q

what are the common intracellular signaling pathways

A

JAK-STAT
MAPK
NFkB

37
Q

what are the five pro-inflammatory cytokines released by macrophages

A
IL-1B
TNF-alpha
IL-6
CXCL 8 (chemokine)
IL-12
38
Q

which of the pro-inflammatory cytokines produce fever?

A

IL-lB, TNF-alpha, IL-6

this decreases the replication of viruses and bacteria

39
Q

what does IL-6 do?

A

induces the liver to produce acute-phase proteins

40
Q

what are acute phase proteins?

A
  • c reactive proteins
  • mannose binding lectin
  • LPS binding protein
  • complement components
  • coagulation factors
  • inflammatory response factors
41
Q

what else do cytokines do?

A

initiate leukocyte recruitment and increased permeability of blood vessels

42
Q

what three things does extravasation depend on?

A

chemokines, adhesion molecules and proteases(MMPs and elastase)

43
Q

chemokines grandients recruitment of cells to tissue

A

immune targeting mechanisms
chemokines released by target (CXCL)
receptors present on immune cells (CXCR)
cells respond to specific chemokines

44
Q

leukocytes extravasate to sites of inflammation how?

A

chemokine receptor(CXCL8) activates LFA-1 and s-Lex on PMN to bind to endothelial cells eg: LFA-1 to ICAM-1 and s-Lex to selectin

45
Q

what does binding of the PMN trigger?

A

protease release

MMPs and elastase which breaks down basement membrane and cell enters the tissue

46
Q

what are the four steps for leukocytes to get into tissues?

A

rolling adhesion
tight binding
diapedesis
migration

47
Q

excessive plasma TNF-alpha causes what?

A

Septic shock syndrome

48
Q

what leads to septic shock syndrome

A
blood borne infection
systemic extravasation
systemic PMN infiltration
vascular collapse
rapid multi-organ failure
49
Q

what is the primary cell of the induced response?

A
  • neutrophils

- mostly found in the blood and most numerous portion of leukocytes

50
Q

what are the effector mechanisms of neutrophils?

A
phagocytosis
degranulation
extracellular traps
cytokine release 
*die after they are done
51
Q

what are the four types of granuels

A

azurophils-defensins
specific
gelatinase-lysozymes
secretory

52
Q

what is the dual purpose of granules in neutrophils?

A

phagocytosis

degranulation

53
Q

the neutrophil oxidative burst kills what two things?

A

pathogen and the PMN

54
Q

what is the non-lytic trap of PMNs

A

chromatin that moves through vasculature

55
Q

what is the lytic trap of PMN

A

cell turns inside out and chews up pathogen

56
Q

dendritic cells are loaded with what receptors? and what do they do?

A

PRR and TLRs

  • phagocytosis
  • process pathogens into antigens
  • present antigens to lymphocytes
  • cytokine regulation
  • basically a big vaccum
57
Q

NK cells

A

large cytotoxic lymphocytes

  • target and kill diseased self cells
  • respond to interferons, MHC I and stress ligands
  • regulate shift from induced innate to adaptive immune system
  • selected for self and non self cells (educated) based on MHC I
58
Q

what type of infections causes the interferon response?

A

viral infections

59
Q

what do interferon alpha and beta do?

A
  • activate NK cells
  • induce resistance to viral replication
  • increase NK cell ligand expression on infected cell
60
Q

NFkB causes the release of

A

interferons and cytokines

61
Q

what TLRs induce interferons

A

TLR 3 and 7

62
Q

interferons do what?

A

reduce viral replication
prevent cell division
induce apoptosis
activate NK cells, Mac, and T cells

63
Q

interferons signal in what type of fashion?

A

autocrine and paracrine

64
Q

interferons activate what type of cells?

A

mostly NK cells and then macs and T cells

65
Q

what is the relationship between macs and NK cells in terms of mac phagocytosis?

A

sometimes macs need extra signaling to complete phagocytosis

  • macs release CXCL8 and IL-12 which brings the NK cell to form a synapse.
  • NK cells proliferate and secrete IFN-gamma
  • IFN gamma binds to mac and activates the mac to increase phagocytosis and secretion of cytokines
66
Q

if there is a large NK response what happens to the dendritic cell?

A

the presentation of antigen is inhibited thus regulating the adaptive immune response

67
Q

if there is a small NK response what happens to the dendritic cells?

A

they are activated and they go and activate the adaptive immune response

68
Q

granulocytes protect local tissues how?

A

express PRRs and degranulate when activated

  • cell-type specific granule components
  • respond to parasitic organisms
  • responsible for type I hypersensitivity
69
Q

what are the effector mechanisms that innate immune cells employ?

A

phagocytosis
degranulation
cytokine production
traps (PMNs only)

70
Q

what do dendritic cells and macs do that PMNs don’t?

A

antigen presentation

71
Q

what do NK cells do that macs and PMNs don’t do?

A

directly target self cells