BIOL 435 Ch. 3 Part Three (Recognition and Response)

Question 1

PRRs

Answer 1

• pattern recognition receptors
• immune An receptor molecules
• recognize PAMPs

Question 2

PAMPs

Answer 2

• pathogen associated molecular patterns

- represent motifs of recurring patterns on bacteria, yeast and parasites

Question 3

receptors for PAMPs

Answer 3

• may uniformly recognize large numbers of bacteria that share the same PAMPs
• not clonally distributed, but are expressed equally on the same cell types
• may be integral membrane proteins or intracellular proteins

Question 4

PRR families

Answer 4

1. Toll-like receptor
2. C-type lectin receptor
3. Retinoic acid inducible gene-1 like receptor
4. Nucleotides oligoermizatlon domain like receptor
5. Absent-in-melanoma-like receptor

Question 5

toll-like receptor (TLR)

Answer 5

• plasma membrane, endosomes, or lysosomes
• production of antimicrobials, antivirals and cytokines
• inflammation
• various ligands (microbial CHO, bacterial flagellin, viral RNA)

Question 6

C-type lectin receptor (CLR)

Answer 6

• plasma membrane
• bind to CHO components of various things
• phagocytosis
• production of antimicrobials and cytokines
• inflammation

Question 7

cytokine signal

Answer 7

• usually generate by the binding of a ligand to a complementary cell-bound receptor
• any event where a chemical messenger binds to a receptor with the result that the cell is instructed to change its metabolic or proliferative state

Question 8

cytokine-receptor binding

Answer 8

-non-covalent

>may be of generally high affinity

Question 9

cytokine-signalling end results

Answer 9

-often induce a change in the transcriptional program of the target cell

Question 10

cytokines

Answer 10

-proteins that mediate the effector functions of the immune system
-can act in several ways:
>endocrine action
>paracrine action
>autocrine action

Question 11

endocrine action

Answer 11

• released into the blood stream to effect distant cells

- sometimes

Question 12

paracrine action

Answer 12

• released to effect nearby cells

- very common

Question 13

autocrine action

Answer 13

• released, but then bind to receptors on the cell that produced them
• less common
• very important way for immune cells to be activated or be more activated

Question 14

general properties of cytokines and chemokines

Answer 14

• pleiotrophic activity
• redundant activity
• synergy effect
• antagonist effect
• cascade effect
• combination of molecules will determine what will occur

Question 15

pleiotrophic activity

Answer 15

-induces different biological effect dependent on target cell

Question 16

redundant activity

Answer 16

-mediates similar effects on target cell

Question 17

synergy effect

Answer 17

-combines 2 cytokine activities to be greater than additive effect

Question 18

antagonist effect

Answer 18

-inhibits one cytokines effect by another’s action

Question 19

cascade effect

Answer 19

-of one cytokine or one target cell to produce additional cytokines

Question 20

6 major cytokine families

Answer 20

1. Interleukin-1 family
2. Class 1 (hematopoietin)
3. Class 2 (interferon)
4. Tumor necrosis factor family
5. Interleukin-17 family
6. Chemokines

Question 21

interleukin-1 family

Answer 21

• first non-interferon cytokine

- important inflammatory mediators

Question 22

class 1 family

Answer 22

• large family of small cytokine molecules

- sequence and functional diversity

Question 23

class 2 family

Answer 23

• antiviral responses
• important modulators of immune responses
• send ‘save yourself’ signals

Question 24

tumor necrosis factor family

Answer 24

• soluble or membrane bound

- immune system development, effector functions and homeostasis

Question 25

interleukin-17 family

Answer 25

- most recently discovered - promote neutrophil accumulation and activation - pro-inflammatory

Question 26

chemokines

Answer 26

-all serve chemoattractant function >attract other immune cells -direct leukocyte migration

Question 27

cytokine receptors

Answer 27

- can have common subunits used by different cells in different ways - pairing of subunits for different molecules and responses

Question 28

chemokine structure

Answer 28

- small proteins | - process highlty conserved disulfide bonds that dictate both structure and category

Question 29

leukocyte migration

Answer 29

-signalling through chemokine receptors help cells move to different body areas

Question 30

chemokine receptors

Answer 30

- examples of GPCR - many can bind to more than 1 chemokine - several chemokines are able to bind to more than one receptor

Question 31

cellular signal

Answer 31

-any event that instructs a cell to change its metabolic or proliferative state

Question 32

singals are usually generated by

Answer 32

-the binding of a ligand to a complementary cell-bound receptor

Question 33

expression of the receptor

Answer 33

-cell can become more or less susceptible to actions of a ligand by increasing or decreasing expression

Question 34

induces a change

Answer 34

-cell signalling often does that in the transcriptional program of the target cell

Question 35

multiple signals through multiple receptors

Answer 35

-are sometimes required to effect particular outcomes

Question 36

integration of all signals

Answer 36

-received by a cell occurs at the molecular level inside the recipient cell

Question 37

receptors and cell signalling

Answer 37

-ligand binding induces a variety of downstream effects, many of which culminate in transcription factor activation

Question 38

An- mediated receptor clustering

Answer 38

-initiates signalling in B and T cells -receptor dimerization is often a result >multimerization can also occur -clustered receptors are localized in lipid rafts

Question 39

lipid rafts

Answer 39

1. Lots of cholesterol 2. Straight FA tails=packed >wont be as mobile and can pass the signal longer

Question 40

tyrosine phosphorylation

Answer 40

- an early step in many signalling pathways - CD3 (T-cells) and Ig alpha/beta (B-cells) are phosphorylated on ITAMs - phosphorylated tyrosines serve as docking points for adapter molecules

Question 41

Class 1+2 cytokines receptors

Answer 41

1. Cytokine brings receptor together 2. JAK 3. STAT: dimerization 4. STAT into nucleus: gene transcription

Question 42

antigen signalling molecules

Answer 42

- bringing dendritic cells into the required locations - macrophages and neutrophils upregulate phagolysosome activity and cytokine production - dendritic cells exhibit antigen peptides on MHC class 1 and MHC class 2 - cytoplasmic proteosomes process An to peptides - dendritic cells induced to secrete cytokines