Innate Immunity: Inflammation: Part One

Question 1

What are cytokines

Answer 1

small molecular weight, soluble proteins that function as chemical messengers and orchestrate innate and adaptive immune responses

Question 2

Who produce cytokines?

Answer 2

• leukocytes
  
  • T helper
  • dendritic cells
  • macrophages
• many other cell types (for example)
  
  • epithelial cells
  • endothelial cells
  • bone marrow stromal cells

Question 3

What are the 5 cytokine types?

Answer 3

• interleukins
• chemokines
• colony stimulate factor
• interferons
• tumor necrosis factor

Question 4

What do interleukins do?

Answer 4

communicators between leukocytes (IL-1 – IL-35)

Question 5

What do chemokines do?

Answer 5

control chemotaxis

Question 6

What does colony stimulating factor (CSF) do?

Answer 6

affect hematopoiesis

Question 7

what do interferons do?

Question 8

What does tumor necrosis factor do?

Question 9

autocrine

Answer 9

cytokines affect the same cell that secretes them

Question 10

paracrine

Answer 10

cytokines affect another local cell

Question 11

endocrine

Answer 11

cytokines affect cells in different parts of the body via blood or lymph

Question 12

pleiotropy

Answer 12

cytokines that affect multiple cell types

Question 13

redundancy

Answer 13

cytokines that affect the same cell BUT you only need one to function

Question 14

synergy

Answer 14

cytokines that work on the same cell AND you require them together to function

Question 15

antagonism

Answer 15

cytokines that have opposite affects

Question 16

TNF function

Answer 16

• pro-inflammatory cytokine
  
  • increase NK cytotoxicity
  • increase phagocytic activation
  • increase vascular permeability

Question 17

IL-1 function

Answer 17

• pro-inflammatory cytokine
  
  • increase endothelial adhesiveness
  • increase chemokine production

Question 18

IL-6 function

Answer 18

• pro-inflammatory cytokine
  
  • promote monocyte recruitment
  • induces fat and muscle to metabolize to raise the local temperature

Question 19

chemokines

Answer 19

• pro-inflammatory cytokine
  
  • attraction of neutrophils, monocytes, and effector T cells

Question 20

IL-10 function

Answer 20

• anti-inflammatory cytokines
  
  • decrease TNF and IL-12 production
  • decrease MHC and B7 expression on macrophages

Question 21

IL-1ra

Answer 21

anti-inflammatory cytokines

Question 22

TGF-beta function

Answer 22

anti-inflammatory cytokines

Question 23

IFN-alpha and IFN-beta function

Answer 23

inhibition of virus replication

Question 24

IFN-gamma function

Answer 24

• macrophage-activating cytokine
  
  • enhance phagocytic cells ability

Question 25

IL-4 function

Answer 25

B cell activating cytokine

Question 26

IL-5 function

Answer 26

B cell activating cytokine

Question 27

IL-6 function

Answer 27

B cell activating cytokine

Question 28

IL-21 function

Answer 28

B cell activating cytokine

Question 29

IL-2 function

Answer 29

T cell activating cytokines

Question 30

IL-4 function

Answer 30

T cell activating cytokines

Question 31

IL-12 function

Answer 31

* T cell activating cytokines * increase IFN-gamma production by NK * increase NK cytotoxicity

Question 32

How does inflammation start?

Answer 32

1. tissue WBCs (macrophages and mast cells) detect PAMPs via PRRs and secrete pro-inflammatory cytokines 2. now permeable capillaries allow antimicrobial proteins and complement proteins to enter infected tissue 3. WBCs slowed by adhesion molecules expressed by vascular endothelium 4. neutrophils enter infected tissue and are guided by CXCL8 gradient 5. phagocytosis, repair, clotting downstream 6. neutrophils die quickly but macrophages last longer

Question 33

histamine

Answer 33

* increase vascular permeability * increase vasodilation

Question 34

C3a

Answer 34

* increase vascular permeability * increase vasodilation

Question 35

C5a

Answer 35

* increase vascular permeability * increase vasodilation * chemoattractant

Question 36

CXCL8

Answer 36

recruits neutrophils from the blood and guides them to the infected tissue

Question 37

How do neutrophils get to the infected tissue?

Answer 37

* vascular endothelium express selectins * neutrophil's s-Lex weakly binds to the selectin and starts rolling and slowing * eventually the neutrophil's LFA-1 binds to the endothelium's ICAM-1 * this allows the neutrophil's CXCL8 receptor to bind to the CXCL8 and be drawn between cells into the tissue * the neutrophil follows the CXCL8 to the infection source

Question 38

3 roles of inflammation

Answer 38

* kill * contain * repair