Inflammatory Mediators Flashcards Preview

USMLE > Inflammatory Mediators > Flashcards

Flashcards in Inflammatory Mediators Deck (30):
1

CD14

Present on macrophages. Recognizes the PAMP LPR of gram neg bacteria. Co-receptor for TLR

2

NFkappaB

Nuclear transcription factor. Activated when TLR activated and lesads to activation of immune response and production of multiple inflammatory mediators

3

Phospholipase A2

Releases arachidonic acid from the phospholipid cell membrane

4

Prostaglandins

PGI2, PGD2, PGE2 mediate vasodilation and increased vascular permeability

PGE2 mediates pain and fever

5

Leukotrienes

Produced by arachidonic acid metabolism by 5-lipoxygenase

LTB4 attracts and activates neutrophils
LTC4, LTD4, LTE4 mediate vasoconstriction, bronchospasm, increased vascular permeability (slow reactors of anaphylaxis)

6

Four things that activate neutrophils

LTB4, C5a, IL-8, bacterial products

7

Three ways to activate mast cells

Tissue trauma
C3a and C5a
Crosslinking of IgE by antigen

8

HIstamine

Causes vasodilation and increased vascular permeability

9

Actions of mast cells

Immediate response: release of preformed histamine

Delayed response: production of luekotrienes from arachidonic acid maintaining acute inflammation

10

Alternate complement activation pathway

Microbial products directly activate complement

11

Mannose binding lectin pathway for complement

MBL binds mannose on microorganisms activating complement

12

C3a

Triggers mast cell degranulation (anaphylatoxic)

13

C5a

Triggers mast cell degranulation (anaphyatoxic) and chemotactic for neutrophils

14

C3b

opsonin for phagocytosis

15

Hageman factor

Actvated by exposure to subendothelial or tissue collagen. Turns on coagulation and fibrinolytic systems, complement, and kinin system

16

Bradykinin

Mediates vasodilation, increased vascular permeability, pain

17

Pain mediators

Bradykinin and PGE2

18

Mediators of fever

Macrophages release IL-1 and TNF which increase COX activity in perivascular cells of hypothalamus. This increases PGE2, raising temp set point

19

Weibel-Palade bodies

On endothelial cells. Contain von willebrand factor and P-selectin, which is involved in leukocyte rolling

20

Selectins

P-selectin from Weibel-Palade bodies. Released in response to histamine

E-selectin induced by TNF and IL-1

Responsible for leukocyte rolling

21

CD18

Component of integrins. Defective in leukocyte adhesion deficiency. Necessary for leukocyte adhesion to endothelium

22

Opsonins

IgG and C3b

23

Myeloperoxidase

Converts H2O2 to bleach

24

IL-10

Anti-inflammatory cytokine made by macrophages

25

TGF-beta

Anti-inflammatory cytokine made by macrophages

26

IFN gamma

secreted by Th1 cells. Activates macrophages. Promotes B cell class switching from IgM to IgG, promotes Th1 over Th2 phenotype

27

Th2 cell secretions

IL-4: B cell class switching to IgE
IL-5: eosinophil chemotaxis and activation, class switching to IgA
IL-13: similar to IL-4
IL-10: inhibits Th1

28

IL-2

From Th1 cell. Serves as second activation signal for CD8+ activation

29

CD8+ killing

Perforin and granzyme: activate apoptosis
FasL-Fas interaction: activates apoptosis

30

CD40

Receptor on B cells binds to lignand on Th cell providing second activation signal for B cell