Lecture 5 Innate Immune RXNS

Question 1

Phagocytosis Major Cell Types

Answer 1

Monocyte < Macrophage
PMN
Dendritic (mainly for APC)
Eosinophil (less)
basophil (VERY MINOR)

Question 2

Opsonization

Answer 2

Pathogens coated with opsonin (cell derived protein) can be recog. via endocytic PRRs & phagocytosed

Question 3

Types of Opsonins

Answer 3

Antibodies (adaptive)
Complement (innate)
C-reactive protein (innate)

Question 4

Phagocytosis Mech.

Answer 4

• bind pathogen/microbe (PRRs, opsonin receptor,etc.)
• phagosome formation
• fusion w/ lysosome - phagolysosome
• low pH, enzymes, RNS, ROS kill microbe

Question 5

PMN contain…

Answer 5

additional vesicles w/ anti microbial peptides

• Primary & Secondary Granules
• cathelicidins, a-defensins, neutrophil elastase

Question 6

Macrophage vs. PMN

• life span
• where found?
• FXN

Answer 6

Macrophage
-long lived
-tissues normally (dominant in healthy)
-phagocytosis (main), APC
PMN
-short lived
-dominant in tissue w/ infection
-phagocytosis
-pus = dead PMNs

Question 7

Antimicrobial Mechanisms of Phagocytes

Answer 7

• acidification
• ROS
• RNS
• Antimicrobials ( alter cell membrane perm.)
• Enzymes
• Competitors

Question 8

Macrophages & Dendritic Cells APC Mech

Answer 8

• phagocytose & digest antigen
• CK receptor alteration to facilitate migration
• entry lymph tissue & express co-stim molecules on surface

Question 9

Licensing

Answer 9

Act. of immature dendritic cell to mature dendritic cell that can activate T cell

Question 10

Degranulation Cell Types

Answer 10

NK, cytotoxic T cells
Eosinophils
Basophils
Mast Cells

Question 11

NK Cells Release

Answer 11

Perforin - forms pores, aids in delivery of granzymes
Granzymes - serine proteases, activate apoptosis

**Targeted Release

Question 12

Mast cells & basophils have… receptors and …. granules?

Answer 12

High affinity IgE receptors

Similar granule contents

Question 13

Eosinophiles have …. receptors and …. granules?

Answer 13

Low affinity IgE, IgA, IgG receptors

Diff. granule contents

Question 14

Degran. Mech of mast, eosinophils, basophils

Answer 14

Antibody binds to Fc receptor = degranulation

**contents not specified = collateral damange

Question 15

Mast Cells & Basophils Release

Answer 15

Histamine

Serine Proteasis

Question 16

Eosinophils Release

Answer 16

Eo Peroxidase - EPO - toxic, trigger hist. release from mast cell
Eo Collagenase - remodel CT matrix
Matrix Metalloproteinase-9 - matrix protein degradation
Major Basic Protein - MBP - toxic, trigger hist. release from mast cell

Question 17

Cytokines use _____ activation pathway?

Answer 17

JAK-STAT

Question 18

Chemokine

Answer 18

Chemo-attractant cytokines

Question 19

CC Chemokines

Answer 19

chemotactic for monocytes, lymphocytes, granulocytes

Question 20

CXC Chemokines

Answer 20

chemotactic for PMN (if preceded by ELR) or lymphocytes

Question 21

Chemokine recepetors?

Answer 21

G-protein coupled receptors

Question 22

Type 1 Interferon

Answer 22

IFN-a
IFN-b
-result of RLH & endosomal TLR activation
-antiviral (stop translation, degrade viral RNA)
-inc. NK cell activity
-inc. MHC class 1

Question 23

IFN Receptor uses _____ pathway?

Answer 23

JAK-STAT

Question 24

Type 2 Interferon

Answer 24

IFN-y

• inc. cytoxic act. of NK cell
• inc. microbicidal act. of macrophage

Question 25

Macrophage activated by?

Answer 25

IFN-y (T2 IFN)

-CK also influence FXN

Question 26

Inc. macrophage activity =

Answer 26

Inc. T cell activation

Question 27

Macrophages and NK reinforce each other with….

Answer 27

IL-12 & IFN-y

Question 28

Mast Cells & Basophils Secrete which cytokines and chemokines

Answer 28

IL-4, IL-13: stim/amplify Th response
IL-3, IL-5, GM-CSF: promote eosinophil production
TNF-a: promote inflammation
CCL3: attracts monocytes, macrophages, PMNs

Question 29

Eosinophils Secrete which cytokines and chemokines

Answer 29

IL-3, IL-5, GM-CSF: amplify eosinophil production
TGF-a, TFG-B: epi proliferation, myofibrilblast formation
CXCL8: promotes influx of leukocytes