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Flashcards in L3 Deck (29)
1

How does neisseria gonorrhoeae evade immunity?

Prevents cell sloughing (mucous/skin)
By ↑adhesion molecules
Esp @ vagina

2

How does pneumococcus evade immunity?

Resists phagocytosis

3

How does staphylococci evade immunity?

Resistance to ROS once phagocytosed
Makes catalase - breaks Hperoxide into water

4

How does streptococcus evade immunity?

Resists alternative complement pathway activation
Blocks C3 binding

5

How does pseufomonas evade immunity?

Resists antimicrobial peptides

6

What defect results in Chronic Granulomatous Disease?

NADPH defect
Can't made O2 --> superoxide
Can't make HPeroxide for phago-lysosomes

7

What defect results in Chediak Higashi syndrome?

MPO defect
Abnormal fusion of phagosome w/ lysosome

8

What defect results in leukocyte adhesion deficiency (LAD)?

Faulty CD18
Neutrophils & monocytes can't attach to endothelium for diapedesis

9

What complement deficiency leads to increased Neisseria infection?

CD8
Can't form MAC
Neisseria are especially susceptible to killing by MAC

10

What kinds of infections are common with IRAK4 deficiency?

= defect in TLR signaling - don't get enough inflammation to kill pathogen
Recurrent (Gram+) bacterial infections

11

What 2 receptors need to be activated for macrophages to be both microbicidal and tumoricidal?

LPS + TLR4
INF gamma + INF gamma receptor

12

Explain the 4 steps from O2 --> water that can happen to get ROS inside phago-lysosomes.

O2 + NADPH --> superoxide
Superoxide + superoxide dismutase --> HPeroxide
HPeroxide + MPO --> halide ion insertion into pathogen membrane
HPeroxide + catalase --> H2O

13

What cells secrete TNF? What are the effects?

Secreted
- Macrophages
- T cells
Action
- Inflam & coag of endothelium
- Neutrophils
- Fever
- Make acute phase reactants
- Possible apoptosis

14

What cells secrete IL1? What is IL1's effect?

Secreted:
- Macrophages
- Endothelium
Actions:
- Inflam & coag endothelium
- Fever
- Make acute phase reactants via IL6

15

What cells secrete chemokines? What is chemokines effects?

Secreted:
- Macrophages
- Endothelium
- T cells
Actions:
- Migration & activation WBCs

16

What cells secrete IL12? Actions?

Secreted:
- Macrophages
- Dendritic cells
Actions:
- IFN-gamma from NK & T cells
- Th1 differentiation

17

What cells secrete IFN gamma? Actions?

Secreted:
- NK cells
- T cells
Actions:
- Macrophage activation
- ↑Abs

18

What cells secrete IFN alpha vs beta? Actions?

Secreted:
- IFN alpha: macrophages
- IFN beta: fibroblasts
Actions:
1. All cells into antiviral state
2. ↑MHC1
3. NK cells ON

19

What cells secrete IL10? Actions?

Secreted:
- Macrophages
- Th2
Actions:
- Inhibit IL12 production from macrophages
- ↓MHC2 & costimulator receptors from macrophage membrane

20

What cells secrete IL6? Actions?

Secreted:
- Macrophages
- Endothelium
- T cells
Actions
- ↑acute phase reactants: C reactive protein & MBL
- ↑Abs from B cells

21

What cells secrete IL15? Actions?

From macrophages
Actions:
- NK & T cell proliferation

22

What cells secrete IL18? Actions?

From macrophages
↑IFN-gamma from NK & T cells

23

What are the 2 signaling pathways for TLR4?

Small differences in receptor conformation with each different ligand bound
1. MyD88 adapter --> NF kappa B TF --> transcribe inflam cytokines
2. Internalize TLR4+antigen --> TRIF adapter --> IR3 TF --> type 1 IFs

24

What is the other PRR that can activate the TRIF/IR3 signaling pathway?

TRL3

25

Describe the structure of TLRs.

Leucine rich repeat C arm
1 alpha helix transmembrane domain
TIR domain = toll/IL

26

What is the role of acute phase reactants? Where are they made? Which cytokine increases the production of APR?

Turn off inflammation
IL6 --> made @ liver
Simultaneously turning on inflammation while already working to limit it

27

When LPS binds macrophages, what are the 3 resulting actions?

1. Lipid metabolites - modulate vessel tightness/edema
2. Cytokines/chemokines - IFN-gamma that feeds back on macrophage to increase macro activity
3. ROS
All need to be balanced
Dysregulation - (gram neg sepsis) circulatory collage, organ failure, shock, death

28

Name the general steps of PRR signal transduction cascade.

1. PAMP + PRR
2. + adapter
3. + kinase --> phosphorylate downstream proteins
4. Proteins bind DNA to ↑transcription
Outcome = inflam response

29

What is the PAMP for gram+ bacteria? What PRR do they bind?

PAMP = peptidoglycan & lipoproteins
PRR = TLR2