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Flashcards in L2 Deck (25)
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1
Q

What is the PAMP for gram negative bacteria? What is the PRR?

A
PAMP = LPS
PRR = TLR4
2
Q

You usually think of innate activating adaptive. How can the reverse occur?

A

Adaptive produces cytokines
Cytokines feedback onto innate cells to make their function more potent
(Forward rxn: innate produces cytokines that activate adaptive)

3
Q

Describe what happens if there is a defect in innate immunity only. Vs. adaptive immunity only.

A
W/o innate: can't stop antigen replication 
Why?
- Lacking/defective cells
- Lacking/block of chemokine gradient
W/o adaptive: can't clear infection
4
Q

What is desiccation?

A

Barrier innate fxn

Skin & mucus membranes sloughing off layers that have trapped pathogens

5
Q

What is the fxn of transferrin & lactoferrin?

A

Bind free Fe in blood so pathogen’s can’t use it
Fe = vital for pathogen survival/toxin production
Innate immune fxn

6
Q

What are host derived antimicrobial peptides? Where are the found - cellular and tissue levels?

A

Small - cationic proteins
Antimicrobial activity b/c cause membrane lysis
IN myeloid cells (innate cells)
OM mucosal surfaces

7
Q

What is the active molecule in defensins? How do they work?

A

Specific type of host derived antimicrobial peptide
CYSTEINE rich
= antibiotic against bacteria, fungi, viruses, etc
Mechanism:
- Insert directly into microbe membrane –> osmotic rupture

8
Q

Where are defensins produced?

A

Paneth cells @ intestinal crypts

9
Q

What is IFN alpha/beta? Where is it made? What is its fxn?

A

Interferon = cytokine
Made by activated immune cells & infected host cells
Fxn:
- Protects uninfected cells
- ↑MHC # w/ antigen –> ↑macrophage activity
- Activates NK

10
Q

Compare the initiating structures for classical vs mannose binding pathways of complement activation.

A

Classical
1. Ab binds pathogen (adaptive immunity tie)
2. C1 complex binds the Fc region of Ab
Mannose
- Mannose binding lectin has parallel structure to Ab
1. MBL binds mannose sugar on bacteria membrane –> complement activation

11
Q

Which bacteria is very susceptible to MAC attack? Aka which bacteria is a big problem if you’re lacking MAC?

A

Neisseria bacteria

12
Q

What are the 2 ways complement increases inflammation?

A
  1. ↑vascular perm - fluid out of vessels –> tissues

2. ↑WBC diapedesis into tissues

13
Q

What is microbial antagonism as seen in the gut?

A

Commensal bacteria compete for nutrients vs pathogens

Stimulates innate innate system via interactions w/ gut epithelium –> tonic inflammation –> preventative (probiotics)

14
Q

What does a monocyte look like on histo?

A

Kidney shaped nucleus

15
Q

What GF pushes a hematopoeitic stem cell towards neutrophil?

A

G-CSF = granulocyte colony stimulating factor

16
Q

What GF pushes a hematopoeitic stem cell towards monocyte?

A

M-CSF - macrophage colony stimulating factor

17
Q

Name the steps of diapedesis and the relevant molecules.

A

Tissue residing WBCs send out alarmins & chemokines

  1. Tethering - selectins
  2. Activation - chemokines
    - Binding of chemokine 7TM receptors
    - Cytoskeleton changes to move WBC
  3. Adhesion - integrin
  4. Transendothelial migration
18
Q

What cells respond to tissue chemokines first? Second?

A
1st = neutrophils - degraulate to kill pathogen
2nd = monocytes --> macrophages - clean up
19
Q

What does it mean that macrophages demonstrate plasticity?

A

Can de-differentiate and re-differentiate

Response to varying stimuli

20
Q

What is classical macrophage activation?

A
Inactive macrophage binds inflam cytokines & TLR agonists 
- Ex: bind IFN-gamma AND LPS
Activated macrophage makes:
1. Pro-inflam cytokines 
2. ↑MHC 2 to present bound TLR agonist 
3. ↑NO = respiratory burst
21
Q

What are the overall goals of classical macrophage activation?

A

Microbicidial - NO
Tissue/cellular damage - NO
Inflammation - pro-inflamm cytokines
DTH - delayed type hypersensitivity

22
Q

What is alternative macrophage activation?

A

Inactive macrophage binds cytokines from Th2 cells (helper T w/ goal inflam) or infected macrophages
- Ex: IL4, IL13
Activated macrophage:
1. ↑MHC 2
2. Eat antigen
3. Release IL4/3 to feedback and sustain macrophage’s own activity

23
Q

What are the overall goals of alternative macrophage activation?

A

Humoral immunity
Allergic (!) and anti-parasite responses
Wound repair (!) and tissue remodeling

24
Q

If you bind a 7 TMD receptor, what is the functional outcome?

A

Migration into tissues via integrin & cytoskeleton changes

25
Q

If you bind a toll-like or mannose receptor, what is the functional outcome?

A

Killing of microbes via cytokines, ROS or phagocytosis