Innate Immune System

Question 1

Complement enzyme

Answer 1

C3 convertase

Question 2

Complement components for inflammatory response

Answer 2

C3a
C4a
C5a

Question 3

Complement components for opsonization

Answer 3

C3b

C4b

Question 4

Complement components for MAC complex

Answer 4

C5b-C9

Question 5

Antimicrobial substance secreted by skin; lytic to microbes

Answer 5

Defensin

Question 6

What types of cells secrete cytokines?

Answer 6

Keratinocytes
Dendritic cells
Mast cells
Endothelial cells

Question 7

PRR that recognizes gram-negative bacterial LPS, fungal mannans, and viral envelope proteins

Answer 7

TRL-4

Question 8

Transcription factor activated by PAMPs via PRRs

Answer 8

NFkB

Question 9

Alternative complement pathway activation

Answer 9

Binding of C3 to a PAMP

Question 10

Classical complement pathway activation

Answer 10

Antibody (IgM or IgG) binds to an antigen

Question 11

Lectin complement pathway activation

Answer 11

Mannose-binding lectin (soluble PRR) in serum binds to mannose residues on microbes (type of PAMP)

Question 12

C5a function

Answer 12

Chemokine to recruit neutrophils

Question 13

C3a and C5a function

Answer 13

Mast cell degradation –> release of histamine

Question 14

C5b function

Answer 14

Binds membrane of microbe; induces formation of the rest of MAC

Question 15

Mechanism of action of Type I IFN

Answer 15

1. Viral RNA is recognized by cytoplasmic PRRs
2. Transcription of IFN alpha and beta
3. Signals to nearby cells to stimulate activation of transcription of antiviral genes (antiviral proteins that inhibit TRANSLATION)

Question 16

Macrophage function

Answer 16

Phagocytosis

Secrete cytokines that attract immune cells

Question 17

Neutrophil function

Answer 17

Phagocytosis; inflammation

Question 18

Eosinophil function

Answer 18

Parasitic infection

Question 19

Mast cell function

Answer 19

Allergic reaction; release histamine

Mediate vasodilation and vascular permeability

Question 20

Basophil function

Answer 20

Allergic reaction; release histamine

Question 21

NK cell function

Answer 21

Cell cytotoxicity

Question 22

What binds to induce opsonization?

Answer 22

1. Fc receptor on phagocyte binds to IgG

2. CR1 receptor binds to C3b

Question 23

How do NK cells bind to other cells?

Answer 23

NK cells have two receptors: killer activating and killer inhibiting

Normal cells will bind to both NK receptors–a common molecule binds to Killer activating and MHC I binds to Killer inhibiting

Abnormal cells lack MHC, therefore they only bind to killer-activating receptor

Question 24

What changes in vascular flow occur during acute inflammatory response?

Answer 24

1. Vasodilation

2. Vascular permeability: “leaky” blood vessels allows for extravasation of neutrophils and other inflammatory cells

Question 25

What are the professional APCs?

Answer 25

Macrophages

Dendritic cells

Question 26

How does the innate system interact with the adaptive system?

Answer 26

Via macrophages and dendritic cells, which are professional APCs

Question 27

What is the result of TLR-4 stimulation of macrophages?

Answer 27

Transcription of genes for cytokines, adhesion molecules and co-stimulatory molecules