B3-004 Innate Immunity

Question 1

Innate Immunity

Answer 1

Natural/native immunity = inflammation and anti-viral defense.
Present in all healthy individuals at birth
Immediate response.
Restricted response without memory (similar response with repeat pathogenic encounters)
Does not react against host in normal circumstances.
Enhances adaptive immune response.

Question 2

Pathogen

Answer 2

a microbe that is causing disease (bacteria, virus, fungus, or other microorganisms)

Question 3

Cytokines

Answer 3

Soluble protein important in cell signaling

Question 4

Chemokines

Answer 4

A cytokine that attracts a particular cell into an environment

Question 5

Opsonization

Answer 5

Coating a microbe with molecules that can be recognized by receptors on phagocytes

Question 6

Phagocytosis

Answer 6

Process by which a cell engulfs a solid particle

Question 7

Pattern Recognition Receptors

Answer 7

Innate immune receptors that recognize PAMPs and DAMPs

Question 8

Pathogen-associated molecular patterns

Answer 8

Microbial molecules, shares by microbes of the same type.
Not on normal host cells
Stimulate innate immune response
Essential for survival/infectivity
-Lipopolusaccharide (LPS) (endotoxin), peptidoglycan, terminal mannose residues, unmethylated CG-rish DNA

Question 9

Damage-associated molecular patterns

Answer 9

Released form damaged or necrotic host cells
Present in injury (infarction) or infection

Question 10

Toll-like receptors (TLRs)

Answer 10

Specific for microbial components
Activate transcription factors to stimulate expression of genes encoding cytokines, enzymes, and other proteins
TLR defect = recurrent and severe infections

Question 11

TLR types

Answer 11

TLR 1, 2, 4, 5 & 6 = bacterial
TLR 3, 7, 8, 9 = viral

Question 12

NOD-like receptors (NLRs)

Answer 12

Family of cytosolic receptors that sense PAMPs and DAMPs in the cytoplasm that contain central nucleotide oligomerization domain (NOD) and different N-terminal domains

Question 13

Inflammasome

Answer 13

Regulates to activation of capase-1 and induces inflammation.
Inflammasome dysregulation = gout and auto-inflammatory syndromes

Question 14

Phagocytes

Answer 14

Neutrophils - most abundant in the blood
Increase rapidly during infection
First cell to response to infections
Dominant cell of inflammation
Recruited to tissues to remove debris and break down microbes
Only live a few hours. Dead ones form “pus”

Question 15

Oxidative burst

Answer 15

Phagocytosed bacteria is fused with lysosome to form phagolysosome.
Rapid release of ROS inside the new vesicle, along with increased NO and lysosomal enzymes, break down and kill the microbe.

Question 16

Dendritic cells

Answer 16

Antigen-presenting cells
Production of cytokines
Bridge innate and adaptive immunities

Question 17

Mast cells

Answer 17

Found in skin and mucosal epithelium
Activated by: microbial products binding to TLRs, antibody interactions (typical allergic reactions), and complement.
Capable of increasing capillary permeability, killing bacteria, inactivating microbial toxins, and stimulating inflammation

Question 18

Natural killer cells

Answer 18

CD16/56+
Identify infected and stressed cells and kill them
Intracellular microbial infections
Secrete IFN-Gamma (macrophage activation)
Activated by cytokines from macrophages and dendritic cells
IL-15: development and maturation of NK cells
IL-12 and type 1 IFN: enhance NK cell killing function