Immunology 2

Question 1

T or F: innate immunity discriminate very effectively between host cells and pathogens

Answer 1

true

Question 2

what is a lysozyme

Answer 2

a chemical barrier present in secretions like mucus, tears, saliva and uses hydrolysis to break apart the peptidoglycan wall -> lysis of bacterial cell wall

Question 3

what are antimicrobial peptide - defensins

Answer 3

• part of innate immunity
• small, heterogeneous, cationic peptides
• kill gram-negative and gram-positive bacteria
  functions:
• destabilize membranes and pore formation in bacterial cell walls
• degradation of bacterial proteins
• inhibit viral binding and entry
• inhibit virus particle assembly

Question 4

explain phagocytosis and phagocytes

Answer 4

• one of the first lines of defense if microbes do invade tissue
• engulf and destroy microorganisms
• key role in innate immunty as they can recognize, ingest, and destroy many pathogens without aid of an adaptive immune response

Question 5

what are the major phagocytes in the body?

Answer 5

macrophages and neutrophils

Question 6

T or F: Phagocytosis can also occur after an antibody has bound to an antigen - the antibody can act as a “signal” that triggers efficient phagocytosis

Answer 6

true

Question 7

what are some examples of pattern recognition receptors?

Answer 7

• toll-like receptors
• nod-like receptors
• lectins

Question 8

Steps of Phagocytosis

Answer 8

1. a PRR binds to a microbe or an opsonin created by another cell binds to the microbe
2. the microbe is engulfed (forms a phagosome)
   3 & 4. microbe killing (phagosome fuse with lysosome)
3. microbe remnants are either digested and used OR excreted

Question 9

what is a NADPH oxidase complex?

Answer 9

• if a particle is too large to phagocytose, macrophages will surround it and “place” their NADPH oxidases close to it to try to kill it
• uses a large amount of oxygen

Question 10

what are some neutrophil granules?

Answer 10

• defensins
• cathepsin
• cathelicidins
• lysozyme
• lactoferrin

Question 11

what can neutrophils do when they’re in an environment with many bacteria?

Answer 11

they can lyse and release their DNA into the ECF known as NET

Question 12

what are the cytokines that are secreted in response to TLR activation?

Answer 12

inflammatory cytokines and interferons

Question 13

what are interferons?

Answer 13

• has interferon alpha, beta, and lambda
• autocrine and paracrine signalling molecules that are effective in activating macrophages, NK cells, and inducing an antiviral state

Question 14

what do Nod-like receptors do?

Answer 14

• recognize DAMPs associated with cellular stress
• activates expression of inflammatory cytokines

Question 15

steps of acute inflammation

Answer 15

1. alteration of vascular caliber - vasodilation
2. capillaries and venules become more “leaky”
3. emigration and activation of leukocytes

Question 16

vasodilation during acute inflammation leads to what?

Answer 16

increased blood flow in inflamed tissue

Question 17

what is lymphangitis?

Answer 17

the lymphatic vessels become inflamed

Question 18

what is a cytokine?

Answer 18

• influence the differentiation of a wide variety of cells including leukocytes
• mediate - activate or inactivate - the activity of many cells
• increase or decrease the production of wide variety of stem/hematopoietic cells

Question 19

what is a chemokine?

Answer 19

• bind to cell-surface receptors
• induce movment of leukocytes along the chemokine concentration gradient
• mediate adhesion of leukocytes for the purposes of: differentiation and inflammation/migration

Question 20

what are the 2 major chemokine families?

Answer 20

CXC and CC

Question 21

CXC chemokines attract…

Answer 21

neutrophils, are angiogenic, and are very similar in structure