Exam 2- Innate Immunity

Question 1

innate immunity has ________ barriers and ________ barriers

Answer 1

anatomical
physiological

Question 2

are neutrophils present in normal, healthy tissues?

Answer 2

no

Question 3

what is the primary function of phagocytes?

Answer 3

identify, ingest, and destroy microbes

Question 4

what do macrophages and neutrophil surface receptors bind to on microbial surfaces (common constituent)?

Answer 4

pathogen-associated molecular patterns (PAMPs)

Question 5

inflammation is traditionally defined by the presence of ______, ______, ______, and ______

Answer 5

heat
pain
redness
swelling

Question 6

what does dilation and increased permeability of blood vessels in inflammation account for?

Answer 6

heat, redness, swelling

Question 7

what causes the pain in inflammation?

Answer 7

migration of cells into tissue and their local actions

Question 8

what do macrophages release in response to invading pathogens?

Answer 8

cytokines

Question 9

what do interleukins 1 and 6 (IL-1 and IL-6) induce?

Answer 9

hypothalamus to induce fever
liver to produce soluble proteins quickly- acute phase proteins (APP)

Question 10

what does TNF-alpha do?

Answer 10

makes blood vessels stickier to induce cell migration and activating migrating macrophages
promotes platelet aggregation and clotting to help limit spread infection

Question 11

what does IL-8 do?

Answer 11

directs neutrophils

Question 12

what does IL-12 do?

Answer 12

promotes local natural killer cell activity and stimulates IFN-gamma release
later in response primes antigen-specific T lymphocytes

Question 13

how are pathogens destroyed?

Answer 13

phagosome
phagolysosome

Question 14

what do macrophages and neutrophils produce after phagocytosis to kill the engulfed microorganism?

Answer 14

hydrogen peroxide
superoxide anion
nitric oxide

Question 15

how can neutrophils kill pathogens extracellularly?

Answer 15

neutrophil extracellular traps (NETs): activated neutrophils generate web extracellular fibers of DNA, histones, granule proteins (elastase)

Question 16

what do mast cells release after being exposed to certain types of bacteria?

Answer 16

TNF
histamine
proteases

Question 17

mast cells are considered to particularly effective in aiding immune cell recruitment in view of their strategic association with __________________

Answer 17

blood vessels

Question 18

what are Toll receptors?

Answer 18

transmembrane receptors that signal the presence of pathogens, from effector cells

Question 19

the effects of bacterial LPS on macrophages are mediated by DC14 binding to ________________________

Answer 19

Toll-like receptor 4

Question 20

true/false: Toll-like receptors are found not only on the cell surface, but also on intracellular membranes

Answer 20

true

Question 21

what are cytosolic receptors?

Answer 21

Toll-like receptors in cytosol
three major classes of

Question 22

what mediates leukocytes leaving the blood stream (extravasation)?

Answer 22

cytokines and chemokines

Question 23

what is the dual function of the innate immune system?

Answer 23

early defense against pathogen attack
alert adaptive immune system to pathogen invasion

Question 24

how does the dual function of the innate immune system operate?

Answer 24

the Toll pathway

Question 25

natural killer cells selectively kill cells that bear ___________ levels of MHC class I molecules

Answer 25

very low

Question 26

how do natural killer cells balance their engagement to distinguish between healthy and infected cells?

Answer 26

both activation and inhibition receptors

Question 27

what activates the lectin-binding pathway in complement?

Answer 27

terminal mannose residues via mannos-binding lectin
N-acetylglucosamine residues

Question 28

what are the two major families of antimicrobial peptides?

Answer 28

defensins and cathelicidins

Question 29

how does host cell damage trigger innate immunity?

Answer 29

damage-associated molecular patterns (DAMPs)

Question 30

what are two physiological barriers to microbes?

Answer 30

acid pH of skin
secretions of mucus membranes

Question 31

what does a pathogen-associated molecular pattern binding to a cell receptor lead to?

Answer 31

phagocytosis
induces secretion of cytokines and chemokines

Question 32

what are some receptors on phagocytes that help macrophages and neutrophils recognize pathogens?

Answer 32

macrophage mannose receptor
scavenger receptors
complement protein receptors
toll-like receptors

Question 33

what do mast cells do in innate immunity?

Answer 33

release TNF, histamine, and proteases
alter vascular permeability, airways, gastrointestinal motility, and epithelial sloughing

Question 34

why is the activation of adaptive immunity dependent upon molecules induced due to innate immune recognition and signaling?

Answer 34

Toll signaling leads to production of molecules on antigen presenting cells that are essential for adaptive immune responses: important for activation CD4 T cells

Question 35

what are the three major classes of cytosolic receptors?

Answer 35

nucleotide-binding oligomerization domain (NOD)-like receptors (NLR)
retinoic acid-inducible gene (RIG)-like (RLR)
cytosolic DNA sensors (CDS)

Question 36

how does rolling along the endothelium result in extravasation?

Answer 36

first leukocytes bind to vascular endothelium through interactions between molecules induced on endothelium and their carbohydrate ligands on the leukocyte
rolling results in induction of cell adhesion molecules (CAMs) and activation receptors on the leukocyte by contact with chemokines such as IL-8

Question 37

what immunomodulatory cytokines do natural killer cells produce?

Answer 37

IFN-gamma
TNF-alpha

Question 38

what are antimicrobial peptides and how/when are they made?

Answer 38

naturally occurring peptide antibiotics
constitutively expressed or induced by microbes or their products
parts of animal most likely to come into contact with pathogens from environment