2 phagocytosis

Question 1

phagocyte

Answer 1

ingest particles through zipper model, receptor driven

Question 2

kinds of phagocytes

Answer 2

neutrophils
macrophages/monocytes
eosinophils
basophils
dendritic cells
microglial cells
osteoclasts

Question 3

monocytes

Answer 3

circulate in the bloodstream

Question 4

dendritic cells

Answer 4

present class II (humoral + T cell response)

Question 5

macrophages

Answer 5

1 long lived
2 present in tissues (when mature)
3 02 dependent killing not vigorous
4 conditions amenable for intracellular growth of pathogens
5 pathogen tactics in battle

Question 6

macrophage pathogen tactics in battle

Answer 6

1 circumvent respiratory burst
2 break out of phagosome
3 prevent phagolysosome fusion
4 resist granule contents

Question 7

polymorphs

Answer 7

1 short lived
2 circulating
3 respond to conditions stimulating inflammation, leaving circulation
4 vigorous respiratory burst during phagocytosis
5 extremely hostile environment
6pathogen tactics

Question 8

pathogen tactics of polymorphs

Answer 8

• resist phagocytes

- kill or be killed

Question 9

receptors on phagocytes

Answer 9

phagocytic receptors, adhesion receptors, activation receptors, MHC class I and II

Question 10

phagocytic receptors

Answer 10

integrins and complement receptors + lectins + Fc receptors

Question 11

3 roles for complement components

Answer 11

bacteria lysis
phagocytic chemotaxis
bacteria opsonizatoin

Question 12

Fc receptor

Answer 12

if you are immune to an organism, phagocytes can still recognize with their Fc receptors

• Fc receptors recognize the constant region of IgG
• Fc receptors help internalize the microorganism and degrade it

Question 13

2 receptor classes

Answer 13

immune + nonimmune

Question 14

opsonization

Answer 14

recognition by specific receptors, convenient way to limit the number of receptors on surface of phagocytic cells

Question 15

lectin

Answer 15

receptors on phagocytes can also recognize yeast; they can recognize carbs on yeast cells

Question 16

in absence of acquired immunity

Answer 16

c3bi and complement receptors

Question 17

in presence of acquired immunity

Answer 17

igG, opson, Fc receptors

Question 18

lectin

Answer 18

direct recognition of specific cabs

-a specific receptor

Question 19

dectins

Answer 19

major class of phagocyte lectins is involved in recognition of fungal pathogens

Question 20

activation receptors

Answer 20

toll like receptors, IL-1 receptor, TNF receptor, IFN gamma receptor

Question 21

toll like receptors

Answer 21

recognize nuclei acids, LPS, lipoproteins specific for microorganisms

Question 22

IL-1 receptor

Answer 22

mediator of inflammation

Question 23

iFN gamma receptor

Answer 23

classical way where phagocytes get activated, associated with inflammatory response

Question 24

early classical activation

Answer 24

1 inflammation

2 bacterial and viral diseases

Question 25

later alternative actiavation

Answer 25

noninflammatory
clears tissue damage
often less restrictive of pathogens

Question 26

properties of classically activated phagocyte

Answer 26

1 enhanced rate of phagocytosis
2 enhanced production of toxic reactive oxygen intermediates (antimicrobial)
3 enhanced production of NOI (nitric oxide; antimicrobial)
4 enhanced phagosome-lysosome fusion
5 increased number of MHC class II molecules
6 secretion of IL-12: differentiation of CD4 T cells

Question 27

transendothelial migration

Answer 27

1 endothelium becomes activated and has receptors for the neutrophils
2 rolling= maing and breaking of contact bewteen phagocytic cell and endothelium
3 increased production of inflammatory mediators
4 phagocyte is mobilized and can transmigrate

Question 28

antimicrobial activity begins

Answer 28

• before the microbe is completely engulfed

- primary mode of killing prior to engulfment is the oxidative burst, in which toxic oxygen free radicals are produced

Question 29

NADPH oxidase assembly in response to microbial adhesion

Answer 29

most important generator of oxygen free radicals is the NADPH oxidase complex

Question 30

mechanism II

Answer 30

suicide by NADPH oxidase release antimicrobial “NETS”

Question 31

histones associated with NETS are

Answer 31

antimicrobial

Question 32

microorganisms get trapped by

Answer 32

these nets and get killed

Question 33

live neutrophils will elicit

Answer 33

oxygen free radicals that will kill organisms that will also kill neutrophils
-neutrophil death willliberate nuclei acid that will create a net

Question 34

if microorganisms are internalized

Answer 34

oxygen independent organisms are used instead

Question 35

killing mechanism III

Answer 35

antimicrobial peptides: defensins and cathelicidins
-proteins inject themselves into the envelope of microorganisms and cause disruption of the envelope so that the microorganisms depolarize and kill

Question 36

defensins

Answer 36

pair of beta sheets

Question 37

cathelicidins

Answer 37

helical

Question 38

tactics used by pathogens to avoid killing by phagocytes

Answer 38

1 kill or be killed (cytotoxicity)
2 inhibit opsonization or inactivate phagocytosis
3 survive intracellular killing

Question 39

pathogens avoid phagocytes by: killing or being killed (cytotoxicity)

Answer 39

• streptococcous streptolysi O

- bordetella pertussis adenylate cyclase

Question 40

pathogens avoid phagocytes by: inhibit opsonization of inactivate phagocytosis

Answer 40

1. capsule: s. pneumoniae
2. M protein: S. pyogenes
3. disrupt signaling: RhoGAP proteins

Question 41

pathogens avoid phagocytes by: survive intracellular killing

Answer 41

1 inhibit phagosome-lysosome fusion: M. Tb
2 escape from phagosome: Rickettsia
3. survive lysosomal enzymes: Salmonella