L5-Exam 2

Question 1

List the three professional phagocytes:

List the two non-professional phagocytes:

Answer 1

Professional Phagocytes:
1.Neutrophils, 2.Monophils/Macrophages
3.Dendritic Cells

Non-Professional Phagocytes:
1.Basophils
2.Eosinophils

Question 2

True or False: Professional phagocytes originate from myeloid lineages

Answer 2

True

Question 3

What is the first leukocyte to the site of an infection?

Answer 3

Neutrophils

Question 4

True or False: Neutrophils cannot renew their lysosomes and can kill intra or extracellularly

Answer 4

True

Question 5

Where are monocytes found? Macrophages?

Answer 5

Monocytes - blood
Macrophages - tissue

Question 6

True or False: Monocytes/Macrophages/Dendritic cells can present antigens to T cells

Answer 6

True

Question 7

Where are dendritic cells predominately found?

Answer 7

Lung, skin, GI (potential sites of pathogen entry)

Question 8

True or False: Dendritic cells actively induce generation of ROS/toxic products that induce local inflammation

Answer 8

False - Dendritic cells do NOT actively induce generation of ROS/toxic products that induce local inflammation

Question 9

Monocytes/Dendritic cells arrive and are activated ___

Neutrophils arrive and are activated ____

Answer 9

Monocytes/Dendritic cells arrive and are activated SLOWLY

Neutrophils arrive and are activated QUICKLY

Question 10

Which have a longer life span: neutrophils vs. monocytes/dendritic cells?

Answer 10

Monocytes/Macrophages/Dendritic Cells

Question 11

_____: directed movement of cells through a chemical gradient - in response to receptors found

Answer 11

Chemotaxis

Question 12

Which endogenous factors encourage chemotaxis?

Answer 12

1) C5a
2) IL-1 and TNF-a
3) Chemokines (IL-8*)
4) LTB4
5) Fibrinopeptide B and Kinin

Question 13

What type of molecules are involved in both pinocytosis and receptor mediated endocytosis?

Answer 13

Soluble molecules

Question 14

___: process where cells ingest and destroy insoluble particles

Answer 14

Phagocytosis

Question 15

____: non-specific invatigations in cell membrane with coincidental internalization of accompanying extracellular molecules

Answer 15

Pinocytosis

Question 16

Phagocytosis is initiated when several types of ___ are bound by pathogens. Provide 4 examples.

Answer 16

receptors
1) PRR/TLR
2) Fc - recognize bottom 1/2 of Ab
3) Complement receptors

Question 17

What type of receptors bind to opsonins on the surface of microbes?

Answer 17

1) Complement Receptors
2) Fc Receptors

Question 18

____: molecules that, when bound to the surface of microbes, makes them more attractive to phagocytic cells

Answer 18

Opsonins (C3b and IgG)

Question 19

True or False: When a microbe is covered with either C3b or IgG, receptors for C3b or IgG can tightly grab onto the microbe and ingest it

Answer 19

True

Question 20

Some organisms produce a hydrophilic ____ that make it hard for phagocytes to surround and phagocytose these organisms

Answer 20

hydrophilic

Question 21

True or False: Production of capsules enable a pathogenic organisms to more readily cause disease

Answer 21

True

Question 22

Once a microorganism is engulfed by a phagocyte, a ___ is formed

Answer 22

phagosome (phagocytic vesicle)

Question 23

What are the three effects that arise due to the formation of the phagosome?

Answer 23

• increase in cell size
• become more phagocytic
• production of destructive molecules

Question 24

Once the phagosome fuses with lysosomes, a ___ is formed

Answer 24

phagolysosome

Question 25

Where does the Oxidative Burst chemical reaction occur? Products of the reaction?

Answer 25

Phagolysosome (O2- and hypochlorite) Note: Oxidative Burst requires oxygen

Question 26

True or False: superoxide (O2-), H2O2, OH- and OCl- are products of the oxidative burst and have potent anti-microbial activities

Answer 26

True

Question 27

A defect in what enzyme leads to Chronic Granulomatous Disease?

Answer 27

Myeloperoxidase

Question 28

True or False: If one has a defect in myeloperoxidase, neutrophils can phagocytose the pathogen but not intracellularly kill it

Answer 28

True

Question 29

How is inducible NO Synthase induced?

Answer 29

Cytokines (TNF-a and INF-gamma)

Question 30

What is the role of iNOS?

Answer 30

Modifies arginine and ultimately makes NO

Question 31

Three roles of NO?

Answer 31

1) Inhibits Fe/sulfur-dependent enzymes 2) Damages DNA 3) Oxidizes membrane lipids

Question 32

Where are Lysozymes, Lactoferrin, and Defensins located?

Answer 32

Within phagolysosome

Question 33

___: attack bacterial cell wall ____: chelates iron (needed for microbial metabolism) ____: disrupt membrane function, induce osmotic lysis

Answer 33

Lysozymes Lactoferrin Defensins

Question 34

What is the function of secreting effector molecules?

Answer 34

Alert and activate the rest of the immune system

Question 35

Chemocytes recruit ____ Cytokines activate ____ cells NO can be ____

Answer 35

Chemocytes recruit additional cells Cytokines active infiltrating cells NO can be secreted

Question 36

True or False: Neutrophils do not require significant stimulus to phagocytose and kill, but monocytes/macrophages/dendritic cells do

Answer 36

True

Question 37

What are three stimuli that enhance neutrophil activation?

Answer 37

1) Stimulation of PRR 2) Complement - increase ox burst 3) Cytokines

Question 38

What are three mechanisms to activate monocytes/macrophages/dendritic cells?

Answer 38

1) Stimulation of PRR 2) Engage complement receptors / Fc receptors 3) Cytokines !! (INF-gamma)

Question 39

Which cytokine can impact monocyte differentiation into macrophages AND increase the ability of macrophages/dendrites to present antigen?

Answer 39

INF-gamma

Question 40

What happens after pathogen is phagocytose and destroyed?

Answer 40

- Nucleic acids and amino acids are re-used - Peptides broken down into peptide fragments that are "presented" to T lymphocytes to activate T cells (macrophages/dendritic cells) via: antigen presentation