Exam 1-2

Question 1

What are four types of non-immune defence mechanisms?

Answer 1

Diarrhea, vomiting, sneezing, and coughing

Question 2

What is the main problem in primary ciliary dyskinesia?

Answer 2

The cilia are no longer moving properly or at all, which impacts the airway negatively

Question 3

Explain the concept of colonization resistance

Answer 3

Colonization resistance, especially in the gut and skin, is the concept that when an area of the body is already colonized, it becomes harder for new bacteria to survive and ‘trash the place’

Question 4

What is the main purpose of sneezing and coughing?

Answer 4

Clearance of the airways from bacteria, viruses, dirt, and irritants

Question 5

What cells and molecules are part of the innate immune system?

Answer 5

macrophages and granulocytes as cells, complement and cytokines as the molecules

Question 6

What cells and molecules are part of the acquired immune system?

Answer 6

Lymphocytes are the cells, antibodies the molecules

Question 7

What are three strategies of the innate immune system for immune defense?

Answer 7

phagocytosis, antimicrobial peptide production, and reactive oxygen species

Question 8

How does tissue damage lead to an immune response?

Answer 8

Severe tissue damage causes necrosis and will initiate the release of DAMPs, which will lead to inflammation in the tissue

Question 9

Apart from the ‘professional cells’ of the immune system, which other cells are involved in innate immunity?

Answer 9

epithelial cells, stromal cells, and endothelial cells

Question 10

What types of receptors recognize PAMPs?

Answer 10

PRRs, pattern recognition receptors

Question 11

What type of immune responses will PRRs initiate?

Answer 11

phagocytosis, proteolysis, immune cell activation, and the release of inflammatory mediators

Question 12

What are the three types of pattern recognition receptors?

Answer 12

Mannose receptors, N-formyl methionyl receptors, and toll-like receptors

Question 13

What do toll-like receptors do?

Answer 13

Toll-like receptors are receptors that can recognize PAMPs, which will initiate the innate immune response

Question 14

What are the general steps of signaling for inflammation through TLRs?

Answer 14

DAMPs/PAMPS will be detected by TLRs, which will activate a signalling pathway through NFkB to the nucleus of the cell. This initiates creation of the inflammasome. The inflammasome then helps regulate the cleavage of IL-1Beta from its pro-form into the active form

Question 15

what is the main role of the inflammasome?

Answer 15

The inflammasome helps in cleaving of the pro-IL-1Beta into its active form, which will activate inflammation pathways

Question 16

What characterizes CGD (chronic granulomatous disease?)

Answer 16

The inability to make hydrogenperoxide, making it harder for phagocytes to kill off bacteria and parasites

Question 17

What are the three main functions of mast cells?

Answer 17

Histamine production
production of chemotaxic factors
cytokine production

Question 18

What are the four functions of macrophages?

Answer 18

phagocytosis
cytokine production
antigen presentation
NET (neutrophil extracellular traps) formation

Question 19

What are the steps of movement by immune cells (leukocytes and neutrophils) from the blood to the tissues?

Answer 19

Step 1: rolling. To slow down, a neutrophil will roll along the blood vessel wall in order to slow down. Slowing down is helped by adhesion molecules on the cell and the endothelium
step 2. Adherance to the vessel wall through LFA-1 and ICAM-1 binding with the cell
Step 3. migration/diapedesis, where the cell will force itself through the vessel wall

Question 20

What are the steps of diapedesis?

Answer 20

destabilization of cell-cell junctions
leukocyte probing
endothelial pore confinement
endothelial pore closure

Question 21

Explain the concept of chemotaxis

Answer 21

Chemotaxis is the movement of a microbe due to a concentration gradient of chemotacic factors

Question 22

What is the difference between M1 and M2 macrophages?

Answer 22

M1 will lead to inflammation, while m2 will inhibit inflammation, instead allowing cell generation and tissue repair

Question 23

When will a natural-killer cell kill?

Answer 23

In the absence of a MHC-class 1 molecule on a cell, there is no inhibition of the NK cell and thus it will kill this cell

Question 24

How does an NK cell kill through the death receptor dependent pathway?

Answer 24

It activates perforin, which makes small holes in the target cell. This allows for granzyme to enter into the cell, which induces apoptosis

Question 25

What does surfactant do in innate immunity?

Answer 25

Surfactants bind to carbohydrates on microbes, and promote phagocytosis by tagging the microbe

Question 26

What do pentraxins do?

Answer 26

Pentraxins opsonizes bacteria and promote complement activation

Question 27

What do mannose binding lectins do?

Answer 27

They bind to bacterial mannose and opsonize bacteria, initiating complement activation

Question 28

What does ficolin do?

Answer 28

It binds to bacterial carbohydrates, opsonizing bacteria and initiating complement activation

Question 29

What are four mechanisms of immune evasion?

Answer 29

Resistance to phagocytosis, resistance to ROS in phagocytes, resistance to complement activation, and resistance to antimicrobial peptide antibiotics

Question 30

Why is murein used as a target for antibiotics?

Answer 30

If formation of murein is blocked, it leads to bacterial lysis, and bacterial death

Question 31

What is the concept of opsonization?

Answer 31

Opsonization is the concept of coating microbes to tag them for phagocytosis

Question 32

What cells fall under the myeloid cells?

Answer 32

macrophages, mast cells, dendritic cells, and granulocytes

Question 33

NK cells can kill through two pathways. Name them

Answer 33

Death-receptor dependent killing, which requires Fas and serine proteases,
and granule-dependent killing

Question 34

Dendritic cells present several signals. What are they?

Answer 34

Signal 1. presenting the antigen
signal 2. co-stimulatory signals to the T-cells
Signal 3. cytokine formation to influence T-cell response

Question 35

What are immunologically priviliged sites?

Answer 35

Immunologically priviliged sites are sites of the body where antigens do no provoke an immune response. These includes the NCS< brain, eyes, and testes

Question 36

What is the major histocompatibility complex?

Answer 36

The MHC is the surface of a cell where cells express surface molecules such as antigens and broken down parts of pathogens

Question 37

What are the fives steps of phagocytosis?

Answer 37

Engulfement and initation
phagosome formation
phagolysosome formation
bacterial killing and digestion
exocytosis of degradation products