Final

Question 1

Toll-like receptors (TLR)

- # of domains and descriptions of each

Answer 1

3 domains:

• an extracellular domain with 18 – 25 leucine rich repeats (LRRs) that interacts with its ligand,
• a single pass transmembrane domain
• a cytoplasmic tail with a Toll-IL-1 domain (TIR domain) to interact with signalling proteins

Question 2

Toll-like receptors (TLR)

- activation (3)

Answer 2

• ligand binding to LRR induces formation of a dimer
• can activate several different signalling pathways, resulting in activation of different transcription factors
• can induce expression of pro-inflammatory cytokines, chemotactic factors and antimicrobial peptides

Question 3

cGAS-STING

- cGAMP formation

Answer 3

• cyclic GMP-AMP synthase; it catalyzes the production of cyclic GMP (cGAMP) from GTP and ATP

Question 4

cGAS-STING

- activation (2)

Answer 4

• cytoplasm: cGAMP will bind to the stimulator of interferon genes (STING) which leads to the activation of the transcription factor IRF3
• IRF3 enters the nucleus to trigger expression of the genes encoding the type I interferons

Question 5

soluble proteins

Answer 5

• recognition molecules of the innate immune system

Question 6

soluble proteins

- when are they produced

Answer 6

• macrophages secrete pro-inflammatory cytokines: IL-1, IL-6, TNF-alpha after they recognize microorganism presence in tissues
• IL-6 induces “acute phase response” that results in production of soluble proteins from the liver

Question 7

neutrophils

- general info (3)

Answer 7

• most abundant leukocyte in blood
• first to be recruited to site of inflammation/infection by chemokine gradient
• major constituent of pus

Question 8

neutrophil

- function (3)

Answer 8

infection site first responders:

• release toxins that kill/inhibit bacteria and fungi
• phagocytose bacteria
• recruit other immune cells to infection site

Question 9

macrophage

- general info

Answer 9

• arise from monocytes that circulate in the blood

Question 10

macrophage

- function (4)

Answer 10

• tissue repair
• apoptotic cell removal
• clearance of pathogens and cancer cells in the tissue through phagocytosis
• stimulates response of other immune cells

Question 11

inflammatory monocytes (2)

Answer 11

• majority of monocytes

- exit blood and enter tissue during infection to differentiate into active inflammatory macrophages

Question 12

patrolling monocytes (2)

Answer 12

• crawl along blood vessels looking for endothelium injury

- do not differentiate

Question 13

conventional dendritic cells

- general info (2)

Answer 13

• located in epithelial tissues and migrate to lymph node after activation
• bridge between innate and adaptive immunity

Question 14

conventional dendritic cells

- function (2)

Answer 14

• ingest pathogens and display peptides to activate T cells

- trigger adaptive immunity

Question 15

mast cells

- general info (2)

Answer 15

• major cell type in allergic reactions

- located in connective tissues and mucous membrane

Question 16

mast cells

- function (3)

Answer 16

• dilates blood vessels
• releases histamine and heparin to induce inflammation
• recruit macrophages and neutrophils

Question 17

plasmacytoid dendritic cells

- general info (2)

Answer 17

• circulate in blood and lymphoid organs

- sometimes effective APCs, but take up less antigen than cDCs

Question 18

plasmacytoid dendritic cells

- function

Answer 18

• potent interferon producers after viral pathogen recognition

Question 19

natural killer cells

- general info (2)

Answer 19

• express TLRs and NODss

- circulate in blood and migrate into tissue

Question 20

natural killer cells

- function (2)

Answer 20

• kill tumour and virus-infected cells directly by antibody-dependent cellular cytotoxicity

Question 21

eosinophils

- general info

Answer 21

• granulocyte released in bloodstream that migrates into tissue

Question 22

eosinophil

- function (2)

Answer 22

• release toxins that kill bacteria and parasites (can eliminate multi-cellular parasites such as helminths)
• can cause tissue damage

Question 23

basophil

- general info (3)

Answer 23

• granulocyte found in tissues that contain heparin granules
• responsible for defence against parasites
• may be responsible for allergic reactions

Question 24

basophil

- function (3)

Answer 24

• may be important in preventing blood clots during parasitic infection
• may provide cytokines to signal B cells to isotype switch to IgE
• can bind and release histamine in response to IgE cross-linking

Question 25

what viruses can continue replication in antiviral state cells

Answer 25

• DNA viruses or RNA viruses that replicate genome in cell nucleus

Question 25

what viruses can continue replication in antiviral state cells

Answer 25

• DNA viruses or RNA viruses that replicate genome in cell nucleus

Question 26

MIC proteins (4)

Answer 26

• resemble MHC class I proteins (α chain)
• don’t present peptides and don’t associate with β2-microglobulin
• not expressed on healthy cells, only cells that are stressed by
  infection, malignant transformation, elevated temperature.
• MIC proteins are recognized by the NK cell’s activating receptors.

Question 27

immune synapse

Answer 27

• prevent damaging granules from spreading out and causing death to non-infected bystander cells

Question 28

leukotrienes

Answer 28

• inflammatory mediators that help recruit neutrophils and promote cytokine production

Question 29

prostaglandins

Answer 29

• type of inflammatory mediator that has various functions such as vasodilation

Question 30

Weibel-Palade bodies

Answer 30

• granules containing P-selectin retained in the cytoplasm of vascular endothelial cells in the absence of infection