Innate Immunity 2

Question 1

What do cytokines do and what do chemokines do?

Answer 1

Chemokines direct cells to site of infection and cytokines tell cells what to do when they arrive at the site of infection

Question 2

What are the most abundant cells at oral epithelium that increase during inflammation?

Answer 2

neutrophils

Question 3

Where are most of immune cells in oral cavity?

Answer 3

oral tissues such as tonsils, buccal epithelium, palate

Question 4

What attracts neutrophils to site of inflammation?

Answer 4

interleukin 8 (IL-8)

Question 5

What controls interactions between immune cells and the endothelial cells they have to pass by?

Answer 5

cell adhesion molecules

Question 6

What are the families of cell adhesion molecules

Answer 6

Selectins (e.g., P and E- selectins)
Integrins (e.g., LFA-I)
Immunoglobulin superfamily

Question 7

What immune cells have select receptors/ligands that allow migration?

Answer 7

monocytes
dendritic cells

Question 8

What are neutrophils?

Answer 8

phagocytic granulocytes

Question 9

What do granules contain?

Answer 9

contain degradative enzymes and antimicrobial substances

Question 10

What are the two main functions of neutrophils?

Answer 10

degranulation
NETs (neutrophil extracellular traps)

Question 11

How are granules/vesicles released from neutrophil?

Answer 11

Released upon activation of receptors (e.g. TLRs)

Question 12

When NET pathway is activated, what occurs?

Answer 12

induces neutrophils to release proteins and some genetic material (chromatin) to form extra-cellular fibril matrix to trap pathogens

Question 13

What is chromatin?

Answer 13

clump of nucleic acids

Question 14

How do monocytes migrate to tissues?

Answer 14

similar to neutrophils
via cell adhesion molecules

Question 15

What are the subsets of macrophages?

Answer 15

Pro- and anti- inflammatory subsets (M1 – pro- and M2 – anti-)

Question 16

What is an example of an anti-inflammatory cell subset?

Answer 16

regulatory T cell

Question 17

What is phagocytosis?

Answer 17

digestion of microbial cells, and degradation – can present antigen to adaptive immune cells

Question 18

What is the primary function of macrophages?

Answer 18

phagocytosis as well as presentation of antigen to adaptive immune cells

Question 19

What are the two types of APC and what do they include?

Answer 19

Non-professional (Epithelial cells/fibroblasts/endothelial cells)
Professional (Macrophages, dendritic cells, B cells)

Question 20

What do cells have that allow attachment to microbes?

Answer 20

Tentacle like structures – help attachment to microbes

Question 21

What cells carry out phagocytosis?

Answer 21

neutrophils, macrophages/monocytes, dendritic cells, and B cells

Question 22

How does phagocytosis occur?

Answer 22

Microbes are internalized in a phagosome and digestive enzymes from lysosome(vesicle) help to degrade microbe

Question 23

What happens to the degraded waste material in both APCs and non APCs?

Answer 23

In non antigen presenting cells (e.g., neutrophils generally are not considered APCs) the degraded waster materials are released – sometimes these discarded materials (e.g., microbial antigens) are picked up by APCs
In antigen presenting cells (e.g., macrophages and DCs) the degraded waste material is processed for antigen presentation on MHC receptors.

Question 24

What is a phagosome?

Answer 24

phagocytic vesicle

Question 25

What does the fusion of a lysosome and phagosome create?

Answer 25

phagolysosome

Question 26

What receptor does the T cell recognise the antigen by?

Answer 26

MHC (I or II)

Question 27

How do APCs work?

Answer 27

dendritic cell internalizes and degrades antigen into linear peptides linear peptides presented on cell Surface attached to MHC (major histocompatibility complex) Class I or II

Question 28

What are the differences between MHC I and MHC II?

Answer 28

MHC II are for intracellular and extracellular bacteria/fungi (found only on APCs for interaction with T helper cells) MHCI are for virally infected cells (found on all cells for interaction with cytotoxic cells)

Question 29

What are granules and what do they contain?

Answer 29

Granules are vesicles containing preformed mediators; Proteinases Antimicrobials (AMPs, lactoferrin etc.) Chemical mediators (e.g., histamine)

Question 30

What do granules respond to?

Answer 30

MAMPs (e.g., microbial antigens) Complement proteins Cytokines and other inflammatory mediators

Question 31

What are the 4 enzymatic cascade systems of plasma?

Answer 31

Complement Kinins Coagulation factors Fibrinolytic system

Question 32

What do plasma systems produce?

Answer 32

various inflammatory mediators

Question 33

What is opsonisation?

Answer 33

coating/tagging of a microbe for removal by antibodies or complement proteins(capsulated organisms are protected)

Question 34

Describe the complement system

Answer 34

A collection of soluble proteins present in circulation. Drives inflammation or opsonisation Three pathways; classical, alternative or lectin pathway

Question 35

What are the 3 pathways of complement and how do they work?

Answer 35

(1) Classical pathway – antibody attached to microbe (2) Alternative pathway – microbial cell wall (3) Mannose binding lectin pathway (MBL) – carbohydrates on pathogen surface

Question 36

What are anaphylatoxins?

Answer 36

Glycoproteins such as complement components C3, C4 and C5 (and their fragments) that drive immune responses

Question 37

What do anaphylatoxins lead to?

Answer 37

Anaphylatoxins lead to smooth muscle contraction and capillary leakage – allowing increased infiltration of immune cells to site of infection

Question 38

What do all pathways form?

Answer 38

C3 convertase and C5 convertase enzymes

Question 39

What do C3 convertase and C5 convertase enzymes degrade?

Answer 39

C3 or C5 protein

Question 40

What are the roles of anaphylatoxins?

Answer 40

Promote immune cell recruitment Increase adhesion of cells to vessel walls Induces granulation Promotes cytokine production Induces antigen presentation Regulate adaptive immune responses

Question 41

What can possibly lead to resolution of PD in mice?

Answer 41

loss of complement system