Innate Immunity - Sentinel Cells

Question 0

How to sentinel cells initially discriminate self from non-self?

Answer 0

PRRs

Question 1

Sentinel or surveillance cells are concentrated where? Why are they concentrated here?

Answer 1

Peripheral tissues where they can come into immediate contact with invading microbes or foreign particles

Question 2

What are 5 types of sentinel cells?

Answer 2

Dendritic cells, macrophages, mast cells, eiosinophils and epithelial cells

Question 3

Dendritic cells present peptide antigens to?

Answer 3

Naive T cells

Question 4

Dendritic cells direct the immune response via?

Answer 4

Cell-to-cell receptor communication and the secretion of cytokines

Question 5

Very briefly list the 7 functions of macrophages

Answer 5

Act as sentinel cells, innate effector cells carrying out phagocytosis, act as APCs for memory T cells, effector cells for CMIR, nutrient recycling by phagocytizing dying cells, regulate inflammation, participate in the resolution phase producing products which aids in tissue remodeling and repair

Question 6

Sentinel cell types except for epithelial cells, are largely derived from?

Answer 6

Bone marrow equivalent tissues

Question 7

Hematopoietic is?

Answer 7

Differentiation of cells from pluripotent stem cells

Question 8

What directs sentinel cells to their constitutive and inductive trafficking to peripheral tissues?

Answer 8

Chemokines

Question 9

What three sentinel cells are part of the mononuclear phagocytizic system (MPS)?

Answer 9

DCs, monocytes and macrophages

Question 10

The majority of the cells in the mononuclear phagocytic system originate from hematopoietic stem cells that differentiate into?

Answer 10

Common macrophage and DC progenitors (CMDP)

Question 11

CMDP give rise to either __________ or monocytes that migrate into tissues and mature into macrophages

Answer 11

Common DC progenitors (CDP)

Question 12

Mast cells are found where?

Answer 12

In the skin an at mucosal surfaces

Question 13

Mast cells can elicit _________ and ______ effects very rapidly via PRE ligation with PAMPs/alarmins and subsequent ____________.

Answer 13

Systemic, local, degranulation

Question 14

Mast cell are motile cells that act as an important effector during what type of infection?

Answer 14

Parasitic

Question 15

Mast cells are key mediators of?

Answer 15

Antibody-mediated atopic hypersensitivity reactions

Question 16

Normally, mast cells undergo what type of degranulation?

Answer 16

Piecemeal

Question 17

In cases of anaphylaxis, mast cells undergo what type of degranulation?

Answer 17

Spontaneous

Question 18

What is spontaneous degranulation of mast cells?

Answer 18

All of their granular contents are released into the surrounding tissues causing immediate and severe inflammation

Question 19

What is present in the granular contents of mast cells?

Answer 19

Vasoactive compounds, pro-inflammatory cytokines, Chemokines, chemo attractants and anti microbial enzymes & peptides

Question 20

Mast cells have the capacity to undergo an alternative death pathway referred to as?

Answer 20

Netosis

Question 21

What occurs during netosis?

Answer 21

Mitochondrial and genomic DNA, just ones, and granule proteins are released from the cell forming antimocrobial extracellular traps

Question 22

True or false - mast cells are also involved in the acquired immune response

Answer 22

True

Question 23

Mast cells contain what receptor which bids to immunoglobulin IgE?

Answer 23

Fcepsilon

Question 24

What occurs when a mast cell comes into contact with a specific antigen in response to IgE cross linking with the antigen?

Answer 24

Degranulation

Question 25

Chicken mast cells are activated by? And are responsible for?

Answer 25

IgY and responsible for local anaphylactic reaction in the gut

Question 26

The cross-linking of two FCeRs activated several?

Answer 26

Tyrosine kinases leading to the activation of phospholipase C

Question 27

What does phospholipase C do?

Answer 27

Splits membrane phosphotidylinositol 4,5- biphosphate (PIP2) into messenger molecules diacylgycerol (DAG) and inositol tri phosphate (ITP)

Question 28

What does ITP do?

Answer 28

Increases intracellular calcium release from storage sites

Question 29

What triggers granule mobilization and transcription of cytokines as well as COX and LOX?

Answer 29

Protein kinases activated by DAG and calcium

Question 30

What does phospholipase A do and how is it activated?

Answer 30

Activated by IgE cross-linking and it acts of cell membrane phospholipids to produce Arachnidonic acid (AA)

Question 31

What is AA converted to by LOX and COX enzymes?

Answer 31

Vasoactive eicosanoid lipids

Question 32

What enzymes are produced by LOX and COX?

Answer 32

``` LOX = leukotrienes COX = prostaglandins ```

Question 33

What are the two major types of mast cells?

Answer 33

Connective tissue mast cells and mucosal mast cells

Question 34

Where are CTMCs found?

Answer 34

Peritoneal cavity and skin

Question 35

Where are MMCs found?

Answer 35

Intestines and lungs

Question 36

What do CTMCs contain?

Answer 36

Proteoglycan heparin

Question 37

What do MMS contain?

Answer 37

Proteoglycan chondroitin sulfate

Question 38

How are MMCs different then CTMCs?

Answer 38

Smaller in size, contain less histamine, shorter life span

Question 39

True or false - mast cells can degranulation in response to PAMPs and alarmins

Answer 39

True

Question 40

What are the two major neuro peptide receptors mast cells express?

Answer 40

Alpha and beta adrenoreceptors (ADR)

Question 41

What is norepinephrine and what does it do?

Answer 41

It's an alpha ADR agonist or beta ADR antagonist and it enhances mast cell degranulation

Question 42

What is epinephrine and what does it do?

Answer 42

It's a beta ADR agonist or an alpha ADR antagonist and it inhibits mast cell degranulation

Question 43

What is the function of eosinophils?

Answer 43

Regulate inflammation, maintain epithelial barrier function at mucosal surfaces

Question 44

Excessive eosinophilia is associated with?

Answer 44

Tissue damage

Question 45

Eosinophil differentiation requires the presence of?

Answer 45

Growth factors

Question 46

Eosinophils are recruited to tissues and become activated by?

Answer 46

IL-33 and IL-5

Question 47

What are IL33 and IL5 produced from?

Answer 47

Th2 cells and by mast cell degranulation products

Question 48

What is present in mast cell degranulation products?

Answer 48

Eotaxin, histamine, leukotriene B4 (LTB4), serotonin, and platelet activation factor (PAF)

Question 49

What can eosinophils do during an acquired immune response?

Answer 49

Phagocytosis and act as antigen presenting cells

Question 50

Eosinophils express __ receptors which means they can undergo _________ degranulation

Answer 50

Fc, antigen-specific

Question 51

True or false - extracellular traps are produced by mast cells and eosinophils

Answer 51

True

Question 52

What do extracellular traps do?

Answer 52

Immobilize and neutralize bacteria

Question 53

What are the two main constituents of eosinophil granules?

Answer 53

Cationic proteins and various RNases

Question 54

What are the cationic proteins?

Answer 54

Major basic protein (MBP) and eosinophil peroxidase (EPO)

Question 55

How do MBP and EPO work?

Answer 55

They bind to helminths or bacteria. Their positive charge disrupts the membrane lipid bilateral affecting membrane permeability leading to cytotoxicity.

Question 56

Eosinophils involved in tissue repair are an important source of?

Answer 56

Matrix metalloproteins (MMPs)

Question 57

What do MMPs do?

Answer 57

Degrade extracellular matrix materials such as collagen enabling inflammatory cells to migrate through tissues and therefore allows for tissue reorganization to occur during healing

Question 58

What is TGF-beta produced from and what does it do?

Answer 58

Produced from eosinophils and promotes differentiation and proliferation of fibroblasts, epithelial cells and smooth muscle cells during tissue healing

Question 59

What are IL-6, IL-8, TGF-beta and vascular endothelial cell growth factor examples of?

Answer 59

Pro-angiogenic factors from eosinophils

Question 60

What are thrombospondin and endosatin examples of?

Answer 60

Anti-angiogenic factors

Question 61

Eosinophils are an important source of _____ at mucosal tissues which allows the steering of the acquired immune response favoring?

Answer 61

IL-4 and Th2 antibody-mediated immunity