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Flashcards in Innate Immunity - Sentinel Cells Deck (62):
0

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

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

1

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

PRRs

2

What are 5 types of sentinel cells?

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

3

Dendritic cells present peptide antigens to?

Naive T cells

4

Dendritic cells direct the immune response via?

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

5

Very briefly list the 7 functions of macrophages

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

6

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

Bone marrow equivalent tissues

7

Hematopoietic is?

Differentiation of cells from pluripotent stem cells

8

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

Chemokines

9

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

DCs, monocytes and macrophages

10

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

Common macrophage and DC progenitors (CMDP)

11

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

Common DC progenitors (CDP)

12

Mast cells are found where?

In the skin an at mucosal surfaces

13

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

Systemic, local, degranulation

14

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

Parasitic

15

Mast cells are key mediators of?

Antibody-mediated atopic hypersensitivity reactions

16

Normally, mast cells undergo what type of degranulation?

Piecemeal

17

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

Spontaneous

18

What is spontaneous degranulation of mast cells?

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

19

What is present in the granular contents of mast cells?

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

20

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

Netosis

21

What occurs during netosis?

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

22

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

True

23

Mast cells contain what receptor which bids to immunoglobulin IgE?

Fcepsilon

24

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

Degranulation

25

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

IgY and responsible for local anaphylactic reaction in the gut

26

The cross-linking of two FCeRs activated several?

Tyrosine kinases leading to the activation of phospholipase C

27

What does phospholipase C do?

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

28

What does ITP do?

Increases intracellular calcium release from storage sites

29

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

Protein kinases activated by DAG and calcium

30

What does phospholipase A do and how is it activated?

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

31

What is AA converted to by LOX and COX enzymes?

Vasoactive eicosanoid lipids

32

What enzymes are produced by LOX and COX?

LOX = leukotrienes
COX = prostaglandins

33

What are the two major types of mast cells?

Connective tissue mast cells and mucosal mast cells

34

Where are CTMCs found?

Peritoneal cavity and skin

35

Where are MMCs found?

Intestines and lungs

36

What do CTMCs contain?

Proteoglycan heparin

37

What do MMS contain?

Proteoglycan chondroitin sulfate

38

How are MMCs different then CTMCs?

Smaller in size, contain less histamine, shorter life span

39

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

True

40

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

Alpha and beta adrenoreceptors (ADR)

41

What is norepinephrine and what does it do?

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

42

What is epinephrine and what does it do?

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

43

What is the function of eosinophils?

Regulate inflammation, maintain epithelial barrier function at mucosal surfaces

44

Excessive eosinophilia is associated with?

Tissue damage

45

Eosinophil differentiation requires the presence of?

Growth factors

46

Eosinophils are recruited to tissues and become activated by?

IL-33 and IL-5

47

What are IL33 and IL5 produced from?

Th2 cells and by mast cell degranulation products

48

What is present in mast cell degranulation products?

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

49

What can eosinophils do during an acquired immune response?

Phagocytosis and act as antigen presenting cells

50

Eosinophils express __ receptors which means they can undergo _________ degranulation

Fc, antigen-specific

51

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

True

52

What do extracellular traps do?

Immobilize and neutralize bacteria

53

What are the two main constituents of eosinophil granules?

Cationic proteins and various RNases

54

What are the cationic proteins?

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

55

How do MBP and EPO work?

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

56

Eosinophils involved in tissue repair are an important source of?

Matrix metalloproteins (MMPs)

57

What do MMPs do?

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

58

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

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

59

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

Pro-angiogenic factors from eosinophils

60

What are thrombospondin and endosatin examples of?

Anti-angiogenic factors

61

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

IL-4 and Th2 antibody-mediated immunity