ToB 18 Innate and Adaptive Immunity Flashcards Preview

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Flashcards in ToB 18 Innate and Adaptive Immunity Deck (56)
1

What is the first barrier of the human body against infection?

Epithelial cells

2

What is a 'cytokine'?

A protein secreted by one cell type, which can alter the behaviour of other cells

3

What is a 'chemokine'?

A type of cytokine (a protein), which attracts other cells, initiating chemotaxis.

4

Some pathogens can damage epithelial cells to gain entry to host. How will this epithelial cell react once damaged?

Becomes 'activated', releasing chemokines and other cytokines

5

What is an 'activated epithelial cell'?

Damaged epithelial cell, which responds by secreting chemokines and other cytokines

6

How do epithelial cytokines affect capillary mesothelium?

Increase the permeability

7

Why is it important that epithelial cytokines increase the permeability of capillary mesothelium?

Allows immune cells to migrate from the blood vessels to the site of damage

8

What is 'oponisation'?

The coating of a microorganism by antibodies or complement, to allow phagocytes to recognise it as foreign, stimulating/enhancing phagocytosis.

9

What are the 5 components of inflammation?

1) Pain
2) Swelling
3) Heat
4) Redness
5) Loss of function

10

Is a lysozyme part of the innate or adaptive immune response?

Innate

11

Is a lymphocyte part of the innate or adaptive immune response?

Adaptive

12

Is a macrophage part of the innate or adaptive immune response?

Innate

13

What type of immune response is non-specific and has no memory?

Innate immune response

14

What type of immune response is enhanced by a second exposure?

Adaptive immune response

15

Name the main 6 cell types necessary for an innate immune response:

1) Mast cells
2) Macrophages
3) Eosinophils
4) Neutrophils
5) Basophil
6) Natural Killer cells

16

How does an eosinophil differ from a neutrophil in a histology slide stained with H&E?

The granules within eosinophil cytoplasm take up the eosin stain so appear red, while those in neutrophils take up haematoxylin so appear purple

17

How can you distinguish between a neutrophil and a lymphocyte?

Neutrophils have a multiple-lobed nucleus, lymphocytes do not.
Neutrophil's are also larger than lymphocytes.

18

What is the smallest type of leukocyte?

Lymphocyte

19

What is the largest type of leukocyte?

Macrophage

20

Name the 3 granular leukocytes:

1) Eosinophil
2) Basophil
3) Neutrophil

21

What is the most common type of leukocyte?

Neutrophil

22

What are the 2 types of phagocytes?

1) Macrophages
2) Neutrophils

23

Define phagocytosis:

The active engulfment of particles into a phagosome.

24

What is required by a phagosome for digestion of the engulfed material?

Lysosome

25

What is the 1st event of an inflammatory response?

Arrival of neutrophils

26

Define granulocyte:

Type of immune cell (WBC) which contains granules in its cytoplasm, which contain enzymes for immune response.

27

What allows neutrophils to recognise bacteria and initiate phagocytosis?

Neutrophils express many different receptors specific to different bacteria types, which bind to bacteria and allow the neutrophils to engulf and digest them.

28

What is the primary type of profession antigen presenting cell?

Macrophage

29

What is the function of antigen-presentation?

To allow T-lymphocytes to recognise a foreign pathogen, and to stimulate an adaptive immune response

30

Which type of leukocyte cannot recognise foreign pathogens?

T lymphocytes

31

What is the complement system:

A part of the immune system that marks pathogens for destruction by covalently binding to their surface.

32

How do natural killer cells induce apoptosis of virus-infected cells?

Create pores in target cells
Pump proteases through these pores into the cell

33

How are T-lymphocytes distinguished from B-lymphocytes and NK cells?

Only T-lymphocytes express T-cell receptors (TCRs)

34

People lacking NK cells are most at risk of what kind of infection?

Viral infections

35

How do most cells activate NK cells if they become infected with a virus?

Release IFα and/or IFβ (interferons) if they become infected, which activate NK cells

36

What type of immune cell produces the earliest response to a viral infection?

Natural Killer cells

37

How does a viral infection stimulate NK cell activation?

Virus infects an epithelial cell,
causing it to become activated and release cytokines
these induce proliferation and activation of NK cells

38

What 2 proteins are secreted by the innate immune system to deprive micro-organisms of iron?

1) Transferrin
2) Lactoferrin

39

How does the secretion of Transferrin cause micro-organisms to be deprived of iron?

Transferrin tightly binds to iron.

40

What is the antimicrobial enzyme found in sweat, tears, and saliva that can specifically break down peptidoglycan?

Lysosome

41

What is the enzyme present in tears which breaks down peptidoglycan?

Lysosome

42

What are the components of the complement system?

C1 - C9

43

Which component of the complement system binds to the surface of microbes and marks them for destruction?

C3(b)

44

Which components of the complement system recruit inflammatory cells?

C3(a)
C4(a)
C5(a)

45

Which component of the complement system forms a pore in the microbial cell membrane?

C9

46

Which are the most essential components of the complement system?

C1-4

47

Define antigen:

Molecule that elicits a specific immune response when introduced into the body

48

Which type of lymphocyte matures in the Thymus gland?

T-lymphocytes

49

Which type of lymphocyte matures in the bone marrow?

B-lymphocytes

50

Name the 2 types of T-lymphocytes:

1) T helper cells (Th)
2) Cytotoxic T lymphocytes (CTL)

51

Which type of B-lymphocyte produces antibodies against an antigenic stimulus?

Plasma cells

52

What is the difference between the antigen receptors expressed by B and T lymphocytes?

B cell antigen receptor is MEMBRANE BOUND
T cell antigen receptor is not, is a DISTINCT MOLECULE

53

How many different antigen receptors are expressed by one lymphocyte?

One, they are very specific

54

What are the 3 ways in which antibodies protect the host from infection?

1) Prevent bacterial adherence to epithelial cell
2) Opsonisation, promoting phagocytosis
3) Activates the complement system

55

What prevents our normal gut microflora from entering our epithelial cells?

Antibodies (IgA) cover the bacteria preventing bacterial adherence to epithelial cells

56

Why does adaptive immunity take time to become effective (compared to the almost immediate innate immunity)?

Adaptive immunity requires clonal selection and expansion of the lymphocytes, which must then differentiate into effector cells.