A Brief Introduction To Immunology And Adaptive Immunity - 13/11

Question 1

Define innate immunity

Answer 1

Instinctive, non specific, does not depend on lymphocytes, present from birth

Question 2

Define adaptive immunity

Answer 2

Specific ‘acquired/learned’ immunity, requires lymphocytes, antibodies

Question 3

What are both innate and adaptive immunity made up of?

Answer 3

Cells and soluble factors (humoural)

Question 4

What layers are present in centrifuged blood?

Answer 4

Upper layer - plasma ( water 90%, electrolytes, proteins, lipids, sugars etc)

Middle layer - white fluffy layer, buddy cost - leukocytes

Lower layer 45% - erythrocytes, platelets (haematocrit)

Question 5

Define haematopoesis

Answer 5

“The commitment and differentiation processes that leads to the formation of all blood cells from pluripotent haematopoietic stem cells.”

Question 6

Name 3 polymorphonuclear leukocytes

Answer 6

Neutrophil
Eosinophil
Basophil

Question 7

Name 3 mononuclear leukocytes

Answer 7

Monocytes, t-cells, b-cells

Question 8

When monocytes exit blood stream and enter tissues what does it change into?

Answer 8

Macrophage

Question 9

When T cells differentiate what 3 cells can they change into?

Answer 9

T-regs
T-helper (CD4) (Th1 &Th2)
Cytotoxic (CD8)

Question 10

Name 5 cells of the immune system

Answer 10

Mast cell
Natural killer cells
Dendritic cells - skin
Kupffer cells - liver
Langerhans - skin

Question 11

What are 3 main groups of soluble factors?

Answer 11

Complement
Antibodies
Cytokines, chemokines

Question 12

Define complement soluble factors?

Answer 12

Group of ~20 serum proteins secreted by the liver that need to be activated to be functional.

Complement is activated only as part of the immune response.

Question 13

What are the 3 main modes of action of complement soluble factors?

Answer 13

Direct lysis

Attract more Leukocytes to site of infection

Coat invading organisms

Question 14

Define antibodies soluble factors?

Answer 14

Bind specifically to antigens (Ag)

Question 15

What are Igs? And features

Answer 15

Immunoglobulin,

soluble
- secreted
- bound to B cells as part of B-cell antigen receptor

Question 16

What are the 5classes of Igs

Answer 16

IgG (1-4)
IgA (IgA1 & 2)
IgM
IgD
IgE

Question 17

What are Igs made of?

Answer 17

Glycoproteins

Question 18

Structure of IgG

Answer 18

Y shape - fab ends and Fc ends (15th slide)

Question 19

Where is IgM mainly found? Why?

Answer 19

Blood - too large to cross endothelium

Question 20

Which have initial contact and primary immune response?

Answer 20

IgM and Ag

Question 21

What is mIgM

Answer 21

Monomeric form of IgM present as antigen-specific receptor on b-cells

Question 22

IgA

Answer 22

Slide 18

Question 23

IgD

Answer 23

Slide 19

Question 24

IgE

Answer 24

Slide 20

Question 25

Antibodies

Answer 25

Slide 21

Question 26

Define cytokines

Answer 26

Proteins secret3d by immune and non-immune cells

Question 27

What is interferons (IFN)

Answer 27

induce a state of antiviral resistance in uninfected cells & limit he spread of viral infection IFNa & b - produced by virus infected cells IFNg - released by activated Th1 cells

Question 28

What is interleukins (IL)

Answer 28

produced by many cells, over 30 types Can be pro-inflammatory (IL1) or anti-inflammatory (IL-10) Can cause cells to divide, to differentiate and to secrete factors

Question 29

What are colony stimulating factors (CSF)

Answer 29

Involved in directing the division and differentiation on bone marrow stem cells – precursors of leukocytes

Question 30

What is tumour necrosis factors (TNFalpha and beta)

Answer 30

Mediates inflammation and cytotoxic reactions

Question 31

Define chemokines

Answer 31

Group of approx 40 proteins that direct movement of leukocytes (and other cells) from the bloodstream into the tissues or lymph organs by binding to specific receptors on cells

Question 32

What are 4 different types of chemokines?

Answer 32

CXCL CCL CX3CL XCL

Question 33

What are CXCL

Answer 33

Mainly neutrophils

Question 34

What are CCL.

Answer 34

Monocytes, lymphocytes, eosinophils, basophils

Question 35

What are CX3CL

Answer 35

Mainly t lymphocytes and NK cells

Question 36

What are XCL

Answer 36

Mainly t lymphocytes

Question 37

What are 2 defence mechanisms?

Answer 37

Innate and adaptive

Question 38

Features of innate immunity

Answer 38

1st line of defence Provides barrier to antigen Instinctive Present from birth Slow response No memory

Question 39

Features of adaptive immunity

Answer 39

Response specific to antigen Learnt behaviour Memory to specific antigen Quicker response

Question 40

What is the innate immunity composed of?

Answer 40

Physical and chemical barriers Phagocytic cells (neutrophils and macrophages) Blood proteins (complement, acute phase)

Question 41

Name some physical barriers in innate immunity?

Answer 41

Mucus and cilia in bronchi, physical barrier of skin, lysozyme in tears, flushing of urinary tract

Question 42

What happens when physical barriers are breached? Eg. Cut

Answer 42

Inflammatory response

Question 43

General stages of inflammatory response

Answer 43

Stop bleeding (coagulation) Acute inflammation (leukocyte recruitment) Kill pathogens, neutralise toxins, limit pathogen spread Clear pathogens/dead cells (phagocytosis) Proliferation of cells to repair damage Remove blood clot – remodel extracellular matrix Re-establish normal structure/function of tissue

Question 44

Define inflammation

Answer 44

‘A series of reactions that brings cells and molecules of the immune system to sites of infection or damage’.

Question 45

What are 2 types of inflammation?

Answer 45

Acute and chronic

Question 46

What are hallmarks of inflammation?

Answer 46

Increased blood supply Increased vascular permeability Increased leukocyte transendothelial migration ‘extravasation’

Question 47

Define acute inflammation

Answer 47

Complete elimination of a pathogen followed by resolution of damage, disappearance of leukocytes and full regeneration of tissue

Question 48

Loosely define chronic inflammation

Answer 48

Persistent, un-resolved inflammation

Question 49

What are the 2 sensing microbes found on blood?

Answer 49

Monocytes and neutrophils

Question 50

What are the 2 sensing microbes found in tissues?

Answer 50

Macrophages and dendritic cells

Question 51

What receptors are found on cells?

Answer 51

PRR (pattern recognition receptors)

Question 52

What receptors are found on microbes?

Answer 52

PAMP (pathogen associated molecular patterns)

Question 53

What are the haemotractants o that bind to receptors on leukocytes in complement process

Answer 53

C3a and C5a

Question 54

What are the receptors that insert onto bacterial membrane in complement process

Answer 54

C3b

Question 55

What lyses microbes directly in complement process

Answer 55

MAC

Question 56

What happens after extravasion of neutrophils towards sight of infection?

Answer 56

Phagocytosis

Question 57

What are the 5 stages of phagocytosis?

Answer 57

1. Binding to antigen on surface 2. Engulfment 3. Phagosome formation 4. Phagolysosome 5. Membrane disruption/fusion See slide 42

Question 58

What are 2 mechanisms of microbial killing present in neutrophils and macrophages?

Answer 58

O2-dependant (Reacticve oxygen intermediates (roi) —> superoxides and nitric oxides O2-independent (enzymes e.g. lysozyme, proteins e.g. defensive, TNF and pH)

Question 59

Where are primary and secondary lymphoid of t and b cells

Answer 59

See slide 50

Question 60

Which immunity type (cell mediated or humoural) requires intimate cell to cell contact?

Answer 60

Cell mediated

Question 61

Which cells do not respond to soluble antigens.

Answer 61

T lymphocytes, they only respond to intracellular presented antigens

Question 62

T cells that recognise self cells are killed where?

Answer 62

In foetal thymus

Question 63

What do major histocompatibility complex (MHC) display?

Answer 63

Self or non self proteins

Question 64

What are the two types of major histocompatibility complex (MHC)?

Answer 64

MHC 1 MHC2

Question 65

What is MHC 1 DO?

Answer 65

coded by HLA (A, B & C genes) - glycoproteins on ALL nucleated cells (graft rejection).

Question 66

What does MHC 2 DO?

Answer 66

coded by HLA (DP, DQ& DR) - glycoproteins ONLY on APC.

Question 67

Slide 58

Question 68

Slide 61&62&63&65

Question 69

B cells that recognise self are killed where?

Answer 69

Bone marrow