Intro to Immunology

Question 1

What are the 3 main compartments of the immune system?

Answer 1

Physical barriers
Innate immune system
Adaptive immune system

Question 2

What are the innate immune cells?

Answer 2

Mast cells 
NK cells
Basophils, neutrophils, eosinophils, monocytes
Macrophages
Dendritic cells

Question 3

Name 4 differences between innate and adaptive immune system?

Answer 3

Adaptive - more specific, takes longer, good memory, cell-mediated
Innate - faster, present at birth, no memory

Question 4

What physical/chemical barriers exist in the respiratory tract?

Answer 4

Mucous + mucociliary escalator
Alveolar surfactant
Epithelial cells as barrier
Nose hairs
Enzymes in mucous

Question 5

Which innate immune cells are present in tissues?

Answer 5

Macrophages
Dendritic cells
Mast cells

Question 6

What are the innate cells?

Answer 6

NK cells
Dendritic cells
Macrophages
Basophils
Eosinophils 
Neutrophils

Question 7

Monocytes form what cells?

Answer 7

Macrophage

Dendritic cells

Question 8

How do tissue cells recognise foreign substances?

Answer 8

Antigen receptor sites

Question 9

How do macrophages signal the presence of foreign substances?

Answer 9

Cytokines

Question 10

Give 3 functions of the innate immune system?

Answer 10

Inflammation
Recruit other cells
Activate complement
Phagocytosis
Opsonisation

Question 11

What is required to help bind immune cells to an infected site?

Answer 11

Adhesion molecules to allow ‘sticking’ to the endothelium

Question 12

Why do macrophages find it difficult to consume mycobacterium?

Answer 12

Waxy coat

Catalase enzyme

Question 13

What is the signalling role of macrophages and dendritic cells?

Answer 13

Antigen presentation with MHC 1 and 2 to T cells

Question 14

What are antibodies made of?

Answer 14

Glycoproteins

Question 15

What is an antigen?

Answer 15

Molecule capable of inducing an immune response

Question 16

What produces antibodies?

Answer 16

B lymphocytes

Question 17

Where is MHC I located?

Answer 17

All nucleated cells and platelets

Question 18

MHC II presents to what?

Answer 18

CD4 cells

Question 19

Where is MHC II located?

Answer 19

ONLY antigen presenting cells

Question 20

MHC I presents to what

Answer 20

CD8 cells

Question 21

Where do T cells mature?

Answer 21

Thymus

Question 22

CD4+ T cells to proliferate into what in exposure to MHC II?

Answer 22

Helper T cells

Question 23

CD8+ T cells to proliferate into what in exposure to MHC I?

Answer 23

Cytotoxic T cells

Question 24

What is required for response by CD4+ T cells?

Answer 24

MHC Class II

Question 25

What are the key cells of the adaptive immune system?

Answer 25

B and T cells

Question 26

How do Dendritic cells function?

Answer 26

Sentinel - activate adaptive immune system Internalise pathogen, break it down into peptides Presents peptides (antibodies) Activates naive T cells

Question 27

Th1 cells signal with which cytokine?

Answer 27

Interferon gamma (y)

Question 28

Th2 cells signal with which cytokine?

Answer 28

IL-4,5,13

Question 29

Th17 cells signal with which cytokine?

Answer 29

IL-17, 22

Question 30

What is the role of Th1 cells?

Answer 30

Activate macrophage Produce IgG Fight intracellular microbes Autoimmune disease

Question 31

What is the role of Th2 cells?

Answer 31

Activate mast cells, eosinophils Produce IgE Parasites Allergies

Question 32

What is the role of Th17 cells?

Answer 32

Neutrophilic/monocytic inflammation Extracellular bacteria, fungi Autoimmune inflammation

Question 33

How do T helper cells facilitate activation of other immune cells?

Answer 33

Cytokines

Question 34

When are cytokines produced?

Answer 34

Normally | In response to microbes or tissue damage

Question 35

What produces cytokines?

Answer 35

T (helper) cells | Macrophages

Question 36

How to CD4 cells help naive CD8 cells?

Answer 36

CD4 aids in response to peptides presented with MHC I

Question 37

How do CD8+ (cytotoxic) T cells kill target cells?

Answer 37

Perforin - puncture cells | Granzyme - induces apoptosis

Question 38

What are the main cells of direct killing of pathogens?

Answer 38

Cytotoxic (CD8+) T cells | NK cells

Question 39

What is the role of NK cells in preventing cancer?

Answer 39

Cancer decreases MHC I expression NK cells will bind to cells with low MHC I expression and release Perforin and Granzyme Trigger apoptosis

Question 40

What is the result of B cell activation?

Answer 40

Antibody secretion

Question 41

What does the fab portion of an antibody do?

Answer 41

Variable - binds to particular antigen

Question 42

What does the Fc portion fo an antibody do?

Answer 42

Bind to Fc receptors on normal cells (to fix)

Question 43

What are the Ig classes? What structure do they form?

Answer 43

``` IgM (Pentamer) IgG IgA (Dimer) IgE IgD (Rest monomer) ```

Question 44

What is unique about IgM?

Answer 44

Pentamer | Best at activating complement

Question 45

What is unique about IgG?

Answer 45

Can cross placenta

Question 46

What is unique about IgA?

Answer 46

Dimer | Contained in secretions

Question 47

What is unique about IgE?

Answer 47

Role in parasitic infections and allergies

Question 48

When are IgM produced?

Answer 48

As fetus

Question 49

When are IgA produced?

Answer 49

Breast milk consumption | At 1-2 months post birth

Question 50

How do B cells respond to infection??

Answer 50

Can present antigens Cytokine production B memory cells Plasma cell formation - antibodies

Question 51

What are the functions of antibodies?

Answer 51

``` Neutralisation Opsonisation and phagocytosis Complement activation Inflammation Antibody dependent cellular cytotoxicity (NK cells) ```

Question 52

How does antibody mediated immunity vary with time/exposure?

Answer 52

First response - Large IgM response then moderate IgG | Second response - small IgM response then huge IgG response

Question 53

What is Opsonisation?

Answer 53

Reduce repellent negative charge of cell | Increases binding sites

Question 54

What are the main opsonins?

Answer 54

Complement C3b, C4b Antibodies plasma proteins

Question 55

What are the stages of complement activation?

Answer 55

1. Chemotaxis (phagocytes to inflammation site) 2. Opsonisation 3. Lysis 4. Maintain Complex solubility