5 Immunopathology

Question 1

What are the general principles of the immune response? (7).

Answer 1

Multilayer. 
Network of pattern recognition.
Communication.
Multiple mechanisms.
Adaptive response.
Self-regulation.
Limitation of host damage.

Question 2

What are the major components of the innate immune system? (5).

Answer 2

Pattern recognition receptors.
Antimicrobial peptides.
Cells.
Complement components.
Cytokines.

Question 3

What do pattern recognition receptors recognise?

Answer 3

Pathogen associated molecular patterns (PAMPs) and Danger associated molecular patterns (DAMPs).

Question 4

What are the two groups of PRRs?

Answer 4

Cell surface and intracellular receptors.

Fluid-phase soluble molecules.

Question 5

What are TLR’s and what do they do?

Answer 5

Toll-like receptors.

Transmembrane proteins that trigger cytokine synthesis and secretion.

Question 6

What are NLRs and RLRs and what do they do?

Answer 6

Nod-like receptors, Rig-like receptors.

Regulate inflammatory/apoptotic response.

Question 7

What are CLR’s? 3 examples.

Answer 7

C-type lectin receptors. Fluid phase molecules.
Mannan-binding Lectin.
Surfactant protein A and D.

Question 8

What do CLRs do?

Answer 8

Recognise microbial carbohydrates and bind to Carbohydrate-Recognition Domains.
Role in neutralisation of pathogens and recruitment of adaptive response.

Question 9

Give some examples of antimicrobial peptides: (7).

Answer 9

Defensives. 
Cathelin.
Protegrin.
Granulsyin.
Histamine.
Secretory leukoprotease inhibitor.
Probiotics.

Question 10

What does IL1 do? (innate) (3).

Answer 10

Increases coagulation and inflammation.
Increases acute phase protein production by hepatocytes.
Tells hypothalamus to induce fever.

Question 11

What does TNF do? (innate) (4)

Answer 11

Increases coagulation and inflammation.
Increases acute phase protein production by hepatocytes.
Tells hypothalamus to induce fever.
Increases activation of neutrophils.

Question 12

What does IL6 do? (innate) (2).

Answer 12

Increases proliferation of B lymphocytes.

Increases production of acute phase proteins by hepatocytes.

Question 13

What does IL23 do? (innate)

Answer 13

Increases IL17 production by T lymphocytes.

Question 14

How are epithelial cells involved in innate immunity?

Answer 14

Produce anti-microbial peptides - e.g. lung epithelial cells produce surfactant proteins that bind and promote clearance of invading lung microbes.

Question 15

What is the central feature of the adaptive immune system?

Answer 15

Unique antigen receptors on each lymphocyte that can trigger clonal expansion. Allows high specificity.

Question 16

What are the primary lymphoid organs and what do they do?

Answer 16

Bone marrow. Thymus.

Lymphocyte development and selection.

Question 17

What are secondary lymphoid organs? (3).

Answer 17

White pulp of spleen.
Lymph noes.
Mucosal surfaces.

Question 18

What is the range of antigenic variability? How many genes do we contain? How is this limitation overcome?

Answer 18

10 to the 9
30,000
V(D)J recombination.

Question 19

What is the structure of T and B cell receptors?

Answer 19

Two heavy chains linked by disulphide bridges with a light chain either side. Variable regions are on the end of the Y, constant at the base. Fab and Fc regions.

Question 20

Describe the mechanism of antigen presentation

Answer 20

Antigens are internalised, broken down to peptides, associated with Class 2 molecules, brought to cell surface. If they are foreign, helper T cells recognise them and produce cytokines.

Question 21

What are histocompatibility antigens also known as? Which genes are they coded by?

Answer 21

Human leukocyte antigens.

MHC.

Question 22

Name the three types of Class 1 HLAs.

Answer 22

HLA-A
HLA-B
HLA-C

Question 23

Name the three types of Class 2 HLAs.

Answer 23

HLA-DP
HLA-DQ
HLA-DR

Question 24

What are the functions of MHC proteins.

Answer 24

Present antigenic peptides to T cells.
MCH Class 1 to cytotoxic T cells
MHC Class 2 to helper T cells

Question 25

What are the functions of the different types of lymphocytes?

Answer 25

Tk: cellular immunity. Kill.
Th: secrete cytokines which control response.
Suppressor: dampen down immune response

Question 26

How does binding of antibodies to antigens inactivate them?

Answer 26

Neutralisation (blocks binding site). Agglutination. Precipitation of dissolved antigens. ALL enhance phagocytosis.

Activation of complement system.

Question 27

How do cytotoxic T cells work?

Answer 27

Binds to infected cell. Perforin enzyme allows entrance of apoptosis promoting enzymes into the infected cell.

Question 28

What does Th1 response favour? (3).

Answer 28

Cytotoxic activation.
B cell IgG opsonisation for phagocytosis.
Macrophage activation.

Question 29

What does a Th2 response favour? (3).

Answer 29

Eosinophil activation to kill parasites.
Mast cell and basophil activation to regulate vascular permeability.
B cell immunoglobulin production for direct antibody killing and opsonisation.

Question 30

What does IL4 do? (adaptive) (4).

Answer 30

Increases IgE response.
Th2 proliferation.
Decrease macrophage response.
Increase mast cell proliferation.

Question 31

What does IL5 do? (adaptive) (2).

Answer 31

Increase IgA response.

Increase eosinophil activation and proliferation.

Question 32

What does IL17 do? (adaptive) (3).

Answer 32

Increase chemokine production by endothelia.
Increase macrophage production of cytokines.
Increase G-CSF and GM-CSF.

Question 33

Define immunosuppression.

Answer 33

A natural or artificial process that turns off the immune response.

Question 34

Define immunodeficiency.

Answer 34

Lack of an efficient immune system.

Question 35

Without an inflammatory response you are more susceptible to: (2)

Answer 35

Pneumococcus.

HSV.

Question 36

Without macrophages/neutrophils, you are more susceptible to: (3)

Answer 36

CGD.
Staphylococcus.
Aspergillus.

Question 37

Without T cells (SCID) you are more susceptible to:

Answer 37

Opportunistic infections.

Question 38

Without complement you are more susceptible to:

Answer 38

Meningococcus.

Question 39

Without TNF or IL-1 you are more susceptible to:

Answer 39

Mycobacterium.

Question 40

Without B cells you are more susceptible to:

Answer 40

Recurrent sino-pulmonary infections.