Immunology Exam Questions

Front 1

1. What are the properties of B and T cell epitopes?

Back 1

B cell:

1. proteins > carbohydrates > fat
2. linear, conformational and discontinuous
3. combine directly with Ab 6-8 amino acids long
4. usually hydrophilic

T cell epitopes
1. Protein
2. conformational or linear (ie: not discontinuous)
3. MHC 1: 9 amino acids long, positions 2 and 9 critical
4. MHC II: 12-15 aa long
5. only recognised when presented on MHC molecules
6. often amphipathic helix

Front 2

2. Compare and contrast primary and secondary immune responses.

Back 2

PRIMARY INFECTION
- Long period to Ab production 7-10 days
- high IgM titre
- low IgG titre
- low affinity Ab

SECONDARY INFECTION
- Shorter period to infection 2-4 days
- Low IgM titre
- High IgG
- High Ab affinity

Front 3

3. what are the criteria for a recent infection?

Back 3

1. Detection of infection consistent with symptoms
2. 4x or greater rise in Ab titre in paired sera collected 7-10 days apart and tested in parallel
3. Detection of IgM Ab compatible with symptoms and collected within 4 weeks of onset of symptoms

Front 4

What are five groups of agents that cause infectious disease?

Back 4

Virus, bacteria, parasite, fungi, helminths, protozoa

Front 5

Give an example of a bacteria species.

Back 5

Streptococcos pyrogenes

Front 6

Give an example of a virus.

Back 6

Epstein Barr Virus

Front 7

Give an example of a parasite

Back 7

Malaria

Front 8

What protects you from infectious disease? Give examples of physical barriers:

Back 8

PHYSICAL BARRIER, Mechanical, Chemical, Biological
• Skin
• Cilia, coughing, sneezing
• Mucous secretions
• Inner surfaces of respiratory, digestive, reproductive tracts
• Flushing of surfaces
• Commensal bacteria
• pH

Front 9

Describe the innate immune system

Back 9

• Rapid, non-specific response to infectious threat
• Recognition by pre-formed, broadly specific effectors
• May be associated with inflammation

Front 10

Give examples of innate immunity effectors - which activities are performed by these effectors

Back 10

Phagocytosis:
1.tissue macrophages, neutrophils (PMNs)
2. Antimicrobials, microbicidals
3. Complement
4. Natural Killer cells

Front 11

Describe the components of the immune system

Back 11

- All white blood cells originate from the pluropotential haemopoetic stem cell (HSC).
1. immunological cells are split in to myeloid cells and lymphocytes.
Myeloid cells: neutrophils, eosinophils, basophils, monocytes, macrophages (granulocytes)
Lymphocytes: B cells, T cells, NK cells

Front 12

Know the location of immunological tissue around the body

Back 12

1':
Bone marrow (all cells)
Thymus (T cells)
2':
Lymph nodes
Spleen
Mucosal associated lymphoid tissue
- Tonsils
- Adenoids
- Bronchus
- Lymphoid nodules
- Peyer's Patch

Front 13

What kinds of cells are involved in immunological
responses? (Initial immune response)

Back 13

Innate:
- macrophage recognition
- recognition of PAMPs
- recognised by PRRs and TLRs
- Phagocytosis --> initiation of inflammatory response
- cytokine secretion
- Complement initiation
- activation of adaptive immune response.

Adaptive

Front 14

Where are these cells located/found?

Back 14

All immunological cells originally arise in the bone marrow
from a pluripotential haemopoietic stem cell (HSC), then circulate in the blood and are recruited to tissue sites of injury

Front 15

What are their basic functions of:
1. neutrophils
2. eosinophil
3. basophil
4. lymphocyte
5. monocyte

Back 15

1. phagocytosis, degranulation and NETosis
2. helminth and asthma, secrete cytokines
3. histmamine & allergy
4. NK (innate) --> virus and tumours
5. B cells --> Ab production
6. T cells --> cell mediation (adaptive)

Front 16

Define antigen

Back 16

Any substance that can bind to a specific antibody (antibodygenerator) / molecules that are specifically recognised by antigen receptors of either B cells or T cells

Front 17

Define immunogen

Back 17

Any substance that can elicit an immune response

Front 18

Define epitope

Back 18

Site on the antigen where the antibody binds or recognises. T cell will recognise a protein, this short protein molecule will bind to an MHC molecule and is recognised by a T cell. B cell epitopes are recnogised directly and are structural motifs on the antigen

Front 19

Define hapten

Back 19

a small molecule that can only elicit an immune response when bound to a larger carrier molecule

Front 20

Define innate immunity

Back 20

also known as non-specific immune system and first line of defense,[1] comprises the cells and mechanisms that defend the host from infection by other organisms in a non-specific manner. This means that the cells of the innate system recognize and respond to pathogens in a generic way, but unlike the adaptive immune system (which is only found in vertebrates), it does not confer long-lasting or protective immunity to the host.

Front 21

Define adaptive immunity

Back 21

pathogen-specific receptors are "acquired" during the lifetime of the organism (whereas in innate immunity pathogen-specific receptors are already encoded in the germline)... The acquired response is said to be "adaptive" because it prepares the body's immune system for future challenges (though it can actually also be maladaptive when it results in autoimmunity)

Front 22

Define chemotaxis

Back 22

attraction and movement to site of injury

Front 23

Innate and adaptive immune responses depend on the
activities of ________________

Back 23

leucocytes

Front 24

What are the adaptive immunity receptor characteristics?

Back 24

1. encoded multiple gene segments
2. gene arrangement (required)
3. clonal distribution
4. ability to discriminate between even closely related molecular structures

Front 25

What ability does innate immnuity have?

Back 25

distinguish self from non self

Front 26

What are the receptor characteristics of innate immunity?

Back 26

1. specifically inherited in the genome
2. expressed by all cells of a particular type
3. triggers an immediate response
4. recognises a broad class of pathogens
5. interacts with a range of molecular structures of a given type

Front 27

How fast is the onset of innate immunity?

Back 27

0-4 hours

Front 28

what are the recognition agents in innate immunity?

Back 28

preformed, already circulating non specific and broadly specific effectors

Front 29

Describe the events of innate immune response

Back 29

- 0-4 hours a response is mounted by preformed, non specific or broadly specific effectors

Front 30

How fast is a response mounted by 'early induced innate response' ?

Back 30

4-96 hours

Front 31

What is the 'early induced innate response'?

Back 31

- activation in 4 - 96 hours
- recognition of microbial -associated molecular patterns
- inflammation and recruitment and activation of effector cells

Front 32

How long does it take for an adaptive immune response?

Back 32

more than 96 hours

Front 33

What is requires in an adaptive immune response?

Back 33

- transport of antigen to lymphoid organs
- recognition by naive B and T cells
- clonal expansion and differentiation to effector cells

Front 34

What would happen if there was no adaptive immunity?

Back 34

- immunodeficiency diseases
- death occurs in infancy due to overwhelming infection
- recurrent infections
- no response to innocuous substances
- vaccines no use

Front 35

Describe the stages of an infection and response in a skin wound

Back 35

1. Infectious agent must adhere to the epithelial cells
2. Local immune response, local healing induced by complement, phagocytes to destroy microorganisms
3*. Local infection of tissues delivers infectious agent to lymph node which initiates immune response.
4. Infection cleared by antibody, T cell macrophages anctivation and cytotoxic t cells.

Front 36

Where do immunological cells arise?

Back 36

• All immunological cells originally arise in the bone marrow from a pluripotential haemopoietic stem cell (HSC)

Front 37

What are the two types of immunological cells?

Back 37

- myeloid
- lymphoid

Front 38

What are exampled of myeloid cells?

Back 38

- granulocytes
- macrophages

Front 39

Describe lymphocyte

Back 39

Leucocyte in highest
concentration in blood.
Lifespan 6-8hrs.
Can move into tissues following
a chemotactic gradient.
Anti-microbial strategies:
- Phagocytosis
- Degranulation
- NETosis

Front 40

What is netosis?

Back 40

Release of net web-like structures called neutrophil extracellular traps which trap and kill microbes. this is used in tandem with degranulation and phagocytosis

Front 41

Describe the roles of the eosinophil

Back 41

Multi-functional.
Mainly respond to helminth infections and asthma.
Recruited to inflammatory area.
Secrete many inflammatory cytokines

Front 42

Describe the basophil

Back 42

- <1% of PB leucocytes.
- Express IgE receptor
- Release histamine in response to allergy,
- IL-4: ?mediate Th2-type immune response

Front 43

Describe the lymphocyte

Back 43

1. Natural killer (NK) cells (innate immunity)
2. Kill virus-infected and tumour cells (intracellular)
2. B cells antibody production
3. T cells cell mediation
(both participate in adaptive immunity)

Front 44

Describe the monocyte

Back 44

Mature to macrophages 
migrate to tissues
Phagocytic function

Front 45

What are the roles of B cells?

Back 45

B cells:
• Humoral immunity
• Antibody production
• Act against extra-cellular pathogens

Front 46

What are the roles of T cells?

Back 46

• Cell-mediated immunity
• Cellular immune response to intra-cellular pathogens eg viruses
• Regulation of B cell responses
• CD4 and CD8 major sub-types

Front 47

What is the function of NK cells?

Back 47

 recognise abnormal cell proteins  cell death

Front 48

What are the types of lymphocytes?

Back 48

- B cells
- T cells
- NK cells

Front 49

What is Leucocytosis?

Back 49

increase in WBCs stimulated by release of inducingfactors from injured cells

Front 50

What is Margination/tethering/adhesion?

Back 50

• injured cells display cell adhesion molecules (CAMs) that adhere the phagocytes to the endothelial capillary wall

Front 51

What is diapedesis?

Back 51

phagocytes pass through capillary wall

Front 52

What is chemotaxis?

Back 52

attraction and movement to site of injury

Front 53

Describe the mobilisation of leukocytes

Back 53

• Leucocytosis
• increase in WBCs stimulated by release of inducingfactors from injured cells
• Margination/tethering/adhesion
• injured cells display cell adhesion molecules (CAMs) that
adhere the phagocytes to the endothelial capillary wall
• Diapedesis
• phagocytes pass through capillary wall
• Chemotaxis
• attraction and movement to site of injury

Front 54

What is the main determinant in neutrophil migration?

Back 54

chemotactic gradient of IL8

Front 55

Describe the roles of macrophages

Back 55

Forms the mononuclear phagocyte
system
• Phagocytosis
• May act as antigen-presenting cell
(APC)

Front 56

Describe the roles of mast cells?

Back 56

Release granule contents upon
activation
• Histamine ( vasoactivity)

Front 57

Describe the roles of dendritic cells

Back 57

Phagocyte
• Professional antigen-presenting
cell (APC)
•  activation of T cells

Front 58

What are the types of dendritic cells?

Back 58

- Classical dendritic cells
- Langerhans cells
- Plasmacytoid dendritic cells
- follicular dendritic cells

Front 59

What are factors which increase immunogenicity of proteins?

Back 59

1- larger the protein the more the immune response
2- intermediate dose
3- subcutaneous is more immunogenic than intraperitoneal, intravenous/intragastric
4- complex composition
5- particulate as opposed to a soluble form
6- denatured as opposed to a native protein
7- very different from self protein
8- slow release adjuvants (pref. bacteria)
9- effective MHC interaction

Front 60

Explain the roles of antibodies in immunity

Back 60

Principal functions:
• 1) recognise and bind to extracellular foreign antigen
• 2) recruitment and activation of ‘effector molecules’ to
eliminate antibody-coated foreign material

Front 61

Name each of the antibody classes and their role in immunity

Back 61

6

Front 62

Draw a diagram of each of the antibody classes and be able to
identify:
• The heavy and light chains
• Domains
• Hinge region
• Presence of J chain

Back 62

6

Front 63

Know the relative concentrations of the Ig classes in serum and secretions

Back 63

6

Front 64

Explain how antibodies attach to antigens and Fc receptors

Back 64

6

Front 65

What role do antibodies and Fc receptors play in immunity?

Back 65

6

Front 66

Where are the primary immunological tissues in the body?

Back 66

6

Front 67

Where are the secondary immunological tissues in the body?

Back 67

6

Front 68

Describe how antigen-antibody connections form

Back 68

6

Front 69

Describe an illustrate the basic types of antigen-antibody reactions that are employed in a laboratory

Back 69

6