Immuno CA test

Question 1

Helper T cells and Cytotoxic T cells are derived from which pluripotent cell found in the bone marrow?

Answer 1

Haematopoietic stem cell

Question 2

Q4. Opsonisation is the deposition of molecules on the surface of a cell, enhancing uptake by phagocytes
Name the 2 types of soluble host molecule involved in opsonisation

Answer 2

Complement (C3b) and antibody

Question 3

What does ITAM stand for?

Answer 3

ITAM (Immunoreceptor Tyrosine-Based Activating Motif)

Question 4

How might the extracellular domain of Toll-like receptors be modified to recognise different molecules?

Answer 4

By the insertion of amino acids and/or glycosylation

Question 5

What is the function of the MD-2 accessory factor?

Answer 5

To bind to lipid A of lipopolysaccharide

Question 6

Give an example of a toxoid vaccine

Answer 6

Tetanus, diphtheria, botulism, anthrax, necrotic enteritis, gas gangrene, or cholera

Question 7

In humans, what disease does HIV-1 cause

Answer 7

Acquired Immune Deficiency Syndrome

Question 8

Why is the HIV virus so devastating to the human immune system?

Answer 8

It is the only virus that infects cells of the immune system (specifically CD4 T cells)

Question 9

What is the name of the process whereby viruses exploit the tissue-specific receptors for host cell invasion.

Answer 9

Tissue tropism

Question 10

Role of antibodies in viral infections

Answer 10

Neutralisation

ADCC (NK cells)

Question 11

Name two opportunistic yeast pathogens of AIDS patients

Answer 11

Candida, Cryptococcus, Histoplasma

Question 12

Name an opportunistic mould pathogen of immunocompromised patients

Answer 12

Aspergillus, Mucor

Question 13

Pulmonary infections by moulds are typically found in patients with which type of cancer?

Answer 13

Haematological malignancies

Question 14

Which two types of immune cells are crucial for maintaining pulmonary immunity to fungal pathogens?

Answer 14

Macrophages and neutrophils

Question 15

What is a advantage of formaldehyde cross linking over genetic toxoids?

Answer 15

Formaldehyde cross linking produces a greater range of antibodies

Question 16

To which receptors on human respiratory epithelia does the influenza virus bind?

Answer 16

To those that have the α-2,6 sialic acid linkage to galactose

Question 17

Which cellular compartments does MHC2 class of molecule monitor for foreign antigen?

Answer 17

Compartments of the endosomal and lysosomal pathways

Question 18

At the molecular level how does formaldehyde cross linking occur?

Answer 18

It causes the formation of inter- and intra-molecular cross-links between amino groups in lysine and glutamine residues

Abolishes toxicity but retains immunnogenicity

Question 19

How are conjugate vaccines processed?

Answer 19

It is believed that the glycol-conjugate is internalized into an endosome of the B cell. It is processed into glycanP saccharides, peptides and glycanP-peptides.
5
There is MHCII presentation of glycanP-peptide to CD4+ T cells. Activation of the T cell by the carbohydrate/MHCII results in T-cell production of cytokines which mature the B cell to become a memory B cell.

Question 20

How can we get around the problem of a polysacharide vaccine?

Answer 20

Link to protein to create glyco conjugate

Question 21

What does the acronym ITAM stand for?

Answer 21

Immunoreceptor Tyrosine-based Activation Motif

Question 22

Name of enzymes which get activated upon binding to ITAM?

Answer 22

Src family tyrosine kinase

These have tandem SH2 (Src Homology 2) domains spaced at exactly the right distance apart to dock onto the two phosphotyrosines, and that activate signaling events downstream of the receptor

Question 23

Which immunoglobulin isotype accumulates in the foetus before birth?

Answer 23

IgG

Question 24

F(ab) vs F(ab)2?

Answer 24

F(ab) refers to just one F(ab) region whereas F(ab)2 refersto two joined together (i.e what you have in a normal complete antibody)

Question 25

What type of improved diphtheria vaccine has been devised?

Answer 25

A genetic toxoid, where a functionally critical amino acid is substituted to abolish toxicity

Question 26

``` Complement deficiencies? C1q C3 C5 C9 ```

Answer 26

C1q: meningitis and sepsis caused by Neisseria meningiditis C3: respiratory tract infections and meningitis caused by Neisseria meningiditis C5: meningitis and sepsis caused by Neisseria meningiditis C9: meningitis and sepsis caused by Neisseria meningiditis

Question 27

Hallmark of trypanosomes

Answer 27

Th1 cytokines + Macrophages

Question 28

What does MASP stand for?

Answer 28

Mannose binding lectin associated serine proteases

Question 29

Hallmark of T.brucei?

Answer 29

Macrophages

Question 30

What is cellular immunity?

Answer 30

Cellular immunity is a protective immune process that involves the activation of phagocytes, antigen-sensitized cytotoxic T cells and the release of cytokines and chemokines in response to antigen.

Question 31

Give the name of the progenitor cell that gives rise to the different lineages of cellular immunity, and its location in the body?

Answer 31

Pluripotent hematopoietic stem cell, in the bone marrow

Question 32

Give the name of a human protozoan parasite that expresses VSGs?

Answer 32

Trypanosome

Question 33

Give 2 examples of the ways in which vaccines can be devised which activate CD8+ T-cells

Answer 33

Using live attenuated microbes Using naked DNA Using dendritic cells exposed to antigen ex vivo

Question 34

What type of experiment can be carried out to prove that antibodies are able to protect against disease?

Answer 34

Passive transfer of sera from immunised to non-immune animals results in the transfer of protection

Question 35

How has diphtheria toxin been developed into a vaccine?

Answer 35

Mutation in the catalytic A-subunit blocks activity | glycine to glutamic acid substitution at residue 52

Question 36

) Provide the 2 possible molecular formulae for each of the three antibody structures shown in the diagram

Answer 36

gM: (µ2κ2)5 or (µ2λ2)5 IgG or IgA, IgE, IgD: e.g. (γ2κ2) or (γ2λ2) and (α2κ2) or (α2λ2) etc. IgA: (α2κ2)2 or (α2λ2)2

Question 37

what does ADCC and CMC stand for?

Answer 37

Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC) and Complement Mediated Cytotoxicity (CMC)

Question 38

Give two reasons why a mouse antibody must be humanised if it is to be used in humans? (

Answer 38

Human Anti-Mouse Antibody (HAMA) reactions and loss of effector functions if Fc domain is mouse

Question 39

Name 3 ligands bound by TLRs

Answer 39

CpG DNA, Lipid A (lipopolysaccharide), | dsRNA, ssRNA, peptidoglycan)

Question 40

Give 2 advantages and 2 disadvantages of hybridoma technology

Answer 40

Advantages: Ability to get high affinity monoclonal antibodies Ability to store and grow the hybridoma cells for “indefinite” mAb production Disadvantages: Dependence on chance: No control over antibodies formed Antibodies must be screened extensively to fish out desired one(s)

Question 41

define antigen

Answer 41

Any molecules or parts of molecules recognised by the variable antigen receptors of lymphocytes

Question 42

clonal delection vs clonal selection

Answer 42

clonal deletion: deletion of cells which bind to self antigens clonal selection: the whole process of VDJ recombination, clonal deletion, activation and clonal expansion