Past Questions Flashcards
What properties are NOT necessary in monoclonal Ab producing cell cutures?
Missing phosphoribosyl phosphate.
What type of T cell R can be found most frequently?
Alpha/ß.
It is not presented on CD1
Polysaccharide.
What is NOT stimulated by interferons in the cells infected with viruses?
Lipase activity.
What kind of cells do NOT express tumour necrosis factor R on their membrane?
Erythrocytes.
Which Vit increases the production of IL-2?
E.
What biological activities are NOT featuring the complement system?
Labelling of cells + Ag presentation.
What is needed for the activation of complement system through the classical pathway?
Connection between ag + IgG.
What is needed for the activation of the complement system through the lectin pathway?
Bacterial CH.
What are the features of the pathogen-associated molecular patterns (PAMP)?
Inherited, immediate effect, ø memory, broad recognition spectrum.
Blocks the activity of B cells
Presence of too many Ig.
The intestinal flora is treated by the immune system as
Immunologically own.
What can be the reason for the development of natural autoimmunity?
has to recognize phylogenetically conserved molecules + do ø react to them.
The high demand for organs in huma transplantation is sated by:
The use of organs from transgenic mini Sus.
What is the function of monoclonal Ab in immunology?
Diagnostics of autoimmune diseases.
In serological reactions to detect Ab we have to use
Specific, standardised Ag.
What do we want to detect in Ascoli test?
Heat-stable cell wall Ag of Bacillus Anthracis.
What makes the Ag-Ab reaction visible in the complement fixation assay?
RBC.
What kind of conjugate is needed in indirect ELISA?
Ab specific AB labelled with enzyme.
During the separation of proteins (PAGE), what can be the SDs used for?
Linearises the proteins + gives them a -ve charge.
The macrophage migration inhibition test is +ve, if in the presence of Ag
Ly are activated + inhibit the emigration of macrophages from the well made in the middle of agar gel.
What is the hapten?
An Ag that is ø immunogenic, but can be immunogenic if attached to a carrier molecule.
What features describe the best immunogen?
Big sized glycosylated protein with a lot of epitopes.
What are the features of the IgG molecule?
The IgG molecule has a size of 160kDa, a gamma type heavy chain, it is bivalent + has the longest lifespan among Ig with a 1/2-life of 10- 20 days, it is able to leave the BV to get into tissues but cannot keep pathogens from entering.
What are the features of the IgA molecule?
Flexible because of the J chain, important on mucous membranes, usually monomer in the bloodstream.
What are the features of the class I MHC?
It presents endogenous Ag to CD8 + cytotoxic T cells.
What are the features of the class II MHC?
It presents endogenous Ag to CD4 + helper T cells.
What are the 2 signals needed to start the humoral immune response?
Ag presented by the B ly + cytokines preoduces by T helper cells.
Choose the correct order of steps in the cellular immune response.
Adhesion, reorganisation, attack, killing.
What type of Ig can go through placenta?
IgG.
What kind of immune response can be seen against viruses + why?
Both, because of cross-presentation.
The neutralisation effect of Ab is important against
Toxin producing bacteria.
Which one is the most important Ig against parasites?
IgE.
How many times can a heterologouc hyper-immune serum be given?
Repeatedly, if the Fc part is manipulated.
What type of vaccine is the BCG?
Live + attenuated.
What happened if we vaccinate an animal with a persistent infection?
There is ø immune response.
How much time is needed for the development of type IV hypersensitivity?
12- 72 hrs.
In pemphigus auto-recessive Ab are produced against
Desmosomes.
Characteristic clinical sign in systemic lupus erythematosus
Skin lesions.
What causes tissue damage in Chediak- Higashi syndrome?
Spontaneous rupture of vulnerable lysosomal membrane.
Viruses causing 2˚ immunodeficiency in cattle
Parainfluenza 3 virus, border disease virus, BO herpes virus.
What kind of conjugate can be used in rapid diagnostic tests?
Enzyme labelled Ab + Ag bound to coloured carrier.
What is NOT featuring the clone selection theory of Ag recognition?
The Ag based on it’s structuregives instructions to the appropriate cells to produce the proper Ab.
What is the anaphylactic reaction?
Systemic, life-threatening immediate hypersensitivity reaction.
Which chromosomes encode for BCR chains?
Kappa-chain.
Lamda chain.
Heavy chain.
- 6.
- 16.
- 12.
Order of heavy chain genes rearrangement:
D-J joining, VDJ joining, unwanted Xs J removal ( RNA splicing)–> VDJC.
What is the order of light chain genes rearrangement:
V-J joining, RNA splicing, VJC.
What is the consequesnces of the BCR genes rearrangement?
The higher organism produces a cell- population having a highly diverse durface R structure, BUT all mature B cells have only 1 type of R.
How is Fab part formed?
The final configuration of the Fab is formed only following the isotype switch + the pt mutations of the Fab coding V- genes helped by the cytokines secreted by helper cells.
When does isotype switching occurs?
Following B cell activation.
How does it happen?
Deletion of genes in different parts to create different Igs.
What are the paratopes made of ?
Sets of CD Rs.
What are CD Rs?
Complementary determinant regions.
Which CDRs are found on IgM + IgD?
CDR3.
How is CDR3 made?
By VDJ rearrangement.
How are CDR1 + 2 made?
generated by pt mutations after B cell activation, parallel with isotype switching, directed by TH cytokines.
What is the form of TCR?
Heterodimer, 1 const., 1 variable, made of a/b chains or g/l chains.
How many CDRs are on the TCR?
1.
How many gene families for TCR?
- 3.
- V (variable), D (diversity), J ( joining) + 1C (const.) gene for each isotype.
How are the genes rearranged?
By deletion, ø pt mutations after activation; ø isotype switching.
What gene families are responsible for alpha + gamma?
VJ gene families.
What gene families are responsible for ß + ∂ ?
VDJ.
Why is the alpha- ß heterodimer variability higher?
Because the immune system always tries first a gamma- ∂ chain combination, if this is ø successful, the ∂ genes are deleted, the gamma genes are suppressed.
What factors are responsible for Ab + TCR diversity?
- Multiple germline V genes. V-J + V-D-J reorganizations, inaccuracies of reorganization, N-region additions/ shortening, inter chain recombination, crossing over, pt mutations.
Potential number of variations?
- Ab: 10^16
- TCR: 10^9.
Characteristics of MHC polymorphism are:
Histocompatibility Ag characteristic of each individual, genes inherited in blocks, high level of polymorphism within a population.
What is the background for polymorphism?
Gene block exchange, recombination, crossing over, high mutation rate, mating preferences, selective abortion.
What is a unique feature about the expression of these genes?
MHC
Different 6 genes are expressed for each individual.
What happens if too many MHC genes are expressed?
-ve TCR selection.
What happens if ø enough MHC genes are expressed?
Increased susceptibility to infections.
What is the structure of MHCI?
Alpha chain (1-3) + ß chain (b2m).
Which cells express MHCI?
All nucleated cells ( ø RBCs), high levels on B + T cells, macrophages.
Where can we never find MHCI?
Endogenous Ag presentation to activate cellular immunity.
How many are needed from Ag fragment to be presented on MHCI?
- 4-8.
- 8-9.
What is the structure of MHCII?
Alpha 1-2, ß1-2.
What is the purpose of MHCII?
- Ag presentation, to activate TH cells.
- Thus permanently found on B cells, macrophages, dendritic cells.
- Induced ones are found on T cells, endothelial cells.
What does it present?
CD1
Ag lipid molecules.
What is it’s structure?
CD1
Similar to MHCI, heterodimer with ß2 microglobulin, binding site larger than in MHCI.
Where is it found?
CD1
Present on APC, B cells, intestinal ep., most actively on DC.
