018 Humoral Immunity and antibody mediated responses Flashcards
Which are the largest immunoglobulins?
IgE and IgM (with CH2,3,4) parts of the constant heavy chain
Which part of the immunoglobin determines the antibody class?
Constant region
What is affinity?
The strength between antigen and antibody bond
What is avidity?
The capacity for the antibody to bind.
What are the 2 light chain isotopes?
kappa and lambda
Where do you find IgG?
In circulation as monomers
Where do you find IgA?
In circulation as monomer and mucosal surfaces as dimers
Where do you find IgD?
On naive BCR
Where do you find IgM?
On naive BCR and as pentamers in circulation
Where do you find IgE?
On mast cells
Which immunoglobins are blood group antibodies?
IgM
Which antibody is able to be transported across the placenta?
IgG (smallest can pass through tissues)
Which antibody is mainly activated in early immune responses & as first line defence against bacteraemia?
IgM
Which immunoglobin has the lowest levels in circulation?
IgE
What receptor on mast cells detects IgE?
FceRI
Where are mast cells found?
Underlying mucosal surfaces and connective tissues
What is the half life for IgG?
21 days
What is the half life for IgM
10 days
What is the half life for igA?
6 days
Which antibody is the most powerful agglutinin?
IgM
Which subtypes of IgG can cross placenta?
1,2,4
What interaction between T and B cells is required for initial activation of B cells?
The coreceptor activation between B7.1/B7.2 on B cells and CD28 on T cells. Further activation between CD40 on B cells and CD40L on T cells is required.
Which interleukin is responsible for switching B cells into IgE antibodies?
IL4
Where does B cell clonal expansion, class switching and somatic hypermutation occur?
In the follicles of lymph nodes
What is somatic hypermutaion?
When there is mutation in adaptation to the foreign substance to better favor the substances
How is the classical pathway activated?
By antigen-antibody complex
How is the alternate pathway activated?
microbial cell wall
How is the Lectin pathway activated?
Microbial wall sugar mannose
Learn the complement system
Check notes
How does the Epstein Barr Virus prevent membrane attack complex damaging them?
It binds to the complement receptor on B cells which prevent the attack of MAC proteins
