Lecture 16 Flashcards
Name the 3 regions of antibodies
Fc region, Complement binding region and hypervariable region
name the 2 classes for antibody light chains
kappa and lambda
name the 5 antibody classes for antibody heavy chains
Mu, Delta, Gamma, Epilson, Alpha
Which antibody is the most abundant Ig in humans
IgA
Which antibody acts as a trigger receptor by delivering activation signals to naive B cells through antigen binding
IgD
What is the largest antibody
IgM
Which antibody is most abundant in blood
IgG
What is IgE important for?
Allergies and parasitic functions
What do IgG2 and IgG4 do
prevent molecular interaction
What do IgG1 and IgG3 do
activate phagocytic cells
How do IgE molecules bind to mast cells
Via the Fc region
Where is IgD found
On the surface of naive B cells
What is the function of IgA
to prevent harmful material getting through the gut, respiratory tract and provide external body surface protection
where is IgM mostly found
blood
what is the function of IgM
important in defense against blood borne spread of infectious organisms such as bacteria
What do CD8 cells bind to
class 1 MHC
What do CD4 cells bind to
class 2 MHC
what gives TCR their specificity
the different amino acids
what complex does CD8 form
CD8 forms a complex with TCR and CD3
How does T cell recognition work
APC need to be presented with the correct antigen in the correct HLA molecule
what are the class 1 HLA genes
HLA - B, HLA - A, HLA - C
How does clonal repertoire work
the larger the CR then the more antigens we can respond to as the different TCRs provide different interactions
where are class 1 cells found
on all nucleated cells
How does presentation work through class 2 MHC
APC that has endocytosed proteins or dead cells are digested in lysosomes and the resulting fragments are processed and loaded into MHC 2 molecules before they are taken to the surface.
what do CD8 T cells do
recognise things that should be in the body such as tumor cells, unhealthy cells and virally infected cells and kill them
What is the first step of T cell clonal activation
The correct APC with its correct MHC molecule finds its correct T cell counterpart and the T cell activates
what are antigens the product of
bacteria and viruses
what conditions do T cells need to have to be activated
needs to be present in the lymph nodes, the antigen must be processed and presented to the T cell
what are the MHC class 2 HLA genes
HLA - DP, HLA - DQ, HLA - DR
How does Class 1 MHC presentation work
this occurs within the cell where small amount of proteins within the cell are removed from the pathway. These molecules are degraded in order to generate a whole series of different peptides.
Where are class 2 MHC molecules found
on specialised APC cells and B cells
why are APC taken to the lymph node
to maximise interaction so the chances of APC finding its correct T cell match is increased
True or false: the T cell can be activated with any APC molecule
False. T cells can only be activated with their correct/unique counterpart APC molecule
what is the second step of T cell clonal activation
The MHC molecule receives additional cytokine signals from other helper T cells in order to drive proliferation
what is the third step of T cell clonal activation
T cell undergoes proliferation because of cytokine signalling. results in millions of T cell clones going out into periphery to find infection.
what is the final step of T cell clonal activation
effector cells are produced which go out to the infection and regulate what is going on. This is an acute response with immediate recovery however a memory population is also made with the same T cell clone and TCR specificity.
which region of the antibody is constant
Fc region
what are present on the tips of antibodies
the epitope binding region which will bind the same antigen on both sides
