8/23/13 Flashcards
Linear epitope
epitope consists of a linear string of 8-20 amino acids
Discontinous or conformational epitope
amino acids in the epitope may be from distant parts of the linear peptide
T-cells (can/cannot) recognize discontinous epitope
cannot
Papain digests antibody to produce a Fab fragment that has a (monovalent/bivalent) binding to antigens
monovalent
Pepsin digests antibody to produce a Fab fragment that has a (monovalent/bivalent) binding to antigens
bivalent
N-terminus/C-terminus is where the variable region of the antibody is located
N-terminus
List of Ig heavy chain genes
alpha, delta, gamma, epsilon, mu
List of Ig light chain genes
kappa, lambda
Which antibody types are the only ones to act as B-cell receptors
IgD, IgM
How many CDRs are there for each heavy and light chain in the variable region of the antibody?
3
Which interleukin is required for lymphocyte maturation?
7
Light chains and alpha chains have only these cassettes
V-J
D-cassettes occur only in these types of lymphocyte receptor segments
heavy chain genes, beta genes of the TCR
Which segments are joined during somatic recombination are random is called this
combinatorial diversity
Junctional diversity
Ligases add random nucleotides to the join sites
This protein activates the somatic recombination complex in immature lymphocytes
RAG
IgD or IgM can be on the BCR because they come from the same mRNA but are
alternatively spliced
Describe how antibody chains are selected during B cell maturation (allelic maturation)
One heavy chain undergoes VDJ recombination–> if unsuccessful the other allele attempts–> if successful, the protein made prevents the other chromosome from recombining and indues kappa light chain locus to start VDJ recombination–> if both kappa alleles fail then lambda has a shot–> if all fails the cell dies
What type of B-cell is in the fetus and where is it located?
B-1, liver
Describe how T-cell receptors are selected
Pro-T-cells recombine one beta chain gene–> if productive, prevents the other chromosome from rearranging and induces alpha chain recombination–> if productive CD4 and CD8 are induced–> if weak reaction with MHC II + peptide, then CD4 is selected–> if weak reaction with MHC I +peptide, then CD8 is selected
Where will you only see double positive T-cells
thymus
