Antigen recognition (Antibody structure and Development of Immune Repertoires) Flashcards
What is the immune repertoire?
Entire collection of lymphocytes in the immune system
What does it mean that antigen receptors are clonally distributed?
Each lymphocyte clone is specific for a specific antigenq
differentiate affinity maturation from somatic hypermutation.
Affinity maturation is actually a result of when somatic hypermutation causes increased Ab affinity to an antigen.
Affinity maturation- process in which Ab affinity to a certain antigen is increased due to prolonged or repeated exposure to that antigen
Somatic hypermutation - mutations in the V gene of the VDJ gene that results in increased, decreased, or unaltered Ab affinity to the antigen its exposed to
Which enzymes work together to cause mutations seen in somatic hypermutation and class switching?
AID (activation induced deaminase) replaces thymine with uracil while repair enzymes introduce mutations
Differentiate somatic hypermutation from class switching.
in somatic hypermutation, the Ab’s affinity for the antigen is likely to change (increase or decrease). In class switching, the affinity DOES NOT change. Class switching instead focuses on changing the heavy chain in order to change the effector elements the antibody will interact with rather than affect its relationship with the antigen as seen in class switching.
Describe the process of class switching/switch recombination
AID enzyme replaces thymine with uracil
Other enzymes remove uracil creating chinks in the DNA
The two DNA segments are brought together, bringing the V region adjacent to a different C region coding for a different heavy chain
Where does the difference between kappa and lambda light chains lie?
They are different in their constant regions (CL) NOT their variable regions (VL)
function of constant region of light chains (CL)
no biological activity
Which type of antibody has 4 constant domains (CH)? [2]
IgM and IgE
Which constant domain of the heavy chain binds complement?
CH2
During class switching, which region of the antibody is changed?
constant domain of the heavy chain
What forms the Fab region?
The part of heavy chain together with light chain
What forms the Fc region?
The heavy chains not attached with the light chain
How many hypervariable regions are in each variable region?
3
During which stage does Beta chain recombination occur in the T cell development?
During Pro-T cell stage
