Adaptive Immunity Flashcards
Name the 2 secondary lymphoid organs
Lymph nodes
MALTs (mucosa associated lymphoid tissue)
What are the primary lymphoid nodes?
Bone marrow
Thymus
Spleen
What is the molecular structure of antibodies? (3)
Glycoproteins
2 light chains
2 heavy chains
What characterises a FAB fragment?
Vary in structure and antigen binding properties
What characterises a FC fragment? (3)
No antigen binding activity
Can bind to phagocytic cells
Can activate the compliment
What do B cell receptors induce? (5)
Signalling cascade: Enhanced survival Proliferation Differentiation Antibody secretion
What are the 3 regions of T cell receptors and what is the purpose? (4)
Variable
Constant
Membrane anchoring
Recognises only MHC class molecules
What is immunoglobulin repertoire?
Total number of antibody specificities a individual can create
~100 billion
What is the benefits of adaptive immunity?
Immunological memory, faster response
Clonal selection
What are the 4 sources of BCR (B cell receptors) variation?
Combinatorial V-D-J joining
Junctional diversity (addition or deletion of bases)
Somatic hypermutation
Variable combinations of H and L chains
How many recombinant variations does V-D-J recombination provide alone?
~2m
What is a V-D-J recombination?
A change in the DNA sequence of a immature B cells
What is needed to cause a change in the L chain of a immunoglobulin?
A recombination that combines a random V and a random J segment
What 2 changes is needed to cause a H chain variation?
1 random D and 1 random J
1random V segment and the combined DJ segment
When does somatic hypermutation occur?
Occurs in rapidly proliferating B lymphocytes
What are the 5 antibody classes?
Monomer
Dimers
Pentamers
What antibody class are IgG, IgD and IgE antibodies?
Monomers
What antibody class are IgM antibodies?
Pentamers
What antibody class are IgA antibodies?
Monomers or dimers
What does Ig stand for? (Eg. IgA)
Immunoglobulin
What are the functions of Ig A,D and E
A: protects mucosal membranes
B: main B cell regulator
E: defends against parasites