Notes: Y1 i&d - immunology | b cells and antibodies
Similar resources:
Y1, I&D, IND, infection and defence, I+D, I and D, y1bcells, Benny Chain I&D: Immunology – Antigen Recognition:
B cells and antibody
Antibodies are immunoglobulins:
• light chain and heavy chain
• chains held together by disulphide bonds
• hinge region allows flexibility
• epitope (part of antigen recognised by immune system) binds to paratope
(antigen binding site on antibody- CDRs)
• Binding to antigen is reversible (non-covalent bonds)
Diversity:
• During B cell development
• One antibody for one type of antigen (specific)
• clonal selection
VDJ Recombination:
Heavy region: (chromosome 14)
• 40V (variable)
• 27D (diversity)
• 6J (joining)
Light Region:
• Kappa= 40V, 5J (chromosome 2)
• Lambda= 30V, 5J (chromosome 22)
• Choose lambda first, if it doesn’t work, use kappa.
• RAG-1 and RAG-2 recombinase enzymes join the genes.
Somatic hypermutation: (affinity maturation)
• uses enzyme AID
• process of getting antibodies that are more specific against an antigen
• occurs in germinal centres of secondary lymphoid organs
