Antigen Receptors (Lymphocyte Receptor Genes) and B Cell Development Flashcards
(18 cards)
What are antibodies?
Proteins made by B cells that bind antigen
Secreted and membrane IG have the same ____ but a different ________
Fab, C-terminus
Antibodies interact with Ag at _____
Complementarity determining regions (CDR)
What is a CDR?
Loops in the Fab region of the antibody
_____ (2 options ) binds to antigen while ___ signals into the cell
CDR and Fab, IG-Alpha/IG-Beta
Does CDR or Fab bind to antigens better?
CDR
What type of bonds mediate the interaction between antibodies and antigens?
Non-covalent
How were antibodies isolated/discovered?
Serum is isolated from rabbits that have been injected with Ovalbumin.
Electrophoresis separates proteins by charge and mass.
Black line shows serum that has been pre-incubated with Ovalbumin (the antigen)
What type of reactions demonstrate that Ab are substances?
Agglutination
What are the 4 biological consequences of Ag binding?
- Neutralization
- Opsonization
- Activation of complement
- Antibody-dependent cell-mediated cytotoxicity (ADCC)
- Trabscytosis
What happens during neutralization (Ag binding process)?
Ab binding blocks binding of toxin or virus to cell
What happens during opsonization (Ag binding process)?
Promotes phagocytosis of Ag via interaction with Ab
What happens during activation of complement (Ag binding process)?
Directly destroys cell
What happens during ADCC (Ag binding process)?
Killing by NK cells
What happens during Transcytosis (Ag binding process)?
Moving Ab across epithelial layers (ex. placenta)
What Ag binding processes are mediated by the Fc portion of secreted antibodies?
Recognition by NK cells, Activation of complement, Opsonization
What are the 5 different types of heavy chain regions in antibodies?
IgG
IgD
IgE
IgA
IgM
What is clonal selection defined as?
Selection of B cell based on interaction with Ag by the BCR
