Antibodies, Antibody Diversity, T-Cell Development Flashcards
What is an antigen?
Anything that can be bound by cells of the adaptive immunity system
What is the process of B and T cells being generated?
Hematopoiesis
Where does Hematopoeisis occur?
Bone Marrow
What are the primary functions of antibodies?
Ag binding and recognition
Trigger the elimination of foreign Ag
T/F - An antigen must be intact for an antibody to bind it.
True
T/F - Binding alone is not sufficient to neutralize an antigen.
False - Binding alone may be sufficient to neutralize an antigen
What are the ways antibodies trigger the elimination of foreign antigens?
Activation of a complement
Opsonizaiton
ADCC
Activation of an antibody complement
Leads to cell lysis
ADCC
NK mediated cytotoxisity
What are the fragments of an antibody?
Fab
Fc
Fab
Antigen binding fragment
Highly variable so it can discriminate between antigens
Fc
Crystalizeable fragment that binds to phagocytotic or cytolytic cells
Heavy chains
Spans the Fab and Fc
Light chains
Spans only the Fc
Light chains
Spans only the Fc
What makes up an antibody?
Fab fragment
Fc fragment
2 Identical light chains
2 identical heavy chains
What are the classes of antibodies
IgG IgA IgM IgD IgE
IgG
Heavy chain gamma
Fab arms are linked to Fc by an extended region of polypeptide chain known as the hinge
Monomer morphology
IgA
Heavy chain alpha
Dimer morphology
IgM
Heavy chain mu
Pentameter morphology
IgD
Heavy chain delta
Monomer morphology
IgE
Heavy chain epsilon
Monomer morphology
Hypervariable region
At the tip of the light and heavy chains in the Fab region
Near where Ags bind
To what does an FCR bind to?
Fc region of an antibody
What is the end result of FCR binding?
Stimulates phagocytotic or cytotoxic cells to destroy the microbes
How is antibody diversity achieved?
VDJ arrangement
Heavy chain construction
Three gene segments:
V, D, and J chains
Light chain construction
Two gene segments:
V and J chains
How many types of Variable chains are there?
100
How many types of Diversity chains are there?
3
How many types of joining chains are there?
6
How many types of joining chains are there?
6
Where do T cells mature?
Thymus
Positive selection of T cells
If the thymocte TCR engages in low-afinity interaction with a self MHC molecule on thymic epithelium, it is rescues from programmed cell death and continues to mature.
Where does positive selection of T cells occur?
thymus
Negative selection of T cells
If the thymocyte TCR binds peptide-MHC complexes on a thymic antigen presenting cell with high addinity or avidity, it is induced to go under apoptotic cell death
Negative selection of T cells
If the thymocyte TCR binds peptide-MHC complexes on a thymic antigen presenting cell with high affinity or avidity, it is induced to go under apoptotic cell death
