antigen + antibody Flashcards
What is an antigen?
protein that reacts with the products of the immune system
What is an Immunogen?
anything that induces a specific immune response
What is an Hapten?
a non-immunogenic molecule that reacts with the products of the immune system
What is an Epitope/antigenic determinant?
portion of the immunogen to which the immune response is directed
How does binding happen at epitope?
lock and key
How does foreignness effect immunogenicity?
The more foreign the component the more immunogenic it is
How does size effect immunogenicity?
The bigger the more immunogenic
How does chemcial composition effect immunogenicity?
The more complex the better immunogen
How does degradability effect immunogenicity?
< immunogenic
How does denaturing effect immunogenicity?
The more degradable the better immunogen
If an immunogen is a protein does it make it a good immunogen?
yes
If an immunogen is a lipid does it make it a good immunogen?
no
If an immunogen is a lipopolysaccharide/ polysaccharide does it make it a good immunogen?
yes
Which antigen- T independent/ t dependent is: resistant to degradation?
t independent
Which antigen- T independent/ t dependent: requires T cell to activate B cell?
t dependent
T independent activates it on its own
What are t independent and t dependent made of?
T independent: polysaccharide
T dependent: proteins
Does the T independent have memory?
no
Which antigen- T independent/ t dependent has: SAME / DIFFERENT antigenic determinants among surface?
T independent: same
T dependent: different
Is hapten carrier conjugate immunogenic?
no
How is hapten carrier conjugate formed?
Covalent bond between hapten and carrier protein
Clinically what is hapten carrier conjugate used for?
vaccination
What is an example of hapten carrier conjugate?
urushiol (found in poison ivy) –> become quinone (hapten) and bind to skin proteins (carrier) –> Type IV hypersensitivity reaction
What does a super antigen activate?
T cells –> hyper-activate immune system
Does a super antigen need to be degraded?
no
What is the chemical nature of immunoglobulins?
Glycoproteins
What is the makes immunoglobulins?
plasma cells
What is the function of immunoglobulins?
Function as antibodies –> bind antigen (stop spread) + activate cells
What are the chains bonding of immunoglobulin?
disulfide bond
What heavy chain type do these immunoglobulins have:IgD, IgA, IgM, IgG?
IgD: delta
IgA: alpha
IgM: mui
IgG: gamma
What are the two light chains?
kappa + lambda
IgG: shape, function?, complement fixing?, opsonin? can it bind to cell? + whats good about it?
shape: monomer
function: all function + cross placenta
complement fixing!
opsonin: yes
Can bind to cell FC
Whats good about it: all functions done
IgG: which IgG is not good at crossing placenta and which is not complement fixing and which cant bind to cell?
Cant cross placenta: IgG2
not complement fixing: IgG4
Cant bind to cell: IgG2 + IgG4
IgM: shape? valence? role? when is it first made? complement fixing? good at agglutinating? can it bind to cell?
shape: pentamer
valence: 10
role: Ag on B cell
when is it first made: fetus
complement fixing: yes
good at agglutinating: yes
can it bind to cell: via FC
What does it mean if IgM is > than 20 ng/dL?
in-utero infection
What is needed to form pentamer in IgM?
J-chain
IgA: shape? valence? role? made by? complement fixing? found in?
shape: dimer
valence: 4
role: secretion- mucosal immunity
made by: epithelial
complement fixing: no
found in: breast milk
What is needed to form dimer in IgA?
J-chain
IgE: shape? do we have a lot? role? binds to? complement fixing?
shape: monomer
do we have a lot: no
role: parasitic + hypersensitive reaction
bind to: mast cell + eosinphil –> degranulate + activate
complement fixing: no
IgD: shape? What makes it LOOK special? do we have a lot? binds to? complement fixing?
shape: monomer What makes it look special: has extra tail piece do we have a lot: no bind to: B cell surface complement fixing: no
