Antibody Structure and Function Flashcards
1
Q
nowmal antibody responses are
A
polyclonal
2
Q
antibodies bind to
A
antigens, specifically at their corresponding epitope
3
Q
multiple myeloma
A
- plasma cell tumor
- creates a monoclonal antibody response
- derived from a single cell
- these are all the exact same antibodies
- hone to bone marrow and dirupt hematopoiesis
- lowered WBCs with increased susceptibility to infection
- decreases RBC leading to anemia
- see a drastic increase in serum gama globulin
4
Q
another word for antibody
A
immunoglobulin
5
Q
antibody structure
A
- consists of a light chain and a heavy chain
- the N terminus has 2 regions with both light and heavy chains and these are the variable regions
- C term conatins only one heavy chain region and this is constant
- variable regions known as Fab (antigen binding) and constant is known as Fc (crystalizable)
- heavy chains and light chains are held together via disulfide bonds
6
Q
CDR
A
- complimentarity determining region
- hypervariable region
- this is the regions that actually makes contact with the epitope on the antigen
7
Q
classes of antibodies
A
- these are antibodies with different constant regions
- mu, delta, gamma, alpha, and epsilon
- within these there are subclasses
8
Q
polymeric immunoglobulins
A
- formed by IgM and IgA
- IgM forms a pentamer, these are always made by IgM producing plasma cells
- IgA forms a dimeric antibody
- polymeric antibodies contain a J-chain protein
9
Q
attachment of antibody to a B cell
A
- one Ig-beta and one Ig-alpha are bound to the anitbody and these are what anchors the antobody to the B cell membrane
- Igb and Iga function in delivering signals to the B cell
10
Q
viral entry into cell
A
- virus binds to receptors on the cell surface
- receptor mediated endocytosis of the virus
- acidification of endosome triggers fusion of virus with cell and entrance of viral DNA
- Ab blocks binding to virus receptor
11
Q
viral and bacterial neutralization
A
-Ab binds to site on capsid/bacteria which would typically facilitate entry into a host cell
12
Q
opsinization via IgG and Fc-gama-R
A
- when immonoglobulin is bound to its target, it can be crosslinked with Fc receptors on macrophages and then endocytosed with its bound antigen
- if an immunoglobulin is not bound to its target antigen, then it can not be cross linked with Fc receptors on macrophages
- Fc-gama receptors mediate opsonization
- IgG is an important opsonin
13
Q
antibody dependent cellular toxicity
A
- antibody binds antigens which are bound to the surface of their target cell
- antibodies are recognized by NK cells via Fc receptors
- this cross linking signals the NK cell to kill the target cell
- target cells dies via apoptosis
- NK cells express Fc-gama-R
- NK cells also induce some virus infected or tumor cells to undergo apoptosis
14
Q
mast cell activation via IgE cross linking
A
- IgE antibodies are bound to Fc receptors on mast cells
- when these antibodies are multivalently cross linked with antigen, this causes release of granular contents
- this response function in immunity to worms
- it is also a key element in allergic reaction
15
Q
what Abs do antigen specific receptor binding
A
all of them
