Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
44 Cards in this Set
- Front
- Back
Plasma vs. Serum |
Plasma: cell free portion of blood containing clotting factors Serum: is the liquid portion of blood without clotting factors etc. that is left after formation of a clot |
|
Polyclonal vs monoclonal serum |
Polyclonal serum contains various antibodies from many B-lymphocytes |
|
What is a multiple myeloma? |
A tumour of plasma B cells |
|
Why is a multiple myeloma beneficial to lab science? |
Considering it is a tumour effecting cells that secrete antibodies it provides a method to produce massive amounts of secreted antibodies |
|
What is a hybridoma? |
A process where cells are harvested from mouse spleen and crossed with mutant multiple myelomas. The mutation prevents the cells from growing in HAT medium although the fusion enables them to. Therefore it produces this hybridoma that is capable of producing massive amounts of the antibody that the mouse was immunized for |
|
What are the five types of immunoglobulin? |
IgA, IgE, IgM, IgG and IgD |
|
Properties of each Ig molecule? |
Antigen binding Effector function |
|
What is the structure of Ig? |
All Ig are composed of at least 1 heterodimer that consists of one heavy chain (two parts) and one light chain |
|
How are the dimers held together? |
By disulphide bonds in the bent region |
|
What is the Fc region |
It is the terminal end of the antibody consisting of two heavy chains that interacts with Fc receptors on the immune cells |
|
How are the effector functions of an antibody achieved? |
Generally occur when the Fc region binds to a receptor on an immune cell and causes biological effects |
|
Three ways that the effector functions can occur |
1. Neutralization: Antibody binds to free toxin in circulation and subsequently prevents it from binding to a receptor (will lead to its engulfment) 2. Opsonization: Bind antigens on a pathogen and interaction with the Fc receptor will lead to its internalization 3. Activation of complement: Binding of Ab to Ag will cause complement to bind the pathogen and lyse it |
|
Cell mediated antibody effector functions |
Antibody binding to surface antigen on target cell (could be our own cell if infected by virus) and in turn recruits NK cells with Fc receptors |
|
What is the response of NK cell binding to the Fc region of the antibody? |
The NK cell receptors will crosslink with the Fc region triggering the release of cytotoxic molecules culminating in apoptosis |
|
Where are disulphide bonds found in an immunoglobulin? |
Interchain: linking heavy chains or linking light and heavy chains Intrachain: within either the heavy or light chain |
|
What are the domains of the heavy chain? |
C1,2, and 3 and V1 The top of the heavy chain that interacts with the antigen is variable and this is followed by the first constant region. After the hinge region there are two more constant regions |
|
What are the domains of the light chain? |
The top portion is variable followed by a single constant region. The light chain doesn't extend past the hinge region. |
|
What is the role of the hinge region? |
Provides flexibility to the antibody to properly bind its antigen if its topology may be difficult to interact with |
|
Which antibodies don't have a hinge region? |
IgM and IgE |
|
What is a characteristic structural feature in the immunoglobulin family? |
The contain domains of antiparallel beta sheets |
|
What are hyper variable regions? |
Specific amino acid sequences in the variable region of either antibody heavy or light chains that have incredible variability, flanked by regions of less variability Region that actually binds the Ab |
|
Papain and pepsin |
common proteases that are used to digest antibodies for the purpose of decoding their structure |
|
Papain site of action |
Papain acts on the hinge region of the antibody cleaving it into two FAB regions (fragment antibody binding) and the FC region |
|
Pepsin site of action |
Cleaves apart the FC region preserving the FAB region (the two parts stay attached) |
|
Which immunoglobulin classes have subclasses? |
IgG (gamma 1,2,3 and 4) and IgA (alpha 1 and 2) |
|
What are the two forms of the light chain and which is more prominent? |
Kappa and lambda (kappa is more prominent) |
|
Order of immunoglobulin content (greatest to least) |
IgG, IgA, IgM, IgD, IgE |
|
Effect of IgG binding to Fc receptors |
Activates complement and cell-mediated cytotoxicity |
|
How do IgG and complement work together? |
IgG binds the pathogen and brings it to the Fc receptor enabling the C3b complement to interact with its receptor CR1 (causes phagocytosis) IgG basically activates the complement |
|
Structure of IgA in secretions |
Forms an immunoglobulin dimer where the individual immunoglobulins are connected by the J chain and a secretory component |
|
What is the secretory component |
It is derived from epithelial cells and helps to hold together the IgA dimer and disguise it from proteases found in these secretions |
|
Common secretions with IgA |
Tears, saliva, breast milk, GI tract etc. |
|
Explain how IgA enters into the gut lumen |
IgA binds to the pIgR (Poly-Ig receptor) on the surface of the epithelium and is transported by vesicle to the surface where it is cleaved from the receptor and can enter the lumen |
|
Main role of IgA |
To neutralize pathogens and prevent their attachment to epithelial cells |
|
True or false, IgA activates the complement pathway |
False, IgA is not capable of activating the complement pathway |
|
Unique structure of IgM |
Is a pentamer in serum where the five immunoglobulin units are connected by disulphide bridges and a j chain |
|
What is the structure of IgM when bound to a B cell |
It is a monomer |
|
First antibody to appear in phylogeny |
IgM |
|
Antibodies that do not cross the placenta |
IgA and IgM |
|
Best Ab at activating complement pathway |
IgG |
|
Lacks a hinge region |
IgM does although it remains relatively flexible |
|
This Ab is largely confined to the B cell membrane |
IgD |
|
Ab responsible for binding mast cells and basophils (what is the role of this) |
IgE plays a major role in allergy response and potential for anaphylaxis Causes degranulation of mast cells |
|
Antigenic determinant |
A portion of the antigen binding region that acts as an epitope and can be bound by other antibodies |