Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/44

Click to flip

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