Immunology 7 Flashcards
These are lymphocytes that develop in the bone marrow.
They express unique antigen receptors/BCR or secreted antibody
B cells
These are activated B cells that secrete antibody
Plasma cells
These are B cells that provide memory
Memory B cells
What is the difference between the maturation/development of B and T cells?
B cells mature in the bone marrow, T cells mature in the thymus
This binds the antigen and activated B cell. It is membrane anchored through a transmembrane domain.
B cell receptor
What are the 3 functions of antibody?
1) neutralisation
2) opsonisation
3) complement activation
This is the process by which B cells make the antigen more attractive to the phagocytes to destroy.
Opsonisation
This is the process by which the B cell has a receptor that ENABLES infection by allowing antibody to bind to receptor.
Essentially, what happens when the antibody binds to a receptor of cell that’s been infected with a virus.
Viral neutralisation
One B cell can produce different classes of antibodies. These different classes are known as:
Isotopes
This is the only class that crosses the placenta. It provides passive immunity. And targets the virus/bacteria.
- when it targets the virus and bacteria that means it OPSONISES AND NEUTRALISES
IgG
This is present in secretions (mucus, tears, saliva and breast milk). And is involved in the defence of mucus membranes. It confers passive immunity on infant as it is present in breast milk.
It also targets virus/bacteria.
- it has a secretory component
IgA
This is first Ig class produced after initial exposure to antigen.
It activates complement, and targets extracellular receptor. It acts as a BCR
IgM
This is present in blood at low concentrations and provides immunity to multicellular parasites and allergic reactions.
IgE
This is expressed on naive B cells, and together with IgM acts as an antigen receptor. (Usually found on most B cells)
IgD
Stimulation of B cells by antigen + T cell leads to formation of:
Plasma cells
Why are memory cells easier to activate than naive B cells?
Because a) they’ve already been exposed to the antigen b) they have a LOWER ENERGY THRESHOLD
Memory cells express antibody as ____ but do not _____ antibody.
BCR; secrete
This is produced when it takes around 7-14 days to produce sufficient antibody to eliminate pathogen.
Mainly IgM is produced during this immune response.
Primary immune response
This is produced when the response is dependent on memory B cells. And sufficient antibody is produced within 2-3 days to eliminate pathogen.
- mainly IgG IgA and IgE is released during this response.
Secondary immune response
The basic antibody unit is composed of:
2 identical heavy and 2 identical light chains
