Recognition of extracellular pathogens Flashcards
What are TLRs
Toll-like receptors
What do TLR’s do
Recognize variety of PAMPS
What receptors do macrophages have
- MAnnose
- CD14
- scavanger receptor
- c reactive protein
- Mannan binding lectin
How are immunoglobulins made
- MIcrobe infects body
- MIcrobe has antigen
- B cell binds to it
- B cells releases antibody which is specific to antigen
- Antibodies also known as immunoglobulins
- Antigen combining site on antibody bind to the antigen
What part of the microbe binds to the antibody
Antigenic determinant/EPITPOPE part of antigen binds to antigen binding site
How does an antibody bind to an antigen
- Non covalent interactions only effective on short distances
- For there to be strong non-covalent interactions to occur between antibody and antigen, the shape must fit snugly (complementary)
- strong binding = specific interaction; high affinity
What are the different immunoglobulins that a B lymphocyte has
- membrane bound immunoglobin (B cell surface immunoglobulin)
- immunoglobins released by B lymphocyte
How are plasma cells formed
Membrane bound immunoglobulin binding to antigen activates B cells and so these can mature to plasma cells.
What do plasma cells do
Release antibodies that bind to the same antigen that the B cell was bound to
What is clonal selection
Each B cell can recognize a single epitome (each has only 1 specific antigen binding site)
How are memory cells and clonal selection linked
Primary response;
- Antigen binds to clones (groups) of B cell which binds to it most strongly (highest affinity)
- THe activated B cell clones itself and loads of that clone of B cell are made
- Some rest in body (memory cells) and some turn into plasma cells
How many polypeptide chains does an antibody have
4
What does each polypeptide chain have on an antibody
Globular regions made of domains
What is the hinge region
Halfway down heavy chain where there is no domain
Where are the disulfide bridges in an antibody
Between cysteine residues
