2/13
Types of humoral immune responses and functional diversificiation of antibodies
...
- review of
- B cell functions
- antibody functions
- allergy
- primary immunodeficiency diseases
this lecture
B cells process protein Ags and display them in the context of MHC II molecules to T cells
endocytosis of extracellular protein (takes it into MHC cell -> process it -> present peptide to T cell)
MAH class II: CD4 T cell
remember that when antigen 1st encounter - typically grabbed by antigen presenting cells, lie dendritic cells
load on MHC molecule -> specific for T cell -> present to T cell
this happens in B cells too
B cells present antigen (APCs) to T cells (Tfh) in the GCs
B cell recognition of native protein antigen
-> receptor mediated endocytosis of antigen
-> antigen processing and presentation
-> T cell recognition of antigen
B cells can see antigen independently,
Can internalize it, and activate T cell
B cells are antigen presenting cells
Interaction is only mechanism for antigen presentation to T cells during geminal center reaction
B cells are very good antigen presenting cells, and their presenting capability is required for last step in immune response, where B cells are left to interact for T cell immune responses
which immune cells present antigen to T cells during a T cell dependent Ab response?
pause for activity
- dendritic cells - present antigen to initiate T activation
- B cells - present antigen to already activated T cells
Ig heavy chain class (isotype) switching
went over this before
allergies
when the immune system attacks non-threatening substances
molecules involved in allergic reactions
IgE
- antigen binding sites in IgE antibody
- antibody constant region binds Fc receptors (FcRs) on innate cells
- FceR bind to the constant region of IgE. FceR receptors are present on mast cells
what antibody is the main receptor involved in allergic reactions?
IgE