Humoral Immunity (Bowden) Flashcards
Humoral Immunity
bracnh of adaptive mediated by Ab produced by plasma cells. principal defense against extracellular pathogens
Where are the Abs produced by plasma cells and where are they functional
produced in lymphoid tissues and organs. function is at distant sites
What mediates the effecter functions of Abs
The Fc region of isotypes
What triggers function of Ab
binding of Ab to Fab (Variable) regions on isotypes
3 general schematics of Ab function
Neutralization- prevents bacterial adherence
Opsonization- promotes phagocytosis
Complement activation- lyses some bacteria
Which classes of Ab can do neutralization
any of them. only requires binding to Ag- higher affinity the better.
Which mechanism do vaccination Ab work
neutralization
What regions of Ab promote phagocytosis and deliver the signals
Fc receptors
What cells are main responders to viruses
NK
Describe the method of NK binding. or Ab dependent cell cytotoxicity ADCC
NK bind Ab coated cell by Fc R and destroy cells
IgE mediated Rxns
IgE binds Fc R on mast cells and eosinphils.
When Ag binds- degranulation of cell occurs
What is FcRn
Fc neonatal R for transporting IgG across placenta
Why is IgG more important than IgM against bacterial infection
IgG has higher affinity and not only does it activate C’ cascade but it also can bind Fc on phagocytes
how many types of Hyper- IgM immunodeficiency exist
5 all are genetic defects inability to switch class form IgM
X linked Hyper IgM immunodeficiency HIGM has what defect
CD40L expression.
