Mucosal mast cells
are found in the connective tissue below epithelial surfaces.
If
antibodies
(such
as IgE)to
a particular antigen 
have sensitized the mast cell surface
and if the mast cell subsequently comes into contact with that antigen,
antibody receptors
on
the mast cell surface are"cross-linked".
Receptor cross-linking initiates phosphorylationand
other signaling cascades that ultimately lead to the secretion of histamine,serotonin
and other inflammatory mediators.The
RBL mast cell line is a well-characterized model system for analyzing
the events that constitute immunological signaling.We
use this system for addressing fundamental biophysical
questions of antigen-inducedgranule
exocytosis and recycling.
