|
||
RI-mediated
Degranulation by CD81
By
From the Departments of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical
School, Boston, Massachusetts 02215
Signaling through the high affinity receptor for immunoglobulin E (Fc
RI) results in the coordinate activation of tyrosine kinases before calcium mobilization. Receptors capable of interfering with the signaling of antigen receptors, such as Fc
RI, recruit tyrosine and inositol phosphatases that results in diminished calcium mobilization. Here, we show that antibodies
recognizing CD81 inhibit Fc
RI-mediated mast cell degranulation but, surprisingly, without
affecting aggregation-dependent tyrosine phosphorylation, calcium mobilization, or leukotriene synthesis. Furthermore, CD81 antibodies also inhibit mast cell degranulation in vivo as
measured by reduced passive cutaneous anaphylaxis responses. These results reveal an unsuspected calcium-independent pathway of antigen receptor regulation, which is accessible to engagement by membrane proteins and on which novel therapeutic approaches to allergic diseases could be based.
This article has been cited by other articles:
| TABLE OF CONTENTS |
|