Hc. Aasheim et al., A splice variant of human ephrin-A4 encodes a soluble molecule that is secreted by activated human B lymphocytes, BLOOD, 95(1), 2000, pp. 221-230
Ephrin-A4 is a ligand for the erythropoietin-producing hepatocellular (Eph)
receptor family of tyrosine kinases, We have identified a secreted form of
ephrin-A4, denoted ephrin-A4 (s), which is encoded by an alternatively spl
iced mRNA and is produced by in vivo activated B cells in tonsils. Blood B
cells secrete ephrin-A4 (s) upon stimulation via the B-cell antigen recepto
r. A subpopulation of tonsil cells in the crypts with a dendritic cell phen
otype was shown to express EphA2, an Eph receptor tyrosine kinase that was
found to be capable of binding an ephrin-A4 immunoglobulin chimeric protein
. We conclude that ephrin-A4 (s) may play a role in the interaction between
activated B lymphocytes and dendritic cells in human tonsils. (C) 2000 by
the American Society of Hematology.