More MS news articles for June 2002

Platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31) acts as a regulator of B-cell development, B-cell antigen receptor (BCR)-mediated activation, and autoimmune disease

Blood 2002 Jul 1;100(1):184-93
Wilkinson R, Lyons AB, Roberts D, Wong MX, Bartley PA, Jackson DE.
Division of Haematology, Hanson Institute, Institute of Medical and Veterinary Science (IMVS), Adelaide, South Australia.

Platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31) is an immunoglobulin-immunoreceptor tyrosine-based inhibitory motif (Ig-ITIM) superfamily member that recruits and activates protein-tyrosine phosphatases, SHP-1 and SHP-2, through its intrinsic ITIMs.

PECAM-1-deficient (PECAM-1(-/-) ) mice exhibit a hyperresponsive B-cell phenotype, increased numbers of B-1 cells, reduced B-2 cells, and develop autoantibodies.

In the periphery, there are reduced mature recirculating B-2 cells and increased B-1a cells within the peritoneal cavity.

In addition, PECAM-1(-/-) B cells display hyperproliferative responses to lipopolysaccharide and anti-IgM stimulation and showed enhanced kinetics in their intracellular Ca(++) response following IgM cross-linking.

PECAM-1(-/-) mice showed increased serum levels of IgM with elevated IgG isotypes and IgA antidinitrophenol antibody in response to the T-independent antigen, dinitrophenol-Ficoll.

Finally, PECAM-1(-/-) mice developed antinuclear antibodies and lupuslike autoimmune disease with age.

(Blood. 2002;100:184-193)