ANTIGEN RECEPTOR-MEDIATED TRANSMEMBRANE SIGNALING IN WISKOTT-ALDRICH SYNDROME

The X-linked immunodeficiency Wiskott-Aldrich syndrome (WAS) is a cond ition that includes a deficient anti-polysaccharide Ab response. Recen tly, it has been suggested that B cells from patients with WAS show a defective calcium mobilization response upon engagement of sIgM. Becau se primarily EBV-transformed cells were used in these studies, we test ed freshly isolated blood B cells for their calcium mobilization capab ility upon engagement of sIg and CD19. No significant differences in t he calcium mobilization capability of CD20(+) B cells of four individu al WAS patients compared with capability in normal controls were found . Receptor desensitization as assessed by calcium mobilization inhibit ion also seemed to be intact. T cells were tested for their anti-CD3-i nduced calcium flux and, again, no abnormalities could be observed whe n compared with T cells from healthy individuals. We conclude that WAS B and T cells can be stimulated into a normal calcium mobilization re sponse when their AgRs are cross-linked. It is highly improbable that the immune dysfunction observed in WAS patients is related to a direct disorder of their B and/or T cell AgRs.