Reconstitution of the ZAP70/Syk-deficient P116 cell line with wild-type ZAP70 restored CD2-mediated induction of LAT phosphorylation.

ZAP70/Syk-deficient Jurkat cells (P116) and the ZAP70-reconstituted clone (P116-ZAP70) were either left unstimulated or stimulated via either CD2 or TCR-CD3 or both receptors for 5 minutes, as described in “Materials and methods.” Immunoprecipitation of LAT was then performed as in Figure 6. Tyrosine phosphorylation of LAT is shown (upper panel). The same membrane was stripped and reblotted with anti-LAT–specific antibody (lower panel). Results are representative of 2 independent experiments.