REQUIREMENT FOR THE LEUKOCYTE-SPECIFIC ADAPTER PROTEIN SLP-76 FOR NORMAL T-CELL DEVELOPMENT

The Leukocyte-specific adapter molecule SLP-76 (Src homology 2 domain- containing Leukocyte protein of 76 kilodaltons) is rapidly phosphoryla ted on tyrosine residues after receptor Ligation in several hematopoie tically derived cell types. Mice made deficient for SLP-76 expression contained no peripheral T cells as a result of an early block in thymo poiesis. Macrophage and natural killer cell compartments were intact i n SLP-76-deficient mice, despite SLP-76 expression in these lineages i n wild-type mice. Thus, the SLP-76 adapter protein is required for nor mal-thymocyte development and plays a crucial role in translating sign als mediated by pre-T cell receptors into distal biochemical events.