Adhesion via CD43 induces Syk activation and cell proliferation in TF-1 cells

The effect of adhesion via CD43 (leukosialin, sialophorin) on cell prolifer ation and phosphorylation signaling were examined in a growth factor-depend ent hematopoietic progenitor cell line, TF-1. TF-1 cells promptly resulted in death after withdrawal of growth factors. However, the viable cell numbe r increased when TF-1 cells were cultured on anti-CD43 monoclonal antibody- coated plates. In this case, sustained activation of protein tyrosine kinas e Syk and extracellular signal-regulated kinase (Erk) 1/2 were detected. Ov erexpression of exogenous Syk on TF-1 cells by the adenovirus vector system induced enhancement of the cell proliferation accompanied with enhancement of the Erk activation by a dominant-positive effect. The signal transducer and activator of transcription (STAT) 5 seemed not to be associated with t he CD43-mediated cell proliferation. These results indicated that adhesion via CD43 induces the proliferation of TF-1 cells in the absence of growth f actors in part by Syk-dependent Erk 1/2 signaling. (C) 2001 Academic Press.