Biological activities of tetrapeptide AcSDKP on hemopoietic cell binding to the stromal cell in vitro.

The biological activity of the tetrapeptide acetyl-N-Ser-Asp-Lys-Pro (AcSDKP) on hemopoietic cell binding to the stromal cells was studied by using a rosette formation technique that quantitatively represents the specific hemopoietic cell binding to the stroma. Marrow hemopoietic cell binding to the stroma was enhanced by AcSDKP. This enhancement was completely neutralized by addition of anti-AcSDKP polyclonal antibody. Furthermore, preincubation of stromal cells with AcSDKP increased hemopoietic cell binding to the stroma, whereas preincubation of hemopoietic cells with AcSDKP showed no increment of the binding. These findings suggest that AcSDKP enhanced hemopoietic cell binding through the activation of stromal cells.