Figure 2

Protein tyrosine phosphorylation of whole PMN cell lysates after short stimulation with GM-CSF Freshly prepared neutrophils were stimulated with GM-CSF for 1 to 10 min and immediately lysed. Lysates were sized on SDS-PAGE followed by western-blotting using anti-phosphotyrosine mAbs to reveal protein phosphorylation. The gel shown here is representative of 10 independent experiments. Image analyzer was used to measure the amount of phosphorylation and represented above the gel for each experimental condition in the case of young (white columns) and elderly donors (black columns). Similar phosphorylation patterns were obtained from others experiments. A significant increase in total phosphorylation in indicated by *p < 0.01, **p < 0.05. A significant difference in basal phosphorylation status of PMN from young and elderly donors was found and indicated by ***p < 0.05.