Cell death induced in lymphocytes expressing the elastin-laminin receptor by excess agonists: necrosis and apoptosis

This manuscript summarizes our experiments carried out during the last pear s on the expression of the elastin-laminin receptor on human activated lymp hocytes and cell death triggered by the activation of this receptor by its agonists, elastin peptides. We could distinguish two types of cell reaction s, depending on the elastin peptide concentration added to the cell culture media of lymphocytes. At low concentrations (1-10 mu g/mL, 1.3-13 x 10(-8) M) of kappa-elastin, there was a stimulation of cell proliferation, elasta se biosynthesis and release. As the concentration of kappa-elastin was incr eased in the culture medium up to 100 mu g/mL, lymphocyte proliferation and elastase production decreased and the proportion of dead cells increased. Cell death was shown to be due to both apoptotic and non-apoptotic mechanis ms. Apoptotic cell death increased with agonist concentration and reached a pproximately 60% of the lymphocyte population at mg/mL elastin peptide conc entrations. This observation was confirmed by the concomitant use of severa l different methodologies, such as flow cytometry and electron microscopy. The precise nature of the non-apoptotic cell death remains to be establishe d. (C) 1998 Elsevier, Paris.