Doxycycline induces Fas Fas ligand-mediated apoptosis in Jurkat T lymphocytes

Tetracyclines have been used in the treatment of chronic inflammatory disea ses associated with local infiltration of inflammatory cells and matrix des truction as observed in rheumatoid arthritis and periodontal disease. Fas/F as ligand (FasL)-mediated apoptosis plays an important role in maintaining T lymphocyte homeostasis and modulating immune response. The present study demonstrates that doxycycline inhibits Jurkat T lymphocyte proliferation an d induces apoptosis. The phytohemagglutinin (PHA)-activated Jurkat cells ar e more susceptible to doxycycline-induced apoptosis. Furthermore, doxycycli ne-induced apoptosis is associated with increased Fas/FasL expression in Ju rkat cells. The increase of apoptosis in Jurkat cells treated with doxycycl ine is consistent with the increase of Fast expression. These results sugge st that doxycycline may downregulate the in-flammatory process in certain d iseases by eliminating activated T lymphocytes through Fas/FasL-mediated ap optosis. (C) 1999 Academic Press.