Involvement of the intrinsic and extrinsic cell death pathways in the induction of apoptosis of mature lymphocytes by the Escherichia coli heat-labile enterotoxin.Involvement of the intrinsic and extrinsic cell death pathways in the induction of apoptosis of mature lymphocytes by the Escherichia coli heat-labile enterotoxin.E. Tamayo, J. Postigo, G. del Giudice, R. Rappuoli, A. Benito, H. Yagita, R. Merino* and J. Merino* Eur. J. Immunol. 2009, 39: 439-446.2009-02-01T23:00:00Z<p style="text-align:justify;">​<span class="ms-rteFontSize-2">Escherichia coli heat-labile enterotoxin (LT) exhibits a broad range of immunomodulatory activities, including the induction of lymphocyte-programmed cell death. In previous studies, we have demonstrated that in vivo LT promotes apoptosis of immature T and B cells through the stimulation of endogenous glucocorticoids. In the present study, we show that the extrinsic cell-death pathway as well as the apoptosis-inducing factor do not participate in the LT-induced elimination of thymocytes. In contrast to developing lymphocytes, LT promotes the death of mature lymphocytes by both glucocorticoid- and Fas death receptor/Fas ligand-dependent mechanisms. However, the dependency of these mechanisms in the LT-induced cell-death activity seems to be different among CD4</span><sup class="ms-rteFontSize-2">+</sup><span class="ms-rteFontSize-2">and CD8</span><sup class="ms-rteFontSize-2">+</sup><span class="ms-rteFontSize-2">T cells. Altogether, our study shows that the same bacterial toxin can induce apoptosis of lymphoid cells through several mechanisms depending on the status of differentiation of these cells.</span><br></p><p><a href="https://onlinelibrary.wiley.com/doi/10.1002/eji.200838993">​Eur. J. Immunol.2009, 39: 439-446. </a><br></p>152