Biphasic activity of cd137 ligand-stimulated monocytes on T cell apoptosis and proliferation
MetadataShow full item record
CD137L (4-1BBL) is a member of the TNFSF and is expressed on APCs as a transmembrane protein. Reverse signaling by CD137L in monocytes causes cell activation and differentiation to mature inflammatory DCs that can stimulate T cell proliferation. However, CD137L agonists have also been reported to induce apoptosis in PBMCs. This study aimed at clarifying these seemingly opposing activities. We find that the dying cells within PBMCs are T cells and that this T cell death is dependent on monocytes and correlates with the monocyte:T cell ratio. This CD137L-induced, monocytemediated T cell apoptosis is reminiscent of MDCD, and both are cell contact-dependent. T cell death is not mediated by CD95 or DR4 or -5 but by ROS produced by the T cells. T cell apoptosis is restricted to the first 24 h of stimulation, and at later time-points, the monocytes differentiate to inflammatory DCs under the influence of CD137L signaling and acquire the capacity to stimulate T cell proliferation from Day 4 onward. This biphasic activity may contribute to infection-induced T cell attrition, where in the early phase (<24 h) of an infection, massive T cell apoptosis occurs before the antigen-specific T cells expand. © Society for Leukocyte Biology.
Showing items related by title, author, creator and subject.
Cryopreservation of monocytes or differentiated immature DCs leads to an altered cytokine response to TLR agonists and microbial stimulationMeijerink, M.; Ulluwishewa, Dulantha; Anderson, R.; Wells, J. (2011)Literature on the effects of cryopreservation and thawing of monocytes or monocyte-derived immature dendritic cells (iDCs) on the subsequent functional capacities of the DCs is limited to a few specific maturation stimuli ...
Hypoxia prolongs monocyte/macrophage survival and enhanced glycolysis is associated with their maturation under aerobic conditionsRoiniotis, J.; Dinh, H.; Masendycz, P.; Turner, A.; Elsegood, Caryn; Scholz, G.; Hamilton, J. (2009)In chronic inflammatory lesions macrophages are abundant and adapt to the low oxygen concentrations often present there. In low oxygen some cell types die by apoptosis, as reported for macrophage cell lines, while others ...
Circulating CD14+ and CD14highCD16− classical monocytes are reduced in patients with signs of plaque neovascularization in the carotid arteryAmmirati, E.; Moroni, F.; Magnoni, M.; Di Terlizzi, S.; Villa, C.; Sizzano, F.; Palini, A.; Garlaschelli, K.; Tripiciano, F.; Scotti, I.; Catapano, A.; Manfredi, A.; Norata, Giuseppe; Camici, P. (2016)Background and aims: Monocytes are known to play a key role in the initiation and progression of atherosclerosis and contribute to plaque destabilization through the generation of signals that promote inflammation and ...