We previously reported that co-stimulation with LFA-1 triggered apoptosis in γδ T cells but not in αβ T cells after TCR engagement. We extended our earlier study on TCR/LFA-1 triggered apoptosis to two autoreactive TCR γδ and TCR αβ T cell clones, which were derived from syngeneic mixed lymphocyte culture of BALB/c mice. A γδ T cell clone, KM1, expressed the Vγ4 and Vδ5 genes and CD4-CD8-CD45RB+ phenotype; and an αβ T cell clone, BASL1.1, expressed Vβ6 and CD4+CD8-CD45RB+. Both clones produced Th-1-type cytokines in response to syngeneic BALB/c stimulator cells. KM1 underwent apoptosis upon stimulation with immobilized anti-CD3/LFA-1 mAbs, whereas BASL1.1 could proliferate successfully in response to stimulation with the immobilized mAbs. BASL1.1 was able to down-regulate the increased cytosolic Ca2+ after the simultaneous stimulation, but KM1 exhibited a sustained increase of cytosolic Ca2+ after stimulation via CD3 and LFA-1. Similar results with respect to the kinetics of cytosolic Ca2+ were obtained with normal heterogeneous γδ and αβ T cell populations after cc-stimulation via CD3 and LFA-1. Our results suggested that persistently high levels of cytosolic Ca2+ might be related to apoptosis in γδ T cell clone triggered by co-stimulation via CD3 and LFA-1.
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology