Summary of Findings Regarding Myosin II Function
| Paper | Cells | Stimulation | Myosin II perturbation |
molecules Signaling at the IS |
cSMAC formation | pSMAC formation | TCR MC translocation |
Actin dynamics | Ca++ signaling | Kinase signaling | Additional Relevant Findings |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Jacobelli 2004 [31] | D10 (murine CD4+ T cell clone) | Ag pulsed B cells | Blebbistatin | Yes | Yes – fixed at late time point | Yes – fixed at late time point | – | – | – | – | T cell migration is inhibited by BB. TCR signals induce phosphorylation of myosin II HC. |
| Ilani 2009 [42] | Jurkat (human CD4+ T lymphoma) | OKT3/ICAM1 on bilayers | Blebbistatin | Yes | Inhibited | – | inhibited | – | Inhibited | pSrc OK, pLAT and pZAP70 reduced | BB destabilizes T cell-APC contacts. TCR signals induce phosphorylation of myosin II light chain. |
| Human primary CD4+ T cell blasts | OKT3/ICAM1 on bilayers | siRNA | Yes | Inhibited | – | inhibited | – | – | pSrc OK, pLAT and pZAP70 reduced | ||
| Yi 2012 [27] | Jurkat | OKT3/ICAM1 on bilayers | Blebbistatin | Yes | Delayed | Poorly focused | slowed, meandering increased | Slowed, arcs buckle | – | – | Rates of centripetal actin flow and TCR MC transport match in the dSMAC/LP and pSMAC/LM. |
| Yu 2012 [29] | Murine CD4+ AND T cell blasts | pMHC/ICAM1 on bilayers | ML-7 | Yes | Slightly delayed | Unaffected | Eliminates early fast phase; later phase unaffected | Eliminates early fast phase; later phase unaffected | Inhibited | pZAP70 reduced | BB and ML-7 inhibit phosphorylation of the mechano-sensing protein CasL. |
| Blebbistatin | Yes | Slightly delayed | Unaffected | Eliminates early fast phase; later phase unaffected | – | – | pZAP70 reduced | ||||
| Babich 2012 [28] | Jurkat | OKT3 on glass | Y-27632 | Yes | – | – | TCR MCs not measured, but SLP76 MCs unaffected | Unaffected | Unaffected | pZAP70 and pPLCγ1 OK | Actin dynamics are required for sustained signaling through PLCγ1. |
| Blebbistatin | – | – | – | – | Unaffected | – | – | ||||
| siRNA | – | – | – | – | Unaffected | – | – | ||||
| Human primary CD4+ T cell blasts | OKT3 on glass | Y-27632 | – | – | – | – | Unaffected | – | – | ||
| Kumari 2012 [45] | Murine CD4+ AND T cell blasts | pMHC/ICAM1 on bilayers | siRNA | Yes | Inhibited | Poorly focused | TCR slowed slightly, path length unaffected, meandering increased | – | Blunted | pSrc inhibited | Myosin II suppression inhibits TCR-induced phosphorylation of CasL. |
| Beemiller 2012 [44] | Murine CD8+ OTI T cell blasts | pMHC/ICAM1 on bilayers | Blebbistatin | Yes | Unaffected | – | Unaffected (track length, speed, straightness) | – | – | – | The central actin depleted zone and the cSMAC are offset in migrating T cells. |
| Ex vivo gene deletion | Yes | Unaffected | – | Unaffected (track length, speed, straightness) | – | – | – |