Hi all,

I have been trying to activate isolated T cells for CAR T generation and something abnormal has happened twice. After the T cells are spiked with a 1:1 ratio of Dynabeads, a day after they begin to clump like normal, but they seem to start dying faster than expected. They are then transduced with lentivirus and after two days the T cells are extremely stringy and clumped around the Dynabeads in long strands. The media is unspent and the cell count is extremely low, and much of cells have died.

I have successfully done this twice and now utilizing the same T cell donor, lentivirus, and same lots of reagents (media, dynabeads, IL-2, etc.) the cells are doing this and I can't figure out why. The entire process is exactly the same as the successful run.

Has anyone ever seen this before? Any ideas what could be causing this?

Thanks!