Hi fellow researchers.

I am working with CAR T cells targeting baffr. We inject jeko WT cells in the mice and treat with non-functional/CD19/BAFFR CAR T cells. My question is: in mice treated with non-functional CAR T cells, we have observed that only 20% of jeko cells are WT, the rest has lost BAFFR (60%) or both CD19 and BAFFR (20%). How can this be? Are they loosing it when they get into the mouse? And why? We use NXG mice. We would expect cd19 car t treated mice to loose cd19 on jeko by antigen escape, but here we also observe that most just loses baffr. Any thoughts?

Best

Kimmie