Generation of non-human primate CAR Tregs using artificial antigen-presenting cells, simian tropic lentiviral vectors, and antigen-specific restimulation.

It is technically challenging to generate large doses of regulatory T cells (Tregs) engineered to express a chimeric antigen receptor (CAR) in non-human primates (NHP). Here, we have optimized the manufacturing of CAR Tregs by stringent sorting of Tregs, stimulation by artificial antigen-presenting cells, transduction by simian tropic lentiviral vectors, and antigen-specific expansion. The result of this method is highly suppressive CAR Tregs for use in a pre-clinical, large animal model of transplant tolerance.

Trafficking and persistence of alloantigen-specific chimeric antigen receptor regulatory T cells in Cynomolgus macaque.

Adoptive transfer of chimeric antigen receptor regulatory T cells (CAR Tregs) is a promising way to prevent allograft loss without the morbidity associated with current therapies. Non-human primates (NHPs) are a clinically relevant model to develop transplant regimens, but manufacturing and engraftment of NHP CAR Tregs have not been demonstrated yet. Here, we describe a culture system that massively expands CAR Tregs specific for the Bw6 alloantigen.