Although this talk is not about Treg (regulatory T) cells and hair, he is discussing how Tregs may be cultured and used therapeutically. I think this may be a key line of research to ensuring that cell therapy can work well for hair loss.
I think there is good reason to believe that the initial target of DHT might be the Tregs cells, instead of the follicle. (This is just speculation on my part, but I think it needs to be studied.)
Note: it is known that androgen receptors can modulate gene expression in regulatory T cells…