Fig 1.
PD-L1 induction of iTregs from human memory CD4 T cells.
Healthy donors’ (upper light green level) naive CD4 CD25− T cells (green cells) and memory CD45RO+CD45RA− CD4 cells (blue cells) were activated with plate-bound anti-CD3 and anti-PD-L1. Memory CD4 cells (blue cells) were the main source of highly suppressive iTreg (violet cells) with high production of IL-10. Same activation of CD4+CD25− memory and naive T cells from rheumatoid arthritis patients (lower pink level) failed to generate major suppressors of autoimmunity—Tregs. Created with biorender.com. hrIFNg, human recombinant interferon gamma; IFNg, interferon gamma; IL-10, interleukin 10; iTregs, inducible regulatory T cells; PD-L1, programmed cell death 1 ligand; pERK, phosphorylated ERK.