CD4 and Sepsis: Regardless of whether MDSCs came from sepsis survivors who developed CCI or rapidly recovered, PBMC-derived CD11b+CD33+HLA-DRdim MDSCs obtained prior to day 7 were not immunosuppressive, while MDSCs obtained at or after day 14 (all CCI patients) suppressed both autologous CD4+ and CD8+ T-cell proliferation to antiCD3/CD28 (Figure 3).