Fig. 2

Dot blot kinetics of MDSC. Representative dot plots of gMDSC (a–c) and mMDSC (d–f) after 2, 4, 6 h, overnight rest and freezing/thawing procedure of three HIV patients (gMDSC) and three patients with solid tumors (mMDSC). PBMC were stored in RPMI media after the ficoll separation gMDSC gated on CD11b⁺ and CD14⁻ population (oval gate); for CD15⁺/CD66b⁺ gating see Additional file 2: Figure S2; mMDSC gated on CD33⁺ and HLA-DR^low/− (rectangle gate); CD14⁺ gating not shown. The majority of dot blots (a) of the CD11b⁺/CD14⁻ population remained similar after 2, 4 and 6 h. However, it was not clearly definable after ON and almost disappeared after the freezing/thawing procedure. Divergent minor presentations were seen and are presented in the remaining panels: increasing gMDSC frequencies after overnight rest and relatively high gMDSC levels after freezing/thawing (b) as well as reduction of gMDSC numbers at 4, 6 h and overnight rest compared to the 2 h time point (c). Looking at mMDSC (CD33⁺ and HLADR^−/low population), again the majority of dot blots presented as shown in 2d: similar numbers of mMDSC after 2 and 4 h and a clear reduction in mMDSC frequencies after 6 h. Populations are not well discriminable after overnight rest and after freezing/thawing. Minor divergent presentations are shown in the remaining panels: very high mMDSC frequencies after freezing/thawing (e) as well as increased frequencies after overnight rest and loss of mMDSC after freezing/thawing (f)