1. Increased, but Functionally Impaired, CD14+ HLA-DR–/low Myeloid-Derived Suppressor Cells in Psoriasis: A Mechanism of Dysregulated T Cells 
David C. Soler, Andrew B. Young, Lori Fiessinger, Fabrizio Galimberti, Sara Debanne, Sarah Groft, Thomas S. McCormick, Kevin D. Cooper 
Journal of Investigative Dermatology 
Volume 136, Issue 4, Pages (April 2016)
DOI: /j.jid
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2. Figure 1
Frequency of monocytic myeloid-derived suppressor cells (Mo-MDSCs) is increased in psoriatic patients. (a, b) Representative flow cytometry panels for isotype-based quantification of Mo-MDSCs from peripheral blood mononuclear cells (PBMCs) subjected to CD14 magnetic bead selection of (a) healthy control subjects and (b) psoriasis patients. (c) Cumulative data representing the frequency of HLA-DR–/low cells among CD14+ cells selected by magnetic separation from 18 healthy controls and 22 psoriatic patients, respectively (P < 0.002). (d) Cumulative data representing the frequency of CD14+ HLA-DR–/low population in 17 healthy donors and 19 psoriatic patients determined by flow cytometry measuring expression of CD14+HLA-DR–/low among PBMCs (P < 0.002). (e) Average HLA-DR median fluorescence intensity (MFI) of CD14+ HLA-DR–/low cells from 13 healthy controls and 16 psoriasis patients (P < 0.02). (f) Correlation analyses among psoriasis severity assessed by psoriasis area and severity index (PASI) and percentage of circulating Mo-MDSCs among CD14+ monocytes revealed a significant positive correlation (n = 22, r = 0.72, P = ).
Journal of Investigative Dermatology  , DOI: ( /j.jid )
Copyright © 2016 The Authors Terms and Conditions

3. Figure 2
Psoriatic peripheral blood monocytic myeloid-derived suppressor cells (Mo-MDSCs) are less potent direct inhibitors of T-cell proliferation. Magnetic bead-sorted CD14+ HLA-DR–/low (bottom 10%) purified from peripheral blood of normal volunteers and psoriatic patients were mixed directly 1:2 with autologous CD8 T cells. Proliferation was assessed by dilution of the far-red dye e670. (a) Representative suppression assays by dye dilution for control (top panel) and psoriasis (bottom panel) Mo-MDSCs compared to stimulated CD8 T cells without Mo-MDSCs or unstimulated CD8 T cells. (b) Normalized average proliferation from mixed Mo-MDSC–CD8 T cell co-cultures from 8 healthy volunteers (47%) and 9 psoriatic patients (106%) compared to basal proliferation of bead-stimulated healthy CD8 T cells alone (100%) and bead-stimulated psoriatic CD8 T cells alone (100%). (c) Representative criss-cross suppression assays mixing control Mo-MDSCs with psoriatic CD8 T cells or vice versa. (d) Normalized average proliferation from control from 4 healthy volunteers (66%) versus psoriatic Mo-MDSCs mixed with control CD8 T cells from 3 psoriatic patients (100%) compared to basal proliferation of bead-stimulated healthy or psoriatic CD8 T cells alone (100%). Whereas control Mo-MDSCs are effective at suppressing CD8 T-cell proliferation (first panel), psoriatic Mo-MDSCs fail to suppress CD8 T-cell proliferation (second panel).
Journal of Investigative Dermatology  , DOI: ( /j.jid )
Copyright © 2016 The Authors Terms and Conditions

4. Figure 3
Psoriatic monocytic myeloid-derived suppressor cells (Mo-MDSCs) exhibit decreased PD-1 and PD-L1 surface expression. (a) Representative flow cytometry scheme for analysis of Mo-MDSC surface expression of PD-1. (b) Cumulative comparison of PD-1 expression on control versus psoriatic Mo-MDSCs (28% vs. 13% respectively, P = 0.028, based on nonparametric testing for equality of medians and equality of distribution, Mann-Whitney U test). (c, d) Representative flow cytometry scheme for analysis of Mo-MDSC surface and cumulative measurement of PD-L1 expression, respectively. Cumulative comparison of PD-L1 expression on control versus psoriatic Mo-MDSCs is shown in panel d (16% vs. 4%, P = 0.055, based on nonparametric testing for equality of medians and equality of distribution, Mann-Whitney U test). Although approximately 50% of the control patients (4/8) exhibit PD-L1 levels below the mean expression, the majority of psoriasis patients (12/14) exhibit less PD-L1 expression than the mean. PD-1, programmed cell death protein 1; PD-L1, programmed death-ligand 1.
Journal of Investigative Dermatology  , DOI: ( /j.jid )
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5. Figure 4
Psoriatic and normal monocytic myeloid-derived suppressor cells (Mo-MDSCs) induce regulatory T cell (Treg) forkhead box p3 (Foxp3) expression, and psoriatic Mo-MDSC–induced Tregs are dysfunctional. (a) CD14+ HLA-DR–/low cells were co-cultured with effector T cells (CD4+ CD25– bottom 20%) for 3 days. Staining for Foxp3 was performed after the 5 day co-culture with Mo-MDSCs from either healthy control volunteers (triangles) or psoriasis patients (circles). Cumulative results of the percentage of induced CD4+ CD25+ Foxp3+ T cells (iTregs) are shown for Mo-MDSC–induced iTreg versus CD4+ CD25– effector T cells alone stimulated with anti-CD2/CD3/CD28 antibody-coated beads. (b) Psoriatic or healthy control subject Mo-MDSCs were mixed with autologous CD4+ CD25– T cells that were previously stimulated with anti-CD2/CD3/CD28 antibody-coated beads for 3 days to generate iTregs. The iTregs were then co-cultured with proliferating autologous CD8 T cells for 5 days. CD8 T-cell proliferation was assessed by dilution of the far-red dye e670. Healthy control Mo-MDSC–induced iTregs suppressed proliferating CD8 T cells effectively (44% proliferation, n = 5), whereas psoriatic Mo-MDSC–induced iTregs did not suppress CD8 T-cell proliferation (83% proliferation, n = 4, P = 0.009).
Journal of Investigative Dermatology  , DOI: ( /j.jid )
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6. Figure 5
In situ localization of monocytic myeloid-derived suppressor cells (Mo-MDSCs) in psoriatic and healthy control skin. Monocytes positive for CD14-Alexa Fluor 647 but negative for HLA-DR–FITC expression (white arrows) were marked as Mo-MDSCs and can be visualized in the dermis of (a) psoriasis or (b) healthy control patients as well as in the dermal epidermal junction region (indicated by the dashed white line), compared to double-positive CD14+ HLA-DR+ (orange arrows) or CD14– HLA-DR+ (gray arrows) cellular infiltrates into psoriasis tissue. Bar = 0.2 mm.
Journal of Investigative Dermatology  , DOI: ( /j.jid )
Copyright © 2016 The Authors Terms and Conditions