Journal: Gut

Article Title: Targeted depletion of an MDSC subset unmasks pancreatic ductal adenocarcinoma to adaptive immunity.

doi: 10.1136/gutjnl-2013-306271

Figure Lengend Snippet: Figure 1 Cancer-conditioned myeloid cells chronicle the evolution of pancreatic ductal adenocarcinoma (PDA) in KPC mice. (A) The number of pancreatic Treg (CD45+CD4+FoxP3+), macrophages (CD45+CD11b+F4/80+), myeloid-derived suppressor cells (MDSC) (CD45+CD11b+RB6-8C5 [Ly6G/ Ly6C]+) and NK cells (CD45+NK1.1+) for each pancreas were quantified from normal pancreas (nl), 6–8-week-old KPC pancreata with confirmed preinvasive disease (Pre) and invasive tumours (PDA). Significant differences were detected in the number of Treg, tumour-associated macrophages and MDSC during disease progression. (B) Evolving profiles of three distinct populations of myeloid cells (gated on CD45+CD11b+) were seen in various organs based on expression patterns of Gr-1 and Ly6C. BM, bone marrow; LN, lymph node. (C) The percentages (top panel) and absolute numbers (bottom panel) of CD45+CD11b+ myeloid populations in the spleen and pancreas in normal (black filled circles) and preinvasive (grey filled circles) and invasive (open circles) disease settings. Data are plotted as mean±SEM and each data point represents an individual mouse. Granulocytic MDSC (Gr-MDSC)=CD45+CD11b+Gr-1highLy6Cint; monocytic MDSC (Mo-MDSC)=CD45+CD11b+Gr-1intLy6Chigh and macrophage (Mac) =CD45+CD11b+Gr1intLy6Cint. (D) Specific immunofluorescence reveals rare Ly6G/Ly6C+ (RB6-8C5) cells in normal pancreas, focal accumulation in pancreata with preinvasive disease and diffuse infiltration in invasive PDA. Specific Ly6G immunofluorescence demonstrates that Gr-MDSC are absent from normal pancreas, rare in preinvasive disease and abundant in invasive PDA. The majority of myeloid cells in normal pancreas and surrounding preinvasive lesions appear to be macrophages. Arrowheads, epithelial cells; arrows, myeloid cells; asterisk, Gr-MDSC. Scale bars, 50 mm. (E) Ly6G/Ly6C (RB6-8C5) staining in normal pancreas and KPC salivary gland. Arrowheads, epithelial cells; arrows, myeloid cells. Scale bars, 10 mm. *p<0.05; **p<0.005; ***p<0.0005.

Article Snippet: For immunofluorescence, OCT tissue sections (7 μm) were fixed in acetone at −20°C, blocked with phosphatebuffered saline (PBS)/1% bovine serum albumin (BSA) and incubated with the following primary antibodies: cleaved caspase-3 (Cell Signalling D175, 1:200), CD8α (BD Biosciences 53-6.7, 1:25), Gr-1 (eBioScience RB6-8C5, 1:50), Ly6G (Bioxcell 1A8, 1:50), PanCK-FITC (Sigma-Aldrich F3418, 1:200), SMA-1 (DAKO 1A4, 1:100), CD31 (BD Biosciences 390, 1:50), GMCSF (Biolegend, 1:50) or granzyme B (R&D Systems, 1:50).

Techniques: Derivative Assay, Biomarker Discovery, Expressing, Staining

Journal: Gut

Article Title: Targeted depletion of an MDSC subset unmasks pancreatic ductal adenocarcinoma to adaptive immunity.

doi: 10.1136/gutjnl-2013-306271

Figure Lengend Snippet: Figure 4 Systemic administration of 1A8 (αLy6G) specifically depletes Gr-myeloid-derived suppressor cells (Gr-MDSC) in autochthonous pancreatic ductal adenocarcinoma (PDA). (A) Representative myeloid cell profiles in peripheral blood mononuclear cells from a normal mouse and untreated (KPC) and 1A8-treated KPC (KPC + 1A8) mice. Numbers indicate the percentage of each subset gated on CD45 mononuclear cells. We note that the gates for the discrete subpopulations defined in the blood were then applied to the tissue-specific analyses. (B) Percentage of Gr-MDSC (squares) and monocytic MDSC (Mo-MDSC; circles) in blood after 1A8 treatment. Data represent mean±SD from three independently treated animals. (C) Representative fluorescence activated cell sorting (FACS) profiles of CD45+ CD11b+ splenocytes from control (−) and 1A8-treated (+) KPC mice (4–6 animals per group). (D) Both the percentage and number of splenic Gr-MDSC at endpoint of 1A8 treatment (day 12) are significantly decreased (**, p=0.005). (E) Representative FACS profiles of intratumoral myeloid cells in control (−) and 1A8-treated (+) KPC mice at day 12 of Gr-MDSC depletion. (F) The percentage and number of Gr-MDSC in PDA at the endpoint are significantly decreased in 1A8-treated mice compared with control KPC mice.

Article Snippet: For immunofluorescence, OCT tissue sections (7 μm) were fixed in acetone at −20°C, blocked with phosphatebuffered saline (PBS)/1% bovine serum albumin (BSA) and incubated with the following primary antibodies: cleaved caspase-3 (Cell Signalling D175, 1:200), CD8α (BD Biosciences 53-6.7, 1:25), Gr-1 (eBioScience RB6-8C5, 1:50), Ly6G (Bioxcell 1A8, 1:50), PanCK-FITC (Sigma-Aldrich F3418, 1:200), SMA-1 (DAKO 1A4, 1:100), CD31 (BD Biosciences 390, 1:50), GMCSF (Biolegend, 1:50) or granzyme B (R&D Systems, 1:50).

Techniques: Derivative Assay, FACS, Control