Volume 22, Issue 1, Pages 27-35 (January 2018) Although Abundant in Tumor Tissue, Mast Cells Have No Effect on Immunological Micro-milieu or Growth of HPV-Induced or Transplanted Tumors  Shanawaz Mohammed Ghouse, Anastasia Polikarpova, Lina Muhandes, Jan Dudeck, Iliana Tantcheva-Poór, Karin Hartmann, Matthias Lesche, Andreas Dahl, Sabine Eming, Werner Müller, Rayk Behrendt, Axel Roers  Cell Reports  Volume 22, Issue 1, Pages 27-35 (January 2018) DOI: 10.1016/j.celrep.2017.12.010 Copyright © 2017 The Authors Terms and Conditions

Cell Reports 2018 22, 27-35DOI: (10.1016/j.celrep.2017.12.010) Copyright © 2017 The Authors Terms and Conditions

Figure 1 Efficient Depletion of MCs in Transformed Skin (A) Representative ear skin sections (Giemsa stain; scale bar, 50 μm; dashed line, basement membrane) and MC numbers in ear skin of K14-HPV16+R26DTA/DTAMcpt5-Cre+ mice, Cre-negative littermates and 6-month-old K14-HPV16-negative controls (n = 3–5 per group). MCs were counted per 5-mm horizontal dermal length per animal (means ± SD; ∗∗∗p < 0.0001 and ∗p < 0.01). (B) Flow cytometric analysis of MCs in ear skin suspensions from 10-week-old K14-HPV16 transgenics (means ± SD; ∗∗∗p < 0.0001 and ∗∗p < 0.001). (C) Representative sections of tumor tissue (chloroacetate esterase, MCs in red) and numbers of MCs in sections of inoculated tumors in R26DTA/DTAMcpt5-Cre+ mice or controls (n = 9–20 per group, 20 days post-inoculation [p.i.] for MB49 and LLC tumors and 16 days p.i. for B16F10 tumors). MCs were counted per 3 random high-power fields at the periphery of tumors (means ± SD; ∗∗∗p < 0.0001 and∗∗p < 0.001). Cell Reports 2018 22, 27-35DOI: (10.1016/j.celrep.2017.12.010) Copyright © 2017 The Authors Terms and Conditions

Figure 2 The Absence of MCs Has No Impact on HPV-Induced Epithelial Growth and Neovascularization Ear skin sections from MC-proficient (R26DTA/DTA Cre-negative) and MC-deficient (R26DTA/DTAMcpt5-Cre+) K14-HPV16 transgenics aged 2 or 6 months and K14-HPV16-negative controls aged 6 months (n = 3–5/group). Representative images of 6-month-old mice are shown. Scale bars, 100 μm; ns, not significant. (A) Epithelial thickness was measured by determining epithelial area per millimeter epithelial length at 5 random positions/animal. Means ± SD; ∗∗∗p < 0.0001. (B) Ki67-expressing (brown staining) cells per total number of epithelial cells were counted in five random fields of vision/animal. Means ± SD; ns, not significant. (C) TUNEL+ cells were counted per ≥5-mm dermal length for each mouse. Means ± SD; ns, not significant. (D) Imaging of blood vessels by 2-photon microscopy upon intravenous (i.v.) injection of fluorescently labeled anti-PECAM antibody in ear skin of wild-type and K14-HPV16-transgenic mice aged 12–15 weeks that either lacked VEGF-A expression selectively in MCs (VegfaFL/FLMcpt5-Cre+) or lacked MCs (R26DTA/WTMcpt5-Cre+). Scale bars, 100 μm. (E) Quantification of vessel area as the percentage of total image area (left) and of vessel-branching points per image area (right). Means ± SD are shown (n = 3 per group, age 12–15 weeks; ∗∗∗p < 0.0001). Cell Reports 2018 22, 27-35DOI: (10.1016/j.celrep.2017.12.010) Copyright © 2017 The Authors Terms and Conditions

Figure 3 No Change of the Immunological Tumor Micro-milieu in the Absence of MCs (A) Composition of the inflammatory cell infiltrate in ear skin of K14-HPV16+R26DTA/WT littermates that were Mcpt5-Cre+ or Cre-negative and littermates negative for the K14-HPV16 transgene, as determined by FACS. Absolute numbers and SD of the cell types obtained from 1 entire ear of 1-year-old animals are shown (∗∗∗p < 0.001 and ∗∗p < 0.01). (B) Transcriptome comparisons of CD45+ non-MCs from MC-proficient versus MC-deficient mice (both groups n = 3 at 2 months and n = 5 at 6 months). MC-specific genes were excluded from the analysis as explained in the legend of Table S2. Significantly deregulated transcripts (p adjusted [padj] < 0.1, log2 fold change ≥ 1) are shown in red. (C) mRNA levels of genes associated with macrophage differentiation in macrophages purified from ear skin of MC-proficient (age 3 months, n = 8–15; age 1 year, n = 9–11) and MC-deficient (age 3 months, n = 3–9; age 1 year, n = 7–10) K14-HPV16 transgenics determined by qRT-PCR. Relative quantification was performed by comparison to mean transcript levels in macrophages from K14-HPV16-negative controls (n = 16), which were set to 1. ∗∗∗∗p < 0.0001, ∗∗∗p < 0.001,∗∗p < 0.01, and ∗p < 0.1. (D) Composition of the inflammatory cell infiltrate in MB49 tumors in MC-proficient or MC-deficient (R26DTA/DTAMcpt5-Cre+) recipients, as determined by FACS. Absolute numbers of the cell types indicated per gram of tumor tissue are shown. Means ± SD; ∗∗∗∗p < 0.0001, ∗∗∗p < 0.001, ∗∗p < 0.01, and ∗p < 0.1. Immune cell numbers of non-lesional back skin of the same mice are shown for comparison. See Figure S3 for results in B16 tumors. (E) Transcriptome comparison of macrophages from inoculated tumors in MC-proficient versus MC-deficient recipients (n = 5 or 6 per group). (F) mRNA levels of genes associated with macrophage differentiation in macrophages purified from inoculated tumors in MC-proficient (MB49, n = 13; B16, n = 7) or MC-deficient (MB49, n = 11; B16, n = 8) mice, determined by qRT-PCR at 20 days p.i. (MB49) or 16 days p.i. (B16 tumors). Mean transcript levels in macrophages from non-lesional skin were set to 1. ∗∗∗∗p < 0.0001, ∗∗∗p < 0.001,∗∗p < 0.01, and ∗p < 0.1. Cell Reports 2018 22, 27-35DOI: (10.1016/j.celrep.2017.12.010) Copyright © 2017 The Authors Terms and Conditions

Figure 4 Malignant Growth in the Absence of MCs (A) Major parts of SCC tissue in aged R26DTA/WTMcpt5-Cre+ K14-HPV16 transgenics are free of MCs. However, expansion of MC clones is found in most tumors (see Figure S1), limiting interpretation. 3 SCCs were completely devoid of MCs. Giemsa stain; scale bar, 50 μm. (B) Incidence of SCC in MC-proficient (R26DTA/WT, n = 28) and MC-deficient (Mcpt5-Cre R26DTA/WT, n = 19) K14-HPV16 transgenics. (C) Growth kinetics of inoculated tumors in MC-proficient and MC-deficient recipients. MB49 (male) growth is slower in female compared to male recipients, however, in any case independent of MCs. Means ± SD; ∗∗∗p < 0.001. Cell Reports 2018 22, 27-35DOI: (10.1016/j.celrep.2017.12.010) Copyright © 2017 The Authors Terms and Conditions