Figure 1. Expression of CXCR2 and its ligands in papillomas and blood.

Papillomas were induced on WT Balb/c mice using DMBA/TPA. (A) Representative papilloma section immunostained with anti-MPO Ab (brown). Original magnification, ×200. (B) Live peripheral blood leukocytes (left) and bone marrow (right) immunostained with anti-Gr1 and anti-CXCR2 Ab and analyzed by flow cytometry. Gates defining Gr1⁺CXCR2⁺ cells (boxes) were set using anti-Gr1– and anti-CXCR2–immunostained Cxcr2^–/– peripheral blood leukocytes and bone marrow and isotype control–stained WT cells. (C) Relative abundance of transcripts for CXCR2 ligands in WT papillomas (determined by Q-RT-PCR). Mean of normal adjacent skin is set to 1. (D) CXCL1, CXCL2, and CXCL5 protein in lysates of WT papillomas and resting normal skin, measured by ELISA. (E) Relative abundance of transcripts for Cxcl1, Cxcl2, and Cxcl5 (determined by Q-RT-PCR) in stromal and tumor cells isolated from papillomas by LCM. Mean of stromal cells is set to 1. (F) Flow cytometry of a disaggregated papilloma (pregated for live cells) stained with anti-Ly6G and anti-CD11b Ab. Gate for CD11b⁺Ly6G⁺ cells (box) was defined using controls in which anti-Gr1 or anti-CD11b Ab had been replaced with an appropriate isotype control. Representative overlaid flow cytometry histogram plots of anti-CXCR2 (line) and isotype control (filled) immunostaining of CD11b⁺Ly6G^hi papilloma-associated cells are also shown. (G) As in F, but for CD11b⁺Ly6G^hi bone marrow cells. (H) As in C, but for Cxcr2. **P < 0.01, Mann-Whitney test.