Plexin B1 and Plexin D1 expression in the mouse lung tissue and its regulation by either allergen or transgenic VEGF exposure. (A) Plexin B1 expression was detected on selected bronchial epithelial cells in control WT mice with increased expression in allergen-treated mice. Under inflammatory condition, its expression was detected on a number of APC-like cells (insert, red arrow). Plexin D1 expression was restricted to endothelial and a number of bronchial epithelial cells. In addition, Plexin D1 was found on underlining epithelium cells (insert, red arrow). (B) Plexin B1 expression on lung conventional DC under inflammation. WT mice were treated with OVA as described in Materials and Methods and lung cDC were identified as CD11c+MHCII+ cells which were gated for further analysis. The histograms show the percentage of Plexin B1+ gated cDC (clear histogram) as compared to the appropriate isotype control stained cells (gray histogram). (C) Notable upregulation of the expression of both Plexins in VEGF tg lungs was mainly targeted to inflammatory macrophages found in the interstitial spaces.