Figure 1.

Vesicular stomatitis virus (VSV) infection and tumor perfusion are restricted to the tumor surface. A three-dimensional (3D) tumor model was reconstructed from two-dimensional (2D) digital images of serial histological sections. A CT-26 tumor-bearing BALB/c mouse was treated with VSV for 24 hours and perfused with fluorescent microspheres. (a) Serial sections from the excised tumor were stained with antibodies to VSV to visualize sites of virus infection. (b) Serial sections of an untreated tumor were then scanned for fluorescent microspheres in order to visualize perfusion. (c) A similar analysis of perfusion was generated from serial sections of a VSV-treated tumor. (d) Viewing the tumor in HTK Histology Toolkit reveals that infection (red) and perfusion (blue) are limited to the tumor surface. Areas of infection are localized to one region of the tumor surface. (e) 3D models of tumor perfusion of a VSV-treated tumor and a phosphate-buffered saline (PBS)-treated tumor were reconstructed from images of serial histological sections. Viewing perfusion of whole and half 3D models reveals that the surface of both VSV- and PBS-treated tumors are perfused. Half models show that the tumor core of the VSV-treated tumor is dramatically less perfused when compared to the PBS-treated tumor. (f) Using HTK Histology Toolkit, scanning through the VSV-treated tumor along x, y, and z axes consistently shows perfusion that is present in the tumor rim but absent from the core. In contrast, visualization of the PBS-treated tumor shows perfusion throughout the tumor.