1. Vascular leukocytes contribute to tumor vascularization
by Jose R. Conejo-Garcia, Ronald J. Buckanovich, Fabian Benencia, Maria C. Courreges, Stephen C. Rubin, Richard G. Carroll, and George Coukos
Blood
Volume 105(2):
January 15, 2005
©2005 by American Society of Hematology

2. Identification and characterization of a new population of vascular leukocytes.
Identification and characterization of a new population of vascular leukocytes. (A) Coexpression of CD45 (labeled with APC-Cy7) and VE-cadherin (labeled with fluorescein isothiocyanate [FITC]) defines a new population of tumor-infiltrating host cells. These are highly frequent in all solid human ovarian carcinoma specimens analyzed but are rare in tumor ascites (top, right) or peripheral blood from tumor-bearing patients (bottom, right). (B) Phenotypic discrimination between VLCs and classical endothelial cells. Results are representative of at least 3 different tumors analyzed for each marker. The y-axis shows antigen-presenting cell (APC)–labeled antibodies; the x-axis, phycoerythrin (PE)–labeled antibodies. A compensation control is also shown. (C) Side scatter (FSC and SSC) characteristics of the 3 main populations found in mechanically dissociated ovarian tumor specimens. (D) Real-time RT-PCR analysis of different leukocyte and endothelial makers in ECs, VLCs, HUVECs, and normal human spleen. Error bars indicate standard deviation.
Jose R. Conejo-Garcia et al. Blood 2005;105:
©2005 by American Society of Hematology

3. VLCs have the capacity to generate functional blood vessels in vivo.
VLCs have the capacity to generate functional blood vessels in vivo. (A) CFSE-labeled VLCs injected in Matrigel plugs into immunodeficient mice assembled into tomato lectin–perfusioned, Cy3-labeled blood vessels within 2 weeks. Combined image of CFSE-labeled cells and counterstaining with DAPI (4′,6-Diamidino-2-phenylindole) is also shown (magnification, × 200). CD45-VE-cadherin+ cells (ECs) also form functional neovessels, whereas CD45+VE-cadherin- cells (leukocytes) sorted from the same specimen remain as individual cells and do not partake in the formation of blood vessels assembled by host cells in the periphery of the Matrigel plugs (arrows). (B) VLCs cultured on fibronectin-coated plates in endothelial cell growth media developed cytoplasmic projections and intercellular junctions after 2 weeks. (Magnification, × 200.) (C) Capillaries in human tumors harbored CD45+ cells coexpressing the endothelial marker VE-cadherin. (Magnification, × 200.)‏
Jose R. Conejo-Garcia et al. Blood 2005;105:
©2005 by American Society of Hematology