Vascular targeting of anti-CD40 antibodies and IL-2 into autochthonous tumors enhances immunotherapy in mice
J. Clin. Invest. Juliana Hamzah, et al. 118:1691 doi:10.1172/JCI33201 [Go to this article.]

Figure 4
CD40 expression on tumor blood vessels. (A) To display blood vessels, 27-week-old RIP1-Tag5 mice were i.v. injected with FITC-labelled tomato lectin. Tumors were harvested and stained with anti-CD40 antibodies. Equally strong CD40 signals were visible in tumor nodules of different sizes analyzed in RIP1-Tag5 mice at 23, 25, and 30 weeks of age (data not shown). (B) CD40 expression is not detectable by immunohistochemistry in normal pancreatic tissue. Dotted lines delineate islet of Langerhans. (C) CD40 expression on lectin-perfused tumor vessels from 27-week-old CD40^–/–→RIP1-Tag5 (CD40^–/–→RT5) mice and (D) absence of CD40 expression on the vasculature of 27-week-old C3H→RIP1-Tag5×CD40^–/– mice displayed after anti-CD31 and anti-CD40 staining. Original magnification, ×40. Scale bar: 25 μm. (E) Survival analyses of chimeric RIP1-Tag5 mice and (F) chimeric RIP1-Tag5 mice after anti-CD40–RGR/IL-2–RGR combination treatment (n = 8; P = 0.004 and P = 0.03 compared with chimeric untreated controls).