Skip to main content
. Author manuscript; available in PMC: 2015 Jan 1.
Published in final edited form as: Crit Rev Oncog. 2014;19(0):91–105. doi: 10.1615/critrevoncog.2014011142

FIG. 1. Accumulation of IL-2–activated NK (A-NK) cells selectively at tumor sites.

FIG. 1

Flow-sorted NKp46+ splenocytes from congenic Thy1.1+ C57BL/6 mice were cultured with IL-2 for 5 days and injected i.v. into C57BL/6 mice (Thy1.2+) with 9-day-old B16 tumors. Each mouse received 5 million A-NK cells. 30,000 IU Peg–IL-2 was injected i.p. every 12 h (max. six injections). Organs were removed at 72 h after injection of the A-NK cells and fresh frozen. Eight micron cryosections were all stained with PE-conjugated anti-Thy1.1 antibodies (NK cells begin to express Thy1 within 24 h of IL-2 activation). Some sections were also stained with FITC-conjugated anti-laminin antibodies. (A) DIC picture of lung tissue with multiple black-pigmented B16 melanoma metastases. (B) Fluorescent photomicrograph of the same sections as in (A), showing a dense accumulation of PE-Thy1.1+ A-NK cells (red dots) selectively in the black-pigmented metastases. White arrow points to a single PE-Thy1.1+ A-NK cell. (C) and (D) same as (A) and (B), respectively, but at higher magnification and with staining of laminin (green fluorescence in (D)). Note the strong preference of the A-NK cells for the tumor tissue. (E) and (F) show a DIC and a fluorescent picture, respectively, of laminin-stained ovarian tissue (green in (F)) with a black-pigmented B16 metastasis infiltrated by PE-Thy1.1+ A-NK cells. Bars in A–B = 200 μm, Bars in C–F = 100 μm.