Dimeric IL-2 is cytotoxic to multiple cell types.

<p>Dimeric IL-2, isolated from murine aortas or conditioned media from EL-4 T lymphoma cells were added to cultures of (A) primary human vascular smooth muscle cells, (B) normal rat kidney cells (NRK cell line), (C) human renal epithelial cells (HK-2 cell line), (D) murine melanoma cells (B16-F10). The cells were incubated for 2 h with increasing concentrations of dimeric IL-2. Cytotoxicity was assessed by release of LDH and expressed as % lysis (experimental/total lysis x 100). Smooth muscle cells cultured under identical conditions with either 1000 ng/ml eluted, commercial, murine IL-2 or eluate from an empty gel slice each yielded a % lysis of 2.9%, and 3.2% respectively. Results shown are the means ± SD of triplicate wells, and are representative of 5–20 experiments. Percent lysis is significantly different across the 4 concentrations of dimeric IL-2 in each figure (A–D, p = 4.8×10⁻⁷, p = 3.2×10⁻⁷, p = 1×10⁻⁴, p = 1.8×10⁻¹⁰, by ANOVA).