Interleukin-4 Receptor Expression on AIDS-Associated Kaposi’s Sarcoma Cells and Their Targeting by a Chimeric Protein Comprised of Circularly Permuted Interleukin-4 and Pseudomonas Exotoxin

Table 2 Cytotoxicity of IL-4(38-37)-PE38KDEL in AIDS-KS cells by protein synthesis inhibition assay

Cell type	IC₅₀ (ng/ml) Mean ± S.D.^a
AIDS-KS
KS248	1.7 ± 0.5
NCB-59	6.2 ± 3.5
KS54A	41^b
KS220B	42.5 ± 17.5
ARL-13	64.5 ± 6.0
Normal endothelial cells HUAEC	>1000^c

For cytotoxic assay, 10⁴ cells/well were cultured in 96-well microtiter plates with different concentrations (0.1 to 1000 ng/ml) of IL-4(38-37)-pe38kdel, as detailed in Materials and Methods.
^aIC₅₀, the concentration of IL-4 toxin at which 50% inhibition of protein synthesis occurred, was calculated from the graphs generated from the experimental data explained in Materials and Methods. The data are shown as the mean ± S.D. of two to five experiments done for each cell type.
^bIC₅₀ was determined from a single experiment.
^cIC₅₀ could not be achieved even at 1000 ng/ml concentration of IL-4 toxin.

ISSN: 1528-3658