Fig. 2.

Tax-dependent constitutive expression of CCL1 in Tax-inducible JPX9 cells. RNA and protein expression of CCL1 in JPX9 cells. JPX9 is a Jurkat (HTLV-1-negative human T-cell leukemia cell line) subclone generated by stable transfection of a functional Tax expression-plasmid vector. Tax expression was induced by adding CdCl₂ to the culture medium (final concentration: 10 μM). RT-PCR (a) and western blotting (b) showed that treatment of JPX9 cells with CdCl₂ induced the expression of Tax at the RNA and protein levels, respectively. c. Flow cytometry data showed that treatment of JPX9 cells with CdCl₂ induced CCL1 expression and that CCL1 was expressed exclusively in cells that also expressed Tax. d. ELISA analysis of culture supernatants showed that the addition of CdCl₂ to the JPX9 cell culture resulted in an increase in CCL1 expression within 24 h. CCL1 levels were found to reach a peak after 48 h of culture