Fig. 4From: The CC chemokine ligand (CCL) 1, upregulated by the viral transactivator Tax, can be downregulated by minocycline: possible implications for long-term treatment of HTLV-1-associated myelopathy/tropical spastic paraparesisHTLV-1 Tax transactivates the CCL1 gene by acting concurrently on AP-1- and CREB-binding sites. The luciferase gene was used to monitor the activity of the CCL1 gene promoter. Four fragments of the 5′-flanking regulatory region of the CCL1 gene were cloned upstream of the luciferase gene, yielding four constructs. These reporter constructs were independently transfected into Jurkat human T-cells with or without the Tax expression plasmid. The results showed that both AP-1- and CREB-binding sites were essential and sufficient for transactivation of the CCL1 gene by HTLV-1 TaxBack to article page