IL4 and tropical spastic paraparesis: To check this possibility, we differentiated monocytes from HAM/TSP patients to DCs using GM-CSF and IL-4 in the presence of azidothymidine (AZT), and the differentiated DCs were then co-cultured with Jurkat cells stably transfected with plasmid that encodes the tandem dimer Tomato (tdTomato) under the control of the Tax responsive element (JET WT35).