Table 1.

HTLV-1 quantitative immortalization assay

# of producer cells	Number of wells with immortalized cells (48 wells/assay)
	HTLV-1	HTLV-1∆CTCF	HTLV-1p12Stop
1	2 (4%)	2 (4%)	0 (0%)
10	9 (19%)	8 (17%)	6 (13%)
100	20 (42%)	14 (29%)	14 (29%)
1000	31 (65%)	27 (56%)	28 (58%)

There is no difference between HTLV-1, HTLV-1 p12Stop, and HTLV-1∆CTCF immortalization capacity. Freshly isolated hPBMCs were cocultured with fixed numbers of lethally irradiated viral producer cells in 96-well plates. The number of wells containing proliferating lymphocytes was enumerated.