FIG. 5.

CD70 expression on CD4⁺ T cells isolated from healthy donors and ATL patients. PBMCs were isolated from (A) an HTLV-1-negative healthy donor (HD-1 in Table 1) and (B) an acute-type ATL patient (ATL-1 in Table 1). The cells were examined for their CD4 and CD70 expression by laser flow cytometry after being gated by their forward and side scattering intensities. The percentage of CD70⁺ cells among CD4⁺ cells was calculated by the following formula: percentage of upper right quadrant/(percentage of upper right quadrant + percentage of lower right quadrant).