Involvement of CD244 in CD8⁺ T cell degranulation and IFN-γ expression of patients with HAM/TSP.

(A) Representative dot plot of spontaneous degranulation and IFN-γ expression in CD8⁺ T cells of a ND and a patient with HAM/TSP after culture for 24 hours. The PBMCs were cultured for 24 hours without any exogenous stimulators. (B) Dose-dependent inhibition of spontaneous degranulation and IFN-γ expression in CD8⁺ T cells of a patient with HAM/TSP by anti-CD244 (closed circle) and anti-CD48 (opened circle). The PBMCs were cultured with each antibody for 24 hours. (C) Inhibitory effects of anti-CD244 and anti-CD48 on degranulation and IFN-γ production in CD8⁺ T cells of patients with HAM/TSP. The PBMCs were cultured with 1 µg/ml of control IgG, anti-CD244 or anti-CD48 for 24 hours. The amount of CD107a/IFN-γ expressions of CD8⁺ T cells cultured with control IgG were normalized to 100%, and then, those in PBMCs cultured with each antibody were calculated. The graph was prepared from data obtained from 7 patients with HAM/TSP. Error bars represent SD. (D) CD48 and Tax expression in HTLV-I-infected cells of a patient with HAM/TSP. The top panels show CD48 and Tax expression in CD4⁺ T cells before (left) and after (right) the culture for 20 hours. The bottom panels show CD48 and Tax expression in CD14⁺ cells before (left) and after (right) the culture for 20 hours.