Masahiro Chiba, Joji Shimono, Takashi Ishio, Norio Takei, Kohei Kasahara, Reiki Ogasawara, Takahide Ara, Hideki Goto, Koh Izumiyama, Satoko Otsuguro, Liyanage P Perera, Hiroo Hasegawa, Michiyuki Maeda, Satoshi Hashino, Katsumi Maenaka, Takanori Teshima, Thomas A Waldmann, Yibin Yang, Masao Nakagawa
Blood 140 (18) 1951 - 1963 2022/08/03
Adult T-cell leukemia/lymphoma (ATLL) is one of the aggressive peripheral T-cell neoplasms with a poor prognosis. Accumulating evidence demonstrates that escape from adaptive immunity is a hallmark for ATLL pathogenesis. However, the mechanisms by which ATLL cells evade NK-cell-mediated immunity have been poorly understood. Here we show that CD48 expression in ATLL cells determines the sensitivity for NK-cell-mediated cytotoxicity against ATLL cells. We performed unbiased genome-wide clustered regularly interspaced short palindromic repeat (CRISPR) screening using two ATLL derived cell lines and discovered CD48 as one of the best enriched genes whose knockout conferred resistance to YT-1 NK cell line mediated cytotoxicity. The ability of CD48-knockout ATLL cells to evade NK cell effector function was confirmed using human primary NK cells with reduced IFNg induction and degranulation. We found that primary ATLL cells had reduced CD48 expression along with disease progression. Furthermore, other subgroups among aggressive peripheral T-cell lymphomas (PTCL) also expressed lower levels of CD48 than normal T-cells, suggesting that CD48 is a key molecule in malignant T-cell evasion of NK cell surveillance. Thus, this study demonstrates that CD48 expression is likely critical for malignant T-cell lymphoma cell regulation of NK cell mediated immunity and provides a rationale for future evaluation of CD48 as a molecular biomarker in NK cell-associated immunotherapies.