Could the Immune Modulation of Invariant Natural Killer T Cell and the Expression of CD244 and CD196 on Natural Killer Cell Subtypes Impact the Treatment Outcomes of Acute Myeloid Leukemia Patients?

BACKGROUND: The present study aimed to assess the CCR6 and CD244 expression on natural killer (NK) and natural killer T (NKT) cells, considering their different subsets and examining their associations with molecular cytogenetics and clinical outcomes in newly diagnosed adult acute myeloid leukemia (AML) patients. METHODS: We recruited 26 new cases of newly diagnosed adult AML and 24 adult healthy participants as controls, after diagnosis of AML, bone marrow studies, cytogenetics, and molecular studies; samples of peripheral blood were collected from all participants for flow cytometry to determine the expressions of CD244 and CD196. RESULTS: Invariant NKT cells were significantly more abundant in controls than in patients. In patients, CD244 expression was associated with increased accumulation of NKT cells, whereas CD196+ NKT cells were more frequently found in controls. Regarding CD3- NK cells, co-expression of CD244 and CD196 was significantly increased in patients compared with controls across all CD3- NK subpopulations. CD244 expression was higher in controls, within CD16brightCD56bright NK, CD16brightCD56dim NK, and CD16dimCD56bright NK subsets. In contrast, in patients' CD16+CD56- NK cells, CD196 showed an inverse pattern: it was expressed more in patients with CD16brightCD56dim NK cells, compared with controls' CD16+CD56- and CD16-CD56+ NK cells. Dim CD56 expression on NK cells, regardless of CD16 level, was associated with treatment remission. In addition, the presence of CD244 and/or CD196 was linked to treatment failure, whereas the dual absence of CD244 and CD196 was associated with remission. CONCLUSION: The expression pattern of CD244 (2B4 receptor) and CD196 on NK and NKT cells was generally associated with remission status and prognostic features of AML patients.