Natural killer (NK) cells are usually identified by the absence of other lineage markers, due to the lack of cell-surface-specific receptors. CD56^neg NK cells, classically identified as CD56^negCD16+, are very scarce in the peripheral blood of healthy people but they expand in some pathological conditions. However, studies on CD56^neg NK cells had revealed different results regarding the phenotype and functionality. This could be due to, among others, the unstable expression of CD16, which hinders CD56^neg NK cells’ proper identification. Hence, we aim to determine an alternative surface marker to CD16 to better identify CD56^neg NK cells. We have found that NKp80 is superior to CD16. Furthermore, we found differences between the functionality of CD56^negNKp80+ and CD56^negCD16+, suggesting that the effector functions of CD56^neg NK cells are not as diminished as previously thought. We proposed NKp80 as a noteworthy marker to identify and accurately re-characterize human CD56^neg NK cells.

由于缺乏细胞表面特异性受体，自然杀伤 (NK) 细胞通常通过缺乏其他谱系标记来识别。 CD56 ^neg NK 细胞，通常被称为 CD56 ^neg CD16+，在健康人的外周血中非常稀少，但它们在某些病理条件下会扩增。然而，对 CD56^阴性NK 细胞的研究揭示了有关表型和功能的不同结果。这可能是由于 CD16 的不稳定表达，阻碍了 CD56^阴性NK 细胞的正确识别。因此，我们的目标是确定 CD16 的替代表面标记，以更好地识别 CD56^阴性NK 细胞。我们发现NKp80优于CD16。此外，我们发现CD56 ^neg NKp80+和CD56 ^neg CD16+的功能之间存在差异，表明CD56 ^neg NK细胞的效应功能并不像之前认为的那样减弱。我们提出 NKp80 作为一个值得注意的标记来识别和准确地重新表征人类 CD56 ^neg NK 细胞。