Watzl, CarstenPicard, Lea Katharina2023-02-012023-02-012022http://hdl.handle.net/2003/41219http://dx.doi.org/10.17877/DE290R-23063Glucose-transporter (GLUT)-inhibitors, like Glutor and Glupin, effectively inhibit the proliferation of different tumor cells, making them potential candidates for cancer therapies. Therefore, assessing the impact of GLUT-inhibitors on NK cell function is crucial, as these cells play an important role in anti-tumor response. Seahorse analysis of the energetic phenotype of NK cells treated with Glutor or Glupin showed decreased glycolysis. To further examine the effect of both inhibitors on NK cell effector functions, resting or pre-activated human NK cells were stimulated through CD16 in the presence or absence of Glutor or Glupin. This acute inhibition of the GLUT had no significant effect on NK cell cytotoxicity, cytokine secretion or killing capacity against tumor cells. To analyze possible long-term effects, we cultured freshly isolated NK cells for 3 weeks in the presence or absence of Glutor or Glupin. We could detect a lack of proliferation in case of Glutor-treatment, whereas Glupin-treated NK cells displayed a delayed proliferation. Analysis of various surface receptors showed that long-term treatment with Glutor or Glupin led to an altered NK cell phenotype compared to the control. Furthermore, we examined the cytotoxic and immunoregulatory function of these NK cells: Long-term treatment with Glutor reduced the degranulation and IFN- secretion after stimulation via CD16 or NKp30. Interestingly, Glupin did not affect degranulation in comparison to the control cells, whereas the IFN- secretion was significantly diminished after stimulation via CD16 or NKp30. Furthermore, the serial-killing capacity of long-term treated NK cells with Glupin was higher than that of control cells. Experiments regarding the usage of other fuels, like glutamine or fatty acids, revealed that NK cells did not use fatty acids to fulfil their functions and that glutamine seems to be not responsible for this increased serial killing capacity. RNA-sequencing data together with the analysis of NAD+/NADH concentrations of Glupin-treated NK cells suggests a possible role of CD38 and NAD+ in the serial killing capacity of NK cells. Further, RNA-sequencing of Glutor-treated NK cells displayed a cell cycle arrest, which could explain the lack of proliferation. These data identify Glupin as a suitable candidate for cancer therapy.enNK cellsGlucosetransporterSerial-killing capacityTumor540TextGlucosetransporterTumor