Natural killer (NK) cells are effector cells of the innate immune system. The cytokine microenvironment influences NK cell function. Dysregulation of NK cell cytotoxicity can manifest in reproductive disorders and is also observed in tumor-transformed tissues. The search for immunotherapies capable of regulating NK cell activity is therefore relevant. This study aimed to evaluate the effect of the TGFβ signaling pathway inhibitor and the cyclin-dependent kinase (CDK) 7/12/13 inhibitor on the transcriptional profile of NK-92 cell line. In the study, the cytokines TGFβ1, IL-12, IL-15, IL-18, and TNFα, and the TGFβ receptor type 1 (TGFβR1) inhibitor LY3200882 and the CDK7/12/13 inhibitor THZ1 were used. The cells were cultured sequentially in the presence of inhibitors and cytokines, followed by assessment of the gene expression of NCR2, NCR3, AHR, NCAM1, B3GAT1, EOMES, GATA3, KLRC1, KLRC2, CCL5, IL10 and TBX21. We observed direct effects of the inhibitors on NK cells. LY3200882 increased the expression of KLRC1 and B3GAT1, and reduced NCAM1. THZ1 increased the expression of KLRC1, KLRC2, AHR and EOMES, while it reduced IL-10 and NCR2. IL-12, IL-15, IL-18, and TNFα modified the gene expression of some phenotypic and cytotoxic receptors and transcription factors. TGFβ1 increased the expression of KLRC1, NCAM1, and B3GAT1. Blocking TGFβ-dependent signaling with LY3200882 abolished TGFβ1 effects. We assessed CD56 presence on NK-92 cell membrane and found its increase in the presence of LY3200882. After LY3200882 treatment, in the presence of TGFβ1 and choriocarcinoma cell line JEG-3, the expression of CD56 receptor on NK cell membrane decreased. Pretreating NK cells with THZ1 decreased the expression of NCAM1, B3GAT1, and EOMES in the presence of TGFβ1. Thus, LY3200882 partially neutralized TGFβ1 effects on the expression of NK cell receptor genes. THZ1 followed by TGFβ1 treatment promoted NK cell transcriptional profile characteristic for CD56dim NK cells. Both LY3200882 and THZ1 affected the NK cell transcription even without cytokine treatment. The independent effects of synthetic inhibitors on NK cells, as well as their influence in the presence of tumor cells, should be considered.
Mikhailova et al. (Fri,) studied this question.