Fig. 6: Tumor-derived CXCL12 drives human NK cell impairment via engagement of the CXCR4/C/EBPβ axis.

A Results of the NicheNet analysis performed on scRNA sequencing, described in 4E. B Graph showing the MFI of CXCR4 in NK-92 cells, treated with TGFβ or tumor-conditioned medium, in presence or absence of TGFβ receptor inhibitor LY2109761 (n = 6 replicates, independently collected batches of tumor-conditioned medium). C, D Quantification of TGFβ release from human (C) and murine (D) prostate cancer cell lines (n = 4 biological replicates). E, F Bar graph showing C/EBPβ activation in NK-92 cells upon administration of CXCL12 (E, n = 4 biological replicates) or PC3-derived conditioned media, with or without Plerixafor (F, n = 3 biological replicates). G, H Relative fold change of key autophagy-related genes in NK-92 cells treated or not with Helenalin Acetate (HA), in absence (G) or presence (H) of tumor-conditioned medium (n = 5 biological replicates). I Graph showing the autophagic flux on NK-92 cells, treated or not with HA, with or without tumor-conditioned medium (n = 5 biological replicates, independently collected batches of tumor-conditioned medium). J Cytotoxicity of control or tumor-conditioned NK-92 cells, in presence or absence of HA, against PC3 target cells (n = 5 biological replicates, independently collected batches of tumor-conditioned medium). K) Graph showing the autophagic flux on NK-92 cells, treated or not with HA, in presence or absence of CXCL12 (n = 6 biological replicates). L, M Tumor growth curves (L) and tumor volume at the end of the experiment (M) referred to mice treated with NK-92 cells, exposed or not to HA (n = 15 NK-92 cells, n = 15 HA-treated NK-92 cells). N Graph showing the absolute number of tumor-infiltrating NK-92 cells. n = 15 NK-92 cells, n = 15 HA-treated NK-92 cells. O, P Graph showing the frequency of LC3B⁺ cells (O) and effector function expression (P) in peripheral blood circulating NK-92 cells. n = 15 NK-92 cells, n = 15 HA-treated NK-92 cells. Data in (B) and (I–K) are presented as Min to Max box-and-whisker plot, the box extends from the 25th to 75th percentiles and the whiskers reach the sample maximum and minimum values, the median is indicated at center line and the mean value is indicated as “+”; one-way ANOVA test with Holm-Šídák’s multiple-comparisons test. Data in (C–F) are presented as scatter plot with mean ± SEM; one-way ANOVA test with Holm-Šídák’s multiple-comparisons test for (E) and (F). Data in (G) and (H) are presented as scatter plot with mean ± SEM; two-tailed unpaired t test. Symbols in (L) represent mean and error bars indicate SEM; two-tailed unpaired t test, comparing area under the curve (AUC). Data in (M–P) are presented as Min to Max box-and-whisker plot, the box extends from the 25th to 75th percentiles and the whiskers reach the sample maximum and minimum values, the median is indicated at center line and the mean value is indicated as “+”; two-tailed unpaired t test.