Fig. 6: NK cell supernatant increased cell surface expression of CD44, CD54, MHC class I and PD-L1 and cytostatic and cytotoxic effects of chemotherapeutics in GSLCs.

GSLCs were incubated with NK cell supernatants for 5 days and TMZ (430 μM) or vehicle control was added to cultures 72 h before cell surface marker expression assessment in cell cultures (n = 3, data points represent independent biological replicates) (a). Super-charged NK cells from at least two different heathy donors were added to tumorospheres in different NK:GSLC cell ratios for 48 h (data points represent measurement for each healthy donor). MHC class I surface expressions were evaluated in dissociated GSLCs (b). GS025 (c, d, g, h) and NCH421k (e, f, i, j) cells were incubated with NK cell supernatant (white bars) for 5 days. Blank NK cell culture medium without secreted factors from NK cells was used as control (gray bars). CDDP (25 and 50 µg/mL) and TMZ (430 µM) were added to cultures 24 h and 72 h, respectively, before cell count and % of dead cells assessments. Data points represent independent biological replicates (n ≥ 3). Schematic presentation of NK cell effects on GSLCs (k). Image was created by BioRender.com. Data are presented as means ± SEM.