Chimeric IFNγR-hIL-12R receptor (CC12R) enhances human primary NK cell proliferation. (A) NK92 cells were cultured in the presence of IL-2 (200 U/ml), IFNγ (100 ng/ml), or without cytokines (media) and measured for (left to right) cell proliferation (CTV gMFI dilution), percentage of live-cell (fixable near-infrared viability dye negative cells), and relative cell numbers (30-s sample acquisition). (A.i) CC12R-negative NK92. (A.ii) CC12R-positive NK92 (≥2 independent experiments). (B) CC12R-transduced human primary NK cells were cultured for 6 d with the indicated stimulation. Cell proliferation, viability, and CC12R expression were assessed relative to donor-matched CC12R-negative cells. Paired t test, parametric; *, P < 0.05; **, < P < 0.01; ***, P < 0.001. Mean ± SD. n = number of donors (≥2 independent experiments). (B.i) Cell proliferation (CTV gMFI). (B.ii) Percentage of CTV^low cells. (B.iii) Representative histograms showing CTV dilution. (B.iv) Relative cell viability (live fixable near-infrared viability dye negative cells). (B.v) Percentage of CC12R⁺ cells evaluated by FLAG expression. (B.vi) Expression of CD56 (y axis) vs. FLAG (CC12R; x axis) relative to the indicated stimulation. (C) IFNγ amounts (pg/ml) after 6 d of culture in IL-2^high (300 U/ml), IL-2^low (15 U/ml) IL-18^high (25 ng/ml) IL-18^low (2.5 ng/ml), IL-12 (2.5 ng/ml) in CC12R-positive samples relative to donor-matched negative samples. Paired t test, parametric; *, P < 0.05; **, < P < 0.01; ***, P < 0.001. Mean ± SD. n = number of donors.