Figure 7.

TGF-β Secretion and T Cell Responses

(A) RNA was extracted from hNPCs at day 9 of neural differentiation, and qRT-PCR was used to determine relative transcript levels of TGF-β1, TGF-β2, and HGF. Values were normalized to internal GAPDH levels and are shown as fold differences compared to undifferentiated hESC expression levels using ΔΔCt calculations; data are presented as averages ± SEM.

(B) ELISA determination of TGF-β1 and TGF-β2 in culture medium conditioned by hNPCs compared to unconditioned medium; data are presented as average ± SEM and representative of three independent experiments.

(C) In hNPC-T cell cocultures, inclusion of anti-TGF-β1 or anti-TGF-β2 alone or in combination impaired the ability of hNPCs to block proliferation of virus-specific CD4⁺ T cells.

(D) Antibody targeting of TGF-β1 or TGF-β2 reduced the numbers of CD4⁺CD25⁺ FOXP3⁺ Tregs. (C) and (D) contain data of a minimum of four mice per group; mean values are presented; error bars represent SEM. Mann-Whitney t tests were used to determine the p values in (A) and (B); paired t tests were used to determine the p values for (C) and (D); ^∗ p < 0.05, ^∗∗ p < 0.01, ^∗∗∗ p < 0.001.