NKG2D regulates CD4+ T cell differentiationvia interaction with DCs
NKG2D genetically modified CD4+ T cells were
co-cultured with the stimulating irradiated DCs to explore the
regulation of NKG2D on CD4+ T cells via the
interaction with DCs. Cytokines secreted by genetically modified
CD4+ T cells were tested. The results are shown in
Figure 4A. NKG2D induced the secretion of IL-12 and suppressed the
production of IL-10 and transforming growth factor-beta (TGF-β) from
LV-NKG2D CD4+ T cells and LV-siRNA
CD4+ T cells of JIA patients (P<0.05).
However, NKG2D significantly increased IL-12 production
(P<0.05) and had no significant effects on production of IL-10
and TGF-β from CD4+ T cells of healthy controls
(P>0.05). Next, we assessed the effects of genetic
modification of NKG2D on the polarization of T cells. As shown in Figure
4B and 4C, LV-NKG2D modified CD4+ T cells had a
significantly increased percentage of
IFN-γ+CD4+ T cells
(P<0.05), but significantly reduced populations of
CD25+Foxp3+CD4+ T
cells (P<0.01) and
IL-4+CD4+ T cells (P<0.05)
compared with the respective blank control in both JIA and healthy
groups. Additionally, genetic modification of NKG2D resulted in an
increase content of the IL-17+ CD4+T cell subgroup in LV-NKG2D CD4+ T cells and reduced
numbers of IL-17+ CD4+ T cell
subgroup in LV-siRNA CD4+ T cells in JIA patients
(P<0.05). No significant influence on the
IL-17+CD4+ T cell subset was evident
in the healthy controls (P>0.05). Expressions of
transcription factors was assessed (Figure 4D). NKG2D upregulated the
expressions of RORc and T-bet (P<0.05), down-regulated the
expressions of Foxp3 (P<0.05) and GATA3 (P<0.01) in
CD4+ T cells of JIA patients, and increased the
expression of T-bet (P<0.05). No statistically significant
change in the expressions of RORc, Foxp3, and GATA3 was observed in
CD4+ T cells of the healthy controls
(P>0.05).