We found that CD39 was enriched in aTreg and rTreg cells in comparison to non-Treg cells in PBMCs (Figure 2(a)).
The frequency of aTreg cells was much higher in patients with NSCLC at stages III-IV (1.30 [+ or -] 0.18% versus 0.38 [+ or -] 0.09%, P < 0.05, Figure 3(a)).
Because the degree of Foxp3 was proportional to CD25 expression (Figure 4(a)), we isolated and defined aTreg, rTreg, and non-Treg cells as [CD4.sup.+][CD45RA.sup.-][CD25.sup.hi], [CD4.sup.+][CD45RA.sup.+][CD25.sup.lo], and [CD4.sup.+][CD45RA.sup.-][CD25.sup.lo] T cells.
In this study we reported significant increase of aTreg cells in peripheral blood of NSCLC patients.
We found lower IFN-[gamma] in aTreg cells compared with non-Treg cells, suggesting that aTreg cells produce lower level of IFN-[gamma] to suppress the antitumor immune responses.