CD10⁺LDNs and CD10⁺NDNs from GDs inhibit proliferation and IFNγ production by T cells. (A-C) CD3/CD28-stimulated T cells were cultured for 96 hours in the absence or presence of CD66b⁺ or CD10⁺ LDN or NDN populations at a 5:1 neutrophil-to-T-cell ratio. T-cell proliferation was measured by 5-bromo-2′-deoxyuridine (BrdU) incorporation (see supplemental Methods), whereas T-cell–derived IFNγ was measured in coculture supernatants by enzyme-linked immunosorbent assay (ELISA). (A) The percentages of increase/decrease of proliferation (left panel) or IFNγ production (right panel) by T cells induced by: CD66b⁺ NDNs from HDs (□), CD66b⁺ NDNs from GDs (○), CD66b⁺ LDNs from GDs (containing >20% mature CD10⁺ neutrophils; represented on the left part of the graphs) (▿) or CD66b⁺ LDNs from GDs (containing <20% mature CD10⁺ neutrophils; represented on the right part of the graphs) (△). Graph values indicate medians from independent experiments (n = 7-13). **P ≤ .01; ***P ≤ .001, by 1-way ANOVA with the Dunnett posttest. (B) Percentage of increase/decrease of T-cell proliferation induced by CD10⁺ NDNs from HDs (□), CD10⁺ NDNs from GDs (○), or CD10⁺ LDNs from GDs (▿). Graph values indicate medians from independent experiments (n = 6). ***P ≤ .001, by 1-way ANOVA with the Dunnett posttest. (C) Percentage of increase/decrease of T-cell proliferation in the presence of total CD10⁺ neutrophils isolated from whole blood (WBNs) of HDs (□) or GDs (▪). Graph values indicate medians from independent experiments (n = 4). *P ≤ .05 by the Mann-Whitney U test. (D) CD3/CD28-stimulated T cells were cultured for 96 hours in the presence or absence of CD10⁺ NDNs from HDs or GDs, at a 5:1 neutrophil-to-T-cell ratio. The percentages of proliferating CD4⁺ and CD8⁺ T cells, either left unstimulated (negative control) or stimulated with anti-CD3/CD28 mAbs, in the absence (positive control) or in the presence of CD10⁺ NDNs from HDs or GDs, were revealed by the CFSE dilution assay (see supplemental Methods). Graph values indicate medians from independent experiments (n = 7). *P ≤ .05; **P ≤ .01, by 1-way ANOVA with the Dunnett posttest.