Antibody blocking assay confirmed that both CD1b and CD1c molecules on moDC could be important for LA-induced proliferations of γδ T cells. In the group of γδ T cell+LA+DC+anti-TCRγδ mAb, γδ T cells were preincubated with anti-TCRγδ mAb at 37°C for 2 h; in the group of γδ T cell+LA+DC+anti-LA, LA-loaded moDCs were preincubated with pAb anti-LA for another 2 h; In other groups, autologous irradiated moDCs were preincubated with mAbs against MHC I, MHC II, CD1a, CD1b, CD1c, CD1d, or CD1b plus CD1c respectively. Then, they were thoroughly washed. (A and B). The proliferations of γδ T cells were determined by 3H-TdR incorporation. The results are expressed as mean ± SD of three independent experiments. (C) The moDCs were incubated with or without purified anti-CD1b or CD1c mAb for 2 h, then stained the CD1b-blocked moDC with FITC-conjugated anti-CD1c mAb and stained the CD1c-blocked moDC with FITC-conjugated anti-CD1b mAb, analyzed CD1b+ and CD1c+moDCs by flow cytometry. (D) CFSE labeled γδ T cell-enriched PBMCs were co-cultured with moDC and LA, with or without purified Abs against CD1a, CD1b, CD1c, CD1d, TCRγδ and LA. The reduction of CFSE fluorescence was detected after 72 h by gating on TCRγδ+ populations. Histograms show overlaps of the group of γδ T cell+LA+moDC without any antibody (black filled histograms) and the groups with anti-CD1a, -CD1b, -CD1c, -CD1d, -TCRγδ or -LA antibody (grey line histograms), respectively. All experiments were performed at least three times with consistent results. Note: -αCD1b/CD1c: without anti-CD1b/CD1c mAbs; +α CD1b/CD1c: with anti-CD1b/CD1c mAbs.