Figure 7.

Vγ2Vδ2 T cells expanded by HMBPP + IL-12 inhibit intracellular mycobacteria growth in IFN-γ- and TNF-α-dependent fashions. (A) HMBPP + IL-12-expanded Vγ2Vδ2 T cells inhibit intracellular BCG growth in THP-1 and hMDM cells, respectively. Vγ2Vδ2 T cells enriched from HMBPP + IL-12 or HMBB + IL-2 co-cultures by positive selection (see Supplementary Figure 1D for the purity) were co-cultured with BCG-infected THP-1 (left panel) or hMDM (right panel) cells at an E: T ratio = 10:1 for 72 h. The reduction of CFU counts induced by Vγ2Vδ2 T cells was significantly more striking than that by B cells or media only. (B) Blocking assays using neutralizing mAb show that Vγ2Vδ2 T cells enriched from HMBPP + IL-12 cultures require effector molecules, IFN-γ and TNF-α, to inhibit intracellular mycobacteria. Vγ2Vδ2 T cells enriched from HMBPP + IL-12 cultures were incubated with BCG-infected THP-1 and hMDM cells at an E: T ratio of 10: 1 for 3 days in the presence/absence of 10 ug/ml neutralizing antibodies against IFN-γ, TNF-α, or matched Isotype. Data are mean ± SEM of three independent experiments pooled from 15 healthy controls, ^****p < 0.0001, ^***p < 0.001 vs. control (ANOVA, Dunnett's test).