Enhancement of BCG-induced Th1 immune response through Vγ9Vδ2 T cell activation with non-peptidic drugs

Since drug-activated γδ T cells promote dendritic cell (DC) maturation, we analyzed the effect of combining γδ T cell specific drugs with BCG in vitro. BCG-induced DC maturation was increased by bromohydrin-pirophosphate (BrHPP) or zoledronate (Zol)-activated γδ T cells. Specifically, the co-culture with activated Vγ9Vδ2 T cells with BCG-infected DC resulted in a significant increase of the expression of CD80, CD86, CD40 and CD25 molecules on DC. Moreover, DC were able to produce increased levels of TNF-α and synthesize ex novo IL-15 without altering the IL-10/IL-12 immunoregulatory pathway. Finally, the Th1 immunity induced by BCG-infected DC on naïve CD4 T cells was increased by γδ T cell activation with BrHpp or Zol. These data indicate that γδ T cell triggering drugs could be used to enhance the BCG induced Th1 immunity.