We investigated the interactions between human monocyte derived DCs (MDDC), generated in the presence of GM-CSF and IL-4 (IL-4 DC), and antigen-stimulated circulating gamma delta T lymphocytes, bearing the Vgamma2 TCR. The studies demonstrated for the first time the existence of a bidirectional activating interaction between DCs and gamma delta T lymphocytes activated by aminobiphosphonates. These data suggest a potential adjuvant role of this early cross-talk in the therapeutic activity of aminobiphosphonate drug that are currently used as anti-tumor drugs.

These T lymphocytes are exposed to HIV-1 to examine if this can directly modulate their functions or interfere with their cross-talk. Preliminary results indicated that, although virus exposure of gamma-delta T cells does not significantly affect their properties, HIV-exposed DCs exhibit a reduced capacity to deliver activation and proliferative signals to gamma-delta T lymphocytes. Moreover, a dysregulated pattern of cytokines and chemokines produced by both cell populations is observed in the presence of the virus.