In vivo effects of zoledronic acid on peripheral gammadelta T lymphocytes in early breast cancer patients.

INTRODUCTION: Amino-bisphosphonates are potent activators of human gammadelta T cells. The aim of our study was to evaluate the immunomodulating properties of a single-dose of zoledronic acid (ZA) on gammadelta T cells in a select group of disease-free breast cancer patients with osteopenia. MATERIALS AND METHODS: Blood samples were obtained, from 23 patients, before and 7, 28, 56, 90 and 180 days after a single-dose (4 mg) of ZA and analyzed by flow cyometry. RESULTS: A significant decrease of the different gammadelta T cell subsets was observed: Naïve (CD3+/Vdelta2+/CD45RA+/CD27+) after 180 days (P < 0.01); Central Memory (CD3+/Vdelta2+/CD45RA-CD27+) after 28 (P < 0.05), 90 (P < 0.01) and 180 days (P < 0.01); and Effector Memory (CD3+/Vdelta2+/CD45RA-/CD27-) after 56 (P < 0.01) and 90 (P < 0.05) days. Based on the observed gammadelta T cells kinetics patients could be divided in two groups: "responders" that showed a significant decrease in total numbers of gammadelta T cells and "non-responders" that showed no significant change. However, in vitro phosphoantigen stimulation of patients cells did not show significant differences in terms of IFN-gamma response by Vdelta2 T cells. CONCLUSION: We describe for the first time a long-lasting activation of effector subsets of gammadelta T cells in disease-free breast cancer patients after a single-dose of ZA. Our results highlight the need to further investigate the clinical significance of the immunomodulating properties of N-BPs.

Zoledronic acid and interleukin-2 treatment improves immunocompetence in HIV-infected persons by activating Vgamma9Vdelta2 T cells.

OBJECTIVE: gammadelta T cells bearing the Vgamma9Vdelta2 T-cell receptor exert many antiviral effector functions in humans, including release of anti-HIV factors and direct cytotoxicity against virus-infected cells. Moreover, they are known to activate dendritic cells, improving antigen presentation function. After HIV infection, Vgamma9Vdelta2 T-cell number and reactivity are rapidly affected and they decrease upon disease progression. Bisphosphonate drugs such as zoledronic acid (Zol), used to treat bone diseases, have been shown to induce in vivo, in combination with interleukin-2, Vgamma9Vdelta2 T-cells' activation. The aim of this work was to verify whether the administration of Zol in combination with interleukin-2 in HIV-infected patients might improve Vgamma9Vdelta2 T-cell function, including immune adjuvancy mediated by gammadelta-dendritic cell cross-talk. DESIGN AND METHODS: In HIV patients naive to antiretroviral therapy, we analyzed the effect of combined Zol and interleukin-2 treatment, in comparison to Zol alone, on Vgamma9Vdelta2 T-cell number, maturation and function, on dendritic cell activation and on HIV-specific CD8 T-cell response. RESULTS: Zol and interleukin-2-combined treatment induced in-vivo Vgamma9Vdelta2 T-cell expansion and maturation. Paralleling Vgamma9Vdelta2 T-cell activation, increased dendritic cell maturation and HIV-specific CD8 T-cell responses were found. CONCLUSION: The specific modulation of Vgamma9Vdelta2 T-cell number and responsiveness after HIV infection may be at least transiently restored in vivo by Zol and interleukin-2 treatment. In this way, the immune effector mechanisms, secondary to Vgamma9Vdelta2 T-cell activation, were improved, suggesting a possible adjuvancy role of Zol and interleukin-2 treatment in restoring innate and specific competence in HIV-infected persons.

Cross-subtype immunity against avian influenza in persons recently vaccinated for influenza.

Avian influenza virus (H5N1) can be transmitted to humans, resulting in a severe or fatal disease. The aim of this study was to evaluate the immune cross-reactivity between human and avian influenza (H5N1) strains in healthy donors vaccinated for seasonal influenza A (H1N1)/(H3N2). A small frequency of CD4 T cells specific for subtype H5N1 was detected in several persons at baseline, and seasonal vaccine administration enhanced the frequency of such reactive CD4 T cells. We also observed that seasonal vaccination is able to raise neutralizing immunity against influenza (H5N1) in a large number of donors. No correlation between influenza-specific CD4 T cells and humoral responses was observed. N1 may possibly be a target for both cellular and humoral cross-type immunity, but additional experiments are needed to clarify this point. These findings highlight the possibility of boosting cross-type cellular and humoral immunity against highly pathogenic avian influenza A virus subtype H5N1 by seasonal influenza vaccination.