Clinical-grade varicella zoster virus-specific T cells produced for adoptive immunotherapy in hemopoietic stem cell transplant recipients

摘要

Varicella zoster virus (VZV) causes life-long latent infection in healthy individuals, which reactivates in 1068% of stem cell transplant patients. Reconstituting immunity through adoptive transfer of T cells specific for VZV may aid in the prophylaxis and treatment of VZV infections. The potential for generating T cells specific for VZV using a clinically approved VZV vaccine strain was investigated. Methods. The Varivax? vaccine was used to stimulate peripheral blood mononuclear cells from healthy donors. Only reagents approved for clinical manufacture were used. Monocyte-derived dendritic cells pulsed with Varivax (R) were used to stimulate autologous mononuclear cells at a responder to stimulator ratio of 10:1. On day 7, a second stimulation was performed; 20 U/mL interleukin (IL)-2 were added from day 7 and 50 U/mL IL-2 from day 14 onwards. Cell phenotype and functionality were assessed after 21 days of culture. Results. A mean increase of 11-fold in cell number was observed (n 18). Cultures were mainly T cells (mean CD3 ~+ 89.7%, CD4 ~+ 54.2%, CD8 ~+ 28.7%) with effector and central memory phenotypes. Cells produced one or more T helper (Th)1 cytokine (interferon-γ, tumor necrosis factor-α and IL-2), and CD4 ~+ (but not CD8 ~+) cells expressed the cytoxicity marker CD107 when restimulated with VZV antigens. Conclusions. We have demonstrated a clinically applicable method that yields high numbers of highly reactive T cells specific for VZV. We propose that reconstructing host immunity through adoptive transfer of VZV-specific T cells will reduce the frequency of clinical VZV infection in the period of severe immune suppression that follows allogeneic stem cell transplantation.