A strategy for treatment of Epstein–Barr virus-positive Hodgkin's disease by targeting interleukin 12 to the tumor environment using tumor antigen-specific T cells

Abstract

Adoptive immunotherapy with Epstein-Barr virus (EBV)-specific cytotoxic T cells (CTL) is effective for the prophylaxis and treatment of EBV-induced lymphoma in hematopoietic stem cell recipients. However, in EBV-positive Hodgkin's disease (HD) the efficacy of adoptively transferred EBV-specific CTL may be limited by tumor-derived immunosuppressive factors, such as T-cell growth factor (TGF) b, interleukin (IL)13 and the chemokine TARC. Local delivery of IL12 to tumor sites by tumor-specific CTL could provide direct antitumor effects and overcome the CTL-inhibitory effects of the Th2 tumor environment while avoiding the systemic toxicity of recombinant IL12. EBV-specific CTL transduced with a retrovirus vector expressing the p40 and p35 subunits of IL12 as a single molecule (Flexi-IL12), produced IL12 following antigenic stimulation. This resulted in an elevated production of Th1 cytokines, including interferon g and tumor necrosis factor a, and a reduction in the Th2 cytokines IL4 and IL5. Flexi-IL12-transduced CTL resisted the antiproliferative and anticytotoxic effects of exogenous TGFb, likely by antagonizing the TGFb-induced downregulation of the Th1 transcriptional factor T-bet. In addition, Flexi-IL12-transduced CTL demonstrated a proliferative advantage in the presence of inhibitory supernatants from HD-derived cell lines. Tumor-specific, Flexi-IL12-transduced EBV-specific CTL should have a functional advantage over unmodified CTL, particularly in the presence of the adverse Th2 cytokine environment produced by Hodgkin tumor cells.

The interplay between Epstein-Barr virus and the immune system: a rationale for adoptive cell therapy of EBV-related disorders

“…This requirement should be achieved by genetically modifying T cells, with the aim of inducing expression of IL-12, a cytokine promoting the Th1 anti-tumor response, or TGFβ receptor dominant negative mutants, as described in vitro. 20,21 Based on these considerations, the results reported so far appear even more impressive, despite the lower success rate, than those obtained in PTLD management. In detail, clinical responses, mainly in patients with limited disease burden, were obtained after infusion of polyclonal, polyspecific CTL lines in 33 NPC patients (3 complete remissions, 3 partial remissions, and 8 stable diseases; Figure 2) 19,68-71 as well as in Hodgkin's lymphoma patients (4 complete remissions and 2 stable diseases out of 20 reported outcomes; Figure 2).…”

“…Nevertheless, several strategies to overcome these problems are currently being investigated to define the optimal conditions for adoptive cell therapy also in these cases. 17,20,21 The aim of this review is to provide a survey of clinical, virological and immunological results of in vivo studies carried out so far in the context of EBV-related diseases, with a particular focus on the continuous and intimate interplay between the virus and the host immune system. We discuss the diseases that arise in both the immunocompromised and immunocompetent hosts, pointing out the particular features of these subsets of virus-related tumors.…”

Therapeutic effect of recombinant plasmid-encoded human interleukin-12 in tumor-bearing mice

“…A number of immune cells types play a role in the correlation between tumor development and immune function. The first line of antitumor defense is the non-specific NK cells, which are followed by more specific T cells (13,14). IL-12, secreted by antigen-presenting cells (e.g., (19).…”

“…Although the mechanisms of tumor development are complicated, malfunction of immune surveillance is considered to be one of the most significant factors in the process (13,14). This suggests that a key approach in antitumor therapy should reinforce the ability of the immune system to recognize tumor antigens as 'foreign' and the enhancement of the activity of specific cellular immunity.…”

Genetic modification of human T lymphocytes for the treatment of hematologic malignancies

“…T cells can be rendered resistant to transforming growth factor beta (TGF-β) by the expression of a dominant-negative TGF-β type II receptor (dnTGF-β II), 80,81 or to be resistant to Fas ligand-induced apoptosis by selective downregulation of Fas/CD95. 82 IL-12 secretion 83,84 or/and expression of constitutively active Akt (caAkt) 85 by T cells also overcome an immunosuppressive tumor environment, and clinical trials evaluating the effects of expressing dnTGF-β II or IL-12 in T cells are ongoing. In patients receiving treatments that inhibit T-cell function, it is also possible to give antigen-specific T cells that are engineered to be resistant to the administered agent.…”