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Allogeneic hematopoietic stem cell transplantation (HSCT) is the treatment of choice for many hematologic malignancies and inherited disorders of the hematopoietic system. Ex vivo T-cell depletion (TCD) of the graft and post-transplantation immunosuppression efficiently prevents the development of GvHD in no- MHC-identical settings. However, the consequence of these non-specific strategies is a long-lasting immunodeficiency associated with increased incidence of disease relapse, graft rejection and reactivation of viral infections. Donor lymphocyte infusion, which is used for treating leukemic relapse after allogeneic HSCT, can result in severe GvHD. Several strategies are being optimized specifically to inactivate anti-host T cells while preserving anti-leukemic or anti-microbial immunocompetence. Based on the ex vivo or in vivo elimination of anti-host T cells, or on the modulation of their anti-host activity, these approaches, which have been explored extensively in pre-clinical studies and tested in some preliminary clinical trials, are discussed in this paper. [ABSTRACT FROM AUTHOR]

GvHD, the most important cause of morbidity and mortality after allogeneic stem cell transplantation, depends primarily on the ability of a donor T-cell subset to react to immunogenic host Ag. Recently developed culture conditions and treatment strategies may bring us closer to the selective elimination of such alloreactive T cells, often considered the holy grail of transplantation. Among the various therapeutic modalities, photodynamic therapy (PDT) offers a biological and global approach to the eradication of unwanted allo-activated T cells by combining mitochondrial targeting, P-glycoprotein inhibition and reactive oxygen species production. Indeed, the high potency of PDT against malignant cells has been harnessed to exert selective and extensive elimination of alloreactive T-cell subsets mediating GvHD, while preserving resting T cells with the ability to reconstitute the immune system for GvL activity and prevent or suppress viruses and fungi. The present paper reviews the basis of the PDT strategy, and the methodology employed. In vitro and in vivo studies that formed the proof of principle as a basis for human studies to investigate the clinical potential of PDT in the context of GvHD will be presented together with insights into future clinical applications of this versatile treatment platform. [ABSTRACT FROM AUTHOR]

IL-15 is a pleiotropic cytokine that plays an important role in both the innate and adaptive immune system. IL-15 promotes the activation of neutrophils and macrophages, and is critical to DC function. In addition, IL-15 is essential to the development, homeostasis, function and survival of natural killer (NK) cells, NK T (NKT) cells and CD8 + T cells. Based on these properties, IL-15 has been proposed as a useful cytokine for immunotherapy. It is currently being investigated in settings of immune deficiency, for the in vitro expansion of T and NK cells, as well as an adjuvant for vaccines. In this paper, we will review the targeting of IL-15 for immunotherapy, with a particular emphasis on its effects on CD8 + T cells. [ABSTRACT FROM AUTHOR]

Background Priming with autologous tumor vaccine followed by ex vivo expansion of activated T cells is a feasible experimental strategy. This paper describes the application of this cellular therapy to treat patients with late-stage non-small-cell lung cancr (NSCLC). Methods Twenty-one patients with Stages III and IV NSCLC were treated. Tumor samples were obtained surgically (five patients) or by using a co-axial biopsy needle (16 patients). Each course of vaccination consisted of irradiated tumor cells, mixed with GM-CSF and injected intradermally on Day 1, followed by GM-CSF only on Days 2–5. The course was repeated 10–14 days later. Lymphocytes were collected 10–14 days after the second course and ex vivo expanded using IL-2 and anti-CD3 Ab. The expansion products were then re-infused into the patients. Results Twelve out of 16 biopsies resulted in optimal cell numbers for vaccine preparation. Nineteen out of 21 patients achieved a delayed type hypersensitivity (DTH) response after two courses of vaccination. In 18/21 patients, the ex vivo expansion products contained >1.6×10 10 cells. Subset analysis showed 77.0–97.2% T cells with a CD4:CD8 ratio of 0.65–4.0; natural killer cells were 2.0–18.6%. There were no significant toxicities. The median survival of all 21 patients was 18.6 months, with a 1-year survival of 51.6%. Conclusion Autologous tumor cell-vaccination may be combined with ex vivo expansion of lymphocytes as adoptive cellular immunotherapy for advanced NSCLC. Overall survival in this cohort of poor prognosis patients compared favorably with results reported in the literature. [ABSTRACT FROM AUTHOR]

The article reviews developments in the research of regulatory Treg (T) cells in the treatment of autoimmunity. A research paper in the issue on attempts to improve the isolation of Treg cells through the addition of CD8-depletion techniques to those currently being practiced is mentioned. The author describes the possible benefits that can arise from Treg cell transfers and the clinical trials that should be performed to evaluate them.