After isolation by CliniMACS, the positive fractions were cultured in T-cell medium containing irradiated autologous feeders (1:5 ratio) and cytokines

After isolation by CliniMACS, the positive fractions were cultured in T-cell medium containing irradiated autologous feeders (1:5 ratio) and cytokines. T lymphocyte lines was examined in three patients with a leukemic relapse following Arecoline allogeneic SCT.14 The administration of HA-1-specific T-cell Arecoline lines was demonstrated to be safe without induction of GvHD. However, HA-1-specific T-cell lines lacked persistence and anti-leukemic reactivity. This lack of persistence and anti-leukemic reactivity may be explained by the long culture period of at least 4 weeks. TCR gene transfer is an attractive strategy to modify T cells with well-defined specificities in a short time period. Recently, the effectiveness of TCR transfer was demonstrated in patients with melanoma or synovial cell sarcoma who were treated with TCR-modified autologous T cells.15C17 To engineer T cells that exert selective GvL without GvHD, we prefer to transfer the HA-1-TCR into virus-specific T cells instead of polyclonal T cells. It has been described that both cytomegalovirus (CMV)-specific18C23 and Epstein-Barr virus (EBV)-specific24C29 donor T cells can be safely reinfused into immunodeficient patients at risk of developing CMV disease, EBV reactivation or EBV-positive B-cell lymphomas, respectively. This adoptive transfer was demonstrated not only to be effective in preventing or curing the viral diseases but also to be safe without inducing GvHD. In addition, long-term persistence of the virus-specific donor T cells was demonstrated.26 We hypothesize that activation of the endogenous TCR by viral antigens can result in both increased numbers of TCR-modified T cells, as well as in increased introduced TCR expression, as T-cell stimulation is followed by increased activation of the retroviral promotor.30C32 Previously, we demonstrated that we could reprogram virus-specific T cells into anti-leukemic effector T cells using TCR gene transfer without loss of their original anti-virus specificity.33,34 Another possible advantage of the use of virus-specific T cells is the exclusion of regulatory T cells from the pool of TCR-modified lymphocytes that can possibly disturb the immune reaction. Since virus-specific T-cell populations consist of a restricted TCR repertoire,35,36 the number of different mixed TCR dimers formed will be limited and from data this appears a viable strategy to prevent neoreactivity37 caused by mixed TCR dimers.37,38 Furthermore, we have modified the HA-1-TCR both to improve cell surface expression of the HA-1-TCR, and to diminish mixed TCR dimer expression with unknown and potentially unwanted reactivity.38,39 For the clinical study, we will selectively isolate permissive virus-specific T cells that highly Arecoline express HA-1-TCR after gene transfer (Table 1).39,40 Table 1. List of different peptide-HLA complexes used for FACS analysis and MACS-isolation. Open in a separate window Recently, Streptamers were used to selectively isolate CMV-specific T cells. 41 CMV-specific T cells were transferred directly after Streptamer-based isolation into patients with CMV reactivation without toxicity, and patients were able to manage CMV virus thereafter.41 Here, we describe a Good Manufacturing Practice (GMP) procedure to rapidly generate dual-specific, donor virus-specific T cells with high avidity anti-leukemic reactivity. The process of Streptamer-based isolation of pure populations of virus-specific T cells and transduction with GMP-grade retroviral supernatant encoding the HA-1-TCR has been validated with four large-scale test procedures in the cleanroom. All HA-1-TCR-transduced, virus-specific T-cell products met the criteria for in process testing and quality control testing, and were highly reactive against HA-1-positive leukemic cells. Methods Selection and isolation of virus-specific T cells This study was approved by the Leiden University Medical Center institutional review board and written informed consent was obtained according to the Declaration of Helsinki. From donor leukocytes from a leukapheresis product or total peripheral blood mononuclear cells either one or two virus-specific T-cell populations were isolated using Streptamers (Table 1) (Stage Therapeutics, G?tingen, Germany) according to the manufacturers instructions. Streptamer-incubated donor leukocytes were purified using autoMACS (Miltenyi Biotec, Bergisch Gladbach, Germany) according to the manufacturers protocol, or in the case of the test-runs using a CliniMACS instrument (Miltenyi Biotec) with the CD34 selection 1 program. Streptamers were dissociated from the eluted cells with 1 mM D-biotin. Eluted cells purified by either auto-MACS or CliniMACS were cultured with irradiated, non-selected, autologous peripheral blood mononuclear cells (ratio 1:5) in T-cell medium consisting of IMDM supplemented with 10% ABOS, 100 IU/mL interleukin-2 (Chiron, Amsterdam, the Netherlands), and 10 ng/mL interleukin-15 (Peprotech, Rocky Hill, NJ, USA). Anti-CD3/CD28 beads (ratio 5:1, Dynabeads, Invitrogen) were added in some of the experiments. Transduction of the virus-specific T cells Some of the virus-specific T cells were transduced 2C3 days after Rabbit polyclonal to LIMK1-2.There are approximately 40 known eukaryotic LIM proteins, so named for the LIM domains they contain.LIM domains are highly conserved cysteine-rich structures containing 2 zinc fingers. MACS-isolation with vectors containing only a NGF-R marker gene, or with GMP-grade retroviral supernatant encoding the HA-1-TCR (EUFETS GmbH, Idar Oberstein, Germany), as previously described.