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Background: Prolonged immunosuppression or delayed T-cell recovery may favor Epstein-Barr virus (EBV) infection or reactivation after allogeneic hematopoietic stem cell transplantation (HSCT), which can lead to post-transplant lymphoproliferative disease (PTLD) and high-grade malignant B-cell lymphoma. Cytokine-induced killer (CIK) cells with dual specific anti-tumor and virus-specific cellular immunity may be applied in this context., Methods: CIK cells with EBV-specificity were generated from peripheral blood mononuclear cells (PBMCs), expanded in the presence of interferon-γ, anti-CD3, interleukin (IL)-2 and IL-15 and were pulsed twice with EBV consensus peptide pool. CIK cells with EBV-specificity and conventional CIK cells were phenotypically and functionally analyzed. Additionally, CIK cells with EBV-specificity were applied to a patient with EBV-related PTLD rapidly progressing to highly aggressive B-cell lymphoma on a compassionate use basis after approval and agreement by the regulatory authorities., Results: Pre-clinical analysis showed that generation of CIK cells with EBV-specificity was feasible. In vitro cytotoxicity analyses showed increased lysis of EBV-positive target cells, enhanced proliferative capacity and increased secretion of cytolytic and proinflammatory cytokines in the presence of EBV peptide-displaying target cells. In addition, 1 week after infusion of CIK cells with EBV-specificity, the patient's highly aggressive B-cell lymphoma persistently disappeared. CIK cells with EBV-specificity remained detectable for up to 32 days after infusion and infusion did not result in acute toxicity., Discussion: The transfer of both anti-cancer potential and T-cell memory against EBV infection provided by EBV peptide-induced CIK cells might be considered a therapy for EBV-related PTLD., (Copyright © 2018 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Background Aims: For patients needing allogeneic stem cell transplantation but lacking a major histocompatibility complex (MHC)-matched donor, haplo-identical (family) donors may be an alternative. Stringent T-cell depletion required in these cases to avoid lethal graft-versus-host disease (GVHD) can delay immune reconstitution, thus impairing defense against virus reactivation and attenuating graft-versus-leukemia (GVL) activity. Several groups reported that GVHD is caused by cells residing within the naive (CD45RA + ) T-cell compartment and proposed use of CD45RA-depleted donor lymphocyte infusion (DLI) to accelerate immune reconstitution. We developed and tested the performance of a CD45RA depletion module for the automatic cell-processing device CliniMACS Prodigy and investigated quality attributes of the generated products., Methods: Unstimulated apheresis products from random volunteer donors were depleted of CD45RA + cells on CliniMACS Prodigy, using Good Manufacturing Practice (GMP)-compliant reagents and methods throughout. Using phenotypic and functional in vitro assays, we assessed the cellular constitution of CD45RA-depleted products, including T-cell subset analyses, immunological memory function and allo-reactivity., Results: Selections were technically uneventful and proceeded automatically with minimal hands-on time beyond tubing set installation. Products were near-qualitatively CD45RA + depleted, that is, largely devoid of CD45RA + T cells but also of almost all B and natural killer cells. Naive and effector as well as γ/δ T cells were greatly reduced. The CD4:CD8 ratio was fivefold increased. Mixed lymphocyte reaction assays of the product against third-party leukocytes revealed reduced allo-reactivity compared to starting material. Anti-pathogen responses were retained., Discussion: The novel, closed, fully GMP-compatible process on Prodigy generates highly CD45RA-depleted cellular products predicted to be clinically meaningfully depleted of GvH reactivity., (Copyright © 2018 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Background Aims: Evidence of the criticality of the adaptive immune response for controlling invasive aspergillosis has been provided. This observation is supported by the fact that invasive aspergillosis, a grave complication of allogeneic stem cell transplantation, occurs long after myeloid reconstitution in patients with low T-cell engraftment and/or on immunosuppressants. Adoptive T-cell transfer might be beneficial, but idiosyncrasies of Aspergillus fumigatus and the anti-Aspergillus immune response render established selection technologies ineffective., Methods: We developed a Good Manufacturing Practice (GMP)-compliant protocol for preparation of A. fumigatus-specific CD4+ cells by sequentially depleting regulatory and cytotoxic T cells, activating A. fumigatus-specific T-helper cells with GMP-grade A. fumigatus lysate, and immuno-magnetically isolating them via the transiently up-regulated activation marker, CD137., Results: In 13 full-scale runs, we demonstrate robustness and feasibility of the approach. From 2 × 10(9) peripheral blood mononuclear cells, we isolated 27 × 10(3)-318 × 10(3)Aspergillus-specific T-helper cells. Frequency among total T cells was increased, on average, by 200-fold. Specific studies indicate specificity and functionality: After non-specific in vitro expansion and re-stimulation with different antigens, we observed strong cytokine responses to A. fumigatus and some other fungi including Candida albicans, but none to unrelated antigens., Discussion: Our technology isolates naturally occurring Aspergillus-specific T-helper cells within 2 days of identifying the clinical indication. Rapid adoptive transfer of Aspergillus-specific T cells may be quite feasible; the clinical benefit remains to be demonstrated. A manufacturing license as an advanced-therapy medicinal product was received and a clinical trial in post-transplantation invasive aspergillosis patients approved. The product is dosed at 5 × 10E3/kg T cells (single intravenous injection), of which at least 10% must be A. fumigatus-specific., (Copyright © 2015 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Background Aims: Human cytomegalovirus (CMV) infection and reactivation is a leading complication of allogeneic hematopoietic stem cell transplantation (HSCT). In addition to drug treatment, the adoptive transfer of virus-specific T cells to restore cellular immunity has become a standard therapy after allogeneic HSCT. We recently demonstrated potent anti-leukemic activity of interleukin (IL)-15-activated cytokine-induced killer (CIK) cells. With the use of the same expansion protocol, we asked whether concurrent CMV antigen-pulsing might generate CIK cells with anti-leukemic and anti-CMV activity., Methods: CIK cells expanded in the presence of interferon-γ, IL-2, IL-15 and anti-CD3 antibody were pulsed once with CMV(pp65) peptide pool. CMV-specific CIK (CIK(pp65)) and conventional CIK cells were phenotypically and functionally characterized according to their cytokine secretion pattern, degranulation capacity and T-cell receptor (TCR)-mediated and NKG2D-mediated cytotoxicity., Results: We demonstrated that among CIK cells generated from CMV-seropositive donors, a single stimulation with CMV(pp65) protein co-expanded cytotoxic CMV-specific cells without sacrificing anti-tumor reactivity. Cells generated in this fashion lysed CMV(pp65)-loaded target cells and CMV-infected fibroblasts but also leukemic cells. Meanwhile, the alloreactive potential of CIK(pp65) cells remained low. Interestingly, CMV reactivity was TCR-mediated and CMV-specific cells could be found in CD3(+)CD8(+)CD56(+/-) cytotoxic T-cell subpopulations., Conclusions: We provide an efficient method to generate CIK(pp65) cells that may represent a useful cell therapy approach for preemptive immunotherapy in patients who have both an apparent risk of CMV and impending leukemic relapse after allogeneic stem cell transplantation., (Copyright © 2015 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Background Aims: Evaluation of the BD Stem Cell Enumeration Kit was conducted at four clinical sites with flow cytometry CD34(+) enumeration to assess agreement between two investigational methods: (i) the BD FACSCanto II and BD FACSCalibur systems and (ii) the predicate method (Beckman Coulter StemKit and StemTrol, Immunotech SAS, Beckman Coulter, Marseille Cedex 9, France)., Methods: Leftover and delinked specimens (n = 1032) from clinical flow cytometry testing were analyzed on the BD FACSCanto II (n = 918) and BD FACSCalibur (n = 905) in normal and mobilized blood, frozen and thawed bone marrow and leucopheresis and cord blood anticoagulated with citrate phosphate dextrose, anticoagulant citrate dextrose-solution A, heparin and ethylenediaminetetraacetate, alone or in combination. Fresh leucopheresis analysis addressed site equivalency for sample preparation, testing and analysis., Results: The mean relative bias showed agreement within predefined parameters for the BD FACSCanto II (-2.81 to 4.31 ±7.1) and BD FACSCalibur (-2.69 to 5.2 ±7.9). Results are reported as absolute and relative differences compared with the predicate for viable CD34(+), percentage of CD34(+) in CD45(+) and viable CD45(+) populations (or gates). Bias analyses of the distribution of the predicate low, mid and high bin values were done using BD FACSCanto II optimal gating and BD FACSCalibur manual gating for viable CD34(+), percentage of CD34(+) in CD45(+) and viable CD45(+). Bias results from both investigational methods show agreement. Deming regression analyses showed a linear relationship with R(2) > 0.92 for both investigational methods., Discussion: In conclusion, the results from both investigational methods demonstrated agreement and equivalence with the predicate method for enumeration of absolute viable CD34(+), percentage of viable CD34(+) in CD45(+) and absolute viable CD45(+) populations., (Copyright © 2014 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Background Aims: Cytokine-induced killer (CIK) cells may offer a novel therapeutic approach for patients with malignancies relapsing after allogeneic stem cell transplantation. Although CIK cells display negligible alloreactivity and cause minimal graft versus-host-disease (GVHD), high CIK cell doses required during relapse may pose a risk for severe GVHD, specifically in the mismatched or haploidentical transplantation setting. Manipulation of CIK cells may reduce risk for GVHD without affecting the anti-tumor potential., Methods: In this pre-clinical study, we provide a detailed functional comparison of conventional and irradiated, CD56-enriched or T-cell receptor α/β-depleted CIK cells., Results: In vitro analysis showed retained anti-leukemic and anti-tumor potential after CIK cell manipulation. Even being sequentially infused into immunodeficient mice grafted with malignant cells, cytotoxic effects were fewest after irradiation but were improved by CD56 enrichment and were best with conventional CIK cells. Hence, considering the proliferative capacity of inoculated malignancies and effector cells, a single dose of conventional CIK cells resulted in prolonged disease-free survival and elimination of rhabdomyosarcoma cells, whereas sequential infusions were needed to achieve comparable results in leukemia-bearing mice. However, this mouse model has limitations: highly effective conventional CIK cells demonstrated both limited xenogenic GVHD and low alloreactive potential in vitro., Conclusions: Our study revealed that conventional CIK cells demonstrate no significant alloreactive potential but provide the strongest anti-tumor efficacy compared with manipulated CIK cells. Conventional CIK cells may therefore be tested in high numbers and short-term intervals in patients with impending relapse even after mismatched transplantation., (Copyright © 2014 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Background Aims: Enumeration of CD34(+) cells in leukocyte-rich cell suspensions is important for clinical decision-making in stem cell transplantation. Single-platform flow cytometry assays offer the significant advantages of speed and reproducibility, and have therefore become the gold standard in stem cell enumeration. The clinical community has recently defined the need for stem cell enumeration kits that incorporate viability dyes. The purpose of this study was to evaluate a novel assay, BD Biosciences' (BD) stem cell enumeration kit (SCE kit(‡)), in relation to Beckman Coulter's (BC) commercially available BC Stem-Kit™., Methods: Fresh/freeze-thawed samples from leukapheresis, bone marrow and cord blood, and fresh normal/mobilized blood, were analyzed with both assays (simultaneous detection of side/forward scatter and three fluorescence signals) on two flow cytometry platforms, BD FACSCanto II and BD FACSCalibur. Results. Results from both assays were highly congruent, with an overall r(2) ≥ 0.99 (all specimen types included), a linear correlation across all CD34(+) cell frequencies and concentrations, and an almost ideal steepness of the trend line., Conclusions: Both assays functioned reliably. Being based on single-platform International Society of Hematotherapy and Graft Engineering (ISHAGE) guidelines and similar staining methods, both assays essentially come to identical results. For most specimen types, the viability of CD34(+) cells was equal to overall leukocyte viability. In summary, in the hands of an experienced technician, the BD™ SCE kit and the BC Stem-Kit are equivalent. The infrequent user might derive benefit from the fact that counting spheres are pre-pipetted into the Trucount tube for the SCE kit, making this assay less susceptible to pipetting inaccuracy.