Tracheal Replacement Therapy with a Stem Cell-Seeded Graft: Lessons from Compassionate Use Application of a GMP-Compliant Tissue-Engineered Medicine.

Tracheal replacement for the treatment of end-stage airway disease remains an elusive goal. The use of tissue-engineered tracheae in compassionate use cases suggests that such an approach is a viable option. Here, a stem cell-seeded, decellularized tissue-engineered tracheal graft was used on a compassionate basis for a girl with critical tracheal stenosis after conventional reconstructive techniques failed.

Vacuum-assisted decellularization: an accelerated protocol to generate tissue-engineered human tracheal scaffolds.

Patients with large tracheal lesions unsuitable for conventional endoscopic or open operations may require a tracheal replacement but there is no present consensus of how this may be achieved. Tissue engineering using decellularized or synthetic tracheal scaffolds offers a new avenue for airway reconstruction. Decellularized human donor tracheal scaffolds have been applied in compassionate-use clinical cases but naturally derived extracellular matrix (ECM) scaffolds demand lengthy preparation times.

Two-Stage Priming of Allogeneic Natural Killer Cells for the Treatment of Patients with Acute Myeloid Leukemia: A Phase I Trial.

Unlabelled: Human Natural Killer (NK) cells require at least two signals to trigger tumor cell lysis. Absence of ligands providing either signal 1 or 2 provides NK resistance. We manufactured a lysate of a tumour cell line which provides signal 1 to resting NK cells without signal 2.

Assessment of the effector function of CMV-specific CTLs isolated using MHC-multimers from granulocyte-colony stimulating factor mobilized peripheral blood.

Background: Adoptive transfer of CMV-specific T cells has shown promising results in preventing pathological effects caused by opportunistic CMV infection in immunocompromised patients following allogeneic hematopoietic stem cell transplantation. The majority of studies have used steady-state leukapheresis for CMV-reactive product manufacture, a collection obtained prior to or months after G-CSF mobilization, but the procurement of this additional sample is often not available in the unrelated donor setting. If the cellular product for adoptive immunotherapy could be generated from the same G-CSF mobilized collection, the problems associated with the additional harvest could be overcome.

CMV-specific T cell isolation from G-CSF mobilized peripheral blood: depletion of myeloid progenitors eliminates non-specific binding of MHC-multimers.

Background: Cytomegalovirus (CMV)-specific T cell infusion to immunocompromised patients following allogeneic Hematopoietic Stem Cell Transplantation (allo-HSCT) is able to induce a successful anti-viral response. These cells have classically been manufactured from steady-state apheresis samples collected from the donor in an additional harvest prior to G-CSF mobilization, treatment that induces hematopoietic stem cell (HSC) mobilization to the periphery. However, two closely-timed cellular collections are not usually available in the unrelated donor setting, which limits the accessibility of anti-viral cells for adoptive immunotherapy.

Manufacturing of highly functional and specific T cells for adoptive immunotherapy against virus from granulocyte colony-stimulating factor-mobilized donors.

Background Aims: Cytomegalovirus (CMV) reactivation remains an important risk after hematopoietic stem cell transplantation, which can be effectively controlled through adoptive transfer of donor-derived CMV-specific T cells (CMV-T). CMV-T are usually obtained from donor peripheral blood mononuclear cells (PBMCs) collected before G-CSF mobilization. Despite previous studies that showed impaired T-cell function after granulocyte colony-stimulating factor (G-CSF) mobilization, recent publications suggest that G-CSF-primed PBMCs retain anti-viral function and are a suitable starting material for CMV-T manufacturing.

Mouse xenograft modeling of human adult acute lymphoblastic leukemia provides mechanistic insights into adult LIC biology.

The distinct nature of acute lymphoblastic leukemia (ALL) in adults, evidenced by inferior treatment outcome and different genetic landscape, mandates specific studies of disease-initiating mechanisms. In this study, we used NOD/LtSz-scid IL2Rγ null(c) (NSG) mouse xenotransplantation approaches to elucidate leukemia-initiating cell (LIC) biology in primary adult precursor B (pre-B) ALL to optimize disease modeling. In contrast with xenografting studies of pediatric ALL, we found that modification of the NSG host environment using preconditioning total body irradiation (TBI) was indispensable for efficient engraftment of adult non-t(4;11) pre-B ALL, whereas t(4;11) pre-B ALL was successfully reconstituted without this adaptation.

Isolation of highly suppressive CD25+FoxP3+ T regulatory cells from G-CSF-mobilized donors with retention of cytotoxic anti-viral CTLs: application for multi-functional immunotherapy post stem cell transplantation.

Previous studies have demonstrated the effective control of cytomegalovirus (CMV) infections post haematopoietic stem cell transplant through the adoptive transfer of donor derived CMV-specific T cells (CMV-T). Strategies for manufacturing CMV immunotherapies has involved a second leukapheresis or blood draw from the donor, which in the unrelated donor setting is not always possible. We have investigated the feasibility of using an aliquot of the original G-CSF-mobilized graft as a starting material for manufacture of CMV-T and examined the activation marker CD25 as a targeted approach for identification and isolation following CMVpp65 peptide stimulation.

Successful isolation and expansion of CMV-reactive T cells from G-CSF mobilized donors that retain a strong cytotoxic effector function.

Cytomegalovirus (CMV) infections post-haematopoietic stem cell transplantation (HSCT) can be effectively controlled through the adoptive transfer of donor-derived CMV-specific T cells (CMV-T). Current strategies involve a second leukapheresis collection from the original donor to manufacture CMV-T, which is often not possible in the unrelated donor setting. To overcome these limitations we have investigated the use of a small aliquot of the original granulocyte-colony stimulating factor (G-CSF) mobilized HSCT graft to manufacture CMV-T.

Stem-cell-based, tissue engineered tracheal replacement in a child: a 2-year follow-up study.

Background: Stem-cell-based, tissue engineered transplants might offer new therapeutic options for patients, including children, with failing organs. The reported replacement of an adult airway using stem cells on a biological scaffold with good results at 6 months supports this view. We describe the case of a child who received a stem-cell-based tracheal replacement and report findings after 2 years of follow-up.

Directly selected cytomegalovirus-reactive donor T cells confer rapid and safe systemic reconstitution of virus-specific immunity following stem cell transplantation.

Background: Adoptive transfer of virus-specific T cells may accelerate reconstitution of antigen-specific immunity and limit the morbidity and mortality of viral infections following allogeneic hematopoietic stem cell transplantation. The logistics of producing virus-specific T cells has, however, limited the application of cellular therapies, particularly following the introduction of more-recent regulatory stipulations.

Methods: We investigated the ability of cytomegalovirus-specific T cells, directly isolated from donor leucapheresates on the basis of interferon γ secretion, to restore antiviral immunity in a group of 25 patients following related-donor transplantation in a single-arm phase I-II study.

The JAK3-selective inhibitor PF-956980 reverses the resistance to cytotoxic agents induced by interleukin-4 treatment of chronic lymphocytic leukemia cells: potential for reversal of cytoprotection by the microenvironment.

Extensive evidence suggests that the malignant cells of chronic lymphocytic leukemia (CLL) patients are in close contact with activated T lymphocytes, which secrete a range of cytoprotective cytokines including interleukin-4 (IL-4). IL-4 induced the rapid phosphorylation and activation of the signal transducer and activator of transcription 6 transcription factor in CLL cells in vitro. Longer incubation with IL-4 resulted in up-regulation of the antiapoptotic proteins, Mcl-1 and Bcl-X(L).

Phase I study of high-stringency CD8 depletion of donor leukocyte infusions after allogeneic hematopoietic stem cell transplantation.

Background: Donor leukocyte infusions (DLI) are given after hematopoietic stem-cell transplantation to eradicate persistent tumor or correct mixed chimerism (MC). The drawback of DLI is the risk of graft-versus-host disease (GVHD). In this phase I study, we examined the potential of highly extensive CD8 depletion of DLI as a means of improving its safety profile.

Class prediction models of thrombocytosis using genetic biomarkers.

Criteria for distinguishing among etiologies of thrombocytosis are limited in their capacity to delineate clonal (essential thrombocythemia [ET]) from nonclonal (reactive thrombocytosis [RT]) etiologies. We studied platelet transcript profiles of 126 subjects (48 controls, 38 RT, 40 ET [24 contained the JAK2V(617)F mutation]) to identify transcript subsets that segregated phenotypes. Cross-platform consistency was validated using quantitative real-time polymerase chain reaction (RT-PCR).

2-Phenylacetylenesulfonamide (PAS) induces p53-independent apoptotic killing of B-chronic lymphocytic leukemia (CLL) cells.

We studied the actions of 2-phenylacetylenesulfonamide (PAS) on B-chronic lymphocytic leukemia (CLL) cells. PAS (5-20 microM) initiated apoptosis within 24 hours, with maximal death at 48 hours asassessed by morphology, cleavage of poly(ADP-ribose) polymerase (PARP), caspase 3 activation, and annexin V staining. PAS treatment induced Bax proapoptotic conformational change, Bax movement from the cytosol to the mitochondria, and cytochrome c release, indicating that PAS induced apoptosis via the mitochondrial pathway.