Biomedical subjects

Paul J Orchard

Publications and source records attributed to Paul J Orchard.

16 recordsLinked to original sources

PubMed2006

Inflammatory cytokines and the development of pulmonary complications after allogeneic hematopoietic cell transplantation in patients with inherited metabolic storage disorders.

Patients with inherited metabolic storage disorders are at a higher risk of developing pulmonary complications after hematopoietic cell transplantation (HCT). This single-center prospective study of 48 consecutive inherited metabolic storage disorder patients was performed to identify risk factors for the development of pulmonary complications after HCT. Before HCT, subjects underwent bronchoalveolar lavage (BAL) for cell count, culture, nitrite levels, and analysis of proinflammatory cytokines and chemokines. The overall incidence of pulmonary complications was 52% (infectious, 23%; noninfectious, 29%) over a period of 4 years. Diffuse alveolar hemorrhage was the most frequent noninfectious complication and occurred in 19% of patients, all of whom had a diagnosis of mucopolysaccharidosis (Hurler and Maroteaux-Lamy syndromes). Levels of interleukin (IL)-1beta, IL-6, IL-8, tumor necrosis factor alpha, macrophage inflammatory protein 1alpha, and granulocyte colony-stimulating factor in BAL fluid samples obtained before HCT were higher in patients with mucopolysaccharidoses than in patients with leukodystrophies. In addition, levels of IL-1beta, IL-6, IL-8, and granulocyte colony-stimulating factor were increased in the BAL fluid of patients who developed noninfectious pulmonary complications compared with those who did not develop pulmonary complications. It is interesting to note that most noninfectious pulmonary complications occurred in patients with mucopolysaccharidoses, especially diffuse alveolar hemorrhage, which occurred exclusively in patients with mucopolysaccharidoses. Higher levels of bronchial proinflammatory cytokines and chemokines may be predictive of the development of subsequent posttransplantation noninfectious complications in patients with mucopolysaccharidoses, especially those with Hurler syndrome. Larger studies will be required to further elucidate etiologic mechanisms and predictive factors.

Adolescent↗

PubMed2006

Long-term results of autologous stem cell transplantation for primary refractory or relapsed Hodgkin's lymphoma.

Autologous hematopoietic stem cell transplantation (ASCT) has become standard therapy for primary refractory (PR REF) or relapsed (REL) Hodgkin's lymphoma (HL); however, more than half of these patients eventually relapse and die of their disease. We studied long-term outcomes and evaluated factors influencing progression-free survival (PFS) in 141 patients with PR REF or REL HL who underwent ASCT between 1985 and 2003. Median age at ASCT was 30 years (range, 7-60 years); 21 patients had PR REF, and 120 had REL HL. With a median follow-up of 6.3 years (range, 1-20 years), the probability of PFS at 5 and 10 years was 48% (95% confidence interval [CI], 39%-57%) and 45% (95% CI, 36%-54%) and that of overall survival (OS) was 53% (95% CI, 44%-62%) and 47% (95% CI, 37%-57%), respectively. Transplant-related mortality at 100 days was 1.4%. Among 45 5- to 20-year survivors, no late relapses of HL were observed. In multivariate analysis, 3 factors were independently predictive of poor PFS: chemoresistant disease (relative risk [RR], 2.9; 95% CI, 1.7-5.0), B-symptoms at pretransplantation relapse (RR, 2.1; 95% CI, 1.3-3.4), and presence of residual disease at the time of transplantation (RR, 2.3; 95% CI, 1.1-4.8). Patients with 0 or 1 of these 3 adverse factors (low-risk disease) had a 5-year PFS of 67% (95% CI, 55%-79%) compared with 37% (95% CI, 22%-52%) in those with 2 factors (intermediate-risk group) and 9% (95% CI, 0-20%) in those with all 3 factors (high-risk group) (P < .001). The rates of OS at 5 years were 71% (95% CI, 60%-82%), 49% (95% CI, 33%-65%) and 13% (95% CI, 0-27%) in the 3 groups, respectively (P < .001). ASCT is associated with durable PFS in appropriately selected patients with PR REF or REL HL. Using a simple prognostic model, we can identify patients with high-risk disease who have predictably unfavorable outcome after ASCT and require novel therapeutic approaches. A risk-adapted approach should be followed in determining treatment options for patients with PR REF and REL HL.

Adolescent↗

PubMed2006

Coexpression of the uracil phosphoribosyltransferase gene with a chimeric human nerve growth factor receptor/cytosine deaminase fusion gene, using a single retroviral vector, augments cytotoxicity of transduced human T cells exposed to 5-fluorocytosine.

Donor T lymphocytes genetically engineered to express a "suicide gene" to facilitate negative selection represent a promising strategy for the management of graft-versus-host disease occurring after allogeneic hematopoietic cell transplantation (HCT). For this purpose, the herpes simplex virus thymidine kinase (HSV-tk) gene, although well studied, has limitations. Cytosine deaminase (CD), an alternative gene for negative selection, converts 5-fluorocytosine (5-FC) to the toxic metabolite 5-fluorouracil (5-FU). Sensitivity of cells to 5-FU can be further increased by expression of uracil phosphoribosyltransferase (UPRT), which catalyzes the conversion of 5-FU to 5-fluorouridine monophosphate. By using a chimeric gene (NG/CD) expressing the truncated human nerve growth factor receptor (NGFR) for positive selection fused to the Saccharomyces cerevisiae CD gene, we investigated strategies to achieve optimal T cell eradication by CD and UPRT expression, utilizing a single retroviral vector. Three vector strategies were compared on the basis of NGFR expression by flow cytometry, western analysis, and enzymatic activity. A construct (NG/CDiU) expressing UPRT and NG/CD, using a bicistronic message, provided the greatest UPRT activity and killing, reducing the lethal dose of 5-FC sufficient to eradicate 90% of cells from 38.7 microg/ml (300 microM) (NG/CD expression alone) to 0.13 microg/ml (1 microM). This approach provides an effective alternative to the HSV-tk system for eradication of donor T lymphocytes after allogeneic HCT.

Cell Line↗

PubMed2005

Stable gene transfer and expression in human primary T cells by the Sleeping Beauty transposon system.

The Sleeping Beauty (SB) transposon system is a nonviral DNA delivery system in which a transposase directs integration of an SB transposon into TA-dinucleotide sites in the genome. To determine whether the SB transposon system can mediate stable gene expression in human T cells, primary peripheral blood lymphocytes (PBLs) were nucleofected with SB vectors carrying a DsRed reporter gene. Plasmids containing the SB transposase on the same molecule as (cis) or on a molecule separate from (trans) the SB transposon mediated long-term and stable reporter gene expression in human primary T cells. Sequencing of transposon:chromosome junctions confirmed that stable gene expression was due to SB-mediated transposition. In other studies, PBLs were successfully transfected using the SB transposon system and shown to stably express a fusion protein consisting of (1) a surface receptor useful for positive T-cell selection and (2) a "suicide" gene useful for elimination of transfected T cells after chemotherapy. This study is the first report demonstrating that the SB transposon system can mediate stable gene transfer in human primary PBLs, which may be advantageous for T-cell-based gene therapies.

Animals↗

PubMed2005

Successful adoptive transfer and in vivo expansion of human haploidentical NK cells in patients with cancer.

We previously demonstrated that autologous natural killer (NK)-cell therapy after hematopoietic cell transplantation (HCT) is safe but does not provide an antitumor effect. We hypothesize that this is due to a lack of NK-cell inhibitory receptor mismatching with autologous tumor cells, which may be overcome by allogeneic NK-cell infusions. Here, we test haploidentical, related-donor NK-cell infusions in a nontransplantation setting to determine safety and in vivo NK-cell expansion. Two lower intensity outpatient immune suppressive regimens were tested: (1) low-dose cyclophosphamide and methylprednisolone and (2) fludarabine. A higher intensity inpatient regimen of high-dose cyclophosphamide and fludarabine (Hi-Cy/Flu) was tested in patients with poor-prognosis acute myeloid leukemia (AML). All patients received subcutaneous interleukin 2 (IL-2) after infusions. Patients who received lower intensity regimens showed transient persistence but no in vivo expansion of donor cells. In contrast, infusions after the more intense Hi-Cy/Flu resulted in a marked rise in endogenous IL-15, expansion of donor NK cells, and induction of complete hematologic remission in 5 of 19 poor-prognosis patients with AML. These findings suggest that haploidentical NK cells can persist and expand in vivo and may have a role in the treatment of selected malignancies used alone or as an adjunct to HCT.

Acute Disease↗

PubMed2005

Long-term follow-up after autologous hematopoietic stem cell transplantation for low-grade non-Hodgkin lymphoma.

Autologous hematopoietic stem cell transplantation (AHSCT) in low-grade non-Hodgkin lymphoma (NHL) can result in a prolonged remission, although most patients eventually relapse and die of their disease. We report long-term outcomes of AHSCT for patients with relapsed low-grade NHL. Between May 1983 and 2001, 67 patients with relapsed or refractory stage III and IV low-grade NHL received an AHSCT at the University of Minnesota at a median of 2.3 years (range, 0.4-15.2 years) after diagnosis. At transplantation, 62 patients (92%) were in complete remission (CR) (6%) or partial remission (PR) (86%); 5 (8%) had resistant disease; and 9 (14%) had transformed to a higher-grade NHL. After AHSCT, 32 (49%) of 65 evaluable patients achieved CR, and 26 (40%) achieved PR. Overall survival (OS) was 50% (95% confidence interval [CI], 38%-62%) at 4 years and 33% (95% CI, 20%-46%) at both 10 and 18 years, whereas progression-free survival (PFS) was 28% (95% CI, 17%-39%) at 4 years, 18% (95% CI, 8%-28%) at 10 years, and 14% (95% CI, 4%-25%) at 18 years. Transplant-related mortality in the first 100 days was 3% (95% CI, 0%-7%). Relapse occurred in 62% (95% CI, 48%-75%) at 4 years and 72% (95% CI, 56%-87%) at 10 years. Eleven patients (16%) developed myelodysplastic syndrome/acute myeloid leukemia 1 to 8 years after AHSCT, and 3 (5%) developed solid tumors. In multiple regression analysis, the International Prognostic Index (IPI) score at transplantation was the most significant predictor for both OS and PFS. The median OS has not been reached in patients with an IPI score of 0 or 1 at transplantation (20 of 35 survive 2 to 18 years after AHSCT), whereas it was 2.3 and 1.6 years for IPI scores of 2 and 3, respectively ( P = .002). A good response (CR/PR) to AHSCT (relative risk [RR], 0.4; 95% CI, 0.2-0.9; P = .04) and age <50 years (RR, 0.5; 95% CI, 0.2-0.8; P = .01) were also independently significant predictors of good OS and PFS. We present mature follow-up data (median follow-up, 8 years; range, 2-18 years) of patients undergoing AHSCT for relapsed low-grade NHL and demonstrate extended OS and PFS. Very long-term remissions were seen in nearly 20% of patients. AHSCT remains promising, especially for patients with sensitive relapse and lower IPI scores. Recurrent lymphoma after AHSCT remains the major problem, and prolonged survival is further tempered by a significant risk of post-transplantation second malignancies, including myelodysplastic syndrome/acute myeloid leukemia and solid tumors.

Adult↗

PubMed2005

The Minnesota Molecular and Cellular Therapeutics Facility: a state-of-the-art biotherapeutics engineering laboratory.

Molecular-, gene-, cellular-, and tissue-based therapies have become increasingly acceptable modes of clinical therapy. Regulatory requirements and oversight have increased, and the need for facilities suited for production of such therapies has become more apparent. The Minnesota Molecular and Cellular Therapeutics Facility is a state-of-the-art laboratory at the University of Minnesota, Saint Paul, Minn, that was designed to support production of biologic products for use in clinical trials. A talented staff experienced in the medical, scientific, technical, and regulatory aspects of the development, production, and administration of such products complements the special design and construction of the facility. Hematopoietic stem cells (HSCs) are manipulated for transplant, and current clinical trials involving novel therapies include the use of allogeneic natural killer (NK) cells and tumor vaccines for the treatment of various malignancies and suicide gene-transduced T cells for the prevention of graft-vs-host disease (GVHD) after bone marrow transplantation. Other therapies, including marrow-derived multipotent adult progenitor cells (MAPCs), umbilical cord blood (UCB) stem cells, regulatory T cells, skeletal myoblasts, and monoclonal antibodies, will be used to treat a spectrum of disease and are in various phases of development. Here we provide an overview of the Minnesota Molecular and Cellular Therapeutics (MMCT) Facility, detailing our approach to the manufacture of novel therapeutics and highlighting current and future activities.

Academic Medical Centers↗

PubMed2004

Osteopetrosis.

Explore the source record for details and available documents.

Animals↗

PubMed2004

Cerebral X-linked adrenoleukodystrophy: the international hematopoietic cell transplantation experience from 1982 to 1999.

Cerebral X-linked adrenoleukodystrophy (X-ALD) is a disorder of very-long-chain fatty acid metabolism, adrenal insufficiency, and cerebral demyelination. Death occurs within 2 to 5 years of clinical onset without hematopoietic cell transplantation (HCT). One hundred twenty-six boys with X-ALD received HCT from 1982 to 1999. Survival, engraftment, and acute graft-versus-host disease were studied. Degree of disability associated with neurologic and neuropsychological function and cerebral demyelination were evaluated before and after HCT. Complete data were available and analyzed for 94 boys with cerebral X-ALD. The estimated 5- and 8-year survival was 56%. The leading cause of death was disease progression. Donor-derived engraftment occurred in 86% of patients. Demyelination involved parietal-occipital lobes in 90%, leading to visual and auditory processing deficits in many boys. Overall 5-year survival of 92% in patients with 0 or 1 neurologic deficits and magnetic resonance imaging (MRI) severity score less than 9 before HCT was superior to survival for all others (45%; P <.01). Baseline neurologic and neuropsychological function, degree of disability, and neuroradiologic status predicted outcomes following HCT. In this first comprehensive report of the international HCT experience for X-ALD, we conclude that boys with early-stage disease benefit from HCT, whereas boys with advanced disease may be candidates for experimental therapies.

Adrenoleukodystrophy↗

PubMed2004

In vitro differentiation of CD14 cells from osteopetrotic subjects: contrasting phenotypes with TCIRG1, CLCN7, and attachment defects.

UNLABELLED: We studied osteoclastic differentiation from normal and osteopetrotic human CD14 cells in vitro. Defects in acid transport, organic matrix removal, and cell fusion with deficient attachment were found. Analysis of genotypes showed that TCIRG1 anomalies correlated with acid transport defects, but surprisingly, organic matrix removal failure correlated with CLCN7 defects; an attachment defect had normal TCIRG1 and CLCN7. INTRODUCTION: Osteopetrotic subjects usually have normal macrophage activity, and despite identification of genetic defects associated with osteopetrosis, the specific developmental and biochemical defects in most cases are unclear. Indeed, patients with identical genotypes often have different clinical courses. We classified defects in osteoclast differentiation in vitro using four osteopetrotic subjects without immune or platelet defects, three of them severe infantile cases, compared with normals. MATERIALS AND METHODS: Osteoclast differentiation used isolated CD14 cells; results were correlated with independent analysis of two key genes, CLCN7 and TCIRG1. CD14 cell attachment and cell surface markers and extent of differentiation in RANKL and colony-stimulating factor (CSF)-1 were studied using acid secretion, bone pitting, enzyme, and attachment proteins assays. RESULTS AND CONCLUSIONS: CD14 cells from all subjects had similar lysosomal and nonspecific esterase activity. With the exception of cells from one osteopetrotic subject, CD14 cells from osteopetrotic and control monocytes attached similarly to bone or tissue culture substrate. Cells from one osteopetrotic subject, with normal CLCN7 and TCIRG1, did not attach to bone, did not multinucleate, and formed no podosomes or actin rings in RANKL and CSF-1. Attachment defects are described in osteopetrosis, most commonly mild osteopetrosis with Glantzman's thrombasthenia. However, this case, with abnormal integrin alphavbeta3 aggregates and no osteoclasts, seems to be unique. Two subjects were compound heterozygotes for TCIRG1 defects; both had CD14 cells that attached to bone but did not acidify attachments; cell fusion and attachment occurred, however, in RANKL and CSF-1. This is consistent with TCIRG1, essential for H+-ATPase assembly at the ruffled border. A compound heterozygote for CLCN7 defects had CD14 cells that fused in vitro, attached to bone, and secreted acid, TRACP, and cathepsin K. However, lacunae were shallow and retained demineralized matrix. This suggests that CLCN7 may not limit H+-ATPase activity as hypothesized, but may be involved in control of organic matrix degradation or removal.

Acid Phosphatase↗

PubMed2004

Effective treatment of alpha-mannosidosis by allogeneic hematopoietic stem cell transplantation.

OBJECTIVES: To study the efficacy of hematopoietic stem cell transplantation (HCT) for ameliorating the clinical manifestations of alpha-mannosidosis. STUDY DESIGN: Four patients with alpha-mannosidosis underwent allogeneic HCT at the University of Minnesota. Diagnosis was established by assay of leukocyte alpha-mannosidase activity level. Physical features, donor engraftment, leukocyte alpha-mannosidase activity, neuropsychologic function, and hearing were monitored before and after transplantation, with follow-up ranging from 1 to 6 years. RESULTS: All 4 patients showed slowing of their neurocognitive development and sensorineural hearing loss before HCT. All patients are alive, with normalization of leukocyte enzyme activity after HCT. Intellectual function has stabilized, with improvement in adaptive skills and verbal memory function in 3 of 4 patients. Hearing has improved to normal or near normal for speech frequencies in 3 patients. No new skeletal abnormalities have developed. CONCLUSIONS: HCT can halt the progressive cognitive loss in patients with alpha-mannosidosis. Early diagnosis and treatment with HCT is critical for optimal results.

Adult↗

PubMed2003

Human nerve growth factor receptor and cytosine deaminase fusion genes.

Cytosine deaminase (CD) converts 5-fluorocytosine (5-FC) to the toxic metabolite 5-fluorouracil (5-FU), and has been investigated extensively as a potential tool for selective cellular eradication. In this paper, genetic constructs were designed to express the CD enzyme fused to the transmembrane and extracellular domains of the human nerve growth factor receptor (NGFR), thus allowing for positive identification of transduced cells by flow cytometry and positive selection by magnetic bead technology. Constructs were designed to encode a [Gly(4)Ser](2) flexible linker between the nucleic acid coding sequences for the NGFR and CD genes. Retroviral vectors constructed with wild-type CD and NG/CD fusion genes were used to transduce 3T3 fibroblasts and the human T cell line CEM. The function of CD fusion genes was comparable to that of wild-type genes as determined in cytotoxicity assays. By flow cytometry, the NGFR antigen was detectable after expression of the fusion gene derived from either Escherichia coli (NG/CDe) or Saccharomyces cerevisiae (NG/CDs), but the greatest antigen density was observed in cells transduced with the NG/CDs vector. Similarly, superior 5-FC sensitivity was observed with NG/CDs fusion gene in both murine fibroblasts and human T cells. In addition, CEM cells expressing NG/CDs were more efficiently eliminated in vivo. Engineering of cells utilizing the chimeric NG/CD genes provides a new modality in gene therapy allowing positive and negative selection using a single protein-coding sequence.

Animals↗

PubMed2003

Cellular engineering of HSV-tk transduced, expanded T lymphocytes for graft-versus-host disease management.

Engineering donor T lymphocytes with inducible 'suicide genes', such as herpes simplex virus thymidine kinase, has potential to improve safety and efficacy in allogeneic transplantation by facilitating management of graft-versus-host disease. Elective administration of a relatively nontoxic pro-drug would induce in vivo negative selection of engineered lymphocytes specifically, sparing other donor hematopoietic cells. The engineered cells must retain immunologic function, and undergo negative selection in response to clinically attainable plasma concentrations of pro-drug. The cell engineering process itself, typically involving activation, transduction, ex vivo expansion, and selection, must produce clinically useful numbers of genetically modified cells at high purity. We discuss development of a cellular engineering manufacturing process that yields transduced, expanded T lymphocytes meeting these requirements.

Adoptive Transfer↗

PubMed2003

Chloride channel ClCN7 mutations are responsible for severe recessive, dominant, and intermediate osteopetrosis.

UNLABELLED: Among 94 osteopetrotic patients presenting with a severe clinical picture and diagnosed early in life, 12 bore mutations in the ClCN7 gene, but only 7 of them had the expected two recessive mutations. The remaining five patients seem to be heterozygous for a ClCN7 mutation, and significant variations were observed in the clinical manifestations of their disease, even within the same family. INTRODUCTION: Human osteopetroses are a heterogeneous group of diseases that include both infantile severe, autosomal recessive (ARO) and adult autosomal dominant (ADO) forms. Two genes, Atp6a3 (TCIRG1) and ClCN7, have been shown to be associated with human ARO, the latter of which is also thought to be responsible for ADO-II. However, patients with an intermediate phenotype have been described: the genetic basis of these observances is unknown. MATERIALS AND METHODS: In this study, we report the clinical and molecular analysis of 94 patients in which a diagnosis of severe osteopetrosis was made within the first 2 years of age. Both TCIRG1 and CLCN7 genes were sequenced in all patients and the molecular findings were correlated to clinical parameters. RESULTS AND CONCLUSIONS: In 56 of 94 patients with a classical picture of ARO, TCIRG1-dependent recessive mutations were found. In contrast, ClCN7 mutations were found in 12 cases (13%) of severe osteopetrosis, but only 7 of them had two recessive mutations identified: in 6 of these 7 cases, central nervous system manifestations were noted, and these patients had a poor prognosis. The remaining five cases were heterozygous for a ClCN7 mutation, including two brothers from a large family with a history of ADO-II in which the presence of a second ClCN7 mutation was formally excluded. Despite an early and severe clinical presentation, these five patients all reached adulthood, suggesting that the degree of dominant interference with chloride channel function can vary widely. Our findings suggest that recessive ClCN7-dependent ARO may be associated with CNS involvement and have a very poor prognosis, whereas heterozygous ClCN7 mutations cause a wide range of phenotypes even in the same family, ranging from early severe to nearly asymptomatic forms. These findings have prognostic implications, might complicate prenatal diagnosis of human osteopetroses, and could be relevant to the management of these patients.

Adolescent↗

PubMed2002

Transplantation of unrelated donor umbilical cord blood in 102 patients with malignant and nonmalignant diseases: influence of CD34 cell dose and HLA disparity on treatment-related mortality and survival.

The potential benefits of unrelated donor marrow transplantation are offset by the immunologic complications of graft-versus-host disease (GVHD) and infection. Therefore, we used cryopreserved umbilical cord blood (UCB) as a strategy to reduce the risks of GVHD and treatment-related mortality (TRM) and improve survival. Data on 102 patients (median age 7.4 years) who received transplants between 1994 and 2001 for the treatment of malignant (n = 65; 68% were high-risk patients) and nonmalignant (n = 37) diseases were evaluated. Log-rank tests and Cox regression analyses were used to determine the effects of various demographic, graft-related, and treatment factors on engraftment, GVHD, TRM, relapse, and survival. As of October 15, 2001, the median follow-up was 2.7 years (range, 0.3-7.2). Incidences of neutrophil and platelet engraftment were 0.88 (CI, 0.81-0.95) and 0.65 (CI, 0.53-0.77), respectively. Notably, incidences of severe acute and chronic GVHD were 0.11 (CI, 0.05-0.17) and 0.10 (CI, 0.04-0.16), respectively. At 1 year after transplantation, proportions of TRM and survival were 0.30 (CI, 0.21-0.39) and 0.58 (CI, 0.48-0.68), respectively. In Cox regression analyses, CD34 cell dose was the one factor consistently identified as significantly associated with rate of engraftment, TRM, and survival. Despite the low incidence of GVHD, the proportion of patients with leukemia relapse at 2 years was 0.17 (CI, 0.00-0.38) and 0.45 (CI, 0.28-0.61) for patients with standard and high-risk disease, respectively. There is a high probability of survival in recipients of UCB grafts that are disparate in no more than 2 human leukocyte antigens (HLAs) when the grafts contain at least 1.7 x 10(5) CD34(+) cells per kilogram of recipient's body weight. Therefore, graft selection should be based principally on CD34 cell dose when multiple UCB units exist with an HLA disparity of 2 or less.

Adolescent↗

PubMed2002

Clinical-scale selection of anti-CD3/CD28-activated T cells after transduction with a retroviral vector expressing herpes simplex virus thymidine kinase and truncated nerve growth factor receptor.

Activation of T cells is necessary for efficient retroviral-mediated gene transfer. In addition, if the population of infused cells is to be limited to transduced cells, a means of positive selection is required. We describe a clinical scale procedure for activation of donor T cells with anti-CD3/CD28 beads followed by transduction with a retroviral construct expressing the herpes simplex virus thymidine kinase (HSV-tk) and human nerve growth factor receptor (NGFR). Optimization of transduction parameters was performed, testing the timing of transduction, centrifugation, and the use of serum. In large-scale experiments, 3-5 x 10(8) peripheral blood mononuclear cells (PBMC) were activated with anti-CD3/CD28 beads and expanded to day 13. Transduction was accomplished using MFG-TKiNG supernatant produced from the PG13 packaging line 48 hr after T-cell activation. The mean transduction frequency was 37.5% based on NGFR expression, and the mean expansion observed was 42.6-fold (mean final cell number 1.85 x 10(10)). A comparison of the ability of the Baxter Isolex 300i and the Miltenyi CliniMACS to perform purification of NGFR+ cells suggests that greater purity can be achieved with the CliniMACS device (67.4% vs. 97.7%), while the yield of transduced cells appears higher with the Isolex 300i (41.3% vs. 23.5%). We conclude that a strategy based on activation of human T cells with anti-CD3/CD28 beads can result in sufficient transduction, expansion, and purification based on NGFR expression for clinical trials.

3T3 Cells↗