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Biomedical subjects

Claudio Bordignon

Publications and source records attributed to Claudio Bordignon.

29 records · Page 2Linked to original sources
PubMed2003

Gene therapy for adenosine deaminase deficiency.

PURPOSE OF REVIEW: Gene therapy for severe combined immunodeficiency due to adenosine deaminase deficiency has moved from the early trials of safety and feasibility to recent studies demonstrating efficacy and clinical benefit. This review describes the latest advances in gene therapy trials for this condition using peripheral blood lymphocytes or hematopoietic progenitors. RECENT FINDINGS: In the first patients with severe combined immunodeficiency due to adenosine deaminase deficiency treated with peripheral blood lymphocytes, transduced T cells have been shown to persist for over 10 years, expressing transgenic adenosine deaminase, but the therapeutic effect of gene therapy remained difficult to assess because of the concomitant treatment with bovine adenosine deaminase conjugated to polyethylene-glycol (PEG-ADA). A recent report showed that discontinuation of PEG-ADA resulted in a strong selective advantage of gene corrected T cells associated with restoration of T cell functions and antibody responses to neoantigen, but incomplete correction of the metabolic defect. Follow-up studies in patients treated with engineered hematopoietic progenitors in the early trials revealed low marking levels of long-term living progenitors and limited clinical effect. Recently, an improved gene transfer protocol in bone marrow CD34+ cells combined with low-dose busulfan resulted in multilineage, stable engraftment of transduced progenitors at substantial levels, restoration of immune functions, correction of the adenosine deaminase metabolic defect, and proven clinical benefit, in the absence of PEG-ADA. Overall, no adverse effect or toxicity has been observed in patients treated with adenosine deaminase gene transfer in mature lymphocytes or hematopoietic progenitors. SUMMARY: Gene transfer in hematopoietic stem cells combined with nonmyeloablative conditioning is efficacious and might be extended to the treatment of other inherited and acquired disorders of the hematopoietic system.

Adenosine Deaminase↗
PubMed2002

Immunologic potential of donor lymphocytes expressing a suicide gene for early immune reconstitution after hematopoietic T-cell-depleted stem cell transplantation.

We have previously shown that the infusion of donor lymphocytes expressing the herpes simplex virus thymidine kinase (HSV-tk) gene is an efficient tool for controlling graft-versus-host disease (GVHD) while preserving the graft-versus-leukemia (GVL) effect. In addition to the GVL effect, the administration of donor HSV-tk(+) cells could have a clinical impact in promoting immune reconstitution after T-cell-depleted stem cell transplantation (SCT). To explore this hypothesis, we have investigated whether in vitro polyclonal activation, retroviral transduction, immunoselection, and expansion affect the immune competence of donor T cells. We have observed that, after appropriate in vitro manipulation, T cells specific for antigens relevant in the context of SCT are preserved in terms of frequency, expression of T-cell receptor, proliferation, cytokine secretion, and lytic activity. A reduction in the frequency of allospecific T-cell precursors is observed after prolonged T-cell culture, suggesting that cell manipulation protocols involving a short culture time and high transduction efficiency are needed. Finally, the long-term persistence of HSV-tk(+) cells was observed in a patient treated in the GVL clinical trial, and a reversion of the phenotype of HSV-tk(+) cells from CD45RO(+) to CD45RA(+) was documented more than 2 years after the infusion. Based on all this evidence, we propose a clinical study of preemptive infusions of donor HSV-tk(+) T cells after SCT from haploidentical donors to provide early immune reconstitution against infection and potential immune protection against disease recurrence.

Antigens, Viral↗
PubMed2002

Correction of ADA-SCID by stem cell gene therapy combined with nonmyeloablative conditioning.

Hematopoietic stem cell (HSC) gene therapy for adenosine deaminase (ADA)-deficient severe combined immunodeficiency (SCID) has shown limited clinical efficacy because of the small proportion of engrafted genetically corrected HSCs. We describe an improved protocol for gene transfer into HSCs associated with nonmyeloablative conditioning. This protocol was used in two patients for whom enzyme replacement therapy was not available, which allowed the effect of gene therapy alone to be evaluated. Sustained engraftment of engineered HSCs with differentiation into multiple lineages resulted in increased lymphocyte counts, improved immune functions (including antigen-specific responses), and lower toxic metabolites. Both patients are currently at home and clinically well, with normal growth and development. These results indicate the safety and efficacy of HSC gene therapy combined with nonmyeloablative conditioning for the treatment of SCID.

Adenosine Deaminase↗
PubMed2002

Nonmyeloablative conditioning followed by hematopoietic cell allografting and donor lymphocyte infusions for patients with metastatic renal and breast cancer.

The feasibility and toxicity of allogeneic stem cell transplantation after nonmyeloablative conditioning including thiotepa, fludarabine, and cyclophosphamide have been investigated in 6 patients with breast cancer and 7 patients with renal cell cancer. The program included the use of escalating doses of donor lymphocyte infusions (DLI) and/or interferon alpha (IFNalpha) for patients showing no tumor response and no graft-versus-host disease (GVHD). Patients were at high risk of transplant-related mortality (TRM) because of age, advanced stage, and previous treatments. We observed a partial remission in 4 renal cancer and in 2 breast cancer patients (one at the molecular level in the bone marrow), occurring after cyclosporine withdrawal or after DLI and/or IFNalpha. All the responses were accompanied by the occurrence of acute GVHD. We conclude that reduced-intensity allogeneic stem cell transplantation is a feasible procedure in renal and breast cancer, and that the exploitation of graft-versus-tumor effect after DLI is a promising finding.

Adolescent↗
PubMed2002

Absence of metabolic cross-correction in Tay-Sachs cells: implications for gene therapy.

We have investigated the ability of a receptor-mediated gene transfer strategy (cross-correction) to restore ganglioside metabolism in fibroblasts from Tay-Sachs (TS) patients in vitro. TS disease is a GM2 gangliosidosis attributed to the deficiency of the lysosomal enzyme beta-hexosaminidase A (HexA) (beta-N-acetylhexosaminidase, EC ). The hypothesis is that transduced cells overexpressing and secreting large amounts of the enzyme would lead to a measurable activity in defective cells via a secretion-recapture mechanism. We transduced NIH3T3 murine fibroblasts with the LalphaHexTN retroviral vector carrying the cDNA encoding for the human Hex alpha-subunit. The Hex activity in the medium from transduced cells was approximately 10-fold higher (up to 75 milliunits) than observed in non-transduced cells. TS cells were cultured for 72 h in the presence of the cell medium derived from the transduced NIH3T3 cells, and they were analyzed for the presence and catalytic activity of the enzyme. Although TS cells were able to efficiently uptake a large amount of the soluble enzyme, the enzyme failed to reach the lysosomes in a sufficient quantity to hydrolyze the GM2 ganglioside to GM3 ganglioside. Thus, our results showed that delivery of the therapeutic HexA was not sufficient to correct the phenotype of TS cells.

3T3 Cells↗
PubMed2002

Reduced-intensity conditioning followed by allografting of hematopoietic cells can produce clinical and molecular remissions in patients with poor-risk hematologic malignancies.

A reduced-intensity conditioning regimen was investigated in 45 patients with hematologic malignancies who were considered poor candidates for conventional myeloablative regimens. Median patient age was 49 years. Twenty-six patients previously failed autologous transplantation, and 18 patients had a refractory disease at the time of transplantation. In order to decrease nonrelapse mortality, and enhance the graft-versus-tumor effect, a program was designed in which a reduced conditioning with thiotepa, fludarabine, and cyclophosphamide was associated with programmed reinfusions of donor lymphocytes for patients without graft-versus-host disease (GVHD), not achieving clinical and molecular remission after transplantation. GVHD prophylaxis consisted of cyclosporine A and methotrexate. Seventeen patients received marrow cells and 28 received mobilized hematopoietic cells. All patients engrafted. The probability of grades II-IV and III-IV acute GVHD were 47% and 13%, respectively. The probability of nonrelapse mortality, progression-free survival, and overall survival were 13%, 57%, and 53%, respectively. Thirteen patients in complete remission had a polymerase chain reaction marker for minimal disease monitoring; 10 achieved molecular remission after transplantation. Nine patients received donor lymphocytes: one patient with mantle cell lymphoma had a minimal response, one patient with refractory anemia with excess of blasts in transformation achieved complete remission, and 7 patients did not respond. At a median follow-up of 385 days (range, 24 to 820 days), 25 patients (55%) were alive in complete remission. Although longer follow-up is needed to evaluate the long-term outcome, the study shows that this regimen is associated with a durable engraftment, has a low nonrelapse mortality rate, and can induce clinical and molecular remissions.

Adult↗
PubMed2002

Growth and expansion of human T regulatory type 1 cells are independent from TCR activation but require exogenous cytokines.

Cloned T regulatory type 1 (Tr1) cells produce IL-10, TGF-beta, IFN-gamma, and very low or non-detectable levels of IL-2 and IL-4, following TCR-mediated activation. In addition, upon TCR stimulation, Tr1 cell clones up-regulate activation markers but show low proliferative responses, partially due to the suppressive effect of autocrine IL-10 and TGF-beta. Here we show that Tr1 cells have growth requirements different from those of Th1 and Th2 cells. Exogenous IL-15, and to a lesser extent IL-2, induce and support the proliferation of Tr1 cells in the absence of TCR activation. This strong cytokine response correlates with high constitutive levels of the IL-2/15Rbeta and common gamma chains expressed by Tr1 cell clones. Furthermore, suboptimal doses of IL-15, in combination with IL-2, induce a significant growth (median value: 25-fold increase in cell number) of Tr1 cell clones during a culture period of 11 days, which leads to an in vitro expansion of Tr1 cell clones comparable to that of Th1 and Th2 cell clones. Tr1 cell clones cultured in IL-15 continue to secrete immunosuppressive cytokines and to proliferate poorly upon reactivation via TCR. These findings indicate that Tr1 cells are constitutively capable of responding to cytokines and mainly to IL-15. This growth factor enables a significant in vitro expansion of Tr1 cells facilitating further biological and biochemical characterization of this unique T cell subset.

Clone Cells↗
PubMed2002

Suicide-gene-Transduced donor T-cells for controlled graft-versus-host disease and graft-versus-tumor.

In allogeneic hematopoietic cell transplantation, donor lymphocytes play a central therapeutic role in both graft-versus-leukemia and immune reconstitution. However, their use is limited by the risk of severe graft-versus-host disease (GVHD). Different strategies have been investigated to obtain all the benefits derived from donor lymphocytes while avoiding the risk of GVHD. Infusions of donor lymphocytes transduced with the herpes simplex virus thymidine kinase (HSV-tk) suicide gene resulted in anti-tumor activity in a substantial number of patients. Acute GVHD could be effectively controlled by ganciclovir-induced elimination of the transduced cells. Haplo-identical stem cell transplantation (haplo-SCT) is a promising therapeutic option for patients with high-risk hematologic malignancies lacking an HLA-matched donor. However, the intensive T-cell depletion required to overcome the risk of lethal GVHD has been associated with a delayed immune recovery with a prolonged risk of posttransplantation viral, fungal, and other opportunistic infections. Donor lymphocyte infusions of HSV-tk represent a promising tool for preventing disease relapse and promoting immune reconstitution after haplo-SCT, and a unique tool for the control of GVHD. The genetic manipulation of donor lymphocytes with a suicide gene is a promising strategy to increase feasibility and safety of allogeneic bone marrow transplantation.

Animals↗
PubMed2002

Wiskott-Aldrich syndrome protein regulates lipid raft dynamics during immunological synapse formation.

Immunological synapse assembly relies on the clustering of lipid rafts and is required for optimal T cell activation. We demonstrate that the Wiskott-Aldrich syndrome protein (WASP) is recruited to lipid rafts immediately after TCR and CD28 triggering and is required for the movements of lipid rafts. T cells from Wiskott-Aldrich syndrome (WAS) patients, lacking WASP, proliferate poorly after TCR/CD28 activation and have impaired capacities to cluster the lipid raft marker GM1 and to upregulate GM1 cell surface expression. T cell proliferation and lipid raft clustering are restored by retroviral transfer of the WASP gene. These results demonstrate that WASP plays a central role in the movements of lipid rafts and identify a potential mechanism underlying the T cell defect affecting WAS patients.

CD28 Antigens↗