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Biomedical subjects

T Seregina

Publications and source records attributed to T Seregina.

12 recordsLinked to original sources
PubMed2003

Transduction of hematopoietic stem cells with a retroviral vector expressing the neomycin phosphotransferase gene.

Transduction of stem cells with a marking gene holds promise to determine if tissue repair or regeneration is derived from the adult hematopoietic stem cell and if relapse of an autoimmune disease should occur whether relapse arises from the stem cell compartment or from lymphocytes surviving the conditioning regimen. New safety concerns about gene-modified stem cell would entail new safety testing such as documentation of the insertional site prior to release.

Antigens, CD↗
PubMed2000

Cellular suicide therapy of malignant disease.

Adoptive cellular therapy is developing as a supplement or alternative to chemotherapy and/or radiation for malignant disease. Our focus is two ongoing clinical studies with transgeneic (genetically altered) cellular therapy; one uses allogeneic (from another person) lymphocytes to treat leukemia, and the second uses xenogeneic (from another species) fibroblast cells genetically altered to contain a toxin-producing suicide gene to treat ovarian cancer. Allogeneic donor lymphocyte infusions (DLI) are known to induce remission of hematologic malignancies. However, the toxicity associated with DLI is related to graft-versus-host-disease, which is due to donor lymphocytes attacking normal tissue in the recipient. Therefore, we have taken the approach of infusing DLI that have been modified to contain a latent suicide gene to treat leukemia. To treat ovarian cancer, we used xenogeneic nonimmune fibroblast-derived cells to deliver a tumor-directed cytotoxic gene to carcinoma cells. These cells release HStk transgene retroviruses that in turn transduce replicating tumor cells but not quiescent epithelium, rendering the tumor selectively susceptible to ganciclovir-mediated killing. These initial trials summarize the early stage of allogeneic/xenogeneic adoptive cellular therapy for cancer, and although the data are limited, it is encouraging to see some patients with evidence of antitumor responses. Advances in our understanding of the basic science of these treatments, together with improvements in the technology of vector design, will be required to streamline these methodologies into broader application.

Animals↗
PubMed2000

Cellular suicide therapy of malignant disease.

Adoptive cellular therapy is developing as a supplement or alternative to chemotherapy and/or radiation for malignant disease. Our focus is two ongoing clinical studies with transgeneic (genetically altered) cellular therapy; one uses allogeneic (from another person) lymphocytes to treat leukemia, and the second uses xenogeneic (from another species) fibroblast cells genetically altered to contain a toxin-producing suicide gene to treat ovarian cancer. Allogeneic donor lymphocyte infusions (DLI) are known to induce remission of hematologic malignancies. However, the toxicity associated with DLI is related to graft-versus-host-disease, which is due to donor lymphocytes attacking normal tissue in the recipient. Therefore, we have taken the approach of infusing DLI that have been modified to contain a latent suicide gene to treat leukemia. To treat ovarian cancer, we used xenogeneic nonimmune fibroblast-derived cells to deliver a tumor-directed cytotoxic gene to carcinoma cells. These cells release HStk transgene retroviruses that in turn transduce replicating tumor cells but not quiescent epithelium, rendering the tumor selectively susceptible to ganciclovir-mediated killing. These initial trials summarize the early stage of allogeneic/xenogeneic adoptive cellular therapy for cancer, and although the data are limited, it is encouraging to see some patients with evidence of antitumor responses. Advances in our understanding of the basic science of these treatments, together with improvements in the technology of vector design, will be required to stream-line these methodologies into broader application.

Apoptosis↗
PubMed1999

Adoptive immunotherapy for leukemia: donor lymphocytes transduced with the herpes simplex thymidine kinase gene.

The overall goal of adoptive immunotherapy with genetically modified lymphocytes is to decrease the morbidity and mortality associated with allogeneic bone marrow transplantation. The initial data reviewed here suggest that the behavior of the allogeneic HStk transgenic cells can be modified after administration to patients. Further study is needed to identify the response rates and risks associated with this procedure. In particular, larger studies will be needed with appropriate randomization to determine if the response rate to genetically modified cells is equivalent to the response rates with unmodified cells. Wider application of these techniques in the initial setting of allogeneic transplantation will undoubtedly occur and such trials have been initiated at several institutions. Careful attention to vector, suicide gene, selectable marker, efficiency of transduction, and cell dose will be necessary when comparing different trials since these variables will probably affect transgenic cell survival and response rates. [figure: see text]

Blood Transfusion, Autologous↗
PubMed1998

Adoptive immunotherapy for leukemia: donor lymphocytes transduced with the herpes simplex thymidine kinase gene for remission induction. HGTRI 0103.

This study will evaluate the safety and efficacy of allogenic donor lymphocyte infusions in patients who have relapsed hematologic malignancies after allogeneic bone marrow transplantation (BMT). Donor lymphocyte transfusions have resulted in the cure of some patients with relapsed leukemia or lymphoproliferative disorder after allogeneic BMT, but has been complicated by the development of graft versus host disease (GvHD). We hypothesize that a retroviral vector containing the Herpes simplex thymidine kinase (HStk) gene will allow for retention of the anti-leukemia response of transfused donor lymphocytes while allowing for the adverse effects of GVHD to be mitigated. Patients with relapsed hematologic malignancies after allogeneic BMT will be infused with ex vivo gene modified donor lymphocytes. The Herpes Simplex thymidine kinase (HStk) gene will be transduced into the cells ex vivo using LTKOSN. 1 vector supernate. Insertion of the HStk gene into lymphocytes confers a sensitivity to the anti-herpes drug ganciclovir (GCV). This selective destruction of donor lymphocytes in situ will be used to abrogate the effect of graft versus host disease, if it develops.

Clinical Protocols↗
PubMed1995

Gene therapy for solid tumors.

Advances in molecular biology have proven that there is a genetic basis to the process of carcinogenesis that allows for the consideration of entirely new approaches to the treatment of cancer. The development of an ability to selectively destroy cancer cells through the manipulation of DNA may provide the opportunity to dramatically improve the quality of care and treatment of cancer patients by decreasing systemic toxicities and enhancing efficacy. These new therapies may occur through the restoration of genetic health, such as the insertion of normal tumor suppressor genes or via down-regulation of oncogene or growth factor receptor expression. Other possibilities include the targeting of genetic alterations in tumor cells that will enhance tumor immunogenicity or induce a specific sensitivity to a prodrug. In this chapter, we have reviewed the current status of gene therapy for solid tumors in the United States and evolving new approaches for this emerging clinical discipline.

Animals↗
PubMedDate not supplied

Murine retroviral vector producer cells survival and toxicity in the peritoneal cavity of dogs.

Retroviral vector producer cells (VPC) can effectively transfer genes in vivo. To develop a safe method to target gene delivery into intraperitoneal tumors, we have examined the toxicity of intraperitoneal (i.p.) infusion of retroviral VPC in a xenogeneic canine model. Mongrel dogs were injected intraperitoneally (i.p.) with 2 x 10(9) murine LTKOSN.2 VPC. The animals did not demonstrate acute toxicity and tolerated the i.p. infusion of the cells without difficulty. Starting 7 days after i.p. injection, the dogs received intravenous injections of ganciclovir (GCV) twice daily (5 mg/kg) for 7 days. The treatment dogs underwent peritoneal washings on days 3, 7 and 14 after their initial infusion of cells to study the persistence of the VPC. GCV treatment did not cause significant toxicities. Dogs underwent serial blood tests to evaluate bone marrow, renal, liver and immunological function. Complete blood counts, electrolytes and renal function remained normal throughout the study. Although, transient mild elevations occurred of serum alkaline phosphate, the remaining hepatic enzymes remained normal. Histologic examination of tissues from animals sacrificed after the i.p. administration of the VPC revealed no tissue destruction of the normal peritoneal lining. The dogs mounted an antibody response to the murine VPC that was first observed 7 days post injection. PCR analysis of selected tissues after GCV administration did not reveal persistent vector sequences. These results demonstrated that the injection of xenogeneic VPC is not accompanied by significant adverse effects over a 1 month period following administration into the canine peritoneal cavity. These data support the potential clinical application of the VPC in Phase I clinical trials in humans.

Alkaline Phosphatase↗
PubMedDate not supplied

Murine retroviral vector producer cells survival and toxicity in the dog liver.

To develop a safe method to target gene delivery into intrahepatic tumors, we examined the toxicity of intrahepatic (IH) injection of retroviral vector producer cells (VPC) into the canine liver. VPC have been demonstrated to effectively transfer genes in vivo. To evaluate for adverse effects form xenogeneic cell transplantation, mongrel dogs were injected IH with 1 x 10(9) murine LTKOSN.2 VPC divided into three aliquots. The animals were then monitored for acute toxicity induced by the VPC. The intraoperative IH injections of the cells were tolerated without difficulty. Starting 7 days after IH injection, the dogs then received intravenous ganciclovir (GCV) twice daily (5 mg/kg) for 7 days. GCV treatment did not cause significant toxicities. Dogs underwent serial blood tests to evaluate bone marrow, renal, liver and immunological function. Complete blood counts, electrolytes, liver function and renal function tests remained normal except for mild elevations of alkaline phosphatase. Histologic examination of liver tissues from the IH injection site revealed no apparent normal tissue destruction induced by the VPC. Two of the four treated dogs underwent liver biopsy on day 3. These biopsy specimens were cultured and persistent, viable VPC were recovered. The dogs mounted an antibody response to the murine VPC that was first demonstrated 5 days post injection. PCR analysis demonstrated low level gene transfer into dog liver tissue. Overall, our results demonstrate that IH xenogeneic VPC injections are not accompanied by significant adverse effects over a 1 month period following administration into the canine liver. These data support the safety aspects of using murine VPC in Phase I clinical trials.

Alkaline Phosphatase↗
PubMedDate not supplied

Eliciting hyperacute xenograft response to treat human cancer: alpha(1,3) galactosyltransferase gene therapy.

Xenograft hyperacute rejection in humans occurs as a secondary response to a cellular glycosylation incompatibility with most non-human mammalian species. A key component of hyperacute rejection, alpha(1,3)galactosyl (agal) epitopes present on the surface of most non-human mammal cells, is bound by host anti-agal IgG antibodies leading to the activation of complement and, cellular lysis (1). The enzyme causing specific glycosylation patterns, alpha(1,3)galactosyltransferase [alpha(1,3)GT], directs the addition of agal to N-acetyl glucosamine residues in the trans Golgi apparatus in most mammalian species including Mus musculus, but not old world primates, apes or humans. In this report, we cloned both a truncated and full length murine alpha(1,3)GT gene into a retroviral vector backbone in order to transfer alpha(1,3)galactosyl epitopes into human A375 melanoma cells. Expression of agal epitopes on A375 cells after alpha(1,3)GT gene transfer was demonstrated using FITC-labeled ligand and FACS analysis. These cells were exposed to human serum for 30 minutes and > 90% of the agal expressing cells were killed by this treatment. These pretreated cells failed to establish tumors after implantation into athymic nude mice. This is the first report of retroviral vector transfer of the alpha(1,3)GT gene into human tumor cells in an attempt to elicit hyperacute rejection as a novel anti-cancer gene therapy strategy.

3T3 Cells↗