AuthorVasanwala, Farha Huseini
AdvisorHarris, David T.
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractTumor cells can be modified with cytokine genes such as the Interleukin-2 (IL-2) gene. The levels of IL-2 expressed are critical for successful treatment. We have tried to achieve higher levels of IL-2 than those currently available by conventional plasmids. Use of a transcriptional activator, e.g; the tat gene along with the HIV promoter driving the IL-2 gene, greatly increased IL-2 levels compared to widely used cytomegalovirus (CMV) driven plasmids. Control of the tat gene with an inducible promoter, i.e; the human HSP70B promoter, permitted control of gene expression. The inducibility of the HSP70B promoter by heat, γ-radiation and geldanamycin (a chemotherapeutic drug) allowed for a combinatorial approach to cancer treatment with hyperthermia, radiation therapy and chemotherapy. Also a brief heat treatment of 10 min at 42°C of target cells increased plasmid uptake, and higher levels of gene expression could be achieved. Another arm of immunotherapy is adoptive therapy with Tumor Infiltrating Lymphocytes (TILs). Insufficient numbers of tumor-specific T-cells limit the success of TIL therapy. An alternative approach to overcome this limitation is to transfer tumor-specific T cell receptor (TCR) into peripheral T-cells, redirecting their specificity to the tumor cell. To prove the feasibility of this technique, T-cell receptors were identified and cloned from hybridomas specific for the tumor cell line, MO5. A three domain single chain T-cell receptor was also constructed from the tumor-specific TCR genes to investigate the ability of a single chain T-cell receptor to activate T-cells. The CD3ζ chain was linked to the single chain to allow signal transduction upon antigen recognition by the TCR. The full length and the single chain TCR were cloned into a retroviral vector and transfected into mouse and human T cell lines. Cell surface expression of the chains were detected by flow cytometry. Functionality of the transfected TCR chains was assessed by IL-2 secretion on co-culture of the tumor cell line MO5 and the transfected T-cells. The two different approaches described here, i.e; higher levels of IL-2 for IL-2 gene therapy and specific redirection of T-cells can potentially greatly enhance the success rate of cancer treatment.
Degree ProgramGraduate College
Microbiology and Immunology