Lecture 6 Gene Delivery Flashcards
Describe gene therapy.
Gene therapy is a technique that modifies a person’s genes to treat or cure disease by mechanisms like replacing a disease-causing gene with a healthy copy or introducing a new gene to help treat a disease.
What are the two main delivery strategies in gene therapy?
The two main delivery strategies in gene therapy are in vivo, where the therapeutic gene is delivered directly to the patient’s cells inside the body, and ex vivo, where the therapeutic gene is delivered into cells outside the body and then administered to the patient.
Define gene addition in the context of gene therapy.
Gene addition involves adding a functioning gene to a cell with a missing or defective gene so that the cell can function normally.
How does gene inhibition work in gene therapy?
Gene inhibition involves adding a blocking gene to inhibit a faulty gene in a cell, allowing the cell to function normally.
Describe cytotoxic gene therapy.
Cytotoxic gene therapy involves adding a suicide gene to a disease cell, which produces a toxic product leading to the death of the disease cell.
How does immune system engineering work in targeting tumor cells?
In immune system engineering targeting tumor cells, T cells are engineered to express a receptor specific for the tumor, allowing the modified T cell to specifically target and kill the tumor cell.
Explain the concept of immune system engineering in targeting diseased cells.
In immune system engineering targeting diseased cells, a marker gene is added to the diseased cell, causing marker proteins to be expressed on the cell, which triggers the immune system to attack and eliminate the marked cell.
List the five main classes of viral vectors used in gene therapy.
The five main classes of viral vectors used in gene therapy are:
1. Retrovirus,
2. Lentivirus,
3. Herpes simplex virus type 1 (HSV-1),
4. Adeno-Associated virus (AAV),
5. Adenovirus,
each with different mechanisms of genome integration or persistence in cells.
Describe the structure of AAV.
AAV is a member of the parvovirus family, a single-stranded small DNA virus.
How does AAV deliver genes into cells without genomic integration?
AAV delivers genes by entering the cell via the endosome, where the therapeutic DNA enters the nucleus as a double-stranded molecule ready for transcription.
Define AAV in vivo and mention its tissue specificity influences.
AAV in vivo refers to the specificity influenced by viral vector and promoter, with routes of administration including IT, IV, ICM, and local.
What is the process involved in AAV production?
AAV production involves transgene development, AAV GRT production, concentration, and quality assurance to ensure high titer, potency, and purity of vectors.
Describe the current status of gene therapy with examples.
Gene therapy includes treatments for lipoprotein lipase deficiency, CAR-T cell therapy, and Strimvelis for ADA deficiency involving bone marrow-derived stem cells.
How does AAV differ from other viruses in terms of pathogenicity?
AAV has several serotypes impacting tropism but is considered non-pathogenic, requiring a helper virus for replication.
Describe the process of insertional mutagenesis in gene therapy.
Insertional mutagenesis involves the integration of therapeutic vectors into the host genome, potentially disrupting normal gene function and leading to cancer.
