Genetic Therapies Flashcards
What is gene therapy?
Transfer of genetic material into the cells of an organism to treat disease or mark cell populations (only somatic cells so not passed on)
Which type of gene therapy is primarily used and why?
Gene augmentation because it is much easier to do than gene transfer
What are some of the challenges of using gene therapy?
Lack of permanence Immune response Rarity of single gene disorders Problems with viral vectors Potentially passed on through germline
What is the criteria for using gene therapy?
Cause of disease is a single gene, that has been cloned
Life-threatening condition with no effective treatment
Technical problems associated with gene delivery and expression resolvable
Regulation of the gene need not to precise
What are the gene delivery strategies?
Can be ex vivo or in vivo
Can be physical (microinjection) or viral (retrovirus)
What are the cells targeted for gene transfer?
Hematopoietic stem cells Lymphocytes Fibroblast skin cells Hepatocytes Respiratory epithelium Skeletal muscle
What are recombinant pharmaceuticals?
Expression cloning in microorganisms/mammalian cell lines generates large amounts of protein which reduces the risk of pathogen contamination and avoids the side affects and immunogenicity other animal proteins cause
What are some examples of recombinant pharmaceuticals?
Interferon (chronic hepatitis/leukaemia)
Insulin (diabetes)
Factors VIII and IX (haemophilia A and B)
What are genetically engineered antibodies?
Artificially produced antibodies designed to recognise specific diseases leading to killing of disease cells
What are the main targets for genetically engineered antibodies?
Cancer
Infectious diseases
Autoimmune disorders
Which type of genetically engineered antibodies are used?
Purely animal antibodies do not work because they evoke an immune response
Chimeric rodent-human antibodies work very well
Fully human antibodies are difficult to engineer but work is being done using transgenic mice with human immunoglobulin
What are some examples of genetically engineered antibodies?
CD20 in lymphoma
IL 2 receptor in transplants/leukaemia/lymphoma
TNF-alpha in septic shock
What is an example of a genetically engineered vaccine?
Hepatitis B vaccine
What are some strategies to genetically engineer vaccines?
Genetic modification of an antigen
Genetic modification of a virus
Genetic modification of micro organisms
What are the three levels of targeted inhibition of gene expression?
DNA level
RNA level
Protein level
