INTRODUCTION DNA VACCINES GENE THERAPY TIME LINE OF DEVELOPING GENE THERAPY GENE THERAPY STRATEGIES TECHNOLOGY OF CLASSICAL GENE THERAPY PRINCIPLES OF GENE TRANSFER VECTORS VIRAL VECTORS NON-VIRAL VECTORS APPLICATIONS OF GENE THERAPY ETHICAL IMPLICATIONS THE FUTURE CONCLUSION REFERENCES

1. GENE MEDICINE
By
KAUSHAL KUMAR SAHU
Assistant Professor (Ad Hoc)
Department of Biotechnology
Govt. Digvijay Autonomous P. G. College
Raj-Nandgaon ( C. G. )

2. SYNOPSIS
 INTRODUCTION
 DNA VACCINES
 GENE THERAPY
 TIME LINE OF DEVELOPING GENE THERAPY
 GENE THERAPY STRATEGIES
 TECHNOLOGY OF CLASSICAL GENE THERAPY
 PRINCIPLES OF GENE TRANSFER
 VECTORS
VIRAL VECTORS
NON-VIRAL VECTORS
 APPLICATIONS OF GENE THERAPY
 ETHICAL IMPLICATIONS
 THE FUTURE
 CONCLUSION
 REFERENCES

3. INTRODUCTION
 While disease modeling uses gene
manipulation to create diseases in model
organisms, gene medicine refers to the use of
the same technology to ameliorate or even
permanently cure diseases in humans.

4. DNA VACCINES
 The basis of DNA vaccination, as first demonstrated
by Ulmer et al. (1993).

5. GENE THERAPY
 Gene therapy is ‘the use of genes as medicine’

6. TIMELINE OF DEVELOPING GENE THERAPY:
 1985-The Drs. W. French Anderson and
Michael Blaese, Culver
 1986-The team studied how safely and
efficiently the correct genes were transferred
into bone marrow cells in animals.
 1988-The researchers decided to use white
blood cells (T cells), in tissue culture, instead of
bone marrow cells.
 1990-The first gene therapy trial for an inherited
disorder was initiated on 14 September 1990.
The patient, Ashanthi DeSilva.

7. SUBDIVISION OF GENE THERAPY
 Classical gene therapy
 Nonclassical gene therapy

8. GENE THERAPY STRATEGIES
1)Gene augmentation therapy (GAT)
2) Targeted killing of specific cells
Direct cell killing
Indirect cell killing

9. Direct cell killing
Indirect cell killing

10. Targeted inhibition of gene expression
Targeted mutation correction

11. CLASSICAL GENE THERAPY
 An essential component of classical gene therapy is
that cloned genes have to be introduced and
expressed in the cells of a patient in order to
overcome the disease.
 Two major general approaches are used in the
transfer of genes for gene therapy:
1) Transfer of genes into patient cells outside of the
body (ex vivo)
2) Inside the body (in vivo).

13. PRINCIPLES OF GENE TRANSFER
 Classical gene therapies normally require efficient
transfer of cloned genes into disease cells so that the
introduced genes are expressed at suitably high
levels. In principle, there are numerous different
physicochemical and biological methods that can be
used to transfer exogenous genes into cells.
 Following gene transfer, the inserted genes may
integrate into the chromosomes of the cell, or remain
as extrachromosomal genetic elements (episomes).

15. VECTORS
VIRAL VECTORS IN GENE THERAPY
 Viral vectors are one of the major vechicles
used by scientists in gene therapy to get their
sequences expressed in the proper host.
 The first recombinant vectors of relevance to
the field of gene therapy were the retroviruses.
Expression cassettes

16. Retroviruses
Adenovirus vectors

17. Lentiviruses

18. NONVIRAL VECTOR SYSTEMS FOR GENE THERAPY
 The transfer of genetic material using non-viral
systems preceded the developed of viral- based
vectors. Non-viral vectors, also called physical
mechanisms of gene transfer.

19. Liposomes
1)CATIONIC LIPOSOMES 2)NEGATIVELY CHARGED LIPOSOMES

20. Particle bombardment
ELECTROPORATION
•Electroporation is the application of high voltage to a mixture of
DNA and cells in suspension. The cell-DNA suspension is placed
between two electrodes and subjected to an electrical pulse. The
DNA enters the cells through holes formed in the cellular
membrane during the electrical pulse.

21. GENE THERAPY FOR INHERITED DISORDERS
Adenosine deaminase (ADA) deficiency
 The novel ADA gene therapy approach involved
essentially four steps;
 cloning a normal ADA gene into a retroviral
vector
 transfecting the ADA recombinant into cultured
ADA- T lymphocytes from the patient;
 identifying the resulting ADA+ T cells and
expanding them in culture;

23. Cystic fibrosis- Cystic fibrosis is an autosomal
recessive disorder that results in defective transport of
chloride ions through epithelial cells, and results from
mutations in a gene, CFTR, which encodes a cAMP-
regulated chloride channel.
Normal lung CF lungs

24. GENE THERAPY FOR NEOPLASTIC DISORDERS AND
INFECTIOUS DISEASE
 Cancer gene therapies

25. Gene therapy for infectious disorders
Current gene therapy trials for infectious disorders are
conspicuously targeted at treating AIDS patients. The infectious
agent for this usually fatal disorder is a class of retrovirus known
as HIV-1 which can infect helper T lymphocytes, a crucially
important subset of immune system cells.
In principle, a variety of gene therapy strategies can be envisaged
for treating AIDS.
This involve transferring a gene that encodes an HIV-1 antigen,
such as the envelope protein gp120, and expressing it in the
patient in order to provoke an immune response against the HIV-1
virus, or the patient's immune system can be boosted by transfer
and expression of a gene encoding a cytokine, such as an
interferon.

26. ETHICAL IMPLICATIONS
 The scientific goal of current gene therapy is
directed at introducing genes into somatic cells
only and not into germ cells containing inherited
genetic material.
 The medical concern is that genetic
manipulation of the germline could produce
damage in future generations.

27. •Well-intentioned efforts at treatment with standard therapeutics can
produce unexpected problems months or years later. Altering the genetic
information in a patient's cells may result in long-term side effects that
are unpredictable at present.
•Considerable experience with germline manipulation in animals, as well
as with somatic cell gene therapy in humans, should be obtained before
considering human germline therapy.
•Human gene therapy trials are tightly regulated and reviewed at
local institutions by Biosafety Committees and Human
Investigation Review Boards and require informed consent from
participants. As with any biological agent administered to humans,
newly developed gene therapy vectors must be approved for use
by the FDA.

28. CONCLUSIONS
 Gene therapy is a powerful new technology that
still requires several years before it will make a
noticeable impact on the treatment of disease.
Several major deficiencies still exist including poor
delivery systems, both viral and non-viral, and
poor gene expression after genes are delivered.
Despite our present lack of knowledge, gene
therapy will almost certainly revolutionize the
practice of medicine over the next 25 years. In
every field of medicine, the ability to give the
patient therapeutic genes offers extraordinary
opportunities to treat, cure and ultimately prevent
a vast range of diseases that now plague
mankind.

29. REFERENCES
 http://www.ornl.gov/sci/techresources/Human
_Genome/medicine/genetherapy.shtml
[Accessed Nov 2012]
 Gene therapy and other molecular genetic
based approaches-Human molecular
genetics-NCBI Bookshelf
 Anderson W F. Human gene therapy. Nature.
(1998); 392 (Suppl.):25–30. [PubMed]
 Principles of genetic manipulation and
genomics-S.B. Primerose and R.M. Twyman;
7th Edition