Augmentation therapy, Biology

Assignment Help:

Augmentation Therapy:

The functional gene is introduced in addition to the defective gene endogeneous to the cell(s) in this somatic cell gene therapy,  i.e. the improved  cells consist  both the defective (endogeneous) and  the normal (introduced) copies of the gene. There are two basic approaches to augmentation therapy. First was used in the first two patients on whom gene therapy was attempted to right the genetic disorder known Severe Combined Immune Deficiency (SCID) syndrome formed by adenosine deaminase (ADA) deficiency. (i) General ADA gene copies were formed by cloning and then (ii) packed into a faulted retrovirus; mostly viral genes were replaced by the ADA gene. (iii) Lymphocytes were linked from the patients, and (IV) the recombinant retroviruses were used to infect the lymphocytes. And (v) the infected cells showing  the ADA gene were injected back into the patients. The usual ADA gene was expressed in the patients, and ADA deficiency was partially right, this resulted in an improvement in the patient's immune system.

Different kinds of viral vectors have been used to deliver genes into target/stem cells, like lymphocytes, cultured in vitro, bone marrow cells. The target cells themselves are obtained from the concerned patient (more desirable) or from a matched donor. The reservations about security of retroviral vectors is sought to be resolved by developing suicide vectors which cannot replicate after delivery of the gene. The other major problems of this approach are: (i) low frequency of transfect ion of stem cells, (ii) persist ability  of the integrated gene, (iii) duration of the gene expression,   (iv) lack of suitable regulation of gene expression etc. More recently, interest has targeted on physical methods of gene delivery like Ca2+ phosphate co precipitation, particle gun, electro oration etc.

The next approach is the direct injection of DNA into the tissues either as protein complexes (in order to bring about receptor-mediated transfer of DNA into a particular tissue, for example liver) or even as naked DNA into skin or muscle. Interestingly these cells obtain the DNA and show the gene product. Exciting results have been obtained with experimental familial hypercholesterolemia, where LDL receptor stage has been augmented by insertion of the gene as a sialoglycoprotein complex. The problems in this approach relate to the frequency of cells taking up and showing the gene and, more specifically, the duration of expression.

The gene delivery methods used for gene therapy may also be used for healing of cancer or AIDS. In the case of cancer, a toxin encoding gene can be delivered into the cancer cells. In the same way, appropriate interleukin genes can be delivered to boost up the body's defence mechanisms (in case of AIDS).


Related Discussions:- Augmentation therapy

Show symptoms and signs of hyperthyroidism, Q. What are some symptoms and s...

Q. What are some symptoms and signs found in patients with hyperthyroidism? The hormones made by the thyroid gland stimulate the basal metabolism of the body in hyperthyroidism

#title.classification., merits and demerits system of classification by Lin...

merits and demerits system of classification by Linnaeus

Reciprocal translocation and fusion, In chronic myelogenous leukemia, white...

In chronic myelogenous leukemia, white blood cells proliferate ceaselessly. In affected white blood cells, the BCR-ABL oncogene, the result of a gene fusion, transmits a constitu

What is vdrl test & rpr test, Question 1 List the cells and organs involve...

Question 1 List the cells and organs involved in immune system. Explain the role of thymus in development of T cells. Add a note on recognition of self antigens by immune system

Give some examples of cloning and molecular biology, Examples of cloning an...

Examples of cloning and molecular biology cloning may produce heterozygous individuals (as mother was heterozygous) and suggests a way to get pure breeding cats molecu

Morphogenetic movements, Morphogenetic Movements Gastrulation is a dy...

Morphogenetic Movements Gastrulation is a dynamic process including a variety of coordinated movements of cells of dissimilar areas of the blastula. The movements of cells in

Define difference between plant systematic and taxonomy, Define Difference ...

Define Difference between Plant Systematic and Taxonomy? Before coming to principles of taxonomy let us discuss the difference between taxonomy and systematic. Systematic is th

Define classification of proteins on the basis of attributes, Define Classi...

Define Classification of proteins on the basis of attributes? Besides classifying proteins on the basis of soluble and insoluble, proteins have been further classified based on

What are cytoplasmic inclusions, Cytoplasmic inclusions are cytoplasmic mol...

Cytoplasmic inclusions are cytoplasmic molecular aggregates, like as pigments, organic polymers and crystals. They are not considered cell organelles. Fat drops and glycogen gra

Explain global burden in the history of mart disease, Explain Global burden...

Explain Global burden in the history of mart disease? In 2001, 17 million people died of CVD of all types. The most important causes were ischemic heart disease (IHD), Hyperten

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd