All You Need To Know About Gene Therapy

The human body is comprised of various organs that each have a specialized role in maintaining the proper health of a person. The brain is involved in thought, reasoning and, in general, controlling our actions; the heart sends blood around our body supplying all the organs with oxygen; the lungs oxygenate our blood thus providing the energy we need to function; the stomach, kidneys, liver, intestine and bladder extract nutrients from our diet and remove toxins. Each organ plays an essential and unique part keeping us alive.

To function correctly, an organ comprises billions of cells of different types, each arranged in tightly controlled structures that form the overall architecture of the body. It is the cells that are in point of fact responsible for the proper functioning of the organ. If an organ is malfunctioning, then to treat it, we must restore the smooth operation of these cells.

Basic Cell Biology

Most cells are made up of similar components: a nucleus, the part of the cell containing genetic information; a variety of organelles, small elements that carry out processes such as energy production, much like the way that different organs perform specific functions of the body (e.g. lysosome, mitochondrion, Golgi etc); the cytoplasm, the liquid medium that comprises the cell, and the plasma membrane, the element that gives the cell its shape.

The nucleus codes for all the information required to produce the cell. Each organelle and cellular makeup are made up of protein, sugars, and lipids (fatty compounds), and the nucleus not only encodes for the production of each of these components but also the information necessary for their correct assemblage and final position. This information is enclosed within the cell's DNA, which is the principal constituent of the nucleus and is tightly condensed in a highly organized manner in the nuclear membrane.

Our Genes

Within the nucleus, our DNA is arranged into 23 sets of chromosomes (or 22 pairs, and one X chromosome and Y chromosome if you are male). These 46 chromosomes are communally known as the human genome, as they contain all of the genes that act as the blueprint for the human body. We can imagine of our DNA as a long linear molecule that is split into 46 separate parts (i.e. the chromosomes). Within each chromosome, there are thousands of genes lined up one after the other one after another and split by intergenic regions. Each gene is a unit of DNA that encodes for a certain protein, with a unique function. It is the combination of many discrete proteins, and their actions on other molecules like sugars and lipids, that comprises the basis of the organelle, and by consequence, of the cell itself.

So one can imagine that in a pathological situation, where an organ is malfunctioning, we can time and again trace the dysfunction to a particular protein that is not working correctly. These protein malfunctions can either be genetic, or acquired in the course of

• An infection,
• An autoimmune reaction,
• Untimely tissue degeneration
• The formation of cancer.

So, in any condition where a disease can be traced to a malfunction of protein, or where a protein of known activity can restore the proper functioning of a cell, gene therapy can be used. This is just because we can now use the correct gene to deliver the exact type of the protein to the cell we want to fix. It is significant to note that by delivering genes exclusively into diseased cells, there is no opportunity of conveying this new genetic information in the future to our children. To do so, our germ cells would have to be the target for gene transfer, a process that is illegal, and extremely technically demanding.

Application of Genetic Therapy

Effectual gene transfer into human cells is known to be the major challenge the Gene Therapy. Gene transfer vector have to be safe, introduce its DNA cargo into a satisfactorily large amount of cells to create a biological response and mediate transcription of the desired gene for a long duration. Identifying a vector that meets these criteria has proven to be a testing task.

Gene Therapy is more often than not used in pathologic conditions where A cells of a distinct organ or system do not function correctly because they do not have the right protein WHICH is required to perform the desired task.