Obviously, there must be a way for our bodies to re-‐lengthen telomeres. Otherwise, our sperm and egg cells would contain telomeres the same length as the rest of our cells, which would yield embryos as old as we are.
However, our reproductive cells do not exhibit telomere shortening, and show no signs of aging. They are essentially immortal. They are our germ line -‐ the same one that has been dividing since the beginning of life on this planet.
The reason these cells are immortal is that our reproductive cells produce an enzyme called telomerase. Telomerase acts like an assembly line inside our cells that adds nucleotides to the ends of our chromosomes, thus lengthening our telomeres.
In a cell that expresses telomerase, telomeres are lengthened as soon as they shorten; it's as though every time the "telomere clock" inside our cells ticks once, telomerase pushes the hands of the clock back one tick.
Telomerase works by filling the "gap" left by DNA replication. Returning to the analogy of the bricklayer that can't lay the last brick on the brick wall, telomerase would be like an angel that flies in and puts the last brick in place.
Telomere Gene Therapy
Fortunately, the telomerase gene already exists in all our cells. That's because the DNA in every one of our cells is identical: a skin cell, muscle cell, and liver cell all contain exactly the same genetic information. Thus, if the cells that create our sperm and egg cells contain the code for telomerase, every other cell must contain that code as well.
The reason that most of our cells don't express telomerase is that the gene is repressed in them. There are one or more regions of DNA neighboring the telomerase gene that serve as binding sites for a protein, and, if that protein is bound to them, telomerase will not be created by the cell.
However, it is possible to ‘insert’ a new gene into the DNA through use of a viral vector. This new gene keeps the telomerase permanently switched on in the cell, thus enabling the cell to replicate without telomere shortening or (TEDS) or damage to the DNA code. In essence this new gene overrides the message of the old genes and through use of the gene therapy that Telomerize is developing most, ideally all cells will have this new gene inserted into their DNA using a vector as transport.