Because the body doesn’t automatically accept new genetic material, scientists have developed innovative ways to insert the genes into cells. New or altered genes can be inserted into viruses (called virus vectors) that no longer have the capability to cause disease but retain the ability to navigate and infiltrate the body. These viruses include retroviruses, adenoviruses, herpes simplex, vaccinia, and adeno-associated virus (AAV). Other ways of introducing the genetic material into cells include non-viral vectors, such as nanoparticles and nanospheres.
When gene therapy techniques modify cells in a laboratory and then doctors reinsert the repaired cells into the patient’s body, both cell and gene therapies are used. This is called gene-modified cell therapy. This approach is used in cell-based immunotherapy and employs a number of cutting-edge techniques, such as Chimeric Antigen Receptor T-cell (CAR-T) therapies, T-cell Receptor (TCR) therapies, Natural Killer (NK) cell therapies, tumor infiltrating lymphocytes (TILs), bone-marrow derived lymphocytes (MILs), gamma delta T cells, and Dendritic Cell (DC) vaccines.
The insertion, deletion, or replacement of DNA at a specific site is called gene or genome editing. To visualize gene editing, scientists often compare the process to deleting and replacing a few words in a computer document. Molecular scissors (usually an engineered nuclease or an adeno-associated virus-derived sequence) make precise cuts in a strand of DNA at a specific location. The cut-out section of DNA is then repaired and reintroduced.
Currently used genome editing nucleases include zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and nucleases that derive from the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR), such as CRISPR/Cas9 and CRISPR/Cas12a). Alternatively, genome editing can be performed with homologous recombination, a natural biological mechanism used by cells to ensure highly precise DNA repair.
The ARM Foundation for Cell and Gene Medicine focuses on the genomic repair of somatic (non-reproductive) cells and does not include the genetic modification or manipulation of human embryos or reproductive cells (germline cells). Somatic cells account for the majority of cells in organs, skin, bones, blood and connective tissue. Most genetic diseases manifest in somatic cells. The DNA in these cells is non-heritable, which means that somatic cell gene editing affects only the patient and will not be genetically transmitted to future children.
Tissue engineering uses a combination of cells, bioengineered materials, as well as an understanding of biochemical and physicochemical factors, to restore, maintain, improve, or replace damaged tissue. Tissue engineering begins with a physical scaffold, which may use any of a number of materials from naturally occurring proteins to biocompatible synthetic materials to provide support for cells to develop and grow.
The goal is to assemble a functional structure that can support organic tissue growth without the body rejecting it. In some cases, the structure itself is mixed with cells and growth factors, which promotes the subsequent tissue growth. Artificial skin, bladders, small arteries, skin grafts, and cartilage are examples of engineered tissues; however, they still have very limited use in human patients.
The human body regenerates skin. If disease damages the liver, doctors can surgically remove the diseased portion, and the liver will actually grow back to its previous size. After years of research and observation, scientists realize that organ tissue can be repaired and even recycled, which presents tremendous therapeutic potential. Right now, more than 3,000 patients a month are added to the nation’s kidney waiting list, according to the U.S. Department of Health and Human Services, Organ Procurement and Transplantation Network. Imagine creating a restored kidney with full healthy function and no need for dialysis. Imagine if human tissue, discarded during surgery, could be combined with a patient’s cells to make customized organs that the body’s immune system would never reject.
One goal of organ regeneration is to understand the body’s capacity to support healing itself, including regenerating vital organs such as kidneys, lungs and heart. Another goal is to learn how to engineer replacement organs so they function properly, allowing patients to renew and restore their lives.
How We Distinguish the Emerging Medical Disciplines
Although genomics medicine, gene medicine, and precision medicine often are used as synonyms, we see them as important, complementary, and distinctive.
Genomics medicine is a research-focused disciple that uses large volumes of data to find variations in DNA sequences that affect health and create curative therapies. Genomics medicine includes prevention, diagnosis and management of communicable and genetic diseases as well as other chronic medical diseases. (In humans, genomics medicine currently means analyzing about 3 billion base pairs of DNA, up to 25,000 protein-coding genes.) Genomics medicine is BIG PICTURE.
Gene medicine is the medical discipline that uses various techniques to replace, regulate, block, or edit one or more genes that are the underlying cause of a particular disease. It enables physicians to make therapeutic, personalized medical decisions that can dramatically improve a person’s health outcome and in many instances provide a functional cure. Gene medicine takes genomics medicine to the clinical level.
Precision medicine refers to tailoring approved therapy/medical treatment to the individual using data (which may include genomic data) to optimize the healthcare outcomes of a patient or patient population.
For more information and/or to offer comments for consideration as we seek precise, easy-to-comprehend definitions and understanding of cell and gene medicine, please contact us at email@example.com.