Antibodies play an important role in the development of modern medicine, both in the clinical treatment of patients and in the basic research of scientists. In the early stage of antibody production, it is inevitable that animals have to be sacrificed in exchange for a sufficient amount of antibodies and the quality is not stable. Today, thanks to advances in biotechnology, it is possible to produce a large number of antibodies using microorganisms or cell lines grown in vitro, called recombinant antibodies, which not only do not require killing but also have many advantages.
Importance of antibodies for medical development
Antibodies are the main components of many screening reagents and anticancer drugs. Without the antibody screening reagents, it is like a computer with a CPU removed and only an empty shell remains, which is like scrap iron. Antibodies are also a research tool that biomedical scientists rely on in their basic research.Biologists who do not have the assistance of antibodies are like explorers without a compass, and the chance of getting lost is greatly increased. The scope of antibodies continues to expand and the demand will continue to grow in the future.How to reduce antibody production costs and improve efficiency is an urgent development direction.
How antibodies fight pathogens
Antibodies are proteins produced by the vertebrate immune system against the invasion of harmful pathogens such as bacteria, viruses, etc. Since antibodies can specifically identify specific pathogens, they can guide immune cells to launch precise attacks without harming innocent people. Furthermore, when the antibody recognizes the pathogen, it will bind to it very tightly and “surround” it, so the antibody itself is sufficient to neutralize the toxicity of the pathogen and prevent damage to the human body.
recombinant antibody
Antibodies, like other proteins, are first transcribed from genes into mRNAs and then translated into proteins. Today, scientists have thoroughly studied the structure and genes of antibodies and have the ability to use microorganisms or cells grown in vitro to express antibody genes to make antibodies. The recombinant DNA of the antibodies must be built into microorganisms using the technology of genetic engineering, so the obtained antibodies are called “recombinant antibodies”.
Antibodies are widely used
The ability of antibodies to specifically identify antigens is very valuable, so they are used in drug and reagent development such as biochemical testing, disease screening, stem cell separation, and purification of specific proteins. The following describes the application of antibodies in three fields.
1. Medicines to cure diseases
Many of the drugs that have been marketed use antibodies as active ingredients, such as “Avastin” for the treatment of colorectal, breast and non-small cell lung cancer, “Not required” for rheumatoid arthritis and leukemia chronic lymphocytic. Cancer “(Rituximab) and the cancer immunotherapy drug” Keytruda “(Keytruda). The global antibody drug market will reach $ 178 billion in 2021 and is estimated to reach $ 450 billion in 2028, about the total budget of the Taiwanese government in five years.
2. Disease and health control
The most important component of the recently widely used novel coronary pneumonia rapid screening reagent (antigen) is the antibody that can recognize the novel coronavirus protein. The key ingredient of the pregnancy test is identifying antibodies to a hormone (human chorionic gonadotropin), which increases during pregnancy and can accurately test for pregnancy. Other screening tests such as liver B, colorectal cancer, and ovarian cancer also rely on various specific antibodies.
3. Isolation of stem cells and immune cells
Regenerative medicine and cancer cell therapy use stem cells or immune cells to help patients repair tissues or destroy cancer cells. But before treatment, doctors must first isolate useful stem cells or immune cells from complex human tissue cells. Cell isolation often uses antibodies that recognize specific cell surface proteins to help remove unwanted cells or capture specific target cells.
Human problems of antibody production in animals
Since only vertebrates produce antibodies in nature, early antibody production consists of inoculating the animals with the target antigen to stimulate the animal to produce antibodies that recognize the target antigen. Animals that often produce antibodies include rabbits and goats. In Europe alone, the annual production of animals with antibodies reached one million. To increase the production of animal antibodies, animals usually need to be vaccinated several times. After humans experience the baptism of the new corona vaccine, they should be able to understand how painful the vaccination side effects are.
When the antibody is collected, since the antibody is mainly present in the animal’s blood, to obtain the maximum amount of antibodies, the animal must be “bled” by “cardiac puncture” until the blood is drained. Although the process is fully compliant with animal welfare standards and the animal must first be anesthetized, animal life is still sacrificed and only the use of non-animal antibody production methods can avoid various humanitarian problems.
The quality of the antibodies produced by animals is relatively unstable
Antibodies produced by early animals (rabbits, goats, etc.), due to individual differences, even though the manufacturing process is fully compliant with the SOP, the quality of antibodies produced by different batches of different animals is still different Some individual antibodies have excellent antigenic specificity, while some animal antibodies are however unusable. Unscrupulous manufacturers can label non-validated antibodies for sale (for basic research) and for quality assured antibodies, the cost will be passed on to the consumer side. Various costs accumulate and the price of antibody drugs for clinical cancer treatment is often millions of yuan, which is not affordable for all patients. The unstable quality of antibodies can also lead to non-reproducible experimental results. The waste of materials, time and money related to biomedical research due to antibodies in the United States is estimated to reach US $ 350 million per year.
Advantages of recombinant antibodies
Recombinant antibodies can be produced without animals, which not only makes the production process more controllable and reliable, but it doesn’t even need to be condemned by humanitarian groups. Now that the gene sequence that expresses the antibody is well known, the optimal antibody can be produced continuously with few batch variations and high yield. When the demand for the product increases and needs to be expanded, it can easily be achieved by simply expanding the number of bacterial strains or cell lines. It is estimated that the production cycle of the recombinant antibodies can be completed in a few weeks. As with traditional animal production, recombinant antibodies are most beneficial when there is an urgent need because it involves inoculating antigens several times and the production cycle is several months.
Epilogue
Technological progress never stops, as does the development of antibody technology. In addition to recombinant antibodies, some scientists are working on miniaturizing antibodies to improve the penetration of antibody drugs; some scientists are trying to combine antibody drugs with chemotherapy drugs to become more potent anticancer drugs; some scientists are even developing simultaneous identification of cancer Bispecific antibodies for cells and immune cells improve the immune system’s efficiency in killing cancer cells. It is hoped that with the rapid development of antibody technology, pharmaceutical companies will be able to provide antibody drugs that are not only environmentally friendly and human, but also affordable for people, benefiting more patients.
(Source of the first image:Freepik image）
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