Our immune defenses are well made: physical barriers (skin and mucous membranes), an inflammation mechanism that disarms the aggressor, proteins that block viruses in cells, and white blood cells that destroy pathogens … But they can have need the boost of immunotherapy, with the administration of molecules that stimulate or regulate the immune system. The vaccines which educate our body to defend itself against certain microbes, or the technique of desensitization in the event of allergy, are the best known and oldest applications. Others are being developed to treat autoimmune pathologies, certain cancers, and to stem the COVID-19 epidemic today.
Block the development of the epidemic
Immunology is at the heart of the fight against the Covid-19 epidemic, in particular to develop a highly anticipated vaccine. Several avenues are being studied, one of which is based on the measles vaccine virus. A discovery for a future treatment has just been made by French and American researchers. “In partnership with Cornell University in the United States, we have identified a feature of a protein (called a spike) present on the surface of the virus and which acts as a key to enter cells and to replicate itself. And at the same time, nanobodies are being studied. These are small antibodies produced by species of camelids (dromedaries or llama) which would neutralize the virus, precisely by blocking a region of the spike protein. The goal is to lower the viral load and prevent a runaway immune response that can damage certain organs when deregulated “, explains Jean Millet from the Virology and Molecular Immunology unit of INRAE. To be followed for the development of a treatment.
Outsmart cancer cells
Immunotherapy has made giant strides in oncology possible over the past decade. It is no longer a question of attacking tumor cells, but of awakening the immune system so that it recognizes and destroys them. Monoclonal antibodies are used for certain cancers of the lung, kidney, bladder, skin, breast, etc. These are molecules naturally produced by the immune system and which have been selected to identify and block cells tumor. For certain leukemias and lymphomas in particular, there are also both cellular and genetic therapies. They consist in reprogramming immune cells (T lymphocytes) into cells called CAR-T, armed against the tumor. Proteins from our natural defenses are also exploited. This is the case with interferons which inhibit the proliferation of pathogenic cells in the context of melanoma, myeloma, lymphoma, as well as the interleukin secreted by lymphocytes to activate the immune response, used in the treatment of adenocarcinoma renal or melanoma. We have also returned to the fundamentals of immunotherapy with therapeutic vaccination, not to prevent but to treat prostate cancer, for example. Not all patients respond and these treatments can be expensive, but they hold great promise.
Restore balance in autoimmune diseases
The immune system sometimes turns against the body, and causes autoimmune diseases such as multiple sclerosis, rheumatoid arthritis, Crohn’s disease, psoriasis … 5 to 8% of the world population is affected and 8 out of 10 people affected are women. Over the past twenty years, new treatments have significantly improved the management of these pathologies. These are biotherapies targeting molecules produced by the body and in particular certain cells of the immune system. Against the overproduction of our protein TNF-alpha for example, playing an inflammatory role of defense, drugs logically named anti-TNF alpha have been developed to reduce the excessive inflammatory response in Crohn’s disease or spondylitis. Other treatments inhibit the interleukin involved in psoriasis. Finally, the immunotherapy approach can be more mechanical for myasthenia gravis or Guillain-Barré syndrome, with the plasmaspheresis technique eliminating the auto-antibodies by filtration of the blood which is then reinjected.
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