Multiple sclerosis, ankylosing spondylitis, rheumatoid arthritis, psoriasis, erythematosus, systemic lupus, vitiligo, Crohn’s disease, Guillain-Barré syndrome. These apparently very different diseases have one thing in common – they are due to a disorder of the immune system which begins to “attack” the body that it normally has to protect. Known as “auto-immune” diseases, they affect millions of people across the globe. They currently sit in the third group of diseases in terms of morbidity and mortality after cancer and cardiovascular disease. Although treatments make it possible to slow down their progress, they still remain incurable.
But now, there is a ray of hope to get rid of auto-immune diseases completely. Several biotechnology companies have made real strides in producing regulatory T cells that can prevent the body from self-destructing.
The body’s immune system comprises an armada of several types of white blood cells, always at work, protecting the body from external threats like viruses and bacteria. However, the same defense system sometimes mistakenly perceives the body as the enemy and starts attacking it. Certain white blood cells like self-reactive lymphocytes specifically attack tissues or organs. Moreover, antibodies normally produced by certain immune cells to neutralize the “enemy” by attaching to certain molecules (antigens) can also appear and target parts of our body. This self-destruct immune response thus results in several ailments, grouped as auto-immune diseases.
Regulatory T cells form the main line of defense against auto-immune disease and other inflammatory conditions arising due to the immune system led by the effector T cells turning on the body. However, producing T cells in a lab is tricky as they are rare and have a tendency to shift identity. Additionally, they produce a variety of molecules, and scientists are still not sure about their functions and role in the body’s defense system.
There is another catch here. The trials of using regulatory T cells against auto-immune diseases have been conducted since 2004. The procedure seems to be relatively safe; however, the efficacy is not very encouraging.
Current therapies involving regulatory T cells to treat auto-immune diseases use a person’s own T cells. They are removed from the body, expanded, and then are re-injected. Not so effective but a safe procedure. Biotechnology Companies, however, are trying a different approach. They are now focussing on creating genetically engineered regulatory T cells. The idea is to tailor each person’s T cells to better combat the rebelling effector T cells. To achieve an improved level of efficiency, biotech companies are counting on two recently emerging technologies. One is chimeric antigen receptor (CAR) T-cell manipulation that can provide T cells with receptor protein for specific cell targets, and the other is CRISPR–Cas9 genome-editing tools. The trials are soon to begin, and although there are still some concerns regarding cell stability and T cells switching sides, companies are hopeful that they can achieve desired results.