Suppressing the immune system

1. Suppressing the immune system Solutions to improve treatment

2. Current immunosuppressors… …suppress the entire immune system, leaving patients more vulnerable to everyday infections and higher rates of cancer. However, this is necessary because the immune system attacks parts of the body which are work well and are needed (in MS, myelin is targeted, causing demyelination) but we cannot isolate the suppression to just one impact of the immune system so to protect the targeted area we must lower the guard of everywhere else.

3. What’s the better solution? • STEP 1: Take white blood cells from the person with MS and insert large quantities of myelin antigens into them. Then inject them back into the patient. • STEP 2: The cells then enter the spleen, which filters the blood and helps remove old and dying blood cells. During this process immune cells learn to recognise the myelin antigen as harmless because in the spleen, the particles are engulfed by macrophages (white blood cells that engulf pathogens and unwanted materials , then send signals to other immune cells to target those materials) so they are recognised as ordinary dying blood cells by the immune system. Macrophage from the blood

4. The effect This creates immune tolerance to the myelin antigen and directly inhibits the myelin responsive T cells that attack them. It also has the advantage of achieving this protection without altering or suppressing the function of the rest of the immune system. The results of the phase 1 trial show the treatment to be safe and well tolerated. It reduced immune system reactivity to myelin by 50-75% and prevented future relapses in mice for up to 100 days, which is the equivalent of several years in the life of an MS patient.

5. Our ideas to further these effects • Simply attach the appropriate set of antigens to the white blood cells to help treat different autoimmune diseases! • Using a patient's white blood cells to transport the myelin antigens to the spleen is expensive and labour-intensive so we thought nanoparticles might be a cheaper and more accessible option. A useful nanoparticle could be from a polymer called PLG (Poly(Lactide-co-Glycolide)) because: • It is made up of lactic and glycolic acid, both of which found in the human body, so is unlikely to be rejected or attacked as a pathogen. • It is biodegradable and will be dissolved naturally by the body. • It is already approved by the US Food and Drug Administration (FDA) for other uses so it will not have detrimental side effects and the testing process will probably be accelerated.