Interview with Dr. Lou Vaickus, Tolerx, Question 2

LV: No one knows the exact mechanism, but we at Tolerx have an educated guess based on a lot of work in animal models and preliminary human data. Anti-CD3 antibodies are thought to have a twofold mechanism of action:

1. The first is to stop the immune attack on a person's own insulin producing pancreatic beta cells by inhibiting T effector/killer cell function. This also serves to decrease local inflammation in the pancreatic islets that contain the beta cells.
2. The second is to protect against further attack by qualitatively and quantitatively enhancing regulatory T cells which potently inhibit the killer/effector cells in the long-term.

The interesting thing about CD3 as a drug target is that it is present on two major types of cells that are important in keeping a balance in the immune system (T effector/killer cells and regulatory T cells). And, anti-CD3 antibodies can affect these cell types differently (inhibiting one while enhancing the other) to help restore a more normal immune response while providing a prolonged disease remission.