Case Study 2: transforming a toxin into a therapeutic: the sea anemone potassium channel blocker ShK toxin for treatment of autoimmune diseases

Diseases with an autoimmune component can affect virtually any organ in the body, and they currently afflict millions of people worldwide. These chronic disorders are oen diagnosed in young adults, or even children, and they can be debilitating and lead to premature death. Immunomodulators such as methotrexate, monoclonal antibodies (natalizumab, inflximab), glatiramer acetate, mitoxantrone, tumour necrosis factor antagonists (etanercept, infliximab) and steroids have considerably improved the management of autoimmune diseases, but they can cause generalized immunosuppression and therefore put patients at an increased risk of tumour cell proliferation or opportunistic infections. Kv1.3 channel blockers represent a new class of immunomodulators with a lower risk of inducing generalized immunosuppression as they preferentially target the effectormemory T (T_EM) lymphocytes involved in autoimmune diseases, with little or no effect on other subsets of lymphocytes.