Selective targeting of T cell subsets: focus on alefacept - a remittive therapy for psoriasis

IL-20: a new target for the treatment of inflammatory skin disease

The discovery of dramatic pro-inflammatory effects of IL-20 on skin highlighted a novel regulatory pathway in cutaneous inflammation. Specific receptor complexes for IL-20 are induced on keratinocytes and transmit potent signals via the signal transducer and activator of transcription-3. In response to IL-20, keratinocytes proliferate and express pro-inflammatory genes including TNF-alpha, which leads to activation of NF-kappaB. Recently, two related cytokines, IL-19 and IL-24, have been shown to trigger the IL-20 receptor, and a second receptor complex has also been found to respond to IL-20 and IL-24. IL-20 signalling appears to be a prominent component of cutaneous inflammation, but the extent to which inflammatory processes rely upon it is unknown. Nonetheless, the prevalence of diseases involving pathological cutaneous inflammation makes the identification of safe and effective anti-inflammatory therapies for the skin a priority. Detailed understanding of the signal transduction pathways by which the skin responds to IL-20 and related factors may make it possible to develop new pharmaceutical agents to selectively suppress cutaneous inflammation.

Therapy of autoimmune diseases: clinical trials and new biologics

Successful clinical efficacy trials have been recently completed for a growing array of new biologics. Prospects are improving for rational therapeutic interventions that potently interrupt adaptive immune response pathways. By contrast, disappointing results with antigen-based therapeutics highlight the difficulties of achieving tolerance in the context of active autoimmunity. Combination immunotherapy is probably necessary to sequentially or simultaneously inhibit inflammation, uncouple innate immune pathways, interrupt or ablate the adaptive memory response and promote antigen-specific tolerance in a suitable immunological context.