IL-33 is a crucial amplifier of innate rather than acquired immunity

IL-33, a member of the IL-1-related cytokines, is considered to be a proallergic cytokine that is especially involved in Th2-type immune responses. Moreover, like IL-1α, IL-33 has been suggested to act as an "alarmin" that amplifies immune responses during tissue injury. In contrast to IL-1, however, the precise roles of IL-33 in those settings are poorly understood. Using IL-1- and IL-33-deficient mice, we found that IL-1, but not IL-33, played a substantial role in induction of T cell-mediated type IV hypersensitivity such as contact and delayed-type hypersensitivity and autoimmune diseases such as experimental autoimmune encephalomyelitis. Most notably, however, IL-33 was important for innate-type mucosal…

• MO
  Ministry of Education, Culture, Sports, Science and Technology
• NI
  National Institute of Biomedical Innovation
• MR
  Medical Research Council
• JS
  Japan Society for the Promotion of Science
• IO
  Institute of Medical Science, University of Tokyo