Skin inflammation induced by lupus serum was inhibited in IL-1R deficient mice.

Skin inflammation induced by lupus serum is a useful tool to investigate the pathogenesis of lupus skin injury. IL-1 is a proinflammatory cytokine, and its role in lupus skin lesion is still unclear. We determined the role of IL-1 in lupus skin injury by using gene deficient mice. We found that skin inflammation induced by lupus serum was significantly reduced in IL-1R deficient mice and caspase-1 deficient mice. IL-1R deficiency did not affect the expression of FcγRI (CD64), FcγRII (CD32) and MHC class II (CD74) induced by lupus serum. IL-1R deficiency reduced the lipid raft clustering, and decreased expression of MCP-1 and TNFα in monocytes. Keratinocyte proliferation induced by lupus serum was significantly decreased in TNFα deficient mice. Our findings indicate that IL-1 plays an important role in skin lesions of SLE. This study suggests that IL-1 is a therapeutic target in skin lesions of SLE.