Interleukin-1β(IL-1β) is one of the most pleiotropic cytokines and a central regulator of the immune and inflammatory responses. Interleukin-1β was initially discovered within mice and humans and over the last 10 years has been characterized within a wide variety of animals. The IL-1β plays a key role in the inflammatory process, enhancing cell-mediated immunity by inducing the growth and proliferation of lymphocytes, connective tissue cells, and by stimulating immune and inflammatory response effector cells. As an immunoregulatory cytokine, IL-1β has the potential to enhance the immune response induced by a vaccine and/or to modulate the immune response leading to different effector mechanisms. It is produced by many cell types, including monocytes, macrophages, T and B lymphocytes, fibroblasts, and endothelial and epithelial cells. Expression is induced by a diverse range of stimuli, including mitogens, cytokines, and microbial products. There have been considerable evidences provided by biological cross reaction that fish produce IL-1β during immune responses, and the bioactivity of IL-1 in fish has been known for over a decade. But only since 1999, IL-1β gene has been cloned from the rainbow trout. And from then on, IL-1β gene has been cloned and expressed in many fish confirming that fish produces IL-1β gene during immune responses. In mammals it is produced as an inactive precursor that is processed by interleukin converting enzyme (ICE) to give a biologically active `mature’ peptide. There is no signal peptide in IL-1β and its mechanism is unknown. This is the special part of the gene structure of the IL-1β. And through the program analyzing, we found this special structure in fish IL-1β gene. This paper reviews the functions and structure of gene IL-1β and the studies of the gene IL-1β in fish recently.
