[Various aspects of IL-1 biological activity. I. The role of IL-1 in parasitic infections].

Interleukin-1 is one of the most potent proinflammatory cytokines involved in many physiologically important processes both beneficial and pathological. It appears in two different forms: IL-1 alpha and IL-1 beta synthesized mainly by macrophages and monocytes. IL-1 alpha remains inside the cells and is released during acute inflammatory diseases accompanied by cell lysis. IL-1 beta becomes biologically active after specific cleavage and is secreted to fulfill its multitude functions. This cytokine is involved in multiple gene up-regulation, higher expression of many cytokine receptors or induction of nitric oxide synthesis. Interleukin-1 is responsible for symptoms like fever or appetite loss during inflammatory diseases. It is capable of lymphocytes, macrophages or NK cells activation. This cytokine has a chemoattractant activity toward neutrophiles and monocytes and takes part in Th2 response development. Apart from other functions and activities, IL-1 is associated with many invasive illnesses such as parasitic infections. This cytokine influences the outcome of numerous parasitoses since it can limit parasite spread and survival within infected host by cooperation with other components of the immunological system and by the induction of anti-parasitic compounds. However, the proinflammatory activity of IL-1 may prove harmful in certain cases and may be responsible for parasite infection development.