INTERLEUKIN-1 IS RELEASED BY MURINE MACROPHAGES DURING APOPTOSIS INDUCED BY SHIGELLA-FLEXNERI

Peritoneal macrophages undergoing apoptosis induced by Shigella flexne ri infection release the inflammatory cytokine interleukin 1 (IL-1), b ut not IL-6 or tumor necrosis factor alpha (TNF alpha). Wild type shig ella causes a very fast and significant release of IL-1 from prestimul ated peritoneal macrophages, before the cell's integrity is compromise d. Both IL-1 alpha and IL-1 beta are released, IL-1 beta in its mature processed form. IL-1 is released from presynthesized cytoplasmic pool s. These results demonstrate that bacteria-induced apoptosis of macrop hages may play an active role in vivo by releasing IL-1, which in turn mediates an early inflammatory response in epithelial tissues.