Interleukin 1 (IL-1) is the major immunoregulatory molecule produced by macrophages and other related cells. It acts as the molecular orchestrator of nonspecific host defense mechanisms against multifarious insults. In this study we report the characterization of an IL-i-like protein from the starfish Asterias forbesi. IL-l-like activity was found in the coelomocytes of this invertebrate and was also isolated and purified from the coelomic fluid. The coelomocytes were capable of phagocytosing latex particles and were adherent to plastic tissue culture dishes. Starfish IL-1 stimulated murine thymocyte proliferation directly and to a greater degree in the presence of submitogenic concentrations of concanavalin A. Starfish IL-1 also stimulated fibroblast proliferation and fibroblast protein synthesis. It was found to have a Mr of 29,500 and pI values of 7.5, 5.9, and 4.8. Starfish IL-1 activity was inhibited by an antibody to human IL-1. These characteristics suggest starfish IL-1 to be very similar to murine and human IL-1. The similarities to vertebrate IL-1 considered along with the evolutionary position of the starfish suggest that IL-1 is an important, ancient, and functionally conserved molecule.
A lipopolysaccharide (LPS) was isolated from the Lyme disease spirochete by a modification of the hot phenol-water method. The material was composed of 45% carbohydrate, 8% protein, 44% lipid A, and 1% 3-deoxy-D-mannooctulosonic acid and accounted for approximately 1.5% of the cellular dry weight. The isolated LPS possessed several biologic activities characteristic of endotoxins. The LPS was pyrogenic for rabbits, mitogenic for human mononuclear cells and murine splenocytes, capable of clotting limulus lysate, and cytotoxic for murine macrophages. LPS extracted from Borrelia burgdorferi by the petroleum-ether:chloroform:liquid-phenol procedure was also characterized. The results show that the Lyme disease spirochete contains a hitherto unknown LPS that is biologically active in vitro, and the expression of such activities in vivo may play an important role in the pathogenesis of Lyme disease. Some of the clinical manifestations of other spirochetal disease may be explained by similar endotoxins in those organisms. To our knowledge this is the first report of an LPS extracted from a spirochete that is known to be a human pathogen.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.