Response of the blood clotting system of the American horseshoe crab, Limulus polyphemus, to a novel form of lipopolysaccharide from a green alga
| Autor: | Alice Child, Mara L. Conrad, Norman R. Wainwright, Peter B. Armstrong, R. L. Pardy |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Lipopolysaccharides
Lipopolysaccharide Physiology Chlorella Biology Biochemistry Exocytosis Microbiology Blood cell chemistry.chemical_compound Zymogen Horseshoe Crabs medicine Animals Blood Coagulation Molecular Biology Cells Cultured Blood Cells Innate immune system Degranulation biology.organism_classification Immunity Innate Horseshoe crab medicine.anatomical_structure chemistry Coagulin Limulus lipids (amino acids peptides and proteins) |
| Zdroj: | Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology. 144:423-428 |
| ISSN: | 1095-6433 |
| Popis: | Lipopolysaccharide (LPS, endotoxin) is a component of Gram-negative bacteria and is the principal indicator to the innate immune systems of higher animals of a Gram-negative bacterial invasion. LPS activates the blood clotting system of the American horseshoe crab, Limulus polyphemus. By stimulating blood cell degranulation, LPS triggers the release of the proteins of the clotting system from the cells, and by activating a protease cascade that converts coagulogen, a soluble zymogen, to coagulin, the structural protein of the clot, LPS triggers the production of the fibrillar coagulin blood clot. Although originally thought to be restricted to the Gram-negative bacteria and the cyanobacteria, LPS, or a very similar molecule, has recently been described from a eukaryotic green alga, Chlorella. Here we show that, like LPS from Gram-negative bacteria, the algal molecule stimulates exocytosis of the Limulus blood cell and the clotting of coagulin. The coagulin clot efficiently entraps the cells of Chlorella in a network of fibrils. Invasion and erosion of the carapace by green algae is an important cause of mortality of Limulus, and it is suggested that the cellular response to aLPS may contribute to defense against this pathogen. |
| Databáze: | OpenAIRE |
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