Coelomocytes and post-traumatic response in the common sea star Asterias rubens

Abstract

Coelomocytes are recognized as the main cellular component of the echinoderm immune system. They are the first line of defense and their number and type can vary dramatically during infections or following injury. Sea stars have been used as a model system to study the regeneration process after autotomy or predation. In the present study we examined the cellular and biochemical responses of coelomocytes from the European sea star Asterias rubens to traumatic stress using immunochemical and biochemical approaches. In terms of trauma and post-traumatic stress period, here we consider the experimental arm amputation and the repair phase involved in the first 24 hours postamputation, which mimicked a natural predation event. Four cell morphotypes were distinguishable in the coelomic fluid of both control and post-traumatic-stressed animals (phagocytes, amoebocytes, vibratile cells, hemocytes), but phagocytes were the major components, accounting for about 95% of the total population. Thus, the effects measured relate to the overall population of coelomocytes. A modest increase in the total number of freely circulating coelomocytes was observed 6 hours post-amputation. Interestingly, a monoclonal antibody (McAb) to a sea urchin embryo adhesion protein (toposome) cross-reacted with isolated sea star coelomocytes and stained the coelomic epithelium of control animals with an increase in trauma-stressed arms. In addition, coelomocytes from trauma-stressed animals showed a time-dependent increase in Hsp70 levels, as detected by both immunocytochemistry and immunoblotting within 24 hours after arm tip amputation, with a peak at 6 hours after amputation. Our findings indicate a clear role for coelomocytes and classic stress molecules in the post-traumatic stress associated with the early repair phase of regeneration.

Manganese: A New Emerging Contaminant in the Environment

“…In echinoderms, immune cells (called coelomocytes) are a heterogeneous population of free moving cells found in all coelomic spaces, including the perivisceral coelomic cavities and the water-vascular system (reviewed in Matranga, 1996;Glinski & Jarosz, 2000;Smith et al, 2010). They are also present sparsely in the connective tissue (mesodermal stromal tissue) and amongst tissues of various organs (Muñoz-Chápuli et al, 2005;Pinsino et al, 2007). Coelomocytes participate as immune cells in function similar to their vertebrate's immune system homologues.…”

“…The coelomic fluid in which the immunocytes or coelomocytes reside and move is a key factor governing the immunological capabilities of echinoderms, as it contains essential trophic and activating factors (for a review see Matranga et al, 2005;Smith et al, 2010). Four different morphotypes have been described in the asteroid Asterias rubens, with the phagocytes as the most abundant type, accounting for approximately 95% of the total population (Pinsino et al, 2007).…”

Induced cell proliferation in putative haematopoietic tissues of the sea star,Asterias rubens(L.)

“…The morphological and biochemical characterization of coelomocytes is, however, still not completely understood, and no reliable, specific cell markers are available. Four sub-populations -phagocytes (previously called amoebocytes), vibratile cells (with flagellum), morula cells (also called haemocytes) and slow-moving cells with an irregular shape (recently called amoebocytes) -have been described (Smith, 1981;Pinsino et al, 2007) but the nomenclature has still not been standardized. Phagocytes are the pre-dominating cell type, comprising 80-95% of total coelomocyte counts.…”

“…Phagocytes are the pre-dominating cell type, comprising 80-95% of total coelomocyte counts. These cells can rapidly convert to petaloid and filopodial stages able to form networks when attached to glass slides (Pinsino et al, 2007). Knowledge of the recruitment of the coelomocytes is poor, and the haematopoietic tissue (HPT) of A. rubens has still not been clearly identified.…”

Introductory Chapter: Sea Urchin - Knowledge and Perspectives

“…Echinoderm immune cells, also known as coelomocytes, are a heterogeneous population of freely moving cells found in all coelomic spaces, including the perivisceral cavities and the water vascular system. They are also present sparsely in the connective tissue and among tissues of various organs [41][42][43][44]. A rapid increase of the number of the red amoebocytes has been shown in samples taken from polluted sea water, whereas petaloid cells are actively involved in the phagocytosis and phylopodial cells trigger the clot formation [5].…”