Some Specific Aspects of Cell-Surface Recognition by Sipunculid Coelomocytes

Cushing, John E.; Boraker, David K.

doi:10.1007/978-1-4684-3261-9_5

Cited by 8 publications

(1 citation statement)

References 20 publications

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“…In this study, we have evaluated some aspects of the interplay between cells directly involved in clot formation and cells having the complementary role of phagocytosing self products, such as cytoplasmic and nuclear remnants shed from the clot, and non-self material. The combination of immune and haemostatic functions has created some historical controversies about whether clotting is present in sipunculans and whether sipunculans form nodules and capsules as occurs in insects and crustaceans (Cushing and Boraker 1975;Dybas 1976;Rice 1993;Towle 1975;Triplett et al 1958). A simple gadget designed to create a liquid column opened at the bottom end in contact with sea The dense cloudy fluorescence arising from several focal planes indicated that the clot contained large amounts of LGL-derived lipid membranes.…”

Section: Discussionmentioning

confidence: 98%

Haemostatic and immune role of cellular clotting in the sipunculan Themiste petricola

et al. 2010

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Sipunculans, a small phylum of coelomated marine worms closely related to polychaete annelids, lack a true circulatory system. We have previously shown that the sipunculan Themiste petricola can form a cellular clot, without congealing, of cell-free coelomic fluid. The clot is formed by the aggregation of large granular leukocytes (LGLs) and may serve not only haemostatic but immune functions, since dissimilar particles may become entrapped within it. We have now evaluated the capacity of a massive clot, induced in vitro by sea water contact, to stop coelomic fluid flow. We have further studied smaller clots induced on glass-slides either with or without the presence of bacteria placed for entrapment within the clot. The fate of clotting LGLs is cell death while forming a cohesive mass, although cytoplasmic and nuclear remnants are shed from the clot. These remnants and any bacteria that avoid clot entrapment or are detached from the clot are engulfed by non-clotting cells that include small granular leukocytes (SGLs) and large hyaline amebocytes (LHAs). Both cell types can be found other than in the clot but SGLs also occur around the clot edges heavily loaded with engulfed material. The cytoskeletal arrangement of SGLs evaluated with phalloidin-rhodamine correspond to motile cells and contrast with that of clotting LGLs that form a massive network of F-actin. Thus, the complementary roles between clotting LGLs and non-clotting SGLs and LHAs act a central immune strategy of Themiste petricola to deal with body wall injury and pathogen intrusion into the coelomic cavity.

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Section: Discussionmentioning

confidence: 98%

Haemostatic and immune role of cellular clotting in the sipunculan Themiste petricola

et al. 2010

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Fine structure and functions of haemerythrocytes and leucocytes of Sipunculus nudus

Valembois¹,

Boiledieu²

1980

Journal of Morphology

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The marine sipunculan worm, Sipunculus nudus Linné, possesses a voluminous coelomic cavity filled with a fluid containing different types of free cells. Most of them (more than 90%) are nucleated haemerythrocytes. They arise from free, small haemerythroblastic cells which are described in this report. Different kinds of leucocytes are also found in the coelomic fluid, particularly granulocytes which are phagocytic cells showing some similarities with vertebrate macrophages. These cells seem to arise from small hyalocytes, which are cells having morphological and physiological resemblances with vertebrate lymphocytes. It appears that the older granulocytes are progressively degranulated and give rise to large hyalocytes. Ciliary cells arising from small cells, very similar to small hyalocytes, have also been observed and it is supposed that they give rise to urn cells. Lastly, some of the biological functions of the free coelomic cells of the sipunculan worms are described.

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Cellular Defense Systems of the Platyhelminthes, Nemertea, Sipunculida, and Annelida

Valembois

Roch

Boiledieu

1982

Phylogeny and Ontogeny

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Some Specific Aspects of Cell-Surface Recognition by Sipunculid Coelomocytes

Cited by 8 publications

References 20 publications

Haemostatic and immune role of cellular clotting in the sipunculan Themiste petricola

Haemostatic and immune role of cellular clotting in the sipunculan Themiste petricola

Fine structure and functions of haemerythrocytes and leucocytes of Sipunculus nudus

Cellular Defense Systems of the Platyhelminthes, Nemertea, Sipunculida, and Annelida

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