Neuroendocrine marker expression on sea urchin coelomocytes and other immunoregulatory parameters may be used to monitor environmental changes

Abstract

Human ‘natural killer’ (NK) cells, small-cell lung-cancer cells, and sea-urchin coelomocytes may share evolutionarily conserved antigens NKH1 (N901) (CD 56) and HNK1 (Leu 7) (CD 57). The shared reactivity, defined by murine monoclonal antibodies, anti-NKH1 (Coulter Immunology), anti-Leu 7, and anti-Leu 19 (Becton Dickinson), was reported previously. 1 By using indirect immunofluorescence and flow cytometry, the reactivity of about 5–10% of coelomocytes from two genera of sea urchins, Strongylocentrotus purpuratus and Eucidaris, was described. In the present study, similar reactivity of coelomocytes from Echinus esculentus is reported. Although the functional significance of the reactivity of a small percentage of coelomocytes with monoclonal antibodies directed at neuroendocrine markers is not known, the fact that human NK cells that have similar phenotypes have functional activity that decreases when humans are ‘stressed’ suggests that monitoring sea urchins' coelomocytes under controlled laboratory conditions that can simulate environmental ‘stress’ offers a model to be extended to environmental surveillance.