title: Proliferation of undifferentiated blood cells from the solitary ascidian, Ciona intestinalis in vitro.
abstract: The proliferative responses of the cytotoxic blood cell population of the solitary ascidian, Ciona intestinalis, were investigated by autoradiography and tritiated thymidine (3H-TdR) incorporation following treatment with mitogens or co-culture with allogeneic cells in vitro. A small number of mitotic figures were seen in untreated circulating blood cells and pulse labelling with 3H-TdR showed that only the undifferentiated "lymphocyte-like" cells within the enriched cytotoxic cell population undergo spontaneous cell division and DNA synthesis in the circulation. Treatment of the cells, cultured for 4 days, with concanavalin A (con A), phytohaemagglutinin-B (PHA-B) or lipopolysaccharide (LPS) produced significantly increased 3H-TdR incorporation, although there were differences in the sensitivity of the cells to mitogen concentration. Significantly enhanced proliferation was also observed following incubation with mitomycin C-treated cells from allogeneic individuals. These results show that the cytotoxic blood cell population of C. intestinalis is capable of mitogen-induced proliferation as well as mixed lymphocyte-type responses and therefore shares some proliferative characteristics with vertebrate lymphocytes.
authors.affiliation: School of Biological and Medical Sciences, University of St. Andrews, Fife, U.K.
authors.forename: C M
authors.initials: CM
authors.lastname: Peddie
authors.forename: A C
authors.initials: AC
authors.lastname: Riches
authors.forename: V J
authors.initials: VJ
authors.lastname: Smith
mesh_terms: D000818:Animals; D001773:Blood Cells / Q000166:cytology / Q000502:physiology*; D018929:Cell Culture Techniques / Q000379:methods; D002455:Cell Division; D002938:Ciona intestinalis / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D008934:Mitogens / Q000494:pharmacology
chemical_list: D008934:Mitogens