| pubmed-article:8654665 | pubmed:abstractText | 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. | lld:pubmed |
