Lymphocyte activation by purified carrageenan.

The induction of polyclonal antibody production and mitogenic response by purified carrageenan was studied in vitro by using spleen cells. It was shown that kappa-CGN, lambda-CGN, and iota-CGN induced significant responses in mice, hamsters, and rats. The less purified CGN also exhibited the polyclonal antibody production in mice. In addition, purified CGN exhibited mitogenic action on B cells and to a lesser extent, on thymocytes. Polyclonal antibody responses induced by purified CGN were not affected by removal of T cells, adherent cells, or iron powder phagocytic cells. These results suggest that CGN may activate B cells resulting in polyclonal antibody responses.