Carrageenan and the immune response.

Since the biological effects of carrageenan were reviewed in 1972 by Di Rosa it has become clear from a large number of reports that this algal polysaccharide markedly influences immune responses. Profound suppression of immunity evidenced by impaired antibody production, graft rejection, delayed hypersensitivity and anti-tumour immunity, has been observed in carrageenan-treated animals and the immunodepressive ability of carrageenan confirmed by in vitro studies. Efforts at analysis of carrageenan-induced immune suppression have focussed on the selective cytotoxic effect of this agent on mononuclear phagocytes. Faith in the ability of carrageenan to eliminate those cells has led to its use in examination of the role played by mononuclear phagocytes in various aspects of immune reactivity. This review documents and discusses the effects of carrageenan on immune responses and assesses the value of carrageenan as a useful tool in both current and future work aimed at broadening our knowledge of mechanisms underlying immune reactions.