Polysaccharide (ANK-102) from Polianthes tuberosa cells deteriorates the resistance of mice to Listeria monocytogenes infection.

Modulatory effect on the murine self defense system by a newly discovered acidic polysaccharide (ANK-102) produced by P. tuberosa cells in liquid culture was examined. Pretreatment with ANK-102 deteriorated the murine survival against lethal infection of Listeria monocytogenes, an intracellular gram-positive bacterium eliminated mainly by macrophages through T-cell mediated immune response. Pretreatment with ANK-102 resulted in the accumulation of Mac 1 and Mac 2 positive cells in the peritoneal cavity of the infected animals and the reduction of Thy1.2 expression on the surface of the thymocytes. A new type of immunosuppressive polysaccharide ANK-102 was introduced.