Blastoid transformation of human lymphocytes cultured with protein-bound polysaccharide preparation, PS-K, in vitro.

The protein-bound polysaccharide preparation, PS-K, isolated from a mushroom, Coriolus versicolor, was found to stimulate human lymphocytes and induce them into blastogenesis in vitro. This stimulatory effect seemed to be nonspecific since lymphocytes from cord blood of newborn babies were also stimulated by PS-K. The highest lymphocyte blastogenesis by PS-K was observed after 5 days in culture.