Effects of extract of cultured Lentinus edodes mycelia (LEM) on polyclonal antibody response induced by pokeweed mitogen.

When polyclonal antibody response induced by pokeweed mitogen (PWM) was estimated by measuring antibody-forming cells produced against trinitrophenylated sheep red blood cells (TNP-SRBC) using hemolytic plaque assay, it was found to be augmented by the extract of cultured Lentinus edodes mycelia (LEM). Since some factor enhancing antibody response was detected in the culture supernatant of LEM-treated macrophages, this was fractionated by gel filtration, which revealed a substance with a molecular weight of about 15,000 daltons. This suggested that interleukin-1 (IL-1) was produced, and that it had caused, at least partially, the enhancement of antibody response. This possibility was confirmed by the direct assay of IL-1 activity, which demonstrated increased DNA synthesis in PHA-stimulated thymocytes.