Abstract: To understand the effect of Lactarius deliciosus Gray polysaccharide (LDG-A) on the proliferation of specific immunocytes and tumor cell apoptosis, we tested and observed the proliferation and morphological changes of T lymphocytes and B lymphocytes in the presence of LDG-A, determined the number of T lymphocytes and B lymphocytes in each stage of the cell cycle, and also evaluated antibody secretion by B lymphocytes under the stimulation of LDG-A. In addition, the apoptosis and cytoskeleton of lung cancer cell A549 were evaluated. The results showed that the proliferation of B lymphocytes and T lymphocytes’ proliferation was promoted LDG-A in a dose-response manner. LDG-A could also reduce the number of B lymphocytes at the G0/G1 phase and promote them to enter the G2/M phase. Meanwhile, LDG-A also promoted the secretion of IgM, IgD and IgE by B lymphocytes. In addition, LDG-A in the range of 12.5–50.0 μg/mL could induce the apoptosis of lung cancer cell A549 in a dose-dependent manner. Moreover, we observed fractured F-actin filaments in the cells as well as damaged protein fiber networks during apoptosis. In conclusion, LDG-A has a promoting effect on the proliferation of specific immunocytes, and accelerates the apoptosis of tumor cells in vitro.

Key words: L. deliciosus Gray polysaccharide, immunocyte, proliferation activity, tumor cells, apoptosis