Ganoderma lucidum polysaccharides promote Thl cell differentiation of human peripheral blood lymphocytes through the upregulation of STAT4

Objective To study the effects of Ganoderma lucidum polysaccharide （GLP） on PBMCs and the related immune mechanism. Methods PBMCs from cancer patients and healthy donors were isolated and treated with different doses of Ganoderma lucidum polysaccharides （10 ng/ml, 50 ng/ml and 100 ng/ml）. DC cell costimulatory molecules （HLA-DR, CD83, and CDllc）, Thl （CD3＋ CDS-IFN- γ ） cells, Th2 （ CD3＋ CDS-IL-4＋） cells and NK （CD3-CD56＊） were analyzed by FCM. Furthermore, The CD3＋ CD4＋ Th cells were separated by immunomagnetic beads and stimulated with Ganoderma lucidum polysaccharides at different concentrations in culture. After 24 h, the cytokine expression levels of Thl and Th2 were detected by RT-PCR. The expressions of Thl differentiation-related transcription factor, STAT4, were analyzed by Western blot. Results Ganoderma lucidum polysaccharides can significantly stimulate in vitro Thl cell differentiation （P〈0.01） in a dose depend manner. It correlates with an increased expression of STAT4 and the elevated mRNA expression levels of Thl cytokineincluding IL-12, IFN-~/ and TNF-α （P〈 0.01 ）. Conclusion Ganoderma lucidum polysaccharides may promote Thl differentiation and increase the secretion of Thl cvtokines through the uoregulation of STAT4. Key words: C.anoderma lucidum polysaccharide （GLP） ;  Thl cells;  STAT4;  IFN-γ