Molecular Cloning of a Porta cocos Protein That Activates Thl Immune Response and Allays Th2 Cytokine and IgE Production in a Murine Atopic Dermatitis Model

摘要

Edible fungus Poria cocos (Schw.) Wolf is a cooking material that has myriad health benefits. However, its active constituents have not been well-defined. We previously purified an immunomodulatory protein, PCP, from P. cocos and described its biochemical features and its ability to activate primary macrophage via TLR4. In this study, we cloned the gene of PCP and demonstrated its ability to activate Thl response in cell cultures and in mice. The complete cDNA sequence of PCP consisted of 807 bp, which included a 579 bp coding sequence that encoded 194 amino acids. With the addition of co-stimulatory CD3/ CD28 signals, PCP significantly increased the surface expression of CD44 and CD69 on effector T cells. PCP could also up-regulate T-bet and STAT4 expressions and IFN-y and IL-2 secretions. Oral administration of PCP suppressed the production of both total and OVA-specific IgGl in serum and enhanced the amounts of serum and OVA-specific IgG2a and Thl-related cytokine production in BALB/c splenocytes. In addition, oral administration of PCP significantly reduced IL-4 and IgE expressions in a murine model of atopic dermatitis. In conclusion, these results provide evidence that PCP could regulate mammalian immune cells and reveal their pharmaceutical potential in developing therapeutic strategies against Th2-mediated immune disorders.