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A Novel Fungal Immunomodulatory Protein (PCP) Isolated From Poria cocos Activates Mouse Peritoneal Macrophage Involved In Toll‐like Receptor 4
Author(s) -
Chang HuiHsin,
Sheu Fuu
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.a738
Subject(s) - toll like receptor , toll , macrophage , receptor , microbiology and biotechnology , biology , chemistry , immunology , innate immune system , biochemistry , in vitro
A novel immunomodulatory protein (PCP) has been purified from the dried sclerotium of an Oriental therapeutic fungus, Poria cocos (Schw.) Wolf. The protein PCP is a heterodimer protein consisting of 14.3 and 21.3 kDa subunits. Our previous studies revealed that PCP had mitogenic capacity toward murine splenocytes and was able to stimulate RAW 264.7 macrophages in vitro . Similarly, in primary mouse macrophages, PCP directly activated peritoneal cavity macrophages to enhance the production of nitric oxide (NO), IL‐1β, IL‐6, IL‐18 and tumor necrosis factor‐alpha (TNF‐α). Besides these cytokines, mRNAs for NF‐κB, TRAF6, TIRAP, and MyD88 were also enhanced that indicated their involvement in tandem in the activity of PCP. Toll‐like receptor TLR4 expression was increased on peritoneal cells by coincubation with PCP, whereas the expression of TLR2 and TLR6 remained unaffected. Moreover, PCP‐induced activities were absent in the cells obtained from TLR4 knockout C57BL/10ScN mice. Furthermore, the binding of PCP to the cell surface of peritoneal macrophages was demonstrated by comparing the flow cytometry results of C57BL/6 and C57BL/10ScN mice. These results suggest that PCP is a potential immune stimulus and TLR4 is primarily responsible in PCP signaling in murine macrophages.