The Elementary Study Of Mechanisms For Immunomodulatory Effects And Anticancer Properties Of Recombinant LZ-8 (rLZ-8), A Fungal Immunomodulatory Protein From Ganoderma Lucidium

Ling Zhi-8 (LZ-8) is a fungal immunomodulatory protein that is isolated from mycelia of Ganoderma lucidium. In terms of immunomodulatory activity, LZ-8 acts as a mitogen for human peripheral lymphocytes(HPBL), human peripheral blood mononuclear cells and mouse spleen cells, and induces the production of cytokines such as interleukin-2, tumor necrosis factor, interferon-γand so on. LZ-8 also can modifies the expression of adhesion molecules on immunocompetent cells. In addition to its immunomodulatory effects, LZ-8 exhibits anticancer properties. However, its mechanisms of immunomodulatory effects and anticancer activity are still not fully understood now.In this study, we expressed and purified the recombinant fungal immunomodulatory protein rLZ-8 in Pichia pastoris expression system, and then, used hemagglutination reaction and cell proliferation assay to check the biological activity of rLZ-8. Cells, treated with FITC-rLZ-8(rLZ-8 is linked with FITC), were observed by confocal microscopy scanning laser microscope to detect the cellular localization of rLZ-8. The result shows that rLZ-8 gathers on cell membrane of some HPBLs, and enters into some other HPBLs. But rLZ-8 gathers only on cell membrane of mouse spleen cells, and it only gathers in the cells of A549 and 293T. This means that rLZ-8 may has different action ways and sites to cells. MTT assay was used to determine the effect of rLZ-8 on the proliferation of A549 cells.The results show that rLZ-8 suppresses the proliferation of A549 cells in a dose and time-dependent manner. Then, we examined the expression of senescence-associated [β]-galactosidase (SA-[β]-Gal) in A549 by staining, the results suggest that rLZ-8 may induce premature senescence in A549, thus it can inhibits the proliferation of A549 cells.We successfully expressed and purified the recombinant fungal immunomodulatory protein rLZ-8, and investigated the cellular location of rLZ-8 by using FITC. We also found that rLZ-8 can suppresses the proliferation of A549 cells, maybe by trigering premature senescence. These studies would provided some possible mechanisms for immunomodulatory effects and anticancer properties of rLZ-8, and the use of LZ-8 may be a powerful new strategy for chemoprevention and antineoplastic therapy.