LING ZHI-8 - STUDIES OF A NEW IMMUNOMODULATING AGENT

Ling Zhi-8 (LZ-8) is a protein derived from the fungus Ganoderma lucid um and has immunomodulatory capacities. It was shown to be mitogenic t oward mouse splenocytes in vitro and immunosuppressive in vivo by redu cing antigen-induced antibody formation and by preventing completely t he incidence of autoimmune diabetes in nonobese diabetic mice. In this study, the mitogenic effects of LZ-8 on human mononuclear cells are r eported. In accordance to its mitogenic effect on mouse splenocytes, L Z-8 proved to be mitogenic for human PBMC. This mitogenic effect of LZ -8 apparently required the presence of monocytes. We also demonstrated it to be immunosuppressive in vitro in a human MLC performed in the a bsence of monocytes, using purified T cells and EBV-transformed alloge neic B cells, Furthermore, we tested LZ-8 for its possible suppressive effects in 2 different models of allogeneic tissue transplantation. L Z-8 proved to have a significant effect on cellular immunity, since it s administration in an allografted mouse skin model resulted in an inc reased survival. time. In a model of transplanted allogeneic pancreati c rat islets, LZ-8 was effective in delaying the rejection process of allografted islets. More frequent or continuous administration resulte d in a further prolongation of survival time. No serious side effects of LZ-8 could be discerned in these experiments.