Immunotherapy based on Th1, Th2 theory

It is very important for immunotherapy to release Th2-dominated immunological conditions in patients with malignant diseases. In the present study, we investigated whether the balance between Th1 and Th2 could be controlled by lentinan (LNT) and OK-432. When peripheral blood obtained from cancer patients was incubated with OK-432, the production of IL-12 and IFN- γ in the culture medium was increased, whereas the production of these cytokines was not increased in some patients in whom the production of IL-10 was also increased. So peripheral blood was cultured with anti-IL-10 antibody, and the production of IL-12 and IFN-γ was strongly up-regulated. On the other hand, the intracellular cytokine profile revealed that the percentage of CD4⁺IFN-γ⁺ cells in cultured blood was increased and that of CD4⁺IL-4⁺ cells was decreased when stimulated by LNT. After intravenous administration of LNT, the production of IL-12 was up-regulated and the production of IL-10 was down-regulated in the cultured medium when peripheral blood was incubated with OK-432. These results suggest that immunotherapy with OK-432 alone could not release Th2-dominated immunological conditions in patients with malignant diseases, but immunotherapy using LNT together with OK-432 may be able to improve the balance between Th1 and Th2.