PsP, the protein-bound polysaccharide, extracted from a strain of Coriolus versicolor (Cov-1) by Professor Qing-yao Yang, has been proved to be effective against tumor both in animal experiments and in clinical patients. Previous results suggested that the antitumor effects of PsP were related to the potentiation of immunological responses, especially T-cell mediated immune responses of tumorbearing hosts. Since T-lymphocytes play an important role in immune response and T-cell deficiency existed in many diseases, the most noticeable one at present time is the acquired immune deficient syndrome (AIDS) which leads to the failure of T-cell functions and death. Until now there is no any
effective drug in curing this disease. It is of great interest to investigate if PsP can potentiate T-cell functions and restore the immune deficient conditions in tumor, AIDS and other viral infections. In this paper both in vivo and in vitro experiments were used to study PsP on: 1) immune organ weights, 2) antibody informations, 3) serum complement contents, 4) T lymphocyte proliferations, 5) interleukin-2 production, 6) delayed type hypersensitivity reaction, 7) phagocytic ability of reticulo-endothelial system and 8) protection of liver injuries from CCl4 intoxication.