Balb/c mice with HAC murine hepatic cancer were fed with oyster extract at a daily dose of 0. 2 ml (20 mg) for ten successive days. We found that the tumor-caused decreased immunological indicarors including total T cell number, the ratio of helper T cells, the transformation strength induced by mitogens, and NK activity increased markedly. Compared with the control, mice fed with oyster extract showed prolonged survive and their tumor weight reduced significantly. When mice earring human colon cancer were fed with oyster extract at the same dose for 15 days, the tumor size reduced to 44. 6% of the control tumors. The possiblity that oyster extract inhibits tumor growth by enhencing host immune function, especially killer cell activity, was discussed.

Objective:As the function of ??T cells and NK in the immunological therapy is showing more and more important,the characteristics of ?? T cells,NK and LAK were analyzed comparatively after that they were richened by isolating and incubating in vitro.Methods:The cells were collected using MACS after the cells were panned respectively with special monoclonal antibodies.Then the characteristics including proliferation,phenotype,cytotoxin and the down regulation blocked by specific antibodies were analyzed.Results:The ?? T cells can expand 600～800 times after culturing 2 weeks and the percent of CD3,CD8 and ?? expressed on the collected cells were 72.29%,58.02% and 65.98% respectively ?? T cells showed the high cytotoxin to K562(NK sensitive cell line),Raji and XG 7 cell lines(NK non sensitive cell lines).The percentage of cytotoxin reached 35.98%,52.27% and 69.08% respectively compared with ??T respectively.No obviously change of percent of ??T cytotxic ability to these target cells were observed using special MHC class I monoclonal antibody to block the ??T cell before coculturing the target cells with ?? T cells.Conclusion:All of ?? T cells,NK and LAK showed the non specific cytotoxin to tumor cells.The cytotoxic capability of ?? T cells did not be effected after blocking with MHC class I monoclonal antibody.These results demonstrated that ?? T cell could kill more kinds of tumor cells than NK and LAK.