Fermented Noni exudate (fNE): a mediator between immune system and anti-tumor activity.

The anti-tumor activity of Morinda citrifolia fruit juice (Noni) has been previously reported. However, the mechanism behind this activity remains unknown. In the present study, we studied the anti-tumor activity of fermented Noni exudate (fNE) and demonstrated that intraperitoneal injection of this material significantly increased the percentages of granulocytes and NK cells in the peripheral blood, peritoneum, and spleen. Furthermore, in preventive and treatment settings, fNE injection induced complete tumor rejection in normal C57BL/6J mice, partial tumor rejection in C57 nude mice lacking functional lymphocytes, and no tumor rejection in NK cell deficient beige mice. Over 85% of the C57BL/6J mice that received fNE survived the first tumor injection and rejected up to 5 x 10(6) tumor cells when re-challenged. The anti-tumor activity remains in the heat-inactivated and filtrated supernatant of fNE. These data demonstrate that fNE appears to be able to stimulate the innate immune system and the adaptive immune system to reject tumor cells. NK cells respond quickly and appear to be among the major players of the innate immune system, while the adaptive immune system reacts later with a retained memory.

Whole tumor cell vaccine with irradiated S180 cells as adjuvant.

Whole tumor cell vaccines have been widely studied and remain promising cancer immunotherapies. In the present study, we discovered that vaccination with irradiated mouse sarcoma S180 tumor cells stimulated robust antitumor immunity to autologous tumor cells in both syngenic and allogenic mice. The antitumor activity requires both T and B cells, but not NK cells. When a mouse lung carcinoma (TC-1) whole tumor cell vaccine was combined with the S180 vaccine, the antitumor immunity against live TC-1 tumor cells is significantly enhanced compared to a TC-1 whole cell vaccine alone. This antitumor immunity not only prevents live tumor challenge but also eradicates existing tumor cells. A similar phenomenon was also observed when S180 vaccine was combined with LL2 Lewis lung carcinoma tumor cells. Therefore, S180 vaccine may serve as an adjuvant for other whole tumor cell vaccines.