Objective: To observe the inhibitory effect of MAGE-3 peptide pulsed DC on transplanted murine gastric cancer in 615 mice.
Methods: The CTL clones directed against MAGE-3 peptide were tested for the ability to lyse the gastric cancer cell line MFC which can express MAGE-3 antigen. In immunoprotection experiment, mice of the study group were immunized with MAGE-3 peptide pulsed DC (DC/MAGE-3) at the dosage of 1 x 10(6) on d0 and d7 by sc inoculation, mice of control groups were immunized with influenza virus peptide pulsed DC (DC/Nup) or unpulsed DC at the same dosage on days as the DC/MAGE-3 group. On d14, all the mice were challenged with sc injections of 5 x 10(5) MFC gastric cancer cells. In immunotherapy experiment, all the mice were sc injected 5 x 10(5) MFC gastric cancer cells on d0, and on d3, d10 mice of each groups were sc inoculated with DC/MAGE-3, DC/Nup or unpulsed DC at the dosage of 1 x 10(6) respectively. All mice were monitored closely with respect to tumor growth and survival times.
Results: The CTL clone induce by MAGE-3 peptide could lyse the MFC cells efficiently. Immunization of mice with DC pulsed with MAGE-3 generated partial protective immunity against MFC tumor, as well as significant inhibition of tumor growth in a 3-day tumor model.
Conclusion: The tumor vaccine with DCs pulsed with MAGE-3 peptide possesses the ability to stimulate tumor specific CTL activity and to establish antitumor immunity when administered in vivo.