Decrease in tumorigenicity and increase in immune response by B7.1 and TAP1 co-expressing tumor cells.

<p>The time of morbidity was recorded for mice (each group, n = 10) inoculated with live tumor cells or immunized with γ-irradiated cells and followed by challenge with CMT.64 cells. Statistics for mouse survival were obtained using the Kaplan–Meier log rank survival test and differences were considered significant at P<0.05. A) Tumorigenicity was detected by injection of C57BL/6 mice i.p. with live CMT.64 cells or their transfectants (5×10⁴ cells per mouse). B) Nude mice were used for determination of tumorigenicity with conditions of tumor injection the same as shown in A), P>0.05 for all comparisons. C) C57BL/6 mice were immunized i.p. with different γ-irradiated tumor cells or PBS at a high-dose (left, 5×10⁶ cells per mouse) or a low-dose (right, 5×10⁵ cells per mouse). After a 20-day immunization, the mice were challenged i.p. with live CMT.64 tumor cells (2.5×10⁵ cells per mouse). Different survival rates and/or times were observed.