Figure 8. Effect of anti-CD40 activated B cells and isotype switched anti-tumor antibody on growth of subcutaneous tumor.

Rag2^−/− SW_HEL+ and Rag2^−/− SW_HEL- mice were injected s.c. with 1×10⁶ tumor cells followed by i.p. anti-CD40 on days 3 and 6. Tumor growth was measured, and serum was collected at the time of death to measure antibody isotypes. A. Kaplan-Meier survival analysis. Mice were euthanized when tumors reached 100mm² or at the termination of the experiment on day 24 after tumor cell inoculation. Black line: anti-CD40 antibody treated Rag2^−/− SW_HEL+ mice (n = 19), red line: CD40 antibody treated Rag2^−/− SW_HEL- mice (n = 17), with arrows indicating days of anti-CD40 dosing. Purple line: Rag2^−/− SW_HEL- mice not treated with CD40 antibody. B. Individual tumor growth curves. Left: Rag2^−/− SW_HEL+ mice (n = 19). Right: Rag2^−/− SW_HEL- mice (n = 17). C. Serum antibody isotypes. MFI of CBA signals for each isotype before tumor challenge (naive) and on day of death (CD40 activated) (mean±SEM, n = 10/group). ** = P < 0.01, *** = P < 0.001, **** = P < 0.0001 by unpaired Student's t test.