Figure 6. Effect of naive B cells in a lung metastasis model.

A. Rag2^−/− mice that did or did not express the SW_HEL BCR (termed SW_HEL+ and SW_HEL-) were injected i.v. with 1×10⁶ B16.mHELMCC tumor cells. Left: Representative photos of lungs from the two groups. Right: Number of metastases on day 21. Each dot represents an individual animal, with the bar representing mean±SEM (Rag2^−/− SW_HEL+: n = 20, Rag2^−/− SW_HEL-: n = 17). Data are pooled from 2 independent experiments. ns = not significant by unpaired Student's t test B. Representative dot plots depicting serum antibody isotype CBA data from Rag2^−/− SW_HEL+ mice (black) overlaid on control CBA plot (grey). Sera were collected at the time of death. Left plot: naïve (prior to tumor challenge) SW_HEL+ mouse. Right plot: SW_HEL+ mouse after i.v. tumor challenge (time of death: Day 21). C. Serum antibody isotype analysis. MFI of CBA signals for each isotype before tumor challenge and on day of death, mean±SEM, n≥7/group. Data are from a single experiment. All isotypes not significantly different by unpaired Student's t test.