In vivo induction of CD80+ and CD86+ lung B cells in response to MADB106 tumor. B cells were purified from the lungs 18 h following tumor injection. We determined the percentage of B cells that expressed MHC II, CD80 and CD86 co-stimulatory surface molecules. The data shown were analyzed by analysis of variance (ANOVA). Data is expressed as the mean ± S.E. (n = 3). Asterisks indicate statistical differences (P less than or equal to 0.001) between rats receiving tumor or PBS sham injection.