T-cell response to factor VIII for hemophilia A/B7-1^−/− and hemophilia A/B7-2^−/−mice.

Spleen cells were obtained 3 days after the fifth intravenous injection of human factor VIII. Pooled spleen cells from 3 mice were used to establish the proliferation data. The open and closed squares are for cells from untreated hemophilia A/B7-1^−/− and B7-2^−/−mice. Five intravenous injections of factor VIII were given to hemophilia A/B7-1^−/−mice (○) and hemophilia A/B7-2^−/−mice (•). The concentration of factor VIII in the cultures is indicated on the horizontal axis.