Donor-specific blood transfusion inhibits the allograft response: possible regulation by nitric oxide and...

We investigated the effective mechanisms of donor-specific blood transfusion (DST) using a sponge matrix allograft animal model. Sponges were harvested on various days postgrafting, and both the sponge infiltrating cells and sponge exudate fluid (SEF) were collected. DST completely suppressed cytotoxic T lymphocyte activity throughout the postgrafting period. SEF *N = O concentration (measured as nitrite) in DST mice was significantly lower than in ST mice. Conversely, the amount of PGE2 in the SEF from DST mice was higher than in ST mice. L)ST may induce intragraft suppressor factors (such as PCE2), resulting in reduced immune activation with suppression of local immune response.