Suppressive influence of surgical stress on the graft-versus-host reaction in mice.

The influence of surgical stress on the local graft-versus-host reaction (GVHR) in F1 mice was studied. Skin incision 1 day prior to injection of parental spleen cells produced impairment of popliteal lymph node enlargement; however, this effect was not observed when GVHR was induced 3 and 5 days after operation. Strong GVHR suppressive activity of spleen cells was observed three hours after leg amputation before a decrease in thymus weight became evident. The GVHR suppressive activity declined by six hours later, but a second peak of 60% inhibition was observed after 24 h. This suppressive activity completely disappeared by treatment with anti-Thy 1.2 and complement. This shows that the GVHR is suppressed by surgical stress, and that this suppression is due to suppressor T lymphocytes.