Kinetics of the plasmacellular reaction in the draining lymph node of mice bearing the BP-8 fibrosarcoma.

The kinetics of the plasmacellular response in the draining lymph node was quantitatively assessed in specific-pathogen-free C3H/He mice grafted S.C. with the syngeneic BP-8 fibrosarcoma. The percentage of plasma cells was estimated on dissociated, cytocentrifuged, and fixed cell preparations by immunoenzymatic staining with either of two B-cell-specific antibody markers. Mice either grafted with liver tumor or given a single implant of tumor homogenate gave a maximal plasma cell response of about 4%. However, this peak was reached at 14 days in the live grafts and at 7 days in the homogenate situations. Moreover, in animals grafted with live tumor an elevated 3% plateau persisted until death, wheras in homogenate-implanted animals a sharp drop to a 0.5% plateau was observed at about Day 20. Homogenate-treated animals displayed a significant enhancement of tumor growth when challenged with a live graft 7 days after homogenate implantation, i.e., during the peak 4% plasmacellular response. Mice given a single implant of X-irradiated (3500 R) tumor responded with a peak of 1.7% plasma cells at 7 days. Despite subsequent boosting with the same material (Days 14 and 21), this value declined and remained at a plateau of about 0.2% until death. Contrary to homogenate-treated mice, these animals were immune to subsequent challenge with a live tumor graft. In the present host-tumor system, there appears to be an inverse relationship between elevated numbers of plasma cells and antitumor immunity.