Mechanism found behind drug-free acceptance of t...( the inflammation u...),Health

For each of the donor-recipient pairs in the study, the scientists extracted antigen from the donor's blood, added it to cells taken from the patient and injected the combination into the footpad or ear of a SCID mouse -- a mouse which lacked functional T and B immune cells.

Ordinarily, (and for the vast majority of transplant recipients), the footpad would have shown swelling -- evidence of a response by the patient's cells against the donor antigen. But for these three unusual cases, the footpads did not swell up.

The natural conclusion would be that the patients' cells had not reacted to the antigen of their respective donors. A non-response, in fact, would be quite expected, since each of the three patients had accepted their grafts.

However, based on what they had learned from mice studies, the researchers suspected that this was a simplistic -- and incorrect - explanation. It didn't explain, for instance, why the presence of the donor antigen prevented the cells from showing a DTH reaction to tetanus toxoid (TT) - a test antigen that normally elicits a response. "We figured that the donor antigen was triggering some sort of a reaction that muffled the normal DTH response," VanBuskirk said.

To unmask what they believed was an anti-inflammatory response working against the natural inflammatory reaction, the researchers blocked c
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Contact: Anne M. VanBuskirk
Vanbuskirk.1@osu.edu
614-292-6774
Ohio State University
9-Sep-2000