H. Harada et al., Abortive alloantigen presentation by donor dendritic cells leads to donor-specific tolerance: a study with a preoperative CTLA4Ig inoculation, UROL RES, 28(1), 2000, pp. 69-74
Donor dendritic cells (DCs) within allografts initiate the induction of an
allospecific T cell response, while an abortive alloantigen presentation by
DCs may induce allospecific unresponsiveness. We thus investigated the tol
erogenic effect of donor DCs that were made incompetent in alloantigen pres
entation by treatment of CTLA4Ig. When we treated rats with donor DCs (2 x
10(6)/rat i.v.) on the preoperative day, nine rejected allografts in an acc
elerated manner (5.0 +/- 2.2 vs. 8.2 +/- 1.6 days in the control group). Pr
eoperative inoculation of DCs pulsed with CTLA4Ig, a procedure which suppre
sses an allogeneic mixed lymphocyte reaction (MLR), also provoked an accele
rated rejection (5.6 +/- 1.7 days). When DCs and CTLA4Ig (500 mu g/rat i.p.
on days -9, -7 and -5) were concomitantly inoculated, allograft survival w
as significantly prolonged (>38.7 +/- 40.0 days); a preoperative CTLA4Ig in
oculation alone failed to do so (7.5 +/- 1.2 days). Long-term graft survivo
rs tolerated skin grafts from the donor but not from those from a third par
ty. These results indicate that abortive alloantigen presentation by donor
DCs, upon which an accessory signal pathway is suppressed by CTLA4Ig, leads
to prolonged graft survival and donor-specific tolerance.