GRAFT-INFILTRATING CELLS IN RATS RECEIVING ORTHOTOPIC SEMIALLOGENEIC SMALL-INTESTINE TRANSPLANTATION WITH PORTAL OR SYSTEMIC VENOUS DRAINAGE

The effect of alterations in venous drainage, from either ivc to porta l vein (pv), along with peritransplant systemic (ivc) or portal (pv) v enous alloimmunization with irradiated semiallogeneic cells, on cell s ubset recovery in lymphoid organs of Lewis rats re receiving orthotopi c small bowel allografts (from Lewis x Brown Norway) F-1, LBNF(1)) was examined, Combined portal, venous drainage and alloimmunization has b een reported to increase graft/recipient survival in this model, FAGS analysis using monoclonal antibodies specific for different lymphocyte subsets was performed on cell suspensions of peripheral (P) and mesen teric (M) lymph node (LN), small bowel intraepithelial lymphocytes (SB IEL), and Peyer's patch (PP) lymphocytes on days 2 and 8 posttransplan tation, Donor cell contributions to these cellular analyses were estim ated by comparison of FAGS staining with polyclonal anti-Lewis or Lewi s anti-LBNF(1) antibodies, Control animals received syngeneic grafts, In both syngeneic and semi-allogeneic transplants with pv or ivc drain age there was no consistent difference in cell subsets from in PLN com pared with those of control nongrafted rats, Approximately 50% to 60% of these cells were alpha beta TcR(+) with a CD4+/CD8+ ratio of 3-4:1 and a (CD4(+) + CD8(+))/alpha beta TcR(+) ratio of 1:1, Some 5% to 12% ED3(+) cells were also present, In IEL, PIILN, and PP by contrast, th ere were significant differences in cells recovered from rats with ivc vs, pv drainage of grafts, The most striking changes reflected a decr eased CD4+/CD8+ and alpha beta TcR+/gamma delta TcR+ cells in these ti ssues in rats predestined to show prolongation of allograft survival l ive vs, pv injected IEL CD4+/CD8+ ratios and alpha beta TcR+/gamma del ta TcR+ ratios were 1.0, 0.7 and 5.0, 1.0, respectively, These data ar e consistent with a proposed role for such gamma delta TcR+ cells in t he local regulation of graft rejection.