title: In vitro analysis of gadolinium chloride abrogation of the systemic tolerance induced by portal venous administration of ultraviolet B-irradiated donor cells.
abstract: BACKGROUND
  Normally, a Buffalo (BUF) recipient (RT1b) rejects a heterotopically transplanted Lewis (LEW) heart (RT1l) drained into the portal vein (PV) within 14 days. However, the addition of PV administration of 25x10(6) ultraviolet B (UVB)-treated LEW spleen cells (SC) to BUF recipients 7 days before cardiac transplantation results in 70% long-term allograft survival.
  
  
  METHODS
  In this study, we used gadolinium chloride (GdCl3) (7 mg/kg/day) to selectively block the phagocytosis of recipient hepatic Kupffer cells before PV injection of UVB-treated donor SC to examine the mechanism of tolerance induction, as measured by in vitro analysis of mixed lymphocyte culture (MLC), T cell cytotoxicity, T helper cell precursors (pTH), and cytotoxic T cell precursors (pCTL) by limiting dilution analysis.
  
  
  RESULTS
  A BUF recipient that received untreated or gamma-irradiated LEW SC intraportally reacted to in vitro stimulation by LEW alloantigen with increased MLC proliferation, T cell cytotoxicity, pTH and pCTL frequencies, and interleukin-2 production. In contrast, SC from BUF that received UVB-treated LEW SC were hyporesponsive on MLC stimulation by donor LEW alloantigen and exhibited markedly reduced cytotoxicity, pTH and pCTL frequency, and interleukin-2 production. However, normal in vitro responsiveness resulted with stimulation by third-party Brown-Norway (RT1n) SC, thus indicating that the systemic hyporesponsiveness was specific for the UVB donor alloantigen given PV. On the other hand, GdCl3 given by intravenous injection daily for 3 days before PV alloantigen blocked the induction of in vitro hyporesponsiveness.
  
  
  CONCLUSIONS
  Therefore, prevention of alloantigen sequestration by GdCl3 inhibition of hepatic Kupffer cell phagocytosis was pivotal in preventing the development of portal venous tolerance.
authors.affiliation: Department of Surgery, Washington University School of Medicine, St. Louis , Missouri 63110, USA.
authors.forename: S
authors.initials: S
authors.lastname: Yu
authors.forename: Y
authors.initials: Y
authors.lastname: Nakafusa
authors.forename: M W
authors.initials: MW
authors.lastname: Flye
mesh_terms: D000818:Animals; D002469:Cell Separation; D005682:Gadolinium / Q000494:pharmacology*; D016027:Heart Transplantation / Q000276:immunology*; D007108:Immune Tolerance / Q000187:drug effects; D007165:Immunosuppression Therapy / Q000379:methods; D007376:Interleukin-2 / Q000096:biosynthesis; D007728:Kupffer Cells / Q000276:immunology; D008099:Liver / Q000276:immunology; D008102:Liver Circulation; D007959:Lymphocyte Culture Test, Mixed; D051381:Rats; D011914:Rats, Inbred BN; D011915:Rats, Inbred BUF; D011917:Rats, Inbred Lew; D013154:Spleen / Q000166:cytology / Q000276:immunology* / Q000528:radiation effects
chemical_list: D007376:Interleukin-2; D005682:Gadolinium; C038958:gadolinium chloride