title: Oral and portal venous tolerance in the interferon-gamma knockout (GKO) mouse.
abstract: BACKGROUND
  The role of the proinflammatory cytokine interferon-gamma (IFN-gamma) in the development of oral or portal venous tolerance is poorly defined. By using knockout mice for IFN-gamma (GKO mice), we investigated the effect of both oral and portal venous administration of alloantigen on the systemic delayed type hypersensitivity (DTH) response to alloantigen rechallenge.
  
  
  METHODS
  C57BL/6 (B6) control and GKO mice (also on a B6 background) were given either saline or BALB/c spleen cells (25 million) by oral gavage (PO) or by injection into the portal vein (PV) on day 0. The injection of 10 million BALB/c spleen cells subcutaneously into the dorsal flanks was performed after 7 days followed by footpad injection of 10 million BALB/c spleen cells on day 14. Specific footpad swelling was measured 24 h later using a micrometer. Splenocyte responsiveness was measured by in vitro mixed lymphocyte culture and cytotoxic T lymphocyte assay. Cytokine production of interleukin (IL)-2, IL-4, IL-10, and IFN-gamma was measured by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  Although B6 mice given PO or PV saline demonstrated a DTH response of 0.47 +/- 0.04 mm and 0.49 +/- 0.05 mm, respectively, in GKO mice, a greater DTH response of 0.72 +/- 0.08 mm and 0.75 +/- 0.05 mm was measured after either PO or PV saline (P < 0.05, P < 0.05, respectively). In vitro MLC and CTL confirmed the heightened DTH response to BALB/c observed in GKO versus B6. Despite this heightened response in control GKO mice, the DTH response was completely suppressed in both GKO and B6 mice, after both PO and PV BALB/c feedings (P < 0.001, P < 0.001, respectively, in both GKO and B6 mice). The unchanged brisk response to third-party C3H/HeJ demonstrated antigenic specificity.
  
  
  CONCLUSIONS
  Although DTH responsiveness to alloantigen is increased in the absence of IFN-gamma, both oral and portal venous alloantigen-specific tolerance can still be established in GKO mice similar to that in control B6 mice. The achievement of a tolerogenic immune response by both oral and portal venous routes indicates that lack of IFN-gamma does not preclude the induction of tolerance in this murine model.
authors.affiliation: Department of Surgery, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
authors.forename: Julie A
authors.initials: JA
authors.lastname: Margenthaler
authors.forename: Masaaki
authors.initials: M
authors.lastname: Kataoka
authors.forename: Wayne M
authors.initials: WM
authors.lastname: Flye
mesh_terms: D000284:Administration, Oral; D019264:Adoptive Transfer; D000818:Animals; D017951:Antigen Presentation / Q000276:immunology; D016207:Cytokines / Q000378:metabolism; D007108:Immune Tolerance; D007275:Injections, Intravenous; D007371:Interferon-gamma / Q000235:genetics*; D007519:Isoantigens / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D023421:Models, Animal; D011169:Portal Vein; D013154:Spleen / Q000166:cytology; D018417:Th1 Cells / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology*
chemical_list: D016207:Cytokines; D007519:Isoantigens; D007371:Interferon-gamma