Increased expression of the novel molecule OX-2 is involved in prolongation of murine renal allograft survival.
BACKGROUND
Portal venous (p.v.) peritransplant immunization with dendritic cells from bone marrow cultures, along with cyclosporine (10 mg/kg), produces antigen-specific increased renal allograft survival compared with recipients receiving intravenous (i.v.) immunization. Increased survival is associated with altered cytokine production from recipient T cells restimulated with donor antigen. We used a suppressive subtractive hybridization approach to explore a role in the regulation of transplant rejection for other genes differentially expressed after p.v. immunization.


METHODS
Subtractive hybridization was performed using tissue from p.v. and i.v. immunized mice and a novel polymerase chain reaction-based approach. A gene-bank search was used to identify the source of the differentially expressed cDNAs. One product, the mouse homologue of rat OX-2, was further analyzed using Western gels and FACS analysis of dendritic cells (NLDC145+) isolated from p.v.-immunized mice.


RESULTS
Eighty cDNA clones were obtained by suppressive subtractive hybridization. Differential expression was confirmed in Northern RNA blots. One clone showed sequence homology to a gene encoding a molecule on rat dendritic cells (MRC OX-2), with homology to genes encoding the costimulatory molecules CD80 (B7-1) and CD86 (B7-2). In p.v.-immunized mice, a monoclonal antibody to the rat OX-2 molecule identified, by Western blot analysis, increased expression of a molecule with molecular weight (43 kDa) analogous to rat MRC-OX-2; labels (by FACS analysis) indentified increased numbers of a population of cells staining with NLDC145; and blocks indentified increased graft survival.


CONCLUSIONS
Our data suggest that OX-2 is functionally important in the increased graft survival seen in p.v.-immunized mice receiving renal allografts.
Gorczynski
R M
RM
The Toronto Hospital, Department of Surgery and Immunology, University of Toronto, Ontario, Canada.
Chen
Z
Z
Fu
X M
XM
Zeng
H
H
D000818:Animals; D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000954:Antigens, Surface / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics*; D001483:Base Sequence; D001854:Bone Marrow Cells / Q000166:cytology / Q000276:immunology; D003001:Cloning, Molecular; D016207:Cytokines / Q000096:biosynthesis; D017931:DNA Primers; D018076:DNA, Complementary; D003713:Dendritic Cells / Q000276:immunology* / Q000637:transplantation*; D006085:Graft Survival / Q000276:immunology*; D006801:Humans; D007165:Immunosuppression Therapy / Q000379:methods; D017403:In Situ Hybridization; D007519:Isoantigens / Q000276:immunology; D016030:Kidney Transplantation / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000096:biosynthesis; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011169:Portal Vein / Q000276:immunology*; D051381:Rats; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D013601:T-Lymphocytes / Q000276:immunology; D013997:Time Factors; D014184:Transplantation, Homologous
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000954:Antigens, Surface; D016207:Cytokines; D017931:DNA Primers; D018076:DNA, Complementary; D007519:Isoantigens; D008562:Membrane Glycoproteins; C042739:antigens, CD200