In vivo-mobilized kidney dendritic cells are functionally immature, subvert alloreactive T-cell responses, and prolong organ allograft survival.
BACKGROUND
Migratory antigen-presenting cells resident in kidneys may have tolerogenic potential. Difficulties inherent in their isolation have limited their characterization. The authors examined the phenotype and function of murine kidney dendritic cells (DC) mobilized in vivo by systemic administration of fms-like tyrosine 3 kinase ligand (Flt3L).


METHODS
Monoclonal antibody staining was used to characterize DC subsets in situ, immediately after their isolation, and after lipopolysaccharide stimulation. Cytokine and CC chemokine receptor (CCR) gene expression was analyzed by RNase protection assay. Mixed leukocyte reactions were performed to assess DC allostimulatory ability and also the function of putative T-regulatory cells. In vivo DC trafficking was monitored by fluorescence imaging of dye-labeled cells and the influence of renal DC on vascularized heart allograft survival was determined.


RESULTS
Flt3L induced a marked increase both in CD11cCD8alpha and in CD11cCD8alpha DC within the renal cortex and medulla. Rarer, CD11cB220 (precursor plasmacytoid) DC were also detected. Bulk freshly isolated DC exhibited no interleukin (IL)-12p35 mRNA, low surface co-stimulatory molecule expression, and CCR transcripts, consistent with immaturity. They elicited only weak allogeneic T-cell proliferative responses, and repeated stimulation induced CD4CD25 IL-10 T cells. In vivo, the freshly isolated DC failed to prime T cells of naive allogeneic hosts for anti-donor cytotoxic T-cell responses. When infused systemically, 1 week before organ transplantation, they prolonged graft survival without immunosuppressive therapy.


CONCLUSIONS
Hematopoietin-mobilized renal DC are functionally immature and exhibit tolerogenic potential. Mobilization of DC within kidneys is likely to affect their antigen-handling capacity, immunogenicity, and tolerogenic ability.
Coates
P Toby H
PT
Thomas E. Starzl Transplantation Institute and Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA.
Duncan
F Jason
FJ
Colvin
Bridget L
BL
Wang
Zhiliang
Z
Zahorchak
Alan F
AF
Shufesky
William J
WJ
Morelli
Adrian E
AE
Thomson
Angus W
AW
D000818:Animals; D002465:Cell Movement; D003713:Dendritic Cells / Q000502:physiology*; D006085:Graft Survival; D016130:Immunophenotyping; D018664:Interleukin-12 / Q000235:genetics; D053765:Interleukin-12 Subunit p35; D053762:Interleukin-12 Subunit p40; D007668:Kidney / Q000276:immunology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D008565:Membrane Proteins / Q000494:pharmacology; D051379:Mice; D008815:Mice, Inbred Strains; D021122:Protein Subunits / Q000235:genetics; D013601:T-Lymphocytes / Q000276:immunology*; D014158:Transcription, Genetic; D014184:Transplantation, Homologous
D053765:Interleukin-12 Subunit p35; D053762:Interleukin-12 Subunit p40; D008070:Lipopolysaccharides; D008565:Membrane Proteins; D021122:Protein Subunits; C084881:flt3 ligand protein; D018664:Interleukin-12