title: Cytokine expression, upregulation of intercellular adhesion molecule-1, and leukocyte infiltration in experimental tubulointerstitial nephritis.
abstract: BACKGROUND
  Cytokines are intercellular polypeptide messengers that mediate immune and inflammatory responses. The temporal profile of interleukin-1 beta (IL-1 beta), IL-6, tumor necrosis factor alpha (TNF-alpha), and monocyte chemotactic protein 1 (MCP-1) expression was examined in anti-tubular basement membrane (TBM) antibody-associated tubulointerstitial nephritis (TIN).
  
  
  METHODS
  TIN was induced by immunization of Brown Norway rats with bovine cortical TBM, whereas control rats received ovalbumin. Whole kidney RNA was assessed with the RNase protection assay 3, 7, 8, 9, 10, 12, and 14 days after immunization. Cytokine mRNA expression was correlated with TNF-alpha bioactivity, renal intercellular adhesion molecule-1 expression, and CD18-positive leukocyte infiltration by immunohistochemistry.
  
  
  RESULTS
  Increased IL-1 beta, TNF-alpha, and MCP-1 mRNA relative to glyceraldehyde-3-phosphate dehydrogenase appeared on day 7 when TIN involved 10 to 40% of the cortex, and peaked rapidly on day 8 when there was 60 to 80% cortical involvement (at which time 75 to 80% of the infiltrating cells were neutrophils). The increase in TNF-alpha mRNA correlated with increased bioactivity. The influx of mononuclear cells on day 8 was preceded by the expression of MCP-1 mRNA. The infiltrating leukocytes expressed the leukocyte beta 2-integrin (CD18) and were found in areas with increased intercellular adhesion molecule-1 expression. The mRNAs for IL-1 beta, TNF-alpha, and MCP-1 were undetectable by day 10 (at which time 95% of the infiltrating cells were mononuclear). An increase in IL-1 receptor antagonist mRNA paralleled those of IL-1 beta. The expression of IL-6 mRNA was similar to that for IL-1, except that it disappeared by day 9.
  
  
  CONCLUSIONS
  There is a temporal association in the expression of IL-1 beta, TNF alpha, MCP-1, and IL-6 with the upregulation of intercellular adhesion molecule-1 and leukocyte infiltration within the tubulointerstitium in anti-TBM antibody-associated TIN. The narrow window of time through which these cytokines are expressed and the coincidence of their peak expression on day 8 suggest complex cytokine interactions in the pathogenesis of anti-TBM antibody TIN.
authors.affiliation: Department of Immunology, Scripps Research Institute, La Jolla, California.
authors.forename: W W
authors.initials: WW
authors.lastname: Tang
authors.forename: L
authors.initials: L
authors.lastname: Feng
authors.forename: J C
authors.initials: JC
authors.lastname: Mathison
authors.forename: C B
authors.initials: CB
authors.lastname: Wilson
mesh_terms: D000818:Animals; D000906:Antibodies; D016375:Antisense Elements (Genetics); D001483:Base Sequence; D001485:Basement Membrane / Q000276:immunology; D002417:Cattle; D015815:Cell Adhesion Molecules / Q000096:biosynthesis*; D016207:Cytokines / Q000096:biosynthesis*; D017931:DNA Primers; D015870:Gene Expression; D005786:Gene Expression Regulation; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000032:analysis / Q000096:biosynthesis; D007114:Immunization; D018799:Intercellular Adhesion Molecule-1; D007375:Interleukin-1 / Q000096:biosynthesis; D007672:Kidney Cortex / Q000378:metabolism / Q000473:pathology; D007684:Kidney Tubules / Q000276:immunology*; D007962:Leukocytes / Q000378:metabolism / Q000473:pathology*; D008969:Molecular Sequence Data; D009395:Nephritis, Interstitial / Q000276:immunology / Q000378:metabolism* / Q000473:pathology*; D016133:Polymerase Chain Reaction; D015347:RNA Probes; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis* / Q000378:metabolism; D051381:Rats; D011914:Rats, Inbred BN; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D000906:Antibodies; D016375:Antisense Elements (Genetics); D015815:Cell Adhesion Molecules; D016207:Cytokines; D017931:DNA Primers; D007375:Interleukin-1; D015347:RNA Probes; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases