CYTOKINE-INDUCED NEUTROPHIL CHEMOATTRACTANT MEDIATES NEUTROPHIL INFLUX IN IMMUNE-COMPLEX GLOMERULONEPHRITIS IN RAT

Chemokines are a family of cytokines whose participation in inflammation in vivo remains to be established. Using the rat model of anti-glomerular basement membrane (GBM) nephritis, we found that mRNA for the chemokine CINC (cytokine-induced neutrophil chemoattractant) was induced in the kidney, and the corresponding protein was elaborated by isolated inflamed glomeruli. Production of CINC by glomeruli was unaffected by complement- or leukocyte-depletion prior to disease induction. Cytokines which induce CINC expression in renal cells (TNF-alpha and IL-1 beta) were also expressed in the kidney during glomerular inflammation. TNF-alpha production, unlike CINC, was complement and leukocyte dependent. In vivo administration of anti-CINC, but not anti-human IL-8, IgG selectively attenuated the influx of PMNs into the glomerulus and commensurately diminished proteinuria. The participation of CINC was not tissue-specific: anti-CINC IgG also diminished the influx of PMNs in dermal immune complex inflammation. In sum, we propose that glomerular immune complex deposition/complement activation leads to cytokine production which results in CINC expression by endogenous glomerular cells. The CINC produced plays a contributory role in the influx of PMNs into the glomerulus in the context of the activation of other inflammatory mediators. These results suggest a potential role for CINC homologues, IL-8 and the GRO family of chemokines, in human immune complex-mediated disease.