Inflamed site-specific delivery of bone marrow-derived cells carrying IL-1Ra

A gene delivery system using bone marrow-derived CD11b(+) CD18(+) cells and their interaction with adhesion molecules was established. After transplantation into mice, these vehicle cells may be recruited into glomeruli upon lipopolysaccharide (LPS) treatment, and the number of recruited cells corresponds to the expression of intercellular adhesion molecule-1 (ICAM-1) in glomeruli. Using this system, interleukin-1 receptor antagonist (IL-1Ra) was delivered into animal models of glomerulonephritis evoked by antiglomerular basement membrane antibody (anti-GBM nephritis). Urinary albumin excretion and the serum creatinine level were significantly elevated after anti-GBM antibody injection in mock-treated mice, whereas they were suppressed in the IL-1Ra-treated mice. Histological analysis revealed that glomerular injuries were also suppressed in IL-1Ra-treated mice. We further confirmed that specificity for inflamed glomeruli was significantly enhanced by a combination of the Cre/loxP system with the IL-1beta promoter. These data suggested that our novel system may be used as a therapeutic intervention for glomerulonephritis.