Leukocyte-derived interleukin-1β interacts with renal interleukin-1 receptor I to promote renal tumor necrosis factor and glomerular injury in murine crescentic glomerulonephritis

The involvement of proinflammatory cytokines interleukin (IL)-1 and tumor necrosis factor (TNF) in crescentic glomerulonephritis (GN) is well established. Recently the requirement of intrinsic renal cell participation via their production of TNF in crescentic GN was demonstrated. The current studies address the relative contributions of leukocyte and intrinsic renal cell-derived IL-1β in the induction of TNF production and glomerular injury by studying bone marrow chimeric mice. Leukocyte-derived IL-1β was critical in the development of crescentic renal injury because IL-1β ^-/-→WT (absent leukocyte IL-1β) chimeric mice had significantly attenuated TNF expression and were protected from the development of crescentic GN. In contrast, WT→IL-1β^-/- chimeric mice (intact leukocyte but absent renal IL-1β) developed similar TNF expression and crescentic GN to wild-type mice. To determine the cellular target for IL-1 in this model, IL-RI chimeric mice were studied. IL-1RI^-/-→WT chimeric (absent leukocyte IL-1RI expression) mice showed no attenuation of crescentic GN, whereas in the absence of renal IL-1RI (WT→IL-1RI ^-/- chimeras), glomerular TNF expression and the development of crescentic GN were significantly decreased. These studies demonstrate that leukocytes are the major cellular source of IL-1β, and that IL-1β acts principally via the IL-1RI on intrinsic renal cells to induce TNF expression and crescentic glomerular injury.