Identification and functional characterization of dendritic cells in the healthy murine kidney and in experimental glomerulonephritis

The kidney tubulointerstitium contains numerous bone marrow-derived antigen-presenting cells, which are often referred to as resident tissue macrophages, although several previous studies had demonstrated characteristics of dendritic cells (DC). In this study, we describe a subset of tubulointerstitial cells expressing the DC marker CDl 1c. A protocol was established to isolate these cells for in vitro analysis. Renal CD l 1c(+) cells resembled splenic DC, but not peritoneal macrophages, in morphology, lysosomal content, phagocytic activity,microbicidal effector functions, expression of T cell costimulatory molecules, and ability to activate T cells. Nevertheless, many CD l 1c(+) renal cells expre sed low or intermediate levels of F4/80 and CDI lb, indicatin that both markers are not absolutely specific for inacrophages in the kidney. Subpopulations of renal DC could be distinguished based on their expression of MHC class II and costimulatory molecules and may represent different maturation stages. In nephrotoxic glomerulonephritis, increased numbers of CDl 1c(+) cells showing DC functionality were found in the tubulointerstitiurn. Focal accumulation was seen within tubulointerstitial rnononuclear infiltrates and ad,jacent to, but not within, inflamed glorneruli. These results are the first to identify and characterize renal CDl 1c(+) cells as DC and to demonstrate marked changes in experimental glomerulonephritis.