Monoclonal antibodies (MABs) directed against cerebrovascular endothelial cells (EC) isolated from SJL/J mice were produced and characterized. A panel of MABs demonstrating strong reactivity (immuno-fluorescence staining) to SJL/J cerebrovascular EC was selected for further study. The cell specificity of antibodies (both IgG and IgM) was determined by assessing binding (immunofluorescence microscopy, FACS analysis and ELISA) to a variety of cell types. These included: cerebral vascular EC isolated from SJL/LJ, Balb/c and PL/J mice and Lewis rats; murine EC derived from other anatomic locations (i.e., kidney tubules and aortas); human umbilical vein EC; and other cell types located in the CNS (i.e., oligodendrocytes, astrocytes and microglia). One particular antibody (JIO) only reacted with SJL/J cerebral vascular EC. Several other antibodies which also reacted with these cells demonstrated varying levels of reactivity to some of the other EC utilized in these studies. None of the antibodies reacted with other cell types found in the central nervous system. Treatment of mice with J10 or other MABs had no effect on the clinical course of experimental allergic encephalomyelitis (EAE) induced by passive transfer system. Neither the severity nor the day of onset were significantly different between treated and control animals.