The role of bacterial lipopolysaccharide in the production of the lupus B cell phenotype

The purpose of this study was to determine the effect of bacterial lipopolysaccharide (LPS) on the expression of RP105 (CD180) in human B lymphocytes from normal, leukemic, and lupus patients. The percentage of cells that express RP105 on their surface increased following a 24 hour exposure to LPS. However, continued exposure for a total of four days resulted in a marked decrease in the expression of this receptor molecule. Human B cells were purified by a combination of density gradient and negative magnetic bead selection and maintained in culture with and without LPS. Enzyme linked immunoassay for the detection of anti-dsDNA antibodies following LPS treatment of isolated B cells was negative. The percentage of RP105 positive or negative B cells from lupus patients could not be accurately determined because too few B cells were available from these lymphopenic patients following negative selection.