human monoclonal antibody Fab reactive to oxidized LDL and carbamylated LDL recognizes human and mouse atherosclerotic lesions.

Abstract

This study was undertaken to produce a Fab fragment of a human monoclonal antibody reactive to oxidized and carbamylated low-density lipoprotein (oxLDL and cLDL) using phage display technology. An analysis of DNA sequences of this Fab, termed plaque 15,16-46 Fab, revealed that the rearranged VH was highly mutated. Complementarity-determining regions of the VH showed a very high R/S ratio and contained many positively charged amino acids. In direct binding and competitive ELISA, the Fab reacted strongly with both MDA-LDL and Cu-oxLDL forms of oxLDL, and also showed high affinity for cLDL. Immunofluorescence and immunohistochemical analyses showed that this Fab positively stained atherosclerotic aortic plaques in ApoE−/− mice as well as those in patients with atherosclerosis. The Fab also showed positive staining in placental decidua from patients with preeclampsia. It is suggested that the plaque 15,16-46 Fab against oxLDL and cLDL might possibly be applicable for developing a diagnostic reagent for both human and rodent animal research to detect and characterize atherosclerotic disease progression in atherosclerotic lesions as well as exploring the pathogenesis of atherogenic diseases such as preeclampsia.