IDENTIFICATION OF PEPTIDES SPECIFIC FOR CEREBROSPINAL-FLUID ANTIBODIES IN MULTIPLE-SCLEROSIS BY USING PHAGE LIBRARIES

The study of the origin and pathogenetic relevance of the oligoclonal antibodies present in the cerebrospinal fluid (CSF) of multiple sclero sis (MS) patients has been hampered by a lack of specific ligands. We recently reported a general strategy, based on phage-displayed random peptide libraries, to identify ligands for disease-specific antibodies even in the absence of any information on the nature of the pathologi c antigen, With this procedure, we identified several peptides specifi cally recognized by antibodies present in the CSF of MS patients, Usin g these peptides as reagents, we demonstrated that they mimic differen t natural epitopes and react with antibodies enriched in the CSF of MS patients. Antibodies recognizing the selected peptides are commonly f ound with equal frequency in the sera of MS patients and of normal ind ividuals. In contrast, the repertoire of CSF antibodies appears to be individual-specific and is probably the result of a nonspecific immuno dysregulation rather than a stereotyped response to a single antigen/a gent.