Monoclonal antibodies raised against Lewy bodies in brains from subjects with Parkinson's disease.

Monoclonal antibodies which immunocytochemically label Lewy bodies on sections of substantia nigra from subjects with Parkinson's disease were produced by immunization of mice with substantia nigra and locus coeruleus containing Lewy bodies from parkinsonian subjects post-mortem. Tests of specificity indicate that the antibodies do not recognize the same antigen. One of the antibodies (G7) immunocytochemically labels only Lewy bodies, the other (G9) also faintly labels the cell bodies of nigral dopaminergic neurons and cerebellar Purkinje cells in both normal and parkinsonian brains. Absorption experiments show, however, that the G7 antigen is present in normal substantia nigra and the G9 antigen in normal substantia nigra and Purkinje cells. Neither of the antibodies seems to be directed against neurofilament protein. Immunoblots after two-directional electrophoresis indicate that antibody G7 labels a protein with an iso-electric point around 5.6 and a mol. wt. of approximately 40 kdalton, whereas the protein labeled by antibody G9 has an iso-electric point of near 8 and a mol. wt. above 70 kdalton.