Immunohistochemical study of the expression of human groEL-stress protein in human nervous tissue.

ABSTRACT

Monoclonal antibody (ML-30) directed against 65 kDa stress protein of mycobacteria, is shown to identify human cellular protein homologous with the groEL heat shock protein in many prokaryotes. Immunohistochemical survey of nervous tissue, both central and peripheral, from patients dying of various inflammatory, degenerative and neoplastic conditions and from experimental animals, using this antibody showed punctate granular staining of the cells to a variable degree. The astrocytes showed strong immunolabelling. The normal neurons and oligodendroglia stained variably, while abnormal neurons were darkly labelled. Ependymal cells showed apical granular positivity. The ubiquitinated inclusion bodies in amyotrophic lateral sclerosis, Alzheimer's disease and Parkinson's disease were not recognised by the ML-30 antibody. In diseased and stressed nervous tissue from experimental animals, the expression of the ML-30 recognisable stress protein was variable. The epitope recognised by ML-30 was found stable in postmortem tissues collected up to 36 h after death and processed for paraffin sectioning, after fixation in formalin for many years. Enhanced expression of the human groEL stress protein homologue in mammalian nervous tissue following various forms of stress may play a role in modulating the extent of tissue damage by autoimmune mechanism because of its high immunogenic nature and constitutive presence in the cells.