MONOCLONAL-ANTIBODIES TO HUMAN INTERMEDIATE FILAMENT PROTEINS .2. DISTRIBUTION OF FILAMENT PROTEINS IN NORMAL HUMAN-TISSUES

Abstract

Monoclonal antibodies generated against different human intermediate filament (IF) proteins were assayed on fixed, embedded tissue by the biotin-avidin-immunoperoxidase method for evaluation of the tissue specificity of these antibodies. An antibody (43.beta.E8) made to fibroblast IF protein stains mesenchymal tissue such as endothelium, histiocytes, stromal fibroblasts and Schwann cells, but does not stain epithelium, skeletal muscle, lymphocytes or neurons. Three different anti-cytokeratin antibodies decorate epithelium in 3 unique patterns. One (35.beta.H11) stains all nonsquamous epithelium but fails to recognize squamous epithelium. Antibody 34.beta.E12 stains the full thickness of squamous epithelium and ductular epithelium but does not react with hepatocytes, pancreatic acinar cells, proximal renal tubules or endometrial glands. Antibody 34.beta.B4 stains only the suprabasal portion of squamous epithelium. None of these 3 anti-cytokeratin antibodies reacts with nerve or mesenchymal tissue. Two anti-neurofilament antibodies recognize only neurons, failing to react with epithelial or mesenchymal tissue. These anti-intermediate filament antibodies apparently can be used as tissue-specific markers. Neoplasms retain the same intermediate filament patterns as the normal parental tissue; therefore, these antibodies can be used as diagnostic aids in surgical pathology.