Cell-Specific Polymorphism of Acid Phosphatase in Human Blood Cells: Their Functional and Leukemic Variants

Abstract

The observation that the cytochemical patterns of certain enzymes represent a stable marker for the identification of blood cells and resist functional stimuli as well as malignant transformation prompted the study of cell-specific polymorphism of acid phosphatase (EC 3.1.3.2) in human blood cells. Normal and leukemic human T and B lymphocytes as well as normal and leukemic blood monocytes and human alveolar macrophages as a functional derivative of blood monocytes were separated and subjected to purity control. Lysosomes collected after cell cavitation were solubilized, and the particle-free supernatant was subjected to a direct assay of acid phosphatase using p-nitrophenylphosphate. Aliquot samples were analyzed by thin-layer isoelectric focusing, and the banding of the acid phosphatase was recorded on gels using naphthol AS-BI phosphate after having demonstrated that on a quantitative term a positive correlation exists between the results with both substrates. The banding patterns proved to be highly cell specific as far as blood cells were concerned. The cell specificity of the acid phosphatase polymorphism defied functional and neoplastic transformation, allowing for a clear recognition and classification of the individual cell lines. The cell-specific polymorphism of lysosomal enzymes seems to bear the potentiality of a further biochemical cell marker as exemplified by the results obtained with acid phosphatase.