Portal de Periódicos da CAPES

Distribution of endocytosed molecules to intracellular acidic environments correlates with immunotoxin activity

1990; Wiley; Volume: 46; Issue: 6 Linguagem: Inglês

10.1002/ijc.2910460628

1097-0215

Roberto Chignola, Marco Colombatti, Lorena Dell'Arciprete, C. Candiani, Giuseppe Tridente,

Microbial Inactivation Methods

We have investigated the internalization to low pH intracellular compartments of transferrin (Tfn), diphtheria toxin (DT) and of anti-cell surface antibodies (MAb) by a cytofluorometric assay based on low pH quenching of fluorescein (FITC) emission. FITC-labelled Tfn, anti-CD3, anti-CD5 and anti-Thy 1.2 MAb internalization resulted in a progressively lower FITC quenching effect. Following internalization, a distinction could be made between molecules that enter low pH compartments without undergoing intracellular degradation (e.g., Tfn, anti-CD3 MAb) and molecules that are internalized through low pH organelles and are then degraded within the cell (e.g., DT). A strict correlation was observed between quenching of internalized FITC-protein fluorescent emission and the cytotoxic activity of DT-based immunotoxins (IT).