Subcellular Localization of Antigens by Immune And Cytochemical Techniques in Electron Microscopy. Mitochondria, a Site of Vaccinia Protein

摘要

The intracellular distribution of the following cellular antigens was studied by the immunouranium technique: Fibrinogen in blood platelets, lysozyme in monocytic leukemic blood, and vaccinia antigen in infected HeLa cells. The results of this study suggest the following conclusions. (1) Platelets store fibrinogen. The nature of this association is unclear but implies that the platelet is an alternate source or at least a transporter of fibrinogen in circulating plasma. (2) Monocytes in leukemic blood contain lysozyme within lysosome-like granules in the cytoplasm. This finding implicates the neoplastic monocyte as the source of the elevated levels of urinary and serum lysozyme found in patients with monocytic leukemia. (3) Protein synthesis in mitochondrial fractions of vaccinia-infected HeLa cells was found to be greater than in uninfected cells and increased as infection progressed. Those mitochondria found to be specific for vaccinia protein are probably sites of virus-induced protein synthesis. These findings may help to explain how some DNA mammalian viruses, such as vaccinia, can replicate in the cytoplasm of mammalian cells without the apparent participation of the host cell nucleus. (Author)