Strong Cytoplasmic Reactivity Research Articles

Characterization by Monoclonal Antibody of a Highly Conserved Antigenic Determinant Expressed on Human Platelet Membranes and Intermediate Filament Type III

The murine monoclonal antibody (MoAb) CB21, raised after immunization with sonicated extracts of human platelets, has been shown to react with a line-restricted surface molecule and also a cytoplasmic structure displaying no restriction in terms of lineage and species. The surface structure recognized by the CB21 MoAb is exclusively expressed on the surface membrane of human platelets, being undetectable on other cells or lines so far tested. After permeabilization, the majority of the cells and lines tested with the CB21 MoAb displayed strong cytoplasmic reactivity with a constant typical filamentous distribution. Biochemical and morphological analyses showed that the cytoplasmic counterpart recognized by the CB21 MoAb is the intermediate filament type III.

Immunocytochemical localization of lysozyme and alpha-1-antichymotrypsin in the term human placenta: an attempt to characterize the Hofbauer cell.

The intracellular localization of lysozyme (LSZ) and alpha-1-antichymotrypsin (A1Ac), glycoproteins associated with macrophages, was used to confirm the monocytic lineage of the Hofbauer cell and to assess the maturity of its macrophage function. The peroxidase-labeled antigen method was used to localize these proteins, as well as immunoglobulins, light chains, and albumin, in Bouin-fixed, paraffin-embedded sections of 24 normal term placentas. The demonstration of the latter substances was used as an indication of passive diffusion or phagocytosis of serum proteins resulting in intracellular localization unrelated to synthesis. In all the placentas examined a strong cytoplasmic reaction for A1Ac was seen in the Hofbauer cells. The same cells on adjacent sections did not stain for LSZ, while the occasional maternal macrophage and numerous polymorphonuclear leukocytes in the intervillous spaces gave a positive reaction. The detection of A1Ac supports the contention that these cells are macrophages, previously suggested by their phagocytic capability and the demonstration of Fc receptors and nonspecific esterases. Since they do not appear to contain LSZ, a bactericidal enzyme, we propose that these cells are not fully differentiated macrophages, and the lack of this enzyme may have some relevance to the pathogenesis of certain placental infections.

Localization of three inhibitors of cysteineproteinases in the human oral mucosa

3 known human cysteineproteinase inhibitors--neutral cysteineproteinase inhibitor (NCPI), acid cysteineproteinase inhibitor (ACPI) and serum alpha-cysteineproteinase inhibitor (alpha-CPI)--were localized immunohistochemically in the squamous epithelium of the mouth by using the peroxidase-antiperoxidase complex method and formaldehyde-fixed paraffin-embedded tissue sections. Neither ACPI nor NCPI was found in the 2 to 3 most basal cell layers of the epithelium, but a strong cytoplasmic reaction was seen in the upper cell layers by using either anti-ACPI or anti-NCPI serum. In some cells the most dense stain precipitate was seen around or in the nucleus, and in the highest cell layers the staining was sometimes associated with the cell membrane. alpha-CPI was localized mainly in the epithelial stroma and in the intercellular space of the epithelium.

Histochemical studies on the distribution of DPN and TPN diaphorases, ?-glucuronidase and some enzymes associated with the krebs cycle in trichomonas vaginalis

T. vaginalis contains a high activity for DPN and TPN diaphorases, most of which are localized in cytoplasmic granules which may be mitochondria, and which sometimes show a perinuclear concentration. Occasionally a weak to strong cytoplasmic reaction and some activity in other organelles has been observed, and possible reasons for such reactions have been offered. DPN diaphorase preparations revealed the possibility of cyclic metabolic activity involving nucleo-cytoplasmic relationships, in which the nucleolus appears to play an important role.

DISTRIBUTION AND PROPERTIES OF INTRACELLULAR ALKALINE PHOSPHATASES

1. Using the histochemical test for alkaline phosphatase reaction in the larval salivary glands of several species of Drosophila, activity was found to be present in three main parts of the cell; the cytoplasm, the nucleolus, and the chromosomes. 2. Phosphatase activity was found rather generally distributed in both the cytoplasm and the nucleus. Within the larval salivary gland chromosomes, the enzyme activity was localized in those chromosomal regions which are Feulgen positive, and thus corresponds to the regions containing large concentrations of desoxyribose nucleic acid. 3. Different naturally occurring phosphate bearing substances were used as phosphatase substrates on mouse tissues, and resulted in demonstration of three different types of phosphatase reactions based on the localization of the enzyme activity. a) A general reaction with phosphatase activity located in both nucleus (nucleolus and chromosomes) and the cytoplasm was present when sodium glycerophosphate and nucleotides were used as substrates. b) No phosphatase reaction occurred on polymerized desoxyribose nucleic acid, but a specific nuclear reaction (nucleolus and chromosomes) was present when nuclease-depolymerized desoxyribose nucleic acid was used as a substrate. c) A strong cytoplasmic reaction with slight reaction in the nucleus was present when ribose nucleic acid was used as a substrate. 4. Subjection to several environmental variables produced little further evidence as to the differences among these three types of localized reactions. 5. The three types of alkaline phosphatase reactions observed were suggested to be due to at least two phosphodiesterases and a phosphomonesterase. 6. The nuclear phosphatase complex and the cytoplasmic phosphatase complex each probably consist of a specific phosphodiesterase, which splits the ester linkage between the phosphate of one nucleotide and the sugar of the neighboring nucleotide, and a phosphomonesterase which splits the second ester linkage and liberates inorganic phosphate.