muramidase and Tuberculoma

The 5' region of the human lysozyme gene from -3500 to +25 was fused to a chloramphenicol acetyltransferase (CAT) reporter gene and three transgenic founder mice were obtained. All three transgenic lines showed the same pattern of CAT enzyme expression in adult mouse tissues that was consistent with the targeting of elicited, activated macrophages in tissues and developing and elicited granulocytes. In normal mice high CAT enzyme activity was found in the spleen, lung, and thymus, tissues rich in phagocytically active cells, but not in many other tissues, such as the gut and muscle, which contain resident macrophages. Cultured resident peritoneal macrophages and cells elicited 18 hr (granulocytes) and 4 days (macrophages) after injection of sterile thioglycollate broth expressed CAT activity. Bacillus Calmette-Guérin infection of transgenic mice resulted in CAT enzyme expression in the liver, which contained macrophage-rich granulomas, whereas the liver of uninfected mice did not have any detectable CAT enzyme activity. Although the Paneth cells of the small intestine in both human and mouse produce lysozyme, the CAT gene, under the control of the human lysozyme promoter, was not expressed in the mouse small intestine. These results indicate that the human lysozyme promoter region may be used to direct expression of genes to activated mouse myeloid cells.

Topics: Animals; Chloramphenicol O-Acetyltransferase; Gene Expression Regulation; Genes, Reporter; Granulocytes; Humans; Intestine, Small; Macrophage Activation; Macrophages, Peritoneal; Mice; Mice, Transgenic; Muramidase; Mycobacterium bovis; Organ Specificity; Promoter Regions, Genetic; Recombinant Fusion Proteins; Transcription, Genetic; Tuberculoma; Tuberculosis, Hepatic; Tumor Cells, Cultured

Focally aggregated epithelioid cells and granulomatous epithelioid cell reactions of different genesis were investigated immunohistochemically by means of PAP method according to Sternberger. We studied the presence of histiocytic markers lysozyme and alpha 1-antichymotrypsin, the content of albumin and of immunoglobulins and the question of immunophagocytosis and the presence of fibronectin. Various forms of activation of epithelioid cells as well as histiocytes and Langhans giant cells were found thereby. In the former, a phagocytosis could never be demonstrated, whereas this was true in histiocytes and giant cells. Fibronectin was not found in epithelioid cells. The findings suggest that epithelioid cells are a specific form of reaction of histiocytic elements. Thus they are a special reaction of MPS in a multiple causal genesis and a morphogenesis according to its own characteristics within a hypersensitivity reaction of a delayed type. Epithelioid cells modulate the immune response and in this way the tissue reaction.

Topics: Albumins; alpha 1-Antichymotrypsin; Fibronectins; Granuloma; Humans; Immunoenzyme Techniques; Immunoglobulins; Immunohistochemistry; Lymph Nodes; Lymphoma; Muramidase; Phagocytes; Phagocytosis; Sarcoidosis; Tuberculoma; Tuberculosis, Lymph Node

The importance of immunologic factors in the local defense against myobacterial disease derives from different mechanisms of action. These may be characterized as follows: mycobacteria act as antigens or antigenic fragments to cause local sensitization, activation, and proliferation of T-lymphocytes leading to the formation of giant cells of Langhans' type. Antibodies play a role only as opsonines and are not directly responsible for the destruction of the invading organisms. Lymphokines on the other hand activate connective tissue cells and thereby contribute to the walling of infection and the development of scar tissue.

Topics: Antibody Formation; Antigens, Bacterial; Humans; Immunity, Cellular; Immunoglobulins; Lung; Lymphokines; Macrophage Activation; Muramidase; Mycobacterium tuberculosis; Phagocytosis; Tuberculoma; Tuberculosis, Pulmonary

To evaluate extracellular hydrolytic enzymes in an in vivo system, plastic chambers were glued over rabbit dermal BCG lesions in various stages of development, after the central epithelium was removed with a scalpel. They were filled with tissue culture medium and left in place 2 days. The following enzymes in the fluid were assayed: collagenase (an enzyme secreted but not stored in macrophages); lysozyme (both secreted and stored); DNase and RNase (released on cell death and possibly regurgitated but not secreted); and, as a control, lactic dehydrogenase (released only on cell death). Tissue sections were prepared and studied histologically for the type of cell infiltrate, for beta-galactosidase (our marker enzyme for macrophage activation), and for necrosis. At 11 and 18 days of age the BCG lesions were largest and the number of activated macrophages in the chamber beds was highest. At this time the levels of the five enzymes assayed in the chamber fluids reached their peaks, tuberculin hypersensitivity was well developed, and the bacilli components would still be plentiful. In general, the chamber fluids from 11- and 18-day BCG lesions contained higher enzyme levels than chamber fluids from tuberculin reactions. Active collagenase was only detected in fluids from such BCG lesions. Evidently, the serum in the chamber fluids was sufficient to inhibit the lower amounts of collagenase probably released from smaller BCG lesions and tuberculin reactions (and from the 2-week polystyrene lesions that were also evaluated). These studies demonstrate that in chronic inflammatory reactions, both acid-acting and neutral-acting hydrolytic enzymes are released extracellularly. Tissue components would be hydrolyzed locally wherever the acid-acting hydrolytic enzymes encounter a drop in pH and wherever the concentration of neutral-acting hydrolytic enzymes exceeds the concentration of their inhibitors.

Topics: Animals; Deoxyribonucleases; Extracellular Space; Female; Hydrolases; Macrophages; Male; Microbial Collagenase; Muramidase; Phagocytosis; Rabbits; Ribonucleases; Tuberculin Test; Tuberculoma

Compared to cells from normal rabbit lungs, BCG-induced alveolar macrophages have a marked increase in hydrolase levels and the number of large electron-dense subcellular structures. This study was performed to investigate the possibility that these electron-dense structures were responsible for the increased hydrolase levels of these cells. Using sucrose gradient centrifugation, nuclei-free homogenates of normal and BCG-induced macrophages were analyzed with respect to the subcellular particles they contain. Gradient fractions were assayed for enzymes commonly associated with lysosomes as well as the mitochondrial cytochrome oxidase. Fractions of peak hydrolase activity from the BCG-induced preparations were consistently more dense than those from the normal cell preparations. Ultrastructural studies of the particulate material found in fractions of peak hydrolase activity from BCG-induced preparations revealed the presence of electron-dense, often dumbbell-shaped, granules. The data suggest that these peculiar granules are responsible for the elevated hydrolase levels of BCG-induced alveolar macrophages.

Topics: Acid Phosphatase; Animals; BCG Vaccine; Centrifugation, Density Gradient; Cytoplasmic Granules; Electron Transport Complex IV; Glucuronidase; Hydrolases; Macrophages; Microscopy, Electron; Muramidase; Proteins; Pulmonary Alveoli; Rabbits; Spectrophotometry; Tuberculoma

Topics: Humans; Lung; Muramidase; Neoplasms; Tuberculoma; Tuberculosis; Tuberculosis, Pulmonary