Lysozyme-positive Macrophages Research Articles

MLKL deficiency elevates testosterone production in male mice independently of necroptotic functions

Mixed lineage kinase domain-like (MLKL) is a pseudokinase, best known for its role as the terminal effector of the necroptotic cell death pathway. MLKL-mediated necroptosis has long been linked to various age-related pathologies including neurodegeneration, atherosclerosis and male reproductive decline, however many of these attributions remain controversial. Here, we investigated the role of MLKL and necroptosis in the adult mouse testis: an organ divided into sperm-producing seminiferous tubules and the surrounding testosterone-producing interstitium. We find that sperm-producing cells within seminiferous tubules lack expression of key necroptotic mediators and thus are resistant to a pro-necroptotic challenge. By comparison, coordinated expression of the necroptotic pathway occurs in the testicular interstitium, rendering cells within this compartment, especially the lysozyme-positive macrophages, vulnerable to necroptotic cell death. We also uncover a non-necroptotic role for MLKL in regulating testosterone levels. Thus, MLKL serves two roles in the mouse testes – one involving the canonical response of macrophages to necroptotic insult, and the other a non-canonical function in male reproductive hormone control.

Pathological and immunohistochemical study of gastrointestinal lesions in dolphins stranded in the Canary Islands

This paper describes the gross, histopathological and immunohistochemical characteristics of gastrointestinal lesions and regional lymph nodes of six common dolphins (Delphinus delphis), 11 striped dolphins (Stenella coeruleoalba) and six Atlantic...

Novel Application of ProteinChip Technology Exploring Acute Rejection Markers of Rat Small Bowel Transplantation

Because no biomarker that reflects small bowel allograft rejection is available, we applied surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) to develop noninvasive markers required for routine diagnosis. Heterotopic small bowel transplantation (SBT) was performed in rats, and they were divided into four experimental groups: sham-operated rats (sham), syngeneic transplants (syngeneic), allogeneic transplants (allogeneic), allogeneic transplants received FK506 (allo+FK). Plasma samples were analyzed with SELDI ProteinChip arrays to detect peaks that predominated in the allogeneic model. Possible biomarkers were identified in combination with SELDI retentate chromatography mass spectrometry (RCMS) and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). The identified protein was further analyzed by immunohistochemistry. An increase in the level of a 14.8-kDa protein, identified as lysozyme, was observed specifically in the plasma of the allogeneic group; the levels of this protein remained unchanged in the plasma of the other groups. On the other hand, the levels of a 10.1-kDa and a 13.0-kDa protein, identified as migration inhibitory factor-related proteins (MRP), MRP-8 and MRP-14, respectively, began to increase from an early stage of acute rejection. We also observed that lysozyme-positive macrophages had strongly infiltrated the lamina propria during acute rejection. We identified three plasma proteins-MRP-8, MRP-14, and lysozyme-that increased during small bowel allograft rejection. The identified proteins appeared to be markers for inflammation associated with allograft rejection. This proteomic approach will be useful for the identification of candidate biomarkers.

Immunohistochemical Analysis of Macrophages and Myofibroblasts Appearing in Hepatic and Renal Fibrosis of Dogs

Some peptide growth factors produced by macrophages play a role in fibrosis following tissue injury, through the induction of myofibroblasts. In the present study, the appearance of macrophages and myofibroblast development in hepatic and renal fibrosis was determined by immunohistochemical analysis of tissue from 15 dogs. The hepatic and renal fibrosis was classified as grade I, II or III, depending on the extent (percentage) of fibrotic areas per unit area measured by morphometry with Azan-stained sections. The presence of α-smooth muscle actin-immunolabelled myofibroblasts was directly related to advancing grade of both hepatic and renal fibrosis. Lysozyme-immunolabelled macrophages also increased in number with increasing grade of hepatic and renal fibrosis. These findings indicate that myofibroblasts and lysozyme-positive macrophages may contribute to progressive fibrosis in canine liver and kidney disease. Interestingly, the number of macrophages recognized by AM-3K, a newly generated monoclonal antibody capable of labelling exuded macrophages and resident tissue macrophages in dogs, fell significantly in grades II and III of renal fibrosis. By contrast, in hepatic fibrosis there were no marked differences in the number of AM-3K-positive macrophages between grades. These findings suggest that there are functional differences between lysozyme- and AM-3K-positive macrophages.

Cellular and humoral immune responses in atrophic lymphocytic pancreatitis in German shepherd dogs and rough-coated collies

The most common cause for the clinical signs of exocrine pancreatic insufficiency (EPI) in dogs is pancreatic acinar atrophy (PAA). In the subclinical phase of EPI, before total atrophy occurs, exocrine pancreas is affected by infiltrative lymphocytic inflammation, which gradually leads to selective destruction and atrophy of the acinar tissue. Here, we analyzed the role of cell-mediated and humoral immune mechanisms in the pathogenesis of atrophic lymphocytic pancreatitis in German shepherd dogs and rough-coated collies. Pancreas biopsies and serum samples were obtained from 12 dogs with subclinical EPI (SEPI), 13 dogs with clinical EPI and 13 healthy control dogs. Immunohistochemical analysis showed that, in the subclinical phase, the majority of the infiltrating lymphocytes were T-cells with an almost equal number of CD4+ ‘T-helper’ and CD8+ ‘cytotoxic’ T-lymphocytes. The distribution of the two lymphocyte subsets was different. Typically, the CD4+ cells were present in large cellular infiltrates in the affected parenchyma, and the scattered CD8+ cells had infiltrated both the affected and the normal parenchyma. In sections where destruction of acinar parenchyma was present, the CD8+ T-cells were predominant. In cases of marked T-cell infiltration, CD79+ B-lymphocytes and plasma cells, and lysozyme-positive macrophages were also detected. Lymphoid follicle germinal centers with a majority of cells staining positively for CD79 were found. The lymphocytic infiltration in the totally atrophic tissue of dogs with clinical EPI was less prominent. Indirect immunofluorescence staining showed serum antibodies reacting weakly with pancreatic acinar cells in five out of nine dogs with subclinical and three out of 10 dogs with clinical EPI, but not in the control dogs. The results suggest that the tissue destruction is largely T-cell-mediated, although the presence of numerous B-lymphocytes and pancreas-specific antibodies in the sera of some dogs indicate that humoral mechanisms are also involved. In conclusion, this study suggests that the atrophic lymphocytic pancreatitis in German shepherds and rough-coated collies is an autoimmune disease.

Porcine circovirus induces B lymphocyte depletion in pigs with wasting disease syndrome.

To disclose the mechanism of cellular injury following porcine circovirus (PCV) infection, 12 pigs were examined by the terminal deoxynucleotidyl transferase-mediated dUTP-nick end labeling (TUNEL) method and immunohistochemistry. Histologically, the lymphoid tissues were characterized by marked apoptosis of lymphocytes, lymphocyte depletion, and macrophages and giant cells containing numerous inclusion bodies with or without apoptotic bodies. Immunohistochemically, there were many lysozyme-positive macrophages in the lymphoid follicles, while the number of CD79a-positive B lymphocytes was scanty. Apoptotic cells, which were proved to be TUNEL positive, revealed CD79a positivity. Although detectable mainly in the cytoplasm of macrophages, PCV antigens were found also in the nuclei of macrophages and apoptotic lymphocytes. Ultrastructurally, the presence of PCV virions was confirmed in apoptotic bodies phagocytosed by macrophages. These findings suggested that lymphocyte depletion with apoptotic death of B lymphocytes was caused by PCV, and that some of the inclusion bodies were phagolysosomes derived from the apoptosis. Thus, PCV may trigger the development of wasting disease syndrome by producing an immunocompromised state in pigs.

Local host response in the lower respiratory tract in nephropathia epidemica.

Various lines of evidence suggest a respiratory route of transmission of nephropathia epidemica (NE). To study the response of the respiratory tract in NE, fiberoptic bronchoscopy with bronchoalveolar lavage (BAL) was performed in 5 patients in the acute phase of the disease. Compared to a reference group of 15 healthy individuals, BAL fluid of NE patients contained significantly higher total numbers of cells (p < 0.05) and significantly higher numbers of lysozyme-positive macrophages (p < 0.01), CD8+ T cells (p < 0.01), and natural killer (NK) cells (p < 0.01). There was no significant difference in numbers of CD4+ T cells, B cells, or neutrophils. When blood samples of 16 patients were examined at various intervals after onset of NE, a significant decrease in the number of NK cells (p < 0.01) was found in the acute phase of the disease. The findings are compatible with the presence of a local host response in the lower respiratory tract to NE virus infection.

The cellular infiltrate in the liver of patients with fulminant hepatitis: analysis of paraffin-embedded tissue sections.

Intrahepatic infiltrate from 18 patients who died of fulminant hepatitis, was analyzed by an immunohistochemical method using formalin-fixed, paraffin-embedded liver sections and monoclonal antibodies. Inflammatory cells were characteristically located in the portal and periportal areas adjoining resting hepatocytes, but were infrequently found in the perivenular areas where hemorrhagic hepatocyte necrosis predominated. In the inflammatory infiltrate, T cells were the most predominant cell type, composing about two-thirds of the total hepatic infiltrate, followed by lysozyme-positive macrophages which composed about one-third of the total hepatic infiltrate, irrespective of the etiology of the fulminant hepatitis. On the other hand, B cells made up less than 2% in all cases, and plasma cells were also few, less than 2% in 12 of 18 cases. Furthermore, an enhanced display of beta 2-microglobulin on hepatocyte membranes was demonstrated in all cases with remaining hepatocytes, indicating an increased expression of class I MHC antigens on these cells. These results suggest that T cells may play an important role in the pathogenesis of the portal and periportal lesions of fulminant hepatitis, probably with a help of MHC class I antigens on hepatocytes, while hemorrhagic necrosis of hepatocytes around the central veins may be caused by a different mechanism, most likely a circulatory disturbance secondary to cell-mediated immune reactions in the periportal areas.

Necrotizing lymphadenitis--a clinico-pathologic study of 36 cases with immunohistochemical analysis

Thirty-six cases of necrotizing lymphadenitis--including 33 cases of unknown etiology, 1 typhoid lymphadenopathy, and 2 cases of suspicious lupus lymphadenopathy--were clinico-pathologically reviewed and analyzed with immunostaining for s-100 and lysozyme. All cases histologically showed architectural effacement by paracortical lesions composed of nuclear karyorrhexis and mononuclear cell proliferation. Immunohistochemical study revealed proliferation of lysozyme-positive macrophages in the necrotizing areas and an increase in the number of s-100-positive cells in the uninvolved paracortical areas. This observation suggests that necrotizing lymphadenitis may be a common morphologic expression of a T cell-mediated hyperimmune condition induced by diverse etiologies.

Bronchoalveolar mastocytosis and lymphocytosis after nitrogen dioxide exposure in man: a time-kinetic study

The combination of environmental chamber exposure and bronchoalveolar lavage (BAL) was used to study the time-course of the cell response in the human lung to nitrogen dioxide (NO2). Healthy subjects were exposed for 20 min to 7 mg NO2.m-3 (4 ppm), a concentration which occurs indoors in industries and is below the peak exposure limit for work places in most countries, 10 mg.m-3 (5.5 ppm). BAL was performed in all subjects several weeks before exposure and 4, 8, 24 and 72 h after exposure, in eight subjects at each time. Mastocytosis and lymphocytosis were found in BAL fluid 4-24 h after exposure, with normalization after 72 h. A mild increase in lysozyme positive macrophages was found 24-72 h after exposure. The time-course of the human pulmonary cell response to NO2, demonstrated in BAL fluid, represents a new and previously not reported finding after exposure to this common air pollutant. Our findings are diverging from results obtained in animal studies, using approximately the same NO2 concentrations, indicating that the results from the animal studies may not be transferable to man.

Cell Response in Bronchoalveolar Lavage Fluid after Exposure to Sulfur Dioxide: A Time-Response Study

Bronchoalveolar lavage (BAL) has been performed in 22 healthy nonsmoking male volunteers after exposure to 8 ppm SO2 (20 mg/m3). The exposure level exceeds the US Short-Term Exposure Limit (STEL) of 5 ppm, but occurs as peak exposures in industrial indoor environments. Exposures were made during light work on a bicycle ergometer in an environmental exposure chamber for 20 min. BAL was performed 2 wk or more before exposure and 4, 8, 24, and 72 h after exposure in eight subjects at each time interval. Four hours after exposure significant increases were found in the numbers of lysozyme-positive macrophages, lymphocytes, and mast cells (p less than 0.02 to 0.05). Lymphocytes, lysozyme-positive macrophages, total count of alveolar macrophages, and total cell number increased to peak values 24 h after exposure (p less than 0.02 to 0.05). Seventy-two hours after exposure the cell numbers and distribution had returned to normal. The time course of the cell reactions found in BAL fluid after controlled SO2 exposure represents a new and previously not reported response to a noxious gas.

Immunohistochemical demonstration of histiocytes in normal ectocervical epithelium and epithelial lesions of the uterine cervix

The numbers of Langerhans cells and lysozyme-positive macrophages were assessed quantitatively in normal ectocervical epithelium, cervical intraepithelial neoplasia (CIN), microinvasive squamous cell carcinoma (MICA), clinical invasive squamous cell carcinoma (CICA), and koilocytotic atypia using the avidin-biotin-peroxidase complex (ABC) method. The distribution of Langerhans cells was different from that of lysozyme-positive macrophages in that the former were intermingled with the cervical lesion, while the latter were present mainly surrounding the cervical lesion and/or on the edge of the cervical lesion. The numbers of Langerhans cells and lysozyme-positive macrophages in CIN were significantly larger than those in normal ectocervical epithelium and significantly smaller than those in invasive squamous cell carcinoma (MICA + CICA). Langerhans cell number significantly increased as the grade of CIN advanced. In contrast, the number of lysozyme-positive macrophages did not differ significantly between progressive grades of CIN. As for koilocytotic atypia, the numbers of Langerhans cells and lysozyme-positive macrophages in koilocytotic atypia were significantly greater than those in normal ectocervical epithelium but did not differ significantly from those in CIN 1 and CIN 2. With respect to stromal lymphoid infiltration, invasive squamous cell carcinoma with moderate or dense stromal lymphoid infiltration showed significantly greater numbers of Langerhans cells and lysozyme-positive macrophages than that with no or scattered stromal lymphoid infiltration, but such a correlation was not found in CIN.

Cell response in bronchoalveolar lavage fluid after sulfur dioxide exposure.

Environmental chamber exposure and bronchoalveolar lavage (BAL) were used to study the dose-response relationship between short-term exposure to sulfur dioxide (SO2) and inflammatory reactions in the human lung as reflected in BAL fluid. Healthy subjects were exposed to 10, 13, 20, or 30 mg/m3 for 20 min. BAL was performed several weeks preexposure and 24 h postexposure. Mast cells, lymphocytes, lysozyme positive macrophages, and the total number of macrophages were significantly increased after SO2 exposure. A dose-dependent increase in the cell response in BAL fluid was observed after exposure to 10-20 mg/m3, but no further increase was detected after 30 mg/m3. Inflammatory cell response was found in BAL fluid at SO2 levels that occur in industrial indoor environments worldwide, and cell response to SO2 was also seen below the short-term exposure limit of Sweden and many other countries (13 mg/m3).

Is the short term limit value for sulphur dioxide exposure safe? Effects of controlled chamber exposure investigated with bronchoalveolar lavage.

Bronchoalveolar lavage (BAL) which has not previously been used in investigating the effect of sulphur dioxide (SO2) on the human lung was performed on 12 subjects before and after controlled chamber exposure with SO2 for 20 minutes. BAL fluid 24 hours after exposure with 10 mg SO2/m3 (4 ppm, 10 subjects) showed increased alveolar macrophage activity as judged by an increase in lysozyme positive macrophages. Twenty four hours after 20 mg/m3 (4 subjects) a further increase was seen, which was accompanied by an increase in total numbers of macrophages and lymphocytes. Seventy two hours after exposure (4 subjects) cell numbers had virtually returned to pre-exposure levels. These previously uninvestigated reactions indicate potentially noxious effects of SO2 in the lungs at exposure levels that are regarded as relatively safe.

S-100 protein-positive dendritic cells in colorectal adenocarcinomas. Distribution and relation to the clinical prognosis.

Dendritic cells (DC) in 121 colorectal adenocarcinomas were investigated immunohistochemically, using anti-S-100 protein antibody. S-100(+)DC were recognized among the malignant cells and/or around the tumor and differed in distribution either from lysozyme-positive macrophages or from neuron-specific enolase-positive neural tissue. Patients with many S-100(+)DC (more than 30 cells per 10 high-power fields) in the tumor survived longer than did those with few such cells (less than 30 cells), most often with no metastases (P less than 0.001). The grade of S-100(+)DC infiltration was related to both density of lymphocytic infiltration in the primary tumor and the degree of paracortical hyperplasia in the regional lymph nodes (P less than 0.05). Dendritic cells, therefore, as antigen-presenting cells, conceivably mediate cell immunity in a tumor with lymphoid infiltration and in the regional lymph nodes. The number of S-100(+) DC in the primary colorectal carcinomas represents one aspect of such a series of antitumor immunoreaction, in vivo.

Langerhans cells and prognosis in patients with gastric carcinoma.

Infiltration of Langerhans cells (LC) and macrophages into tumor tissues was investigated using immunohistochemical methods, anti-S-100 protein and anti-lysozyme antibodies in 174 cases of gastric carcinoma. Varying population densities of S-100-positive LC were noted in tumor tissues; lysozyme-positive macrophages, however, were found in almost equal quantities. LC were mainly interspersed among the tumor cells, whereas macrophages were present in the stroma and around the necrotic foci. Although the survival time of patients with Stage I, II or IV gastric carcinoma did not relate to the density of LC, survival time in Stage III patients correlated well with the density of LC. In patients with a marked infiltration of LC, survival time was longer than in cases of only a slight infiltration (P less than 0.001). Therefore, LC in immunological defense mechanisms of the host against the tumor may be clinically effective in a certain phase of tumor development.

Mast cells and lysozyme positive macrophages in bronchoalveolar lavage from patients with sarcoidosis. Valuable prognostic and activity marking parameters of disease?

In the deteriorating group of sarcoidosis patients, progress towards pulmonary fibrosis is a major problem. In order to benefit from corticosteroids, it is important for the treatment to start early. We studied a group of 45 patients with sarcoidosis. Most of them were newly detected patients and none were under or had currently received corticosteroid therapy. The patients were followed for at least six months. We found that increased amounts of polymorphonuclear neutrophils (PMN) or lysozyme-positive macrophages (Lys+MF) and mast cells (MC) in bronchoalveolar lavage (BAL) could implicate a bad prognosis.

Heterogeneity of Histiocytes in Primary Lung Cancer Stained with Anti-S100 Protein, Lysozyme and OKT 6 Antibodies

The heterogeneity of histiocytes in primary lung cancer was investigated by immunohistochemical methods using anti-S100 protein and anti-lysozyme antibodies on paraffin sections and OKT-6 monoclonal antibody on frozen sections. T-zone histiocytes (Langerhans cells and their precursors stained by anti-S100 protein and/or OKT-6 monoclonal antibodies) heavily infiltrated tumor tissues and regional lymph nodes in cases of moderately or well-differentiated adenocarcinoma, especially in areas of papillary growth or bronchiolo-alveolar pattern. These cells were interspersed amongst tumor cells showing dendritic figures and were occasionally present in squamous cell carcinoma. However, they were seldom found in other histological types, particularly in small cell carcinoma and carcinoid tumor. The distribution of these cells was different from that of lysozyme-positive macrophages. In this connection, T-zone histiocytes were thought to have a different immunological function from that of the monocyte-macrophage series against lung cancer. The closely similar reactivity of T-zone histiocytes with anti-S100 protein and OKT-6 monoclonal antibodies indicated that these two markers can be employed for paraffin and frozen sections, respectively.

Macrophages in human tumours: An immunohistochemical study

Forty-five human malignant tumours and three benign lesions were stained histochemically for non-specific esterase (NSE) and acid phosphatase (AP), and immunohistochemically for lysozyme. Most of the tumours contained small numbers of lysozyme positive macrophages (LPM), but colonic tumours showed moderate numbers of LPM around the edge of the lesions. Gastric and secondary duodenal tumours (n = 3) contained moderate numbers of intralesional LPM in addition. Most squamous and all mesenchymal tumours contained no lysozyme positive macrophages. The usefulness of the three staining methods was assessed and it was concluded that lysozyme was specific but detected only part of the macrophage population. Neutrophil polymorphs were also stained but could be recognised by nuclear morphology. AP and NSE detected more cells but stained tumour cells as well as macrophages, making these methods of limited use in tumours showing invasion of the stroma by single cells or small groups of cells.