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C Sorg

Publications and source records attributed to C Sorg.

At least 163 records · Page 9Linked to original sources
PubMed1989

Immuno-competent cells in the murine epididymis.

Cryostat sections of epididymides from mice were stained with monoclonal antibodies against immuno-competent cells. This investigation was undertaken to gain basic data about the distribution of macrophages. T lymphocytes, MHC class II and MIF in the normal murine epididymis to establish the mouse as a model for immunological epididymal research. The most important findings were as follows. (1) Macrophages, T lymphocytes, MHC class II and MIF positive cells were distributed similarly in the caput, corpus and cauda epididymis. (2) Macrophages were the most frequent leucocytes and the majority were located in the peritubular layer. (3) The MHC class II determinant was also expressed mostly in the peritubular layer and interstitium. These cells were similar in appearance and location to macrophages. (4) Significantly fewer T lymphocytes were found and their main location was the interstitium. T-helper and T-suppressor/cytotoxic lymphocytes did not differ significantly in their regional or histological distribution patterns. (5) The ratio of T-helper to T-suppressor/cytotoxic lymphocytes was 1:1. (6) MIF was detected almost exclusively in blood vessels and the surrounding connective tissue. (7) No invasion of leucocytes into the epididymal lumen was observed. It is concluded that macrophages seem to be the most important immunological cell type in the murine epididymis.

Animals↗
PubMed1989

Phenotypic dynamics of macrophage subpopulations during human experimental gingivitis.

The purpose of the present study was to investigate whether functionally different macrophages are present in clinically healthy gingiva and during human experimental gingivitis. Eight male probands were introduced to an oral hygiene program until all reached mean Plaque and Gingival Index scores approaching zero. During the following 19 days all oral hygiene was abandoned. At d -14, 0, 2, 4, 7, 11 and 19 clinical indices and gingival biopsies were taken. Cryostat sections were incubated with monoclonal antibodies against mature macrophages (25F9), inflammatory macrophages (27E10) and anti-inflammatory macrophages (RM 3/1). Positive cells were counted in the inflammatory infiltrate (IF) and the connective tissue (CT). At d -14 elevated numbers of 27E10-positive cells were observed which decreased significantly at d 0 (p less than 0.018) and increased again at d 19 (p less than 0.026). Significant differences in the number of RM 3/1-positive cells were found between d 0 and d -14, 2, 4 and 7 (p less than 0.05) while no differences in the number of 25F9-positive cells were observed throughout this study. It was concluded that experimental gingival inflammation is characterized by the appearance and disappearance of functionally different macrophage subpopulations.

Adult↗
PubMed1989

Characterization and differential expression of an endothelial cell-specific surface antigen in continuous and sinusoidal endothelial, in skin vascular lesions and in vitro.

Continuous and sinusoidal endothelial cells display marked morphological and functional heterogeneity as to their plasmalemmal vesicle content, to the kind of intercellular junctional complexes, to the existence and kind of fenestrae and gaps, to the existence and character of their basement membrane, to their ability for phagocytosis and to other functional parameters. Monoclonal antibody 1F10, raised against human umbilical vein endothelial cells (HUVE cells), reflects these differences in recognizing--without any nonendothelial side reactions--an endothelial cell surface antigen, abundantly expressed in continuous endothelia, low and inconsistently expressed in liver sinusoidal and dermal lymphatic endothelia and absent from splenic sinusoidal endothelial cells. In differentiated skin vascular tumors, 1F10 antigen is expressed in normal amounts while it is only low and inconsistently expressed in the dedifferentiated endothelial cells of Kaposi's sarcoma and hemangiosarcoma. HUVE cells in culture, in contrast to their in situ ancestors, express variable amounts of 1F10 antigen. When endothelial cell-conditioned medium (ECC medium) is supplied to HUVE cells in culture, no 1F10 antigen is expressed, while supplementation with fresh serum-containing medium (FSC medium) or cytokines, such as bFGF, suffices to maintain 1F10 expression in 10-70% of the cells. From this we conclude that developmental regulation, environmental influences and cytokine supply contribute to the differentiation and maintenance of the 1F10+ and 1F10-endothelial cell phenotypes, both in vivo and in vitro.

Animals↗
PubMed1989

Phenotypic characterization of macrophages in human term placenta.

Immunohistological techniques have been used to study heterogeneity, frequency and distribution of macrophages and T lymphocytes in chorionic villous mesenchyme, stroma of the amniochorion and decidua of 36 human term placentas obtained at spontaneous normal delivery and by caesarean section, using a panel of monoclonal antibodies (mAb) specific for macrophage phenotypes appearing in acute early (mAb 27E10), late (mAb 25F9) and down-regulatory (mAb RM3/1) stages of inflammation. Significant numbers of macrophages were identified. It could be shown that RM3/1+ macrophage phenotypes which in vitro are strongly dexamethasone-inducible and in vivo appear in down-regulatory stages of inflammatory processes are the major cell population in human term placenta. Macrophages characterized by monoclonal antibodies 27E10 and 25F9, as well as CD4+ and CD8+ cells, were distributed sparsely or were completely absent. The finding of anti-inflammatory macrophage phenotypes to be the predominant mononuclear cell population in human term placenta provides support for a mechanism whereby placenta functions as an active immunosuppressive biological barrier between mother and fetus.

Female↗
PubMed1988

Immunolocalization of an angiogenic factor (HAF) in normal, inflammatory and tumor tissues.

The distribution of a novel human angiogenic factor (HAF) (Schulze Osthoff et al., 1987) has been investigated on various human cell lines, isolated blood cells as well as in normal, inflammatory and tumor tissues. Localization was performed by using the monoclonal antibody (MAb) 5F4 directed against HAF. It was found that 30% of freshly isolated human monocytes expressed the 5F4 antigen. The number of positive cells increased to 75-90% on day 4 to 7 upon culture and then decreased. Twenty percent of freshly isolated human lymphocytes also stained positively, whereas granulocytes and platelets were negative. In cryostat sections of normal human tissue (skin, lung, liver, spleen, placenta) 5F4 is positive with capillary endothelial cells and few macrophages. In inflammatory tissue derived from gingivitis and rheumatoid arthritis, more macrophages than in normal tissues and less endothelial cells were positive. In tumor tissues some endothelial cells and a subset of tumor-infiltrating macrophages expressed the antigen. Tumor cells were positive in advanced melanomas, but only occasionally in stomach carcinomas. We conclude that the angiogenic factor is produced mainly by a subset of inflammatory macrophages which appear to be the principal source of HAF in regenerating or growing tissues.

Adult↗
PubMed1988

Efficient inhibition of endogenous peroxidase without antigen denaturation in immunohistochemistry.

The immunoperoxidase technique is commonly used for the antigenic characterization of cells and tissues. However, the occurrence of endogenous peroxidase-positive cells frequently complicates such evaluations. In some instances it is impossible to distinguish between these cells and antibody-stained cells. Methods so far described for inhibiting the endogenous peroxidase, are not always satisfactory - either the endogenous peroxidase is not satisfactorily blocked, or the cellular antigens lose their reactivity. A new two-step method is described which involves transient inhibition of endogenous peroxidase by sodium azide and hydrogen peroxide and a final blocking of this enzyme by lowering the pH to 2.3, while antigens remain undamaged. This method may be of value in immunohistochemical studies of various tissues, especially inflammatory tissues which contain many endogenous peroxidase-positive cells.

Animals↗
PubMed1988

Inflammatory cell infiltrates in human melanoma at different stages of tumor progression.

Progression of human melanoma is associated with changes in antigenic phenotypes of tumor cells. To establish whether inflammatory infiltrates in progressing melanoma also change, we studied 146 cutaneous melanomas at different stages of progression. Monoclonal antibodies (MAbs) against lymphocyte and macrophage subpopulations, interleukin-2 receptor (IL-2 R), immune interferon (IFN-gamma), and the IFN-gamma-inducible, progression-associated melanoma antigens HLA-DR and gp89 were applied in situ. During the course of melanoma progression, decreased amounts of peritumoral T cells, IL-2 R-expressing lymphocytes and dermal T6+ dendritic cells were found, while increased numbers of intratumoral T cells, inflammatory (27E10+) and mature (25F9+) macrophages were associated with local progression of primary melanomas. In metastases, most infiltrate components except 25F9+ macrophages were rare. Positive correlations were observed between: (1) dermal T6+ cells and IL-2 R+ lymphocytes, and (2) presence of IFN-gamma in the infiltrate and HLA-DR and gp89 antigens on tumor cells. In all stages, HLA-DR expression on tumor cells was correlated with: (1) a shift towards T8+ lymphocytes in the infiltrates and (2) a loss of IL-2 R expression. Our data suggest mutual influences between melanoma cells and mononuclear cell infiltrates in situ.

HLA-DR Antigens↗
PubMed1988

Level of HLA antigens in locoregional metastases and clinical course of the disease in patients with melanoma.

Immunohistochemical staining with monoclonal antibodies showed marked variations in the percentage of melanoma cells stained by anti-HLA Class I and anti-HLA Class II monoclonal antibodies among 48 locoregional metastases removed from 39 patients with malignant melanoma. On the other hand there was limited variation in the percentage of melanoma cells stained by anti-HLA antibodies in autologous locoregional metastases removed from 8 of 9 patients. In the remaining patient marked differences were found in the percentage of melanoma cells stained by anti-HLA Class I antibodies in the two parts of the lymph node metastasis analyzed. Therefore this patient was not included in additional analyses to correlate the level of expression of HLA antigens with the clinical course of the disease. In all the lesions tested the percentage of melanoma cells stained by anti-HLA Class II antibodies was lower than or equal to but never higher than that stained by anti-HLA Class I antibodies. According to the level of expression of HLA Class I and Class II antigens the 38 patients could be divided into three groups: Pattern A included lesions with more than 50% of tumor cells stained by anti-HLA Class I antibodies (mean, 86.1; median, 85) and 50% or less by anti-HLA Class II antibodies (mean, 10.5; median, 5); Pattern B included lesions with 50% or less tumor cells stained by anti-HLA Class I antibodies (mean, 14.9; median, 5) and by anti-HLA Class II antibodies (mean, 4.1; median, 1); Pattern C included lesions with more than 50% tumor cells stained by anti-HLA Class I antibodies (mean, 88.8; median, 92) and by anti-HLA Class II antibodies (mean, 70.0; median, 70). The survival of 21 patients with Pattern A was significantly longer than those of 13 and 4 patients with Patterns B and C, respectively. No difference in the survival of patients in the latter two groups was found. These results suggest that HLA antigens play a role in the biology of melanoma and that analysis of the level of HLA antigens in locoregional metastases of patients with melanoma may provide clinically useful information.

Adult↗
PubMed1988

Two calcium-binding proteins associated with specific stages of myeloid cell differentiation are expressed by subsets of macrophages in inflammatory tissues.

Using a monoclonal antibody to macrophage migration inhibition factor (MIF), two proteins were isolated from supernatants of Concanavalin A-stimulated human peripheral blood mononuclear cells which seem to have complexed to a third component carrying the MIF activity. They are therefore designated MIF-related proteins or MRP-8 and MRP-14 according to their apparent molecular weights. Partial amino acid sequences have been determined and their cDNA have been cloned and expressed in Escherichia coli. Both are calcium-binding proteins and MRP-8 seems to be largely homologous to the cystic fibrosis antigen (Dorin et al., 1987). Antisera were raised in the rabbit against the recombinant proteins and their expression in cells and tissues studied using immunohistological techniques. The proteins are only found in blood granulocytes and monocytes. In culture the number of positive monocytes sharply increased and then declined with time, suggesting that their expression is associated with early stages of monocyte/macrophage differentiation and absent from resident macrophages in all tested tissues. In acute inflammatory reactions, e.g. gingivitis, MRP-8 is never seen in the tissue, whereas MRP-14 is expressed by intravascular monocytes and perivascular macrophages. In contrast, in chronic inflammation, e.g. rheumatoid arthritis, MRP-8 is also expressed by macrophages in the tissue. From this it is concluded that MRP-8 and MRP-14 are expressed sequentially at defined stages of monocyte/macrophage differentiation and that dysregulation of this process in chronic inflammation is mirrored by the presence of MRP-8-positive macrophages in the tissue.

Acute Disease↗
PubMed1988

Immunohistochemical demonstration of migration inhibitory factor (MIF) in experimental allergic contact dermatitis.

The kinetics of appearance of MIF+ cells was investigated in experimental contact dermatitis using a monoclonal antibody (7D10) against murine MIF which was reacted with cryostat sections of tissues and detected by the indirect immunoperoxidase test. Four groups of BALB/c mice were investigated: (1) sensitized with 2,4-dinitrofluorobenzene (DNFB); (2) unsensitized controls; (3) tolerized; (4) unsensitized. A challenge dose of DNFB was applied to the ear of animals of groups 1-3 and of croton oil to those of group 4. Three phases could be distinguished in group 1: (a) an initial vascular and exudative reaction; (b) an early cellular phase; and (c) a late cellular phase. At zero time rarely any T lymphocytes (Lyt 1+; Lyt 2+) were seen in all four groups. Within less than 30 min venous endothelial cells became strongly MIF+. This was followed by an influx of monocytes/macrophages reaching a maximum of 72 h in group 1 and a slight peak at 12 h in groups 2 and 3. At 16-24 h in all groups the endothelial reaction weakened while many 7D10+ macrophages appeared in group 1. By double-labelling it was shown that lymphocytes were 7D10-. The influx of lymphocytes, part of which carried the T cell receptor, began at 12 h, reaching a maximum at 72 h in group 1. In groups 2 and 3 only a weak lymphocytic infiltrate developed which declined at 24 h. Group 4 developed an inflammatory reaction after the initial phase with similar kinetics as in group 1. The data suggest that an immune inflammatory reaction is preceded by a nonspecific reaction of the vascular endothelium and the mononuclear phagocytic system and that MIF is playing a central role in these events.

Animals↗
PubMed1987

Purification and characterization of a novel human angiogenic factor (h-AF).

Serum-free supernatants of the human melanoma cell line A-375/2 contain an angiogenic activity as detected by the chorioallantois membrane assay which does not induce proliferation of cultured endothelial cells. This human angiogenic factor (h-AF) was purified by immunoaffinity chromatography as well as by conventional chromatographic procedures. A monoclonal antibody designated 5F4 was raised against h-AF, which binds but does not neutralize angiogenic activity. h-AF consists of a protein at MW 67 kD which focuses at pH 5.0. By biological and biochemical criteria it is shown that h-AF differs from other known growth factors.

Angiogenesis Inducing Agents↗
PubMed1987

Tumor progression in human malignant melanoma: five stages defined by their antigenic phenotypes.

The antigenic profile of melanocytic cells in the course of local and systemic tumor progression of human malignant melanoma was investigated by the reactivity of a panel of monoclonal antibodies (MAbs) in frozen sections of histologically defined melanocytic lesions. Specific antigenic phenotypes made it possible to distinguish 5 groups of lesions which could be ranked in relation to each other due to the sequential acquisition or loss of progression markers. On this basis, a scheme of antigenic changes which accompany the stepwise transformation of normal skin melanocytes into highly malignant metastatic melanoma cells is proposed. The steps of tumor progression identified solely by phenotyping with MAbs were in complete concordance with the concept of melanoma progression derived from histological, statistical and clinical analyses. Furthermore, our finding that the expression of gp89 as well as HLA-DR antigens can be induced by interferon-gamma in vitro provides evidence that immune interferon may play a role in the regulation of genes leading to phenotypic changes in progressing melanoma cells.

Animals↗
PubMed1987

Infiltration of primary and metastatic melanomas with macrophages of the 25F9-positive phenotype.

In order to gain insight into the role of macrophages in human melanoma, we studied fresh-frozen material from 15 dysplastic nevi, 199 primary melanomas, 107 melanoma metastases, and paraffin sections from 98 primary melanomas with the monoclonal antibody 25F9 which recognizes an 86 x 10(3) dalton protein present on a subset of mature human macrophages. Considerable infiltration of tumors with 25F9-positive macrophages was observed in 2 dysplastic nevi (13%), 87 primary melanomas (44%), and 45 metastases (42%). The degree of intratumoral macrophage infiltration correlated with expression of class II HLA-DR antigens on tumor cells, in primary melanoma with a tumor thickness above 0.75 mm, and with the occurrence of metastases within 2 years. In paraffin sections, intratumoral 25F9-positive macrophages also correlated with metastatic spread of primary tumors after longer follow-up. Metastases revealed a higher degree of macrophage infiltration following systemic or local immunotherapy, compared with untreated metastases, or metastases removed during chemotherapy. Of 38 patients who died within an observation period of 1 year, 19 (50%) had considerable infiltration of metastases with 25F9-positive macrophages, whereas this was found in only 4 of 12 patients (33%), who survived for longer than 2 years following metastases removal. A higher degree of 25F9-positive macrophages correlated with a shift towards the T8-positive subsets within the T cell compartment of the infiltrate. Our results suggest that accumulation of 25F9-positive macrophages in melanomas indicates more aggressive tumor properties.

Antibodies, Monoclonal↗
PubMed1987

Criteria for selecting monoclonal antibodies with respect to accumulation in melanoma tissue.

Immunohistology provides a necessary but insufficient criterion for selecting monoclonal antibodies (MAbs) capable of tumour targeting in vivo. Additional selection procedures have been evaluated using a panel of anti-melanoma MAbs, including immunoreactivity of (labelled) MAbs, antibody affinity, kinetics of binding and release, apparent antigen density and accumulation in nude mouse transplants. According to these criteria, MAbs M.2.7.6 and M.2.9.4 showed the most favourable properties, i.e. high immunoreactivity and pronounced internalization into melanoma cells. With MAbs M.2.10.15 and KG 6-56, moderate immunoreactivity and a binding pattern characterized by temperature dependence in the absence of internalization was observed. According to the paired label assay, all four MAbs showed specific accumulation into solid melanoma tissue. However, application in the patient still requires evaluation of the side effects of antigen cross-expression on normal human tissues.

Antibodies, Monoclonal↗