Search PubMed⌕ Search

Biomedical subjects

G Moldenhauer

Publications and source records attributed to G Moldenhauer.

At least 109 records · Page 6Linked to original sources
PubMed1987

Monoclonal antibody Ki-B3 detects a formalin resistant antigen on normal and neoplastic B cells.

A new monoclonal antibody Ki-B3 produced by a fusion with leukemic cells of a centroblastic/centrocytic lymphoma (m.l. follicular) is introduced. This antibody predominantly recognizes B cells of follicular mantle and germinal center cells, as well as plasma cells in normal lymphoid tissue. Furthermore, 80% of all low- and high-grade B cell lymphomas are stained, whereas among T cell lymphomas, only four of 15 T lymphoblastic lymphomas were positive to Ki-B3. All peripheral T cell lymphomas showed a negative reaction. Additionally, Ki-B3 detects a small percentage of monocytes and some myelomonocytic leukemias. All epithelial tissues as well as all sarcomas tested were invariably negative. Ki-B3 precipitates a 220 kiloDalton (kD) molecular weight antigen similar to the leukocyte common antigen. Presumably Ki-B3 detects a subtype of the leukocyte common antigen that is predominantly expressed on mature and immature B cells. As the antigen is formalin resistant, Ki-B3 can be used in routine hematology on paraffin sections for the detection and differential diagnosis of B cell lymphomas.

Antibodies, Monoclonal↗
PubMed1986

HD39 (B3), a B lineage-restricted antigen whose cell surface expression is limited to resting and activated human B lymphocytes.

The B cell-restricted antigen HD39, whose cell surface expression is limited to resting and activated human B lymphocytes, is described in this report. The monoclonal antibody HD39 detects a two-chain glycoprotein with apparent molecular weights of 130,000 and 140,000. During B cell ontogeny, HD39 is first expressed in the cytoplasm of bone marrow derived pre-B cells, then appears on the cell surface of sIgM+ B cells, and finally on the majority of sIgM+ sIgD+ resting B cells. After activation in vitro, the expression of HD39 on the cell surface first increases, and then the antigen is lost as cells begin to differentiate. HD39 is weakly expressed on very few non-T cell ALL and B cell CLL, on approximately 50% of B cell lymphomas, and not on Waldenström's macroglobulinemias and myelomas. In contrast, it is strongly expressed on all hairy cell leukemias. Its limited cell surface expression in B cell ontogeny suggests that HD39 may be important in the events that regulate the activation of the human resting B lymphocytes.

Animals↗
PubMed1986

An immunoenzymatic staining assay (ISA) for the rapid screening of monoclonal antibodies detecting membrane and cytoplasmic antigens.

We report a rapid and very sensitive immunoenzymatic staining assay (ISA) for the determination of the fine specificity of monoclonal antibodies directed against cellular antigens. Reactivity is analysed at the single cell level by light microscopy using alkaline phosphatase-conjugated second and third antibodies on cells bound to Terasaki plates. Reactive cells can be defined by their morphology even in preliminary screening procedures. Only small numbers of cells are necessary for this assay which is comparable to radioimmunoassays in its sensitivity. Plates with fixed cells can be stored at 4 degrees C so that a permanent 'library' of various cell types is always immediately available for use. The test is also suitable for human blood cell phenotyping. Moreover, a simple modification of the procedure by short pretreatment of the cells with the detergent Brij allows the detection of antigens within the cytoplasm. The importance of evaluating the cytoplasmic compartment in order to define antibody specificity and study the distribution of different cytoplasmic and membrane antigens is emphasized.

Antibodies, Monoclonal↗
PubMed1986

Loss of HLA-A,B,C and de novo expression of HLA-D in colorectal cancer.

One hundred primary colorectal carcinomas and 19 metastases were studied for the expression of HLA-A,B,C and HLA-D antigens using monoclonal antibodies (MAbs) against framework determinants and a sensitive immunoperoxidase technique on frozen sections. With MAb W6/32, 65 tumors were intensely stained for HLA-A,B,C; 22 showed a reduced staining intensity, in 5 carcinomas a minor or major subset of the tumor cells lacked HLA-A,B,C, and in 8 cases all tumor cells were unreactive. The loss of HLA-A,B,C was inversely correlated with the degree of differentiation. No relation was found to type, stage and site of the tumor, or to age and sex of the patients. With MAb 2.06, 58 tumors were HLA-D negative, 20 exhibited small positive foci, 19 showed a patchy staining pattern, and 3 were homogeneously HLA-D positive. There was no apparent correlation between HLA-D expression and any of the clinico-pathological features mentioned, nor was it related to the loss of HLA-A,B,C. About half of the metastases displayed the same staining pattern for HLA-A,B,C and -D as the respective primary tumors. The remainder differed from the primary carcinoma by gain or loss of HLA antigens.

Adult↗
PubMed1986

Differential expression of Ia and Ia-associated invariant chain in mouse tissues after in vivo treatment with IFN-gamma.

B10.BR mice were injected i.v. with varying doses of recombinant IFN-gamma on three consecutive days. In tissue sections of 13 organs, the distribution of Ia antigens and Ia-associated invariant chain (Ii) was studied by using an immunoperoxidase technique. In the control animal, Ia and Ii were shown to be co-expressed in most tissues. However, on Kupffer cells, a small number of hepatocytes, and a subset of lymphocytes in lymph nodes and in the splenic red pulp only Ii, and no Ia, was detectable. In contrast, strongly Ia+ interdigitating reticulum cells of T-dependent areas of lymph nodes and spleen were only weakly stained for Ii. IFN-gamma treatment resulted in a dramatic increase of MHC antigen expression throughout the body, with striking differences in the inducibility of certain tissues for Ia and Ii: Bronchial epithelium was clearly induced to express the invariant chain, whereas Ia antigens remained entirely absent. Moreover, in kidney tubules and colon epithelium, Ii was induced more broadly than Ia. In contrast to the induction of Ii on endothelial cells of larger vessels in kidney, heart, and lungs, no de novo expression of Ia or Ii in capillary endothelial cells was observed. The number of detectable Ia+/Ii+ interstitial dendritic cells considerably increased upon exposure to IFN-gamma. Neither neurons nor glial cells were induced to MHC antigen expression. Our data demonstrate that IFN-gamma applied i.v. is a potent inducer or enhancer of Ia antigens and invariant chain in a variety of cell types.

Animals↗
PubMed1986

In vivo induction of H-2K/D antigens by recombinant interferon-gamma.

B10.BR mice received i.v. increasing doses of recombinant interferon-gamma (rIFN-gamma) on three consecutive days. Using an immunoperoxidase technique the distribution of H-2K/D antigens was studied in frozen tissue sections of thirteen organs (kidney, liver, pancreas, esophagus, stomach, small intestine, colon, lungs, heart, brain, thymus, lymph node and spleen). Class I antigens were shown to be induced or enhanced in almost every organ after exposure to IFN-gamma. This effect was particularly conspicuous for renal tubular cells, hepatocytes, bronchiolar epithelial cells, gastric mucous cells, thymic cortical lymphocytes and capillary endothelial cells in heart and kidney. Neurons, glial cells, gastric chief and parietal cells, and pancreas cells were not inducible. The findings show that i.v. application of IFN-gamma leads to strong induction or enhancement of major histocompatibility complex class I antigens in a wide variety of tissues.

Antibodies, Monoclonal↗
PubMed1986

Selective killing of normal and neoplastic human B cells with anti-CD19- and anti-CD22-ricin A chain immunotoxins.

Monoclonal antibodies directed against two human B cell-restricted antigens, CD19 and CD22, were conjugated to highly purified ricin A chain. These A chain immunotoxins (A-IT) were specifically cytotoxic to Daudi cells and normal human peripheral blood B cells in vitro. The concentration required for 50% inhibition of protein synthesis (IC50) in these cells ranged from 7.5 X 10(-10) M to 4.2 X 10(-9) M. The specific toxicities of these A-ITs for Daudi cells were augmented 2- to 6-fold in the presence of 20mM NH4Cl. These studies demonstrate that A-ITs specific for CD19 and CD22 may be useful in the clinical treatment of B cell malignancies.

Ammonium Chloride↗
PubMed1986

Simultaneous demonstration of lectin-binding sites and antigens detected by monoclonal antibodies in a parallelized double-staining technique: a highly discriminative and quickly developing technique for frozen sections.

A sensitive immunoenzymatic double-staining technique is presented for the simultaneous visualization of lectin-binding sites and antigenic structures detected by monoclonal antibodies. The lectin is demonstrated by an extended unlabeled peroxidase-antiperoxidase (PAP) technique and the monoclonal antibody by an alkaline phosphatase-antialkaline phosphatase (APAAP) method, which corresponds to the standard PAP technique. 3-amino-9-ethylcarbazole (AEC) and fast blue BB salt serve as substrates for the peroxidase and the alkaline phosphatase, respectively. The antisera and the enzyme complexes raised in different animals enable the performance of three parallel incubation steps. The staining procedure requires three and a half hours altogether. This method proved to be highly discriminative and rather insensitive to interference by various artifacts.

Antibodies, Monoclonal↗
PubMed1986

The primary mediastinal clear cell lymphoma of B-cell type has variable defects in MHC antigen expression.

Eight cases of the recently reported 'primary mediastinal clear cell lymphoma of B-cell type' (Möller et al., 1986) were examined immunohistologically for the expression of cytoplasmic and/or surface antigens of MHC class I and II with mAbs directed against framework determinants of HLA-A,B,C (W6/32; B9.12.1), HLA-DP,DR,DQ (2.06), -DQ (Leu 10; Tü22), -DR (Tü34) gene products, and with mAbs specific for beta 2-microglobulin (BBM-1) and the HLA-D associated invariant chain (Vic-Y1). Besides the reported Ig-deficiency, the neoplastic B-cells of 7/8 tumours have variable defects in MHC antigen expression. Three lack both class I and class II antigens, one tumour lacks class I antigens but expresses HLA-DQ and -DR on the majority of neoplastic cells, three others contain varying proportions of MHC-antigen deficient tumour cells. The expression of Ii is closely correlated with HLA-D(R) expression and its antigenic sites are strictly located in the cytoplasm. Against the background of current knowledge, the variable and occasionally severe defects in MHC antigen expression within the herein presented series of B-cell lymphomas suggest that this unusual feature might be another characteristic of a novel lymphoma type.

Adult↗
PubMed1986

[Immunohistologic analysis of chronic obstructive sialadenitis. I. Changes in the expression of antigens of the major histocompatibility complex].

In the course of electrolyte sialadenitis progressing towards obstructive sialadenitis, changes in the epithelial expression of antigens of the major histocompatibility complex (MHC) occur even before morphological alterations and inflammatory cells can be detected. Class I antigens are enhanced and induced, and Class II antigens are induced. These changes begin focally. Only the expression of HLA-A,B,C and -DR in acinar epithelium is linked to the close vicinity of lymphohistiocytic infiltrates. In later stages of the disease the foci tend to fuse and antigenic changes are pronounced in areas of fibrosclerosis and parenchymal atrophy. The altered MHC antigen expression induced by chronical saliva congestion probably represents an important part of the postulated "immunoreaction in the duct epithelium" supposedly giving rise to this type of immunosialadenitis.

Adult↗
PubMed1985

Induction of HLA class-II antigen expression on human carcinoma cell lines by IFN-Gamma.

The effects of recombinant interferon gamma (IFN-gamma) on HLA antigen expression were examined in various human carcinoma cell lines: carcinomas of the lung (ChaGo, Oat 75, SK-LC-LL), colon (HT-29, WiDr), larynx (HEp-2), cervix (ME-180) and mammary gland (AlAb). Surface expression of HLA antigens was determined using monoclonal antibodies directed against monomorphic determinants of HLA class II (HD II, 2.06) and HLA class I (W6/32) by several techniques including indirect immunofluorescence, immunoperoxidase assay, radioimmunoassay of cells, and immunoprecipitation of radioiodinated cells. Without previous exposure to IFN-gamma, HLA class-II antigen was surface-expressed on a small subpopulation of HEp-2 only. All cell lines examined, except AlAb, could be induced to cell-surface expression of HLA class-II antigen after 48 hr incubation in the presence of IFN-gamma (10 units/ml). HLA class-I antigen was present on all cell lines even without treatment, and it was increased after IFN-exposure. Incorporation of 3H-thymidine and 3H-leucine and expression of the transferrin receptor were not significantly altered by IFN-gamma application, indicating a specific regulatory effect of IFN-gamma on HLA antigen expression. Our data demonstrate that HLA class-II surface expression is inducible by IFN-gamma in a variety of epithelial tumor lines. This may have implications for the host immune system defense mechanisms against tumors.

Breast Neoplasms↗
PubMed1985

Detection of glucagon in pancreatic A-cells by monoclonal antibodies.

The production of a mouse monoclonal antibody from a hybrid myeloma and its use for the detection of glucagon in tissue sections is reported. The hybrid clone isolated after fusion of mouse myeloma cells with hyperimmune spleen cells from a mouse previously immunized with porcine glucagon allowed us a standardized and permanent source of monoclonal antibodies in a culture cell system. The monoclonal antibody (3 GL 31) specifically reacts with pancreatic A-cells in several species including pig, rabbit, tupaia belangeri and sheep. No immunoreactivity is observed against gut cells and neurons.

Animals↗
PubMed1983

Immunoperoxidase slide assay (IPSA)--a new screening method for hybridoma supernatants directed against cell surface antigens compared to other binding assays.

A modified immunoperoxidase assay on microscope slides (IPSA) was adopted as a screening procedure for hybridoma supernatants with specificity for human lymphocyte subpopulations. The method proved to be suitable for testing a large number of hybridomas with a minimum of cells and reagents. In addition, the slide-technique yields considerable information about the type and morphology of target cells. This allows a first differentiation between cell types in the assayed preparation, e.g. between lymphocytes and monocytes. Compared to indirect immunofluorescence, solid-phase radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA) with intact cells as antigen, IPSA turned-out to be as sensitive as RIA and superior to indirect immunofluorescence and ELISA. Nevertheless, none of the assays used detected all supernatants binding to cells in the right manner and could, thus, be considered ideal. In our hands, the combination of RIA and IPSA proved to be an excellent system for screening procedures on lymphocytes.

Animals↗
PubMed1982

Monoclonal antibodies to the rat liver glucocorticoid receptor.

Monoclonal antibodies against the 90 000 mol. wt. form of the activated rat liver glucocorticoid receptor were generated from mice immunized with a partially purified receptor preparation. The screening assay was based on the precipitation of liver cytosol, labelled with [3H]triamcinolone acetonide, with monoclonal antibodies bound to immobilized rabbit anti-mouse IgG. Out of 102 hybridomas obtained, 76 produced immunoglobulin and eight of them were found to react with the receptor molecule. Only one of the positive clones secreted IgG whereas the other seven produced IgM. The complexes of receptor and antibodies were identified by sucrose density gradient centrifugation. All seven monoclonal antibodies tested reacted with the 90 000 mol. wt. form of the receptor but not with the 40 000 mol. wt. form that contains the steroid and DNA binding domains. None of the monoclonal antibodies interfered with the binding of the receptor to DNA cellulose, thus suggesting that the antigenic determinants are located in a region of the receptor that is not directly implicated in either steroid binding or DNA binding. These antigenic determinants were common to glucocorticoid receptors from several tissues of the rat, whereas glucocorticoid receptors from other species react only with some of the antibodies.

Animals↗