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J Zeuthen

Publications and source records attributed to J Zeuthen.

At least 91 records · Page 5Linked to original sources
PubMed1994

New serum markers for small-cell lung cancer. I. The ganglioside fucosyl-GM1.

The ganglioside fucosyl-GM1 (FucGM1) has been suggested as a marker for small-cell lung cancer (SCLC). Immunohistochemical analyses have shown the expression of the ganglioside in tumors in 75 to 90% of patients with SCLC. We have demonstrated that the ganglioside is shedded from SCLC cells both in vitro and in vivo, and that the antigen can be detected in sera from SCLC patients by an immunochemical analysis. The FucGM1 antigen has recently been shown to act as a target for antibody-dependent cellular cytotoxicity. This may provide a rationale for developing immunotherapy against SCLC. We used an immunoassay based on the scintillation proximity assay to analyze the concentrations of FucGM1 in sera from 112 SCLC patients, 21 patients with non-SCLC, 4 patients with other cancer forms, and 20 healthy controls. Sera were collected at the time of diagnosis before initiation of chemotherapy. The expression of FucGM1 was related to age, sex, blood group of the patient, and to the stage of disease and organ site involvement of metastases. The sera of 50% of the patients with SCLC were positive for FucGM1, and 12 of 21 sera from non-SCLC patients were markedly elevated. In SCLC sera, the concentration of FucGM1 in positive sera ranged from 7 to more than 3000 ng/ml FucGM1. None of 20 controls were positive. FucGM1 correlated to organ site involvement of metastases (p = 0.0016). The ganglioside was detected both at significantly higher concentrations (p = 0.0005) and in significantly more patients (p = 0.0026) with metastases to both the liver and bone marrow, compared to patients with metastases to the liver only.(ABSTRACT TRUNCATED AT 250 WORDS)

Biomarkers, Tumor↗
PubMed1993

Assembly of the T-cell antigen receptor. Participation of the CD3 omega chain.

The human TCR is composed of the Ti alpha beta heterodimer in association with the CD3 chains CD3 gamma delta epsilon zeta 2. Another chain, referred to as CD3 omega, has recently been described in T cells. CD3 omega is an intracellular protein transiently associated with the CD3 complex during the assembly of the TCR in the endoplasmic reticulum (ER) and it is not expressed on the cell surface. The function of CD3 omega is unknown but it has been suggested that it plays an important role in the assembly of the TCR. We have studied the possible function of CD3 omega in the human leukemic T-cell line Jurkat and different variants of this cell line. Cells were metabolically labeled, subjected to lysis, immunoprecipitated, and analyzed by SDS-PAGE. The results indicate that: 1) CD3 omega associates primarily with the CD3 delta epsilon complex; 2) CD3 omega is not associated with single Ti alpha or Ti beta chains, but is present in complexes composed of both the CD3 and the Ti chains; 3) CD3 omega is part of the complete, intracellular receptor complex Ti alpha beta/CD3 gamma epsilon delta omega zeta 2; and 4) CD3 omega dissociates from the Ti/CD3 complex in the ER before maturation of the Ti alpha beta heterodimer. On the basis of these results, we propose a model for the assembly and subunit stoichiometry of the TCR complex which includes the participation of the CD3 omega chain.

Animals↗
PubMed1993

Induction of CD3 delta epsilon omega by phorbol 12-myristate 13-acetate.

The effect of phorbol 12-myristate 13-acetate (PMA) on the synthesis, assembly and processing of the components of the T cell receptor (TcR) was studied with special focus on the CD3 omega chain. Treatment of the human leukemic T cell line Jurkat with PMA increased the synthesis of the Ti alpha, CD3 gamma and CG3 zeta chains two- to threefold and the synthesis of Ti beta and CD3 delta epsilon omega complexes five- to sevenfold as assessed by metabolic labeling, immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by scanning densitometry. The amount of total assembled TcR complexes increased approximately threefold and the maturation of the TcR was not affected as determined by analysis of oligosaccharide side chain processing in the Golgi apparatus. Activation of Jurkat cells with anti-CD3 monoclonal antibody, calcium ionophore, or mitogenic lectins did not affect the synthesis of the TcR components. In other cells studied (the human leukemic T cell line CEM, a panel of variants of the Jurkat T cell line and peripheral blood mononuclear cells) PMA also increased the synthesis of the TcR components. However, for all cell lines studied the amount of TcR complexes expressed on the cell surface was decreased after 16 h of PMA treatment. Based on these results we propose a role of CD3 omega in retention of TcR complexes. From PMA-treated CEM cells more than 50-fold the amount of CD3 delta epsilon omega complexes was immunoprecipitated as compared to the amount obtained from untreated Jurkat cells, and these observations indicate that the CEM cell line may be a qualified candidate for purification of CD3 omega.

Ammonium Chloride↗
PubMed1993

Monoclonal antibody against a lactose epitope of glycosphingolipids binds to melanoma tumour cells.

Mice were immunized with a neoglycoprotein consisting of a chemically modified carbohydrate moiety (reductively aminated 3'-sialyllactose) linked to human serum albumin. By this procedure an antibody response to the normally non-immunogenic carbohydrate structure was obtained. Hybridomas were established, and monoclonal antibodies were selected in ELISA based on their binding to the saccharide hapten, or to a lactosylceramide-mimicking neoglycolipid, lactose-bis-sulfone. One of the selected antibodies, 2H4, was of particular interest, since it also bound to glycolipids present on melanoma cells. FACS analysis of a panel of 14 melanoma cell lines showed that the 2H4 antibody bound to the majority of these. In frozen, non-fixed sections or paraffin sections of biopsies the monoclonal antibody 2H4 stained melanoma cells, but not tumour infiltrating lymphocytes or normal skin. Detailed immunochemical analysis of 2H4, using thin layer chromatography revealed that it recognized an internal lactose epitope in several glycosphingolipids.

Animals↗
PubMed1993

Utilization of interleukin-2 gene transfer in local immunotherapy of cancer.

It has been previously found that local administration of Balb/c plasmacytoma cells transformed and made non-tumorigenic by insertion of the cloned murine interleukin-2 (IL-2) gene induced regressions of a variety of murine tumours including the original Balb/c plasmacytoma X63-Ag8.653 growing in syngeneic mice. The tumour-inhibitory effect of the plasmacytoma cells transformed by IL-2 cDNA and designated as X63-m-IL-2 was due to their high constitutive production of IL-2. Here we show that admixture of syngeneic spleen cells to the X63-m-IL-2 transformants substantially (P < 0.025) increased the antitumour efficacy of the transformants. Balb/c spleen cells co-cultivated with X63-m-IL-2 cells in vitro yielded predominantly Thy 1.2+, CD3+, LFA-1+ lymphocytes, cytolytic for the X63-Ag8.653 plasmacytoma as well as for other murine tumours, including the X63-m-IL-2 target cells.

Animals↗
PubMed1993

Monoclonal antibodies for diagnosis and potential therapy of small cell lung cancer--the ganglioside antigen fucosyl-GM1.

Lung carcinomas represent a highly heterogenous group of tumors, which includes small cell lung cancer (SCLC). The ganglioside fucosyl-GM1 (FucGM1) was originally identified as a highly selective marker for SCLC. A number of monoclonal antibodies against FucGM1 have been produced against the purified ganglioside, and their specificity validated. With monoclonal antibodies, FucGM1 has been detected in tissues as well as in serum samples from SCLC patients. A sensitive, quantitative assay method for FucGM1 was developed based on scintillation proximity immunoassay (SPA): A specific monoclonal antibody against FucGM1 is bound to immunosorbent particles that contain a fluor. When radiolabelled FucGM1 binds to these particles, the fluor is excited, and the photons emitted can be measured directly in a beta-counter. This sensitive assay for FucGM1 has several potential diagnostic applications: differential diagnosis of SCLC, development of serum assays for diagnosis and monitoring of disease progression, and monitoring of patient response to therapy. The expression of FucGM1 in SCLC cells is heterogeneous, and may depend on the differentiated state of tumor cells. However, monoclonal antibodies specific for FucGM1 may have important future applications for radioimmunoimaging as well as in immunotherapy for SCLC.

Antibodies, Monoclonal↗
PubMed1993

Effect of cell-derived growth factors and cytokines on the clonal outgrowth of EBV-infected B cells and established lymphoblastoid cell lines.

Epstein-Barr virus (EBV) is a potent inducer of polyclonal B lymphocyte proliferation and is widely used as a tool for the establishment of B cell lines producing human monoclonal antibodies. However, because of low transformability, low clonability, and the inherent instability of EBV-infected B cells, valuable antibody-producing B cells are often lost during this procedure. We have here examined various cell-derived cytokines for their ability to enhance both the cellular outgrowth of newly infected B cells and the clonability of infected B cells and lymphoblastoid cell lines. Our results show that the murine thymoma cell line EL-4 is superior to peripheral blood mononuclear cells in both cellular outgrowth and cloning experiments, whereas monocyte-derived factors and monocyte cell lines were less capable than peripheral blood mononuclear cells in enhancing cellular outgrowth and cloning. Furthermore, the human T cell hybridoma cell line MP6 that secretes a B cell growth and differentiation factor, recently identified as an isoform of thioredoxin, is also capable of stimulating EBV-infected B cells and lymphoblastoid cell lines. Co-cultivation of EBV-infected B cells with MP6 cells significantly enhanced the cloning efficiency at the 1 cell/well level. The present results also suggest that one potential role of the MP6-derived thioredoxin could be the up regulation of IL-6 receptor expression in EBV-infected B cells.

B-Lymphocytes↗
PubMed1992

Recombinant interleukin-2 and lymphokine-activated killer cell treatment of advanced bladder cancer: clinical results and immunological effects.

The purpose of this study was to evaluate the efficacy of treatment with recombinant interleukin-2 (rIL-2) and lymphokine-activated killer cells in patients with advanced bladder cancer and to study the induced changes in the distribution of leukocyte subsets in blood and tumor. Nine patients with metastatic transitional cell cancer of the bladder were treated with a continuous infusion of rIL-2 combined with lymphocytes stimulated in vitro with rIL-2. None of the patients responded to the therapy despite substantial changes observed in the immunological cells, both in tumor and blood. The rIL-2 infusion induced migration of leukocytes to the tumors, which was related to increased expression of the adhesion molecule VLA-1 on both peripheral blood mononuclear cells and the endothelial cells of small tumor vessels. Only T-cells, predominately expressing IL-2 receptors, and macrophages infiltrated the tumors. Natural killer cells remained few or absent in the tumors, even though the natural killer cells in peripheral blood were activated by the treatment. This study shows that the present technique of rIL-2 and lymphokine-activated killer cell therapy is able to induce substantial changes in the immune system of patients with metastatic bladder cancer. However, this treatment did not induce tumor regression, which may be due to the advanced stage of disease.

Adult↗
PubMed1992

Serum immunoassay of a small cell lung cancer associated ganglioside: development of a sensitive scintillation proximity assay.

We here report an enzyme linked immunosorbent assay (ELISA) and a scintillation proximity assay (SPA) for detection of the ganglioside FucGM1 in sera from small cell lung cancer (SCLC) patients. The SPA was more sensitive and reproducible than the ELISA. In this assay, monoclonal antibodies specific for FucGM1 were bound to SPA particles and incubated with labelled FucGM1 and 100 microliters test-serum overnight, and counted in a beta-counter. The sensitivity was 0.2 ng. Seven out of twenty sera from SCLC patients were positive, whereas none of twenty sera from healthy individuals were positive for FucGM1. The SPA was more sensitive than the previously reported HPTLC as well as a direct ELISA.

Carbohydrate Sequence↗
PubMed1991

Immunochemical detection of a small cell lung cancer-associated ganglioside (FucGM1) antigen in serum.

Recently, the ganglioside FucGM1 (Fuc alpha 1-2Gal beta 1-3GalNAc beta 1-4[NeuAc alpha 2-3]-Gal beta 1-4Glc beta 1-1 Cer) was identified as a small cell lung cancer (SCLC) marker both in chemical and histochemical studies. In order to further determine whether the FucGM1 ganglioside is shed from the tumor site and consequently is present in the serum of SCLC patients, we produced a series of new monoclonal antibodies raised against FucGM1 and related glycolipids. Shedding of the FucGM1 ganglioside was studied both in vitro and in vivo using SCLC cell lines and nude mice xenografts of SCLC cells as model systems, and finally immunochemical analyses were performed on serum samples from patients with SCLC. High-performance thin-layer chromatography immunostaining demonstrated the presence of FucGM1 in conditioned culture media obtained from FucGM1-positive SCLC cell lines. Furthermore, tumor extracts of SCLC cell line xenografts in nude mice were positive for the FucGM1 marker, and more importantly the marker was also present in serum samples from these mice. Twenty serum samples were obtained from patients with histologically verified SCLC. Eight patients had localized disease, and the remaining patients had disseminated cancer involving metastases to other organ sites. Sera from 4 of these patients were clearly positive, and 2 additional cases were found to be weakly positive. The positive patient sera were all from patients with extensive disease. Sera from 12 patients with non-SCLC and 20 healthy individuals were all found to be negative. These results clearly establish the FucGM1 glycolipid as a potential serum marker of SCLC for which a sensitive immunoassay should be developed and tested using a larger series of serum samples.

Adult↗
PubMed1991

Interleukin-2 dose, blood monocyte and CD25+ lymphocyte counts as predictors of clinical response to interleukin-2 therapy in patients with renal cell carcinoma.

The purpose of this study was to determine immunological parameters in the peripheral blood that correlate with the clinical effect of interleukin-2 (IL-2) in patients with metastatic renal cell cancer. A group of 26 patients with metastatic renal cell cancer underwent IL-2 treatment using a 36-day schedule with continuous intravenous IL-2 infusion (3 x 10(6) units m-2 day-1) administered from days 1 to 5 and days 12 to 16. The white blood cell count and the absolute and relative number of neutrophils, lymphocytes, eosinophils and monocytes were recorded six times in peripheral blood during the treatment. Also the blood counts of T cell and NK cell subsets and cells expressing the T cell activation markers IL-2R alpha and VLA-1 were measured. The lymphokine-activated killer (LAK) cell cytotoxicity was measured either with or without additional in vitro stimulation by IL-2. Multivariate statistical analysis showed that the clinical responses were related to the administered dose of IL-2, to a low number of blood cells expressing IL-2 receptors and to a reduction in the blood monocyte count (P less than 0.05).

Adult↗
PubMed1991

Gastrin releasing peptide GRP(14-27) in human breast cancer cells and in small cell lung cancer.

Immunoreactivity related to the gastrin-releasing peptide (GRP) precursor was detected in four different human breast cancer cell lines. The amounts and the characteristics in extracts from different breast carcinoma cells were compared with cell extracts from small cell lung cancer (SCLC) cells. Two different radioimmunoassays were employed, directed against the amino acid sequence 14-27 of GRP (IR-GRP) or the 42-53 amino acid sequence at the C-terminal end of the GRP precursor (GRP precursor fragment). In extracts from T47D cells cultured under serum free conditions, IR-GRP coeluted with GRP(14-27) or GRP(18-27) in Sephadex G-50 chromatography. No immunoreactivity was detected in the fractions containing high molecular weight components. In a total of 41 human breast carcinoma biopsies from different postmenopausal patients, IR-GRP was detected by immunohistological staining in 39% of the samples. When the GRP(14-27) peptide was added exogenously to breast cancer and SCLC cell lines under serum-free culture conditions, (3H)-thymidine incorporation was stimulated by GRP(14-27) in the SCLC cell lines. Of the breast cancer cell lines only the T47D cell line responded with an increase in (3H)-thymidine incorporation comparable to the increase observed with SCLC cells. Recently, it has been reported that GRP-like receptors are present in some human breast cancer cell lines, including the T47D cell line studied here. The breast cancer cell line T47D therefore expresses the GRP peptide and the receptor for GRP. The identification of GRP-like receptors on T47D cells is in accordance with our present observation of a growth response to GRP(14-27) as evaluated by increased (3H)-thymidine incorporation.

Breast Neoplasms↗
PubMed1991

Intravesical BCG therapy in bladder carcinoma. Effect on cytotoxicity, IL-2 production and phenotype of peripheral blood mononuclear cells.

The purpose of the study was to examine the effects of intravesical BCG treatment on the cytotoxicity, interleukin-2 (IL-2) production and distribution of the subsets of peripheral blood mononuclear cells (PBMC) in patients with carcinoma in situ of the bladder. Treatments were made in 6 patients during a conventional BCG treatment schedule. Four patients showed a complete response, one a partial response and one had a progressive disease after BCG treatment. Intravesical BCG did not induce significant changes in the cytotoxicity of PBMC. The distribution of NK-cells and T-cells also remained unchanged and so did the lectin induced production of IL-2. The results suggest that the effects of intravesical BCG on the immune system should be studied in lymphocytes isolated from the bladder.

Administration, Intravesical↗
PubMed1990

[Interleukin-2 based immunotherapy of cancer].

Interleukin-2 (IL-2) is produced by activated T-helper lymphocytes and stimulates both the antigen-specific and the non-specific immune defence. In vitro, IL-2 activated peripheral blood lymphocytes (LAK-cells) can lyse a broad spectrum of both NK-sensitive and NK-resistant tumour cell lines and IL-2 expanded tumour infiltrating lymphocytes (TIL) are, in certain cases, selectively able to lyse autologous tumour cells. In vivo, the mechanism behind the anti-tumour effect of IL-2 is unknown. Recombinant IL-2 has been available since 1984 and world-wide more than 3,000 patients have been treated. IL-2 has most frequently been administered in combination with either in vitro activated autologous effector cells and/or other cytokines or anti-cancer chemotherapeutic agents. The generation of autologous effector cells for patient treatment demands considerable resources and their contribution to the clinical effect is uncertain. The best responding tumour-types have been renal cell carcinoma and malignant melanoma with response rates up to 35% and 24%, respectively. IL-2 therapy is associated with considerable side-effects. The most serious are due to the development of a "capillary leak syndrome" with peripheral vasodilation and increased vascular permeability resulting in hypotension, oedema and organ-dysfunction. The majority of these side-effects are reversible with improvement within hours after terminating the IL-2 administration. It is concluded that IL-2 therapy is still experimental and it should be limited to treatment according to protocols in highly specialized clinical departments in a close cooperation with immunological laboratories.

Animals↗
PubMed1990

Reduced LAK cytotoxicity of peripheral blood mononuclear cells in patients with bladder cancer: decreased LAK cytotoxicity caused by a low incidence of CD56+ and CD57+ mononuclear blood cells.

The cytotoxicity of unstimulated peripheral blood mononuclear cells (US-PBMC), phytohemagglutinin (PHA)-stimulated PBMC (PS-PBMC) and interleukin-2 (IL-2)-activated PBMC (LAK cells) was assessed in patients with noninvasive and invasive transitional-cell bladder cancer and compared with those determined in healthy controls. The differences in the cytotoxicities were correlated with specific changes in the subsets of peripheral blood mononuclear cells (PBMC). PBMC from 37 patients and 13 healthy controls were tested against the bladder cancer cell line T24 in 51Cr-release assays. The PBMC subsets were analyzed using monoclonal antibodies against T cells, natural killer (NK) -cells, monocytes, and activation markers. The cytotoxicities of US-PBMC, PS-PBMC, and LAK cells were all significantly lower in the cancer patients than in the controls (P less than 0.05). The percentages of PBMC positive for the NK-cell markers CD56 and CD57 were lowest in the patients and were correlated to the decrease in cytotoxicity. Depletion of CD56+ or CD57+ cells from PBMC prior to or after 2 days stimulation with IL-2 demonstrated that these cells are the major source of LAK-cell cytotoxicity and showed that the reduced ability of bladder cancer patient PBMC to develop LAK-cell cytotoxicity is a result of a low incidence of CD56+ and CD57+ cells in the blood. These findings indicate that IL-2 therapy alone might not be a sufficient therapy of bladder cancer patients.

Aged↗
PubMed1990

Analysis of a highly immunodominant epitope in the human immunodeficiency virus type 1 transmembrane glycoprotein, gp41, defined by a human monoclonal antibody.

A human monoclonal antibody, 41-7 [immunoglobulin G1(kappa)], directed against the transmembrane glycoprotein gp41 of the human immunodeficiency virus type 1 (HIV-1) has been produced by direct fusion of lymph node cells from an HIV-1-infected individual with a human B-lymphoblastoid cell line. The minimal essential epitope for 41-7 was mapped to a conserved seven-amino acid sequence, N-CSGKLIC-C, located within the N-terminal part of gp41. Antibodies blocking the binding of 41-7 could be detected in the serum of all HIV-1-infected individuals tested, irrespective of the stage of the infection. The epitope is located externally to the plasma membrane, and it is accessible to antibody in the native conformation of the glycoprotein. Despite this, no neutralizing activity of 41-7 could be demonstrated in vitro. These data indicate, directly and indirectly, that this immunodominant epitope on gp41, although exposed on the viral surface, elicits antibodies lacking antiviral activity and, hence, should be avoided in future vaccine candidates.

Amino Acid Sequence↗
PubMed1989

Recognition of insulin on MHC-class-II-expressing L929 cells by antibody and T cells.

In the present experiments, we attempted to obtain evidence that T-cell receptors (Tcr) and immunoglobulins can react against the same antigen-peptide/MHC class II complexes on antigen-presenting cells (APC). Use was made of monoclonal APC, i.e. I-Ak alpha/beta gene-transfected L929 fibroblasts, monoclonal anti-insulin antibodies and selected insulin-specific T-cell lines. Evidence for similarities in antibody and T-cell recognition of insulin presented by I-Ak alpha/beta gene-transfected L-cell fibroblasts was not obtained after serious attempts. Furthermore, we found no evidence for synthesis of antibodies specific for insulin-peptide/MHC class II complexes.

Animals↗