Biomedical subjects

H Koprowski

Publications and source records attributed to H Koprowski.

At least 127 records · Page 7Linked to original sources

PubMed1989

Transformation of normal human melanocytes and non-malignant nevus cells by adenovirus 12-SV40 hybrid virus.

Infection of normal human melanocyte and nevus cultures with an adenovirus 12-Simian Virus 40 hybrid virus (Ad12-SV40) produced transformed cells that expressed SV40-T antigen. The Ad12-SV40 cells exhibited rapid cell proliferation to high cell densities and efficient growth in soft agar, but none of 15 transformed melanocyte and nevus cultures formed tumors when injected s.c. or under the renal capsule into athymic nude mice. While the Ad12-SV40-transformed cells lost certain properties associated with the melanocytic phenotype, i.e., pigmentation, tyrosinase activity and melanosome content, the expression of melanoma-associated antigens, including nerve growth factor receptor, p97 melano-transferrin, and chondroitin sulfate proteoglycan, remained stable. The transformed melanocytes acquired the ability to express HLA-DR antigen, which is found on nevus and melanoma cells. Total ganglioside patterns in Ad12-SV40-transformed cells changed to reflect more advanced stages of tumor progression. Transformed melanocytes, like nevus and melanoma cells, showed increased GD3 content and transformed nevus cells increased GD2 which is a feature of malignant melanoma cells. Ad12-SV40-transformed human melanocytes and nevus cells are useful tools for studying tumor progression under experimental conditions.

Adenoviruses, Human↗

PubMed1989

Flow cytometric determination of the frequency and heterogeneity of expression of human melanoma-associated antigens.

We used flow cytometry to measure the expression of human melanoma antigens on cell suspensions dissociated from metastatic masses. The objective was to study the heterogeneity between tumor samples from different patients and between different tumors excised from a single patient. Fifty-three metastases excised from 34 melanoma patients were analyzed with a panel of nine murine monoclonal antibodies (MOABs). Melanoma cells were stained by an indirect fluorescent method and analyzed on a Coulter EPICS C flow cytometer after gating to exclude tumor-infiltrating leukocytes and dead cells. The most consistently and most strongly expressed antigen was the high-molecular-weight proteoglycan (detected by the MOAB 9.2.27), which was expressed on 95% of the melanoma specimens and by a high proportion of cells within each specimen (mean +/- SE, 79.2 +/- 5.5). However, strong expression of this antigen was limited to melanoma cells that had been dissociated mechanically and was markedly diminished by exposure to collagenase. Culture of collagenase-dissociated tumor cells for 24 to 48 h resulted in reexpression of the antigen. The expression of other melanoma-associated antigens was not affected by collagenase treatment, but for these antigens there was more variability between cells from an individual tumor and between tumors from different patients. The percentage of enzyme-dissociated tumors considered positive for MOAB binding (defined as at least 10% of cells positive) and the mean +/- SE of the percentage of positive cells within a tumor were as follows: MOAB ME-9-61 (antigen, p97) = 84% + (41.2 +/- 5.4%); MOAB ME-20.4 (antigen, nerve growth factor receptor) = 40% + (18.7 +/- 5.1%); MOAB ME-24 (antigen, ganglioside GD3) = 84% + (50.8 +/- 4.8%); MOAB ME-311 (antigen, ganglioside 9-O-acetyl-GD3) = 76% + (42.5 +/- 5.1%); MOAB ME-361 (antigen, mainly ganglioside GD2) = 3% + (1.9 +/- 0.8%); MOAB 3F8 (antigen, ganglioside GD2) = 36% (10.5 +/- 3.8%); MOAB 14G2a (antigen, ganglioside GD2) = 86% + (46.0 +/- 6.7%); MOAB L243 (antigen, HLA-DR) = 56% + (22.5 +/- 5.5%). In 19 cases, we were able to compare the antigenic profiles of two tumors excised from the same patient at different times. Analysis by nonindependent t test showed no significant differences in MOAB binding between the paired tumors. Moreover, linear regression analysis indicated that there was a linear relationship, with a slope approximately = 1, between the percentage of positive cells in Tumor 1 versus Tumor 2.(ABSTRACT TRUNCATED AT 400 WORDS)

Antibodies, Monoclonal↗

PubMed1989

Levels of disialogangliosides in sera of melanoma patients monitored by sensitive thin-layer chromatography and immunostaining.

Levels of GD2, GD3, and 9-O-acetyl GD3 were monitored in sera of patients with melanoma and healthy adults with two monoclonal antibodies that specifically detect these gangliosides. By direct measurement of radioactivity in the immunolabeled chromatogram, GD2 could be detected in normal sera at 2 ng/mL. Serum levels of GD2 and GD3 were increased approximately sixfold and fivefold, respectively, in patients with disseminated melanoma, compared with those of healthy adults. The acetylated derivative of GD3, which is highly specific for melanoma cells, was not detected in serum. This sensitive assay allows the quantitation of tumor-associated gangliosides that are circulating in sera of melanoma patients.

Adult↗

PubMed1989

Antagonistic effect of PDGF and NGF on transcription of ribosomal DNA and tumor cell proliferation.

The molecular mechanism by which NGF and PDGF affect growth of tumor cells was tested in human melanoma WM 266-4 and colorectal carcinoma SW 707 cell lines. We present evidence that NGF translocated to the nucleus and bound to the chromatin of SW 707 cells, which express the cell surface and the chromatin receptor for NGF, inhibits ribosomal RNA synthesis which in consequence leads to inhibition of cell proliferation. In WM 266-4 cells, which do not express NGF receptor, NGF does not affect cell proliferation. In contrast, PDGF translocated to the nucleus of both SW 707 and WM 266-4 cells activates ribosomal RNA synthesis. We report here that NGF abolishes PDGF-activated ribosomal RNA synthesis and PDGF-stimulated growth of tumor cells.

Cell Division↗

PubMed1989

Inhibition of metastases of a human melanoma xenograft by monoclonal antibody to the GD2/GD3 gangliosides.

A human melanoma variant cell line was obtained from a lung metastasis that arose spontaneously after we inoculated melanoma cells sc into a nude mouse. In this model, IgG2a monoclonal antibody (MAb) ME 36.1 defining the GD2/GD3 gangliosides inhibited melanoma growth at the primary site and metastatic spread of the cells, whereas an IgG1 variant of MAb ME 36.1 inhibited lung metastasis formation only. Possible mechanisms of antitumor effects of MAb ME 36.1 are discussed.

Animals↗

PubMed1989

Epidermal growth factor (EGF) and monoclonal antibody to cell surface EGF receptor bind to the same chromatin receptor.

Cellular uptake, nuclear translocation, and chromatin binding of epidermal growth factor (EGF) and monoclonal antibodies (MAbs) against the protein domain of the EGF surface receptor (MAb 425) and against the carbohydrate Y determinant on the EGF receptor (MAb Br 15-6A) were analyzed in cell lines that express surface EGF receptor. Both EGF and MAb 425 were translocated to the nucleus and bound in nondegraded form to the chromatin of all cells tested. MAb Br 15-6A was taken up only by SW 948 colorectal carcinoma cells which express EGF receptor whereas neither EGF nor MAb 425 was taken up by SW 707 colorectal carcinoma cells which do not express EGF receptor. MAb 425 immunoprecipitated a 230- to 250-kDa chromatin protein, which appears to be the EGF chromatin receptor. EGF was localized in a single EcoRI DNA fragment suggesting that the chromatin binding was highly specific. Binding of EGF to primarily DNase II-sensitive chromatin regions protected these regions from nuclease action. The role of growth factor binding to chromatin in neoplastic transformation is discussed.

Antibodies, Monoclonal↗

PubMed1989

Amplification and molecular cloning of HTLV-I sequences from DNA of multiple sclerosis patients.

Techniques of gene amplification, molecular cloning, and sequence analysis were used to test for the presence of sequences related to human T-lymphotropic virus type I (HTLV-I) in peripheral blood mononuclear cells of six patients with multiple sclerosis (MS) and 20 normal individuals. HTLV-I sequences were detected in all six MS patients and in one individual from the control group by DNA blot analysis and molecular cloning of amplified DNAs. The viral sequence in MS patients were associated with adherent cell populations consisting predominantly of monocytes and macrophages. Molecular cloning and nucleotide sequence analysis indicated that these amplified viral sequences were related to the HTLV-I proviral genome.

Adolescent↗

PubMed1989

Rapid and sensitive method to detect expression of growth factor receptors.

A sensitive method to analyze growth factor receptor expression is described that is based on precipitation of the receptor by the growth factor. The precipitate that forms after incubation of pure, membrane-free cytoplasm with the growth factor contains both the receptor and the corresponding mRNA. With this method, nerve growth factor (NGF), epidermal growth factor (EGF) and platelet-derived growth factor (PDGF) receptors were detected in several tumor cell lines thought previously to be receptor-negative. This method is more sensitive than existing cell surface approaches, permitting the detection of growth factor receptor synthesis even in the absence of detectable cell surface expression. The method is comparable in sensitivity to Northern blot hybridization but does not require DNA probes.

Biological Assay↗

PubMed1989

Specific detection of antibodies in cancer patients following immunotherapy with anti-idiotype.

Assays were compared for specificity and sensitivity in detecting in cancer patients' sera antibodies (Ab) raised during the course of immunotherapy with goat anti-idiotypic antibodies (Ab2) bearing the internal image of a colon carcinoma-associated antigen defined by monoclonal antibody (MAb) CO17-1A (Ab1). The human Ab were tested for binding to tumor cells, isolated tumor antigen (Ag), and Ab2, and for the capacity to inhibit binding of Ab2 to Ab1. Chimeric (human/mouse) MAb CO17-1A was used as a positive control in all assays. Of the four different cell binding assays used, the mixed hemadsorption assay (MHA) showed the highest specificity and sensitivity. For detection of Ag-binding human Ab, the enzyme-linked immunosorbent assay (ELISA) with Ag as target and peroxidase (PO)-labeled anti-human IgG antibodies as tracer for detection of human Ab binding to the target, showed higher specificity and sensitivity as compared to radioimmunoassay (RIA). For detection of human Ab binding specifically to Ab2, three different ELISAs and three RIAs were used. Best results were obtained in the ELISA with anti-human IgG antibodies as target and biotinylated Ab2 as tracer for detection of human Ab binding to the target. Of four different inhibition assays used, the ELISA which measures inhibition of binding of biotinylated Ab2 to Ab1 by human Ab or chimeric antibody at 37 degrees C was the most sensitive and specific. These assays have general applicability for the characterization of human Ab responses in Ab2 vaccination approaches to various tumors and pathogens and therefore provide the basis for the establishment of a correlation between Ab responses and clinical outcome of the disease.

Animals↗

PubMed1989

Intracellular receptor binding and nuclear transport of nerve growth factor in intact cells and a cell-free system.

Nuclear uptake of 125I-labeled nerve growth factor (NGF) by cells that either express or do not express the cell surface receptor was tested using intact cells and a cell-free system. Intracellular and consequently nuclear uptake of NGF in intact cells was dependent on the presence of surface NGF receptor, whereas nuclear uptake in a cell-free system did not correlate with cell surface receptor expression. In the cell-free system, nuclear transport was inhibited when NGF receptor was being actively synthesized. Preincubation of intact cells with unlabeled NGF, cycloheximide, puromycin, or actinomycin D increased nuclear uptake up to threefold. The data suggest that, in intact cells, NGF transported into the cell via the surface receptors is also bound by the NGF receptor being synthesized in the cytoplasm. NGF taken up by the nucleus inhibited transcription of ribosomal RNA genes by 70% and, in turn, inhibited cell proliferation by 60%. A direct effect of NGF on transcription is discussed.

Biological Transport↗

PubMed1989

Rabies oral immunization.

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Administration, Oral↗

PubMed1989

Nuclear uptake of monoclonal antibody to a surface glycoprotein and its effect on transcription.

Nuclear transport and chromatin binding of monoclonal antibody (MAb) ME491, directed against a cell surface glycoprotein, was tested in intact cells and in a cell-free system. After a 24-h incubation with 125I-MAb ME491, the chromatin of melanoma cells and of colorectal carcinoma cells contained approximately 10 and 20%, respectively, of the antibody in nondegraded form. 125I-MAb ME491 was bound to a 55-kDa chromatin protein and localized in two HincII-digested chromatin fragments. Taken up by the nucleus, MAb ME491 inhibited transcription of ribosomal RNA genes by 70%. Nuclear uptake of 125I-MAb ME491 was increased up to ninefold when cells were preincubated with puromycin or actinomycin D. Nuclear uptake of MAb ME491 in a cell-free system was inhibited by ME491 antigen newly synthesized in the cytoplasm. Binding of 125I-MAb ME491 to the newly synthesized ME491 antigen caused precipitation of polysome-bound ME491 mRNA. The effect of MAb ME491 on transcription is discussed.

Antibodies, Monoclonal↗

PubMed1989

Expression of A-type PDGF receptor in cytoplasm of tumor cell lines synthesizing PDGF.

Two tumor cell lines, WM 266-4 melanoma and SW 707 colorectal carcinoma, both of which synthesize platelet-derived growth factor (PDGF) but do not express cell surface PDGF receptor, were tested for the presence of intracytoplasmic PDGF receptor. Using a novel method of intracytoplasmic (newly synthesized), receptor precipitation by the growth factor, we identified a 125,000 molecular weight protein crosslinked with 125I-labeled PDGF in a 140,000 molecular weight complex. In vitro translation of the corresponding mRNA revealed a 125,000 molecular weight product which presumably represents the A-type PDGF receptor. Exogenous PDGF was found to activate synthesis of RNA and cell proliferation.

Cell Division↗

PubMed1989

Sequence investigation of the major gastrointestinal tumor-associated antigen gene family, GA733.

The monoclonal antibody-defined, tumor-associated antigen GA733 was purified from the SW948 human colorectal carcinoma cell line and its partial amino acid sequence was determined. By using a synthetic oligonucleotide probe, two recombinants were isolated from a total human genomic library. We prove the existence of a family of GA733 genes. One of the genomic isolates is demonstrated to be an intronless gene, which is transcribed in pancreatic carcinoma cell lines and in placenta. The GA733 proteins were observed to contain sequences homologous to a repeat unit occurring 10 times in thyroglobulin and once in the HLA-DR-associated invariant chain. A more evolutionarily distant relationship was found with the alpha chain of the interleukin 2 growth factor receptor.

Amino Acid Sequence↗

PubMed1989

Idiotypic cascades in cancer patients treated with monoclonal antibody CO17-1A.

We have previously shown that gastrointestinal cancer patients treated with monoclonal antibody CO17-1A (Ab1) developed anti-idiotypic antibodies (Ab2) to the Ab1. We now demonstrate that patients produce anti-anti-idiotypic antibodies (Ab3) to their autologous Ab2. Ab3 were demonstrated in culture supernatants of peripheral blood mononuclear cells from five Ab1-treated patients after stimulation of the cells with heterologous Ab2 that functionally mimicked the tumor antigen (Ag) defined by Ab1 and immunologically cross reacted with the patients' Ab2. Ab3 shared idiotopes with Ab1 and were Ab1-like in their binding specificities to tumor cells, Ag, and Ab2. Such antibodies were also elicited by stimulating cells with Ag. However, they were not produced by stimulating posttreatment mononuclear cells with control proteins or by stimulating pretreatment cells with either Ag or Ab2. Our results demonstrate idiotypic cascades in cancer patients treated with monoclonal antibody. Ag-specific Ab3 responses may underlie delayed clinical responses often observed in cancer patients treated with monoclonal antibodies of various specificities.

Adenocarcinoma↗

PubMed1989

Rabies virus-specific T cell hybridomas: identification of class II MHC-restricted T-cell epitopes using synthetic peptides.

Rabies virus-specific T-cell hybridomas were produced from immune mice by somatic cell fusion. Cloned T-cell hybridomas were studied for antigen specificity using purified virus, a recombinant vaccinia virus expressing rabies glycoprotein and synthetic peptides containing amino acid sequences of rabies viral antigens. Two closely situated T-cell epitopes of rabies glycoprotein, and one of rabies nucleoprotein were identified using synthetic peptides corresponding to amino acid sequences of these proteins. The major histocompatibility gene complex elements that determine the recognition of antigen by these T-cell hybrids were determined using mouse fibroblasts (L cells) transfected with and expressing the I-Ad and I-Ed genes. Some of the T cell hybridomas exhibited significant cytotoxic activity against target cells expressing surface rabies antigens. This T cell mediated cytotoxicity requires cell-to-cell contact between target and effector cells since no by-stander cytotoxicity was observed. The results are discussed in the context of their significance for the design of newer subunit vaccines to prevent rabies infection.

Animals↗

PubMed1989

Colon carcinoma-associated glycoproteins recognized by monoclonal antibodies CO-029 and GA22-2.

Two murine monoclonal antibodies (MAb) CO-029 and GA22-2 are described which reacted specifically with the human gastrointestinal tumor cell lines LS180 and SW1222, respectively. CO-029 specific antigen was found by immunoprecipitation and Western blotting to be a highly expressed protein consisting of a single polypeptide chain of 32kDa. The gastric tumor associated antigen GA22-2 was a 185kDa polypeptide which did not comigrate with the 180 kDa carcinoembryonic antigen (CEA), neither was it immunologically crossreactive with the latter. Both CO-029 and GA22-2 antigens were shown to be glycosylated by their retention on Sepharose-lectin columns. CO-029 was highly bound by wheat germ agglutinin indicating the accessibility of N-acetylglucosamine or N-acetyl-neuraminic acid residues. GA22-2 showed higher specificity to soybean agglutinin inferring the preferential accessibility of galactose or N-acetylgalactosamine-like residues on its saccharide moiety.

Animals↗

PubMed1989

Modulation of cancer patients' immune responses by administration of anti-idiotypic antibodies.

Thirty patients with Dukes stage D colon carcinoma who had undergone operative removal of the primary tumor and had growing hepatic metastases each received four intradermal injections of 0.5-4 mg of alum-precipitated goat anti-idiotypic antibodies (anti-Id). The anti-Id had been produced against murine monoclonal antibody (mAb) CO17-1A, which defines a human colon carcinoma associated antigen. All patients elaborated anti-anti-Id that shared idiotopes with mAb CO17-1A, bound to tumor cells and isolated tumor antigen, and competed with the mAb for binding to tumor cells. The clinical response was monitored by ultrasonography, CT, radionuclide scanning, and serum marker assays. Six patients had partial tumor responses; five of these had received additional booster anti-Id injections along with chemotherapy. Seven patients had stabilized tumor; six had received additional anti-Id, with chemotherapy also in four. Conclusions about the clinical role of such immunization await further study, but in demonstrating a specific response to anti-Id, our results support the use of this approach in human immunotherapy against tumors or pathogens.

Antibodies, Anti-Idiotypic↗