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Z Steplewski

Publications and source records attributed to Z Steplewski.

At least 163 records · Page 9Linked to original sources
PubMed1982

Monoclonal antibody-defined human lung cell surface protein antigens.

Monoclonal antibodies were used to define four distinct antigens present on the surface of human lung tumors. Immunoprecipitation of the four antigens by monoclonal antibodies and sodium dodecyl sulfate:polyacrylamide gel electrophoresis reveals that they have distinct complex structures. Different patterns of expression of these antigens on cells of other than lung tumor origin were detected by the same panel of monoclonal antibodies.

Antibodies, Monoclonal↗
PubMed1981

Monoclonal antibodies directed against the human Leb blood group antigen.

Four monoclonal antibodies produced by hybridomas obtained from a mouse immunized with a human adenocarcinoma cell line SW1116 (Koprowski, H., Steplewski, Z., Mitchell, K., Herlyn, M., Herlyn, D., and Fuhrer, P. (1979) Somatic Cell Genet. 5, 957-972) are directed against the Leb antigen of the human Lewis blood group system. Their specificities were established by binding studies using purified Leb-active ceramide hexasaccharide and by hapten inhibition studies involving oligosaccharides obtained from human milk.

Antibodies, Monoclonal↗
PubMed1981

Specific antigen in serum of patients with colon carcinoma.

The binding of monoclonal antibody specific for colon carcinoma was inhibited by serum from patients with adenocarcinoma of the colon but not by serum from patients with other bowel diseases or from healthy volunteers. Of other malignancies studied, serum from two patients with gastric carcinoma and two patients with pancreatic carcinoma also inhibited the specific binding of monoclonal antibody. The levels of carcinoembryonic antigen in these serum samples were not correlated with their levels of binding inhibition. Such monoclonal antibodies may prove useful for the detection of colorectal carcinoma.

Adenocarcinoma↗
PubMed1981

A monosialoganglioside is a monoclonal antibody-defined antigen of colon carcinoma.

The antigen of a monoclonal antibody that is specific for cells of human carcinoma of the colon is a monosialoganglioside as determined by the direct binding of antibody to thin-layer chromatograms of total lipid extracts of tissues. Binding of antibody to chromatograms is detected by autoradiography after the application of iodine-125-labeled F(ab')2 of rabbit immunoglobulin G antibodies to mouse immunoglobulins.

Adenocarcinoma↗
PubMed1981

Epstein-Barr virus in nontumorigenic and tumorigenic nasopharyngeal carcinoma (NPC) somatic cell hybrids.

Somatic cell hybrids between mouse fibroblasts and human cells derived from nasopharyngeal carcinoma (NPC) biopsies or NPC tumors propagated in nude mice were examined for the expression of the Epstein-Barr nuclear antigen (EBNA), retention of Epstein-Barr viral (EBV) DNA, and tumorigenicity in nude mice. In all hybrids the expression of EBNA correlated with the detection of EBV-DNA. After more than 2 years in culture, the hybrids examined retained similar amounts of EBV-DNA when compared to previously published data. Retention of EBV-DNA did not correlate with the presence of any particular human chromosome. Use of either rodent cell lines, clone 1D or IT-22, did not affect the retention nor loss of EBV-DNA. For tumorigenicity studies, NPC cells were fused with IT-22 cells and injected into nude mice. Tumor formation did not depend on the presence or absence of EBNA and detectable EBV-DNA sequences; tumorigenicity in these studies could not be correlated with the presence of any particular human chromosome or the origin of the NPC biopsy.

Animals↗
PubMed1981

Detection of monoclonal antibody-defined colorectal carcinoma antigen by solid-phase binding inhibition radioimmunoassay.

We have established a solid-phase binding inhibition radioimmunoassay for the detection of colorectal carcinoma-specific antigens in tissue culture supernatants of human colorectal carcinoma cell lines and in serum and urine of colorectal carcinoma patients. Using the [3H]glucosamine-labeled cell membrane glycolipid antigen and colorectal carcinoma-specific monoclonal antibodies in this assay, we have been able to detect several human colorectal carcinoma membrane-specific antigens that are released from the cell membrane into tissue culture supernatants, and an antigen detected by antibodies 1116-NS-19-9 and 1116-NS-52a that is found only in the serum and urine of cancer patients.

Antibodies, Monoclonal↗
PubMed1981

Release of monoclonal antibody-defined antigens by human colorectal carcinoma and melanoma cells.

Many but not all of the cell surface antigens studied were released into tissue culture medium of human colorectal carcinoma and melanoma cells maintained in vitro. Two groups of monoclonal antibody-defined antigens are described. One group is composed of molecules that are released easily and in large quantitites into the tissue culture milieu. In this group, four glycolipid antigens of colon carcinoma, including a monosialoganglioside, and five glycoproteins of melanoma were detected in tissue culture supernatants. Antigens of the second group could not be detected in tissue culture supernatants. This group included one colorectal carcinoma antigen, the nature of which is unknown, and a glycoprotein of melanoma cells.

Antibodies, Neoplasm↗
PubMed1980

Production of human hybridomas secreting antibodies to measles virus.

Monoclonal antibodies against a variety of antigens can be produced using techniques of somatic cell hybridization between cells of rodent myeloma lines and B cells derived from animals immunized against a given antigen. However, because of the monoclonal antibodies secreted by these hybridomas are of rodent origin, their use in human immunotherapy is limited. Thus the production of B-cell hybrids that secrete human monoclonal antibodies may be of considerable value. We have hybridized a hypoxanthine phosphoribosyl transferase (HPRT)-deficient human B-cell line derived from a patient suffering from multiple myeloma with peripheral lymphocytes obtained from a patient with subacute sclerosing panencephalitis (SSPE). These hybridomas were found to secrete human IgM specific for measles virus nucleocapsids.

Antibodies, Viral↗
PubMed1980

Production of monoclonal antibodies in serum free medium.

We have succeeded in growing several established hybridoma cell lines (1116NS-19; 116NS-33a; 1116NS-52a; 1083-17-1A; 691-19-19) in a serum free medium supplemented with physiological concentrations of insulin (5 microgram/ml) and transferrin (5 microgram/ml). The hybridoma cells replicate in this medium and will secrete monoclonal antibodies in quantities comparable to those produced in the presence of serum. Adapted hybridoma cultures have been secreting antibodies in the supplemented serum free (SSF) medium for more than 3 months. Parental mouse myeloma P3x63Ag8 cells and non-secreting subclone 653 cells cannot survive longer than 6 days under the same conditions. Both insulin and transferrin are necessary for hybridoma cells to grow in serum free medium and omission of either one will not permit cell multiplication.

Antibody-Producing Cells↗
PubMed1980

Biochemical characterization of human melanoma cell surfaces: dissection with monoclonal antibodies.

This report describes the structures of three distinct human melanoma surface antigens detected by monoclonal anti-melanoma antibodies. One antigen, expressed on all melanoma cells and on certain astrocytoma cells but not on any other kind of normal or tumor cell tested, has been shown to consist of our associated polypeptide chains. A second antigen expressed on many but not all melanomas has been identified as the antigenic product of the HLA-D locus, the DR antigen. A third protein antigen is not found on any normal cell tested but occurs on some, but not all, tumors of various origins.

Antibodies, Neoplasm↗
PubMed1980

Antibody-directed cytotoxic agents: use of monoclonal antibody to direct the action of toxin A chains to colorectal carcinoma cells.

We have constructed cell-specific cytotoxic agens by covalently coupling the A chain from diphtheria toxin or ricin toxin to monoclonal antibody directed against a colorectal carcinoma tumor-associated antigen. Antibody 1083-17-1A was modified by attachment of 3-(2-pyridyldithio)propionyl or cystaminyl groups and then treated with reduced A chain to give disulfide-linked conjugates that retained the original binding specificity of the antibody moiety. the conjugates showed cytotoxic activity for colorectal carcinoma cells in culture, but were not toxic in the same concentration range for a variety of cell lines that lacked the antigen. Under defined conditions virtually 100% of antigen-bearing cultured cells were killed, whereas cells that lacked the antigen were not affected. Conjugates containing toxin A chains coupled to monoclonal antibodies may be useful in studying functions of various cell surface components and, possibly, as tumor-specific therapeutic agents.

Animals↗
PubMed1980

Specific immunoreactivity of hybridoma-secreted monoclonal anti-melanoma antibodies to cultured cells and freshly derived human cells.

The specificities of monoclonal antibodies against melanoma cells were analyzed using radioimmunoassay, mixed-hemadsorption assay, and quantitative absorption on a variety of malignant and nonmalignant cells. Three of the six hybridoma-secreted antibodies bound to the majority of melanoma cell lines, melanoma tumors, and astrocytoma cell lines as well as to all normal and Epstein-Barr virus-transformed lymphocytes tested. The binding pattern coincides with the presence or absence of the DR antigen on human cells. Conversely, two other antibodies, 19-19 and Nu4B, detected two different antigens common to melanoma and astrocytoma cells only. Cloning of melanoma cells resulted in establishment of DR-positive and DR-negative clones, with the binding of Nu4B antibody retained in all.

Animals↗
PubMed1980

Inhibition of growth of colorectal carcinoma in nude mice by monoclonal antibody.

Hybridoma-derived monoclonal anti-colorectal carcinoma antibodies suppressed the growth of colorectal carcinoma in nude mice as evidenced by a lower incidence of tumors, a longer latency period, and a smaller volume of tumors in antibody-treated than in control animals. The growth-inhibiting properties of monoclonal anti-colorectal antibodies seem to be specific for colorectal carcinoma cells. This is indicated by the lack of effect of the antibodies on the growth of melanomas or bronchogenic carcinomas and by the binding of the antibodies in vivo to colorectal carcinoma cells but not to lung or kidney cells from tumor-bearing animals or to other tumor cells implanted in other animals. Inhibition of tumor growth was most probably mediated by antibody-dependent cell-mediated cytotoxicity. The results of these studies could provide an approach to the study of immunotherapeutic possibilities for anti-colorectal carcinoma antibodies in humans.

Animals↗
PubMed1979

Reactivity of monoclonal anti-melanoma antibodies with melanoma cells freshly isolated from primary and metastatic melanoma.

Human melanoma cells, freshly obtained from nine primary and metastatic melanoma cases, were tested for binding of monoclonal anti-melanoma antibodies produced in vitro by hybridoma clones. Monoclonal anti-melanoma antibodies bind to melanoma cells but do not react with nonmalignant cells obtained from the same patients or with cells obtained from giant hairy nevus. These results confirm the existence of tumor-specific antigens. Binding of monoclonal antibodies to melanoma cells of several origins, primary or metastatic, from different patients suggests the existence of tumor antigens shared by human melanoma cells. The binding pattern of different antibodies to various cells also predicts the existence of more than one tumor-specific antigenic determinant on melanoma cells.

Animals↗
PubMed1979

Monoclonal antibodies in cell-mediated cytotoxicity against human melanoma and colorectal carcinoma.

Hybridoma-derived monoclonal anti-melanoma antibodies and anti-colorectal carcinoma antibodies were found to mediate in vitro antibody dependent cell-mediated cytotoxicity (ADCC) reactions against melanoma and colorectal carcinoma cells, respectively. The antigen(s) detected in ADCC on melanoma cells maintained for more than one hundred passages in tissue culture were also found on two recently established melanoma cell lines. These antigens were not detected on skin fibroblasts of the same patients from whom the melanomas were obtained. The ADCC reactivities of anti-melanoma and anti-colorectal carcinoma antibodies were found to be specific for melanoma cells and colorectal carcinoma cells, respectively.

Animals↗