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N I Smorodinsky

Publications and source records attributed to N I Smorodinsky.

33 records · Page 2Linked to original sources
PubMed1992

Phenotypic properties of 3T3 cells transformed in vitro with polyoma virus and passaged once in syngeneic animals.

Cloned BALB/c 3T3 cells transformed in vitro with polyoma virus (PyV) acquired a higher tumorigenicity phenotype after a single in vivo passage. Some of the in vivo passaged cells (CTC cells) exhibited also a higher metastatic phenotype than cells from the same clones that were maintained only in culture (C cells). A phenotypic comparison between CTC and C cells was performed. It was found that most CTC lines exhibited a higher binding to laminin compared to their clonal C cell ancestors. Some CTC cells were less sensitive to the cytotoxic effects of TNF-alpha than the corresponding C cells. CTC cells originating from tumors which appeared after a long latency period (late tumors) tended to express Fc gamma RII while CTC cells originating from tumors which appeared after a short latency period (early tumors) as well as the corresponding C cells tended not to express Fc gamma RII. The expression of a membrane epitope recognized by a monoclonal antibody expressing specificity towards PyV transformed cells, was down-regulated on late tumor cells compared to early tumor cells. Transfection of cloned PyV-transformed BALB/c 3T3 cells with the beta 1Fc gamma RII gene augmented the tumorigenicity and metastatic phenotype of the transfectants compared to control transfectants.

3T3 Cells↗
PubMed1991

Recognition of peptidyl epitopes by polymorphic epithelial mucin (PEM)-specific monoclonal antibodies.

Peptidyl epitope recognition by several murine monoclonal antibodies (MAbs E29, H23, HMFG-1, HMFG-2, MA5, MA6 and MA9) which react with the polymorphic epithelial mucins [PEM; epithelial membrane antigen (EMA)] was studied by using ten synthetic peptides representative of the 20 residue tandem repeat as test antigens. Antibody binding to 6-10 residue overlaps and to peptides having a common carboxy-terminus and staggered amino-termini (8-31 residues) was assessed by solid phase and competition ELISA techniques. From these analyses, all MAbs except MA9 were found to react predominantly with the carboxy-terminal half of the repeat motif. Polyclonal antibody responses in mice immunized with intact EMA/PEM-containing preparations also displayed significant reactivities against synthetic repeat peptide antigens and, conversely, synthetic peptides as carrier-conjugated immunogens induced antibodies recognizing intact antigens. These results are discussed vis-à-vis peptide conformation, the potential effects of O-glycosylation on secondary structure, and the possible effects of these parameters on immunogenicity and antigenicity.

Amino Acid Sequence↗
PubMed1990

Adherence pili of avian strains of Escherichia coli O78.

Avian colisepticemia starts with the invasion of the trachea by virulent strains of Escherichia coli, with strains of serotype O78 responsible for about 50% of the cases. Several O78 strains isolated from poultry with colisepticemia produced pili with a subunit of molecular weight of 18,000 that mediated adherence to avian epithelial tissues in vitro and in vivo.

Animals↗
PubMed1989

Use of monoclonal antibodies in the purification of an inhibitor of virus replication by affinity chromatography.

Mouse monoclonal antibodies (MAbs) were prepared to an inhibitor of virus replication (IVR), released from protoplasts or leaf tissue of hypersensitive tobacco plants infected with tobacco mosaic virus. The MAbs were highly specific for IVR and reduced its antiviral activity. Using these MAbs in affinity chromatography enabled the recovery of purified IVR. SDS-PAGE of the immunoaffinity-purified IVR gave a single Mr 23K band. Immunoblots of IVR from extracts of protoplast or leaf tissue also revealed a single Mr 23K band which suggests that protoplast and tissue IVR are closely related.

Antibodies, Monoclonal↗
PubMed1988

Towards an idiotype vaccine against mammary tumors. Induction of an immune response to breast cancer-associated antigens by anti-idiotypic antibodies.

Previously we have reported on the production of two sets of human monoclonal antibodies reacting with mouse mammary tumor virus (MMTV) and human mammary tumor virus (HuMTV) cross-reacting antigens. B11 is a monoclonal IgG generated by the human-human hybridoma technique using axillary lymph node of breast cancer patients. 4.6/6 is a monoclonal IgG established by the mouse-human hybridoma procedure using peripheral blood lymphocytes of a healthy investigator working with the breast cancer cell line T47D which secretes HuMTV antigens. Two anti-idiotypic (Id) antibodies were produced by immunizing rabbits with B11 or 4.6/6. Following exhaustive adsorption on unrelated human-Ig, fetal calf serum and purification on B11 or 4.6/6 affinity columns, the anti-Id antibodies were shown to react specifically with their respective Id. The binding of these anti-Id antibodies to the respective Id was specifically inhibited by prior incubation of the Id with MMTV and/or HuMTV antigens. Rabbit anti-B11 and rabbit anti-4.6/6 anti-Id antibodies were employed to immunize female C3Heb mice. Following immunizations, humoral and cellular immune responses to MMTV-related antigens could be demonstrated. The sera of the mice contained anti-MMTV antibodies and delayed-type hypersensitivity was specifically expressed when irradiated cells of the Mm5MT line (which carry surface MMTV antigens) were injected. Our results support the notion that anti-Id antibodies harboring the internal image can immunize animals against tumor cells bearing on their surface viral-associated antigens.

Animals↗
PubMed1988

The immune system during the precancer period: naturally-occurring tumor reactive monoclonal antibodies and urethane carcinogenesis.

Previous results obtained in our laboratory suggested that natural antibodies reactive with L5178Y lymphoma cells play a role in the induction of lung tumors by the chemical carcinogen urethane. In order to characterize some of the naturally-occurring L5178Y reactive antibodies we prepared hybridomas that secreted natural monoclonal IgM antibodies reactive with L5178Y lymphoma cells. In the present study we characterized some of these antibodies and provided further proof as to their role in urethane carcinogenesis. One hybridoma secreted a cytotoxic antibody that reacted only with mouse lymphoma cell lines. Other non-cytotoxic monoclonal L5178Y-reactive antibodies showed various degrees of cross-reactivity with syngeneic, allogeneic and xenogeneic cells of normal or malignant origin. One of these antibodies reacted much better with activated T cells than with resting ones. Four groups of mice were treated with urethane. Three groups were injected twice a week during 5 months with different IgM preparations of natural monoclonal antibodies. The mice in the fourth group were not treated with IgM and served as controls. Five months after the urethane treatment the mice were sacrificed and the number of tumor foci in the lungs of each mouse was determined. The results show that the group treated with the cytotoxic monoclonal antibody 1.80 had a significant decrease, while the group treated with the IgM myeloma protein 104E had a significant increase in the number of tumor foci compared to urethane-treated mice that did not receive any IgM treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Naturally-occurring tumor-reactive autoantibodies: a monoclonal antibody from normal mice reacts with tumor cells and with DNA.

A natural IgM monoclonal antibody, 1.67, was generated from apparently healthy unstimulated BALB/c mice. This antibody reacted with L5178Y murine T cell lymphoma, with human Raji cells, and with several normal cells. Further analysis of its ligand binding capacity disclosed strong binding to single-stranded DNA (ssDNA). However, this naturally-occurring monoclonal antibody binds to different epitopes on cell membranes and on DNA than another anti-DNA monoclonal antibody (18/103/1) from human origin. This conclusion was based on competition assays. Furthermore, NOA 1.67 lacks the 16/6 idiotype expressed on the 18/103/1 antibody. The 16/6 idiotype is shared by human and mouse lupus monoclonal autoantibodies that bind simultaneously to lymphoid cells and DNA. This is a first report on a natural autoantibody that binds to malignant and to normal cell membrane(s) as well as to ssDNA. It may have regulatory functions controlling malignancy and or autoimmunity.

Animals↗
PubMed1987

Human monoclonal antibodies derived from lymph nodes of a patient with breast carcinoma react with MuMTV polypeptides.

Nine human hybridoma cell lines were established from a fusion of axillary lymph node lymphocytes of a patient with breast ductal carcinoma with a human lymphoblastoid cell line. The human hybridoma nature of the fusion products was confirmed by chromosomal analysis and HLA typing. The hybridomas are stable over a year of growth, and can be frozen, thawed and regrown. The carcinoma cells of the patient harbor mouse mammary tumor virus (MuMTV) cross-reacting antigens. The patient's serum and the purified monoclonal antibodies reacted with MuMTV polypeptides. Radioimmunoprecipitation studies using labeled MuMTV confirmed the binding of the patient's serum to the viral proteins. None of the control immunoglobulins reacted with the virus. No binding of the hybridoma immunoglobulins was observed with two other retroviruses (avian myeloblastosis virus and simian sarcoma virus). The ligand binding characteristics of the monoclonal antibodies suggest binding to epitopes on the various structural virus polypeptides. These monoclonal antibodies may serve as a probe to analyze the MuMTV-human breast carcinoma relationship.

Adult↗
PubMed1987

Human monoclonal antibodies derived from pleural effusion lymphocytes of a patient with breast carcinoma react with human breast cancer-associated antigens and mouse mammary tumor virus polypeptides.

Four human hybridoma cell lines (PEB1-4) were established from a fusion of pleural effusion lymphocytes isolated from a breast cancer patient with metastatic disease, 6 years postmastectomy. The hybridomas secreted IgG-k (3 micrograms/ml/10(6) cells). These monoclonal antibodies (PEB1-4) reacted to different degrees with mouse mammary tumor virus (MMTV) and T47D particles (HuMTV). Immunological cross-reaction was also detected with antigens isolated from body fluids of breast cancer patients (BF-Ag). The binding capacity of the monoclonal antibodies (MAbs) PEB1-4 to the above-mentioned antigens was measured by RIA. The specificity of these antibodies was further demonstrated by radioimmunoprecipitation of MMTV, T47D (HuMTV) and BF-Ag. The binding of PEB1-4 to surface antigens of intact cells grown in culture was measured by RIA. Some of the MAbs were shown to bind more avidly to breast cancer cells than to nonbreast cancer cells or nonmalignant cells. The PEB1-4 human monoclonal antibodies may be found useful in analyzing the virus-breast cancer relationship.

Aged↗
PubMed1985

Human lupus monoclonal autoantibodies bind to Raji cells.

Seven of 60 human monoclonal anti-DNA autoantibodies derived from 3 patients with SLE were shown to bind to Raji cells by radioimmunoassay. The binding of the lupus autoantibodies to the Raji cells in solution was not affected by prior incubation of the cells with DNase. Preincubation of the monoclonal autoantibodies with polynucleotides and cardiolipin, resulted in significant inhibition which correlated with the direct binding characteristics of these antibodies. Previous results with mouse IgG monoclonal anti-DNA antibodies supported by our results with human IgM anti-DNA autoantibodies suggest caution in interpreting analyses of immune complexes of sera containing anti-DNA antibodies entailing Raji cells.

Antibodies, Monoclonal↗
PubMed1984

A radioimmunoassay with monoclonal antibodies for the detection of antigenic cell-free Fc receptor.

Making use of 125I-labelled monoclonal rat antibodies against mouse Fc receptor we have developed a solid-phase radioimmunoassay for cell-free antigenic mouse Fc receptor (FcR). An 80% acetone solution was used for fixation of relatively large amounts of soluble proteins on PVC microtiter plates. As a result of this treatment FcR practically lost its activity to bind the Fc portion of an IgG molecule but retained its antigenicity, the binding of specific anti-FcR (aFcR) antibody being increased following acetone fixation. Concentrations of cell-free FcR in NP-40 extracts of FcR-expressing cells were calculated from the linear part of a standard curve and expressed in units of antigenic activity, 1 unit being the amount of antigenic FcR capable of binding 1 microgram of 125I-aFcR. The method may be used for detecting cell-free FcR as a minor constituent in a mixture of proteins.

Acetone↗
PubMed1982

Serologically detectable MHC and tumor-associated antigens on B16 melanoma variants and humoral immunity in mice bearing these tumors.

We compared the expression of serologically detectable MHC and tumor-associated antigens on low and high metastasis variants of B16 melanoma tumor. Complement-dependent cytotoxicity, radioimmunobinding, and quantitative absorption assays showed that with respect to both types of antigens the low metastasis variant B16-F1 expressed a higher serologically detectable antigenicity than B16-F10, its high metastasis counterpart. A reverse situation existed in terms of in vivo immunogenicity of these metastasis variants. Sera from C57BL/6 mice bearing locally growing B16-F10 tumors had a higher binding activity to B16 cells than sera from B16-F1 bearers. Accordingly, in vivo propagating B16-F10 tumors had a higher content of tumor-associated Ig than B16-F1 tumors.

Animals↗