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Biomedical subjects

T Ternynck

Publications and source records attributed to T Ternynck.

At least 55 records · Page 3Linked to original sources
PubMed1986

Autoimmunity induced by HgCl2 in Brown-Norway rats. II. Monoclonal antibodies sharing specificities and idiotypes with mouse natural monoclonal antibodies.

Spleen cells derived from BN rats receiving HgCl2 were fused with the nonsecreting rat myeloma cell line IR983F. We screened 59 supernatants from immunoglobulin-secreting hybrids for antibody activity against actin, tubulin, autologous and heterologous myosin, myoglobin, dsDNA, peroxidase, and the haptens TNP, NIP, NNP, and NBrP. Six monoclonal antibodies (mAb) were found to react with antigen(s) of the panel. At least three groups of antibody specificities were identified: clones reacting with TNP (1 IgM, 1 IgE); clones reacting with horseradish peroxidase (1 IgM); and clones possessing widespread reactivity for several antigens as found for mouse natural autoantibodies (2 IgM, 1 IgE). We also analyzed the idiotypic (Id) determinants of the 59 mAb by using anti-Id antibodies described elsewhere prepared in rabbits against the BALB/c D23 natural monoclonal autoantibody and recognizing a BALB/c recurrent Id (Id D23) of natural polyspecific autoantibodies. We found that all rat mAb that possessed widespread reactivities bore this Id. We performed similar studies in sera from normal and mercury-stimulated rats. The results indicate a role for HgCl2 in the stimulation of natural antibodies producing cells and the existence of interspecies cross-reactive Id among mouse and rat natural antibodies.

Animals↗
PubMed1986

Murine natural monoclonal autoantibodies: a study of their polyspecificities and their affinities.

We have demonstrated that natural monoclonal antibodies (NmAbs) prepared from the spleens of either adult or neonatal non-immunized mice are polyspecific, i.e., they react with various self or non-self antigens. In the present study the polyspecificity of several NmAbs is analyzed in terms of dissociation constants (KDs) using a recently published sandwich-type immunoassay (Friguet et al. 1985). We calculated the NmAb KDs for various croos-reacting self (actin, myosin, tubulin, DNA) or non-self (spectrin, DNP-lysine, TNP-protein) antigens, and we compared the values obtained with those of experimentally-induced antibodies derived from immunized animals. The results show the NmAb KDs for macromolecule range between 10(-5) and 10(-10)M and, for a given antigen they are often of the same order of magnitude as those of induced monoclonal or polyclonal antibodies. On this basis, it appears that antibody specificity and affinity do not always correlate. In contrast to those of induced antibodies, the KDs for free hapten are high, whereas they are low when the same hapten is complexed to a macromolecule. Thus, it seems that although NmAbs and induced antibodies exhibit similar "functional affinities" for a macromolecule, they differ in their "intrinsic affinities" for a given epitope (hapten). Although the NmAbs examined exhibit similar broad reactivities for several antigens, their fine specificities for these antigens, as defined by the measurement of their KDs, are different. Thus, it appears that each NmAb can be considered unique.

Animals↗
PubMed1985

Quantitation of 5-bromo-2-deoxyuridine incorporation into DNA: an enzyme immunoassay for the assessment of the lymphoid cell proliferative response.

As an alternative to the measurement of radiolabeled thymidine incorporated into DNA, a method is presented in which thymidine has been replaced by its analogue, 5-bromo-2-deoxyuridine (BUdR). BUdR incorporated into DNA (BUdR-DNA) is measured by a sandwich-type enzyme immunoassay using a monoclonal anti-BUdR antibody. This method allows the quantitation of 4 ng of BUdR-DNA. Comparative experiments with myeloma cells and LPS stimulated spleen B-cells have shown that this technique is at least as sensitive as the traditional counting of [3H]thymidine.

Animals↗
PubMed1985

Mapping of the pattern of DNA replication in polytene chromosome from Chironomus thummi using monoclonal anti-bromodeoxyuridine antibodies.

We present results from a nonautoradiographic study of DNA replication in polytene chromosomes from dipteran larvae. Monoclonal antibodies with specificity for 5-bromodeoxyuridine (BrdUrd) were used to localize by indirect immunofluorescence the sites of BrdUrd incorporation and to follow the dynamics of DNA synthesis in salivary gland cells of 4th instar Chironomus thummi larvae. This technique presents numerous advantages over autoradiographic procedures and allows mapping of DNA synthesis patterns at the level of resolution of one chromosomal band. Several replication patterns were observed, classified according to characteristic features, and tentatively assigned to specific periods of the S-phase. In early S-phase, DNA synthesis is first detectable in puffs and interbands, later in bands. Most chromosomal bands appear to initiate DNA synthesis synchronously; however, in bands within centromeric and heterochromatic regions the start of synthesis is delayed. At mid S-phase, all the bands show uniform staining. Subsequent staining patterns are increasingly differential with the bands displaying characteristic fluorescence intensities. As replication progresses through the late S-phase period, the chromosomes show a decreasing number of fluorescent bands. The last bands to terminate replication are located in centromeric and heterochromatic DNA-rich regions and a few bands of low DNA content in region IIAa-c.

Animals↗
PubMed1985

A high incidence of cross-reactive idiotypes among murine natural autoantibodies.

Anti-idiotypic (anti-Id) antibodies were produced in rabbits against two natural monoclonal IgM autoantibodies (NmAb), D23 and E7, which exhibited a broad reactivity and were derived from fusions of spleen cells from adult unprimed BALB/c mice and nonsecreting myeloma cell lines. They were used to test the reactivities of 12 NmAb obtained from adult and newborn unprimed mice. Both anti-Id recognized cross-reactive idiotopes frequently shared by NmAb; 8 out of the 12 NmAb reacted with anti-IdD23, while 5 of them also reacted with anti-IdE7. All of the Id-bearing antibodies possessed widespread reactivity with structurally dissimilar self and nonself antigens. In most cases, their cross-reactive Id determinants seemed to be located outside of their antigen-binding sites. Furthermore, the presence in normal mouse sera of significant levels of D23 and E7 idiotopes correlated with the presence of natural antibody activity and was mainly associated with IgM and IgG2b fractions. Finally, D23 idiotope(s) were also found on induced murine anti-myosin antibodies. The high incidence of cross-reactive idiotopes found among NmAb produced by clones derived from different mice and their presence in normal BALB/c mouse serum Ig fractions suggest that families of germ-line genes may encode for at least a part of them.

Animals↗
PubMed1984

An antibody chimera technique applied to enzyme immunoassay for human alpha-1-fetoprotein with monoclonal and polyclonal antibodies.

A 2-step enzyme immunoassay (EIA) for human alpha-1-fetoprotein (AFP) is proposed, which uses covalently coupled anti-AFP IgG and anti-horseradish peroxidase (HRP) IgG (antibody chimera) binding HRP as the marker enzyme immunologically. The use of polyclonal and monoclonal anti-AFP linked to anti-HRP antibodies was compared with a conventional 2-site binding EIA with HRP covalently bound to anti-AFP IgG. The sensitivity of the conventional EIA is increased by the use of an antibody chimera comprising a molar ratio of anti-AFP IgG: anti-HRP IgG of 1:8, especially if monoclonal antibodies are employed. This improved sensitivity may be achieved by a very simple coupling procedure without purification of conjugate and with very crude HRP preparations.

Animals↗
PubMed1983

Enzyme/anti-enzyme monoclonal antibody soluble immune complexes (EMAC): their use in quantitative immunoenzymatic assays.

Enzyme/anti-enzyme antibody soluble immune complexes were prepared with monoclonal mouse antibodies (MA) which were directed against peroxidase (PO) and beta-galactosidase (GAL). These enzyme monoclonal antibody complexes (EMAC) functioned as markers to quantify mouse antibodies using an enzyme immunoassay which incorporated an anti-mouse Ig as the bridge between the EMAC and the specific antibody bound to an antigen immobilized on a polystyrene plate. EMAC prepared with PO (PO-MAC) or with GAL (GAL-MAC) were both effective in quantifying polyclonal as well as monoclonal mouse antibodies, and gave sensitivity equal or superior to that obtained with covalent enzyme/anti-mouse Ig conjugates. The smaller amount of antibodies detected with EMAC depended on the affinity of both the antibody tested and the monoclonal antibody used to prepare EMAC. This method is an improvement on the 'antibody bridge' method, because EMAC can be prepared easily by simply mixing the enzyme and the MA at the appropriate amounts 2 h prior to use. In addition, EMAC can be prepared using crude preparations of enzyme and unpurified ascitic fluids containing the MA, thus decreasing the cost of the test considerably.

Antibodies, Monoclonal↗
PubMed1982

A general method for the cytochemical and ultrastructural studies of human lymphocyte subsets defined by monoclonal antibodies.

After incubation with monoclonal mouse antisera raised against membrane differentiation antigens, subsets of human lymphocytes can be detected by means of latex microspheres or ox erythrocytes coated with anti-mouse Ig antibodies. Optimal conditions are described using a panel of monoclonal antisera (Ortho Pharmaceuticals and New England Nuclear). The method is as sensitive as the complement-mediated microcytotoxicity assay, is rapid, easy to perform and permits exhaustive light and electron microscopic studies of lymphocytes bound to the carrier particles. The advantages of the simultaneous analysis of cytological features and monoclonal antibody-defined surface markers in normal and pathological individual lymphocytes are discussed with regard to lymphoid cell maturation and neoplastic lymphocyte classification.

Animals↗
PubMed1979

The use of avidin-biotin interaction in immunoenzymatic techniques.

Biotin was covalently attached to antibodies, antigens and enzymes, and the effects of this labeling on the antigen and antibody binding capacity and on enzymatic activity were tested. Based on avidin-biotin interaction, the labeled proteins were used in quantitative enzyme-immunoassay and enzyme-immunohistochemical staining procedures. Two procedures were developed. In the first procedure, named the Bridged Avidin-Biotin (BRAB) technique four steps were used sequentially in order to quantify or detect an immobilized antigen: 1) incubation with biotin-labeled antibody; 2) incubation with avidin; 3) incubation with biotin-labeled enzyme; 4) measurement or histochemical staining of the enzyme. The technique is based on the observation that avidin possesses four active sites. In the second procedure, named the Labeled Avidin-Biotin (LAB) technique, biotin-labeled antibody and enzyme-labeled avidin are used sequentially. Enzyme-associated antigen is then quantified or revealed immunohistochemically. The optimal conditions for enzyme-immunoassay and enzyme-immunohistochemical staining using BRAB and LAB procedures were established.

Animals↗
PubMed1979

Subpopulations of Ig-secreting cells induced by peroxidase immunization: discrimination according to antibody storage and secretion.

Mice were injected in their hind footpads with peroxidase (PO) emulsified in Freund's complete adjuvant. The development of cells secreting anti-peroxidase antibody (Ab) and cells secreting immunoglobulins (Ig) were detected in the draining popliteal lymph nodes in the subsequent 35 days, using local haemolysis plaque assay with sheep red cell blood cells coated with either PO or anti-mouse Ig antibody. Plaque-forming cells (PFC) were isolated from the centre of plaques by micromanipulation and after appropriate treatment, were examined by electron microscopy for their intracellular Ab content and in corporation of [3H]-thymidine. Four subpopulations of Ig secreting cells were distinguished: (1) cells secreting Ig without Ab function and not containing intracellular Ab detectable between days 5 and 20; (2) cells secreting Ig without Ab function but containing Ab appearing on day 6 and present throughout the immune response; (3) cells secreting Ab and containing Ab; (4) cells secreting Ab, but without detectable intracellular Ab. These last subpopulations appeared on day 7 and were found in all subsequent assays. The analysis of the kinetics of these subpopulations suggest that cells secreting Ig without Ab function might be precursors of Ab secreting cells.

Animals↗
PubMed1977

Contribution of quantitative immunocytology to the study of lymphoid hemopathies.

Forty-three patients with a lymphoid hemopathy, three with agammaglobulinemia and six normal controls were investigated with regard to their blood lymphocyte membrane-associated light chains. Detection and quantitation of antigenic determinants were performed by means of peroxidase-labeled antibodies. Compared to normal controls, values found in chronic lymphocytic leukemia (CLL) were very low (tenfold decrease). The number of antigenic determinants on lymphoid cells from patients with blast crises supervening in CLL, prolymphocytic leukemia, Waldenström's macroglobulinemia and Burkitt-cell acute leukemia were significantly higher than those seen in patients with CLL. The data obtained in this investigation through quantitative immunocytology constitutes a new parameter for the classification of lymphoid hemopathies and for an approach to their pathogenesis, in particular if the quantity of membrane immunoglobulin correlates with the stage of cell maturation.

Adult↗
PubMed1976

Methods for identification of recombinants of phage lambda.

Two methods are described which allow the screening of a large number of phage plaques for a specific DNA sequence carried by the phage or a specific antigen produced within the phage plaque. These methods were set up with lambda and lambdalac phages. Phage plaques were transferred onto nitrocellulose filters by desiccation in 0.1 M NaOH, and the lac sequence was detected by hybridization to radioactive lac mRNA. Beta-Galactosidase was detected by reaction with anti-beta-galactosidase immune serum included in the soft agar of the titration plates; the precipitate thus formed was revealed by means of enzyme-coupled antibodies and in situ coloration. These methods are potentially useful for the identification of lambda transducers, including those which are generated by in vitro recombination with eukaryotic DNA.

Base Sequence↗
PubMed1976

Comparison of normal and chronic lymphocytic leukemia lymphocyte surface Ig determinants using peroxidase-labeled antibodies. II. quantification of light chain determinants in atypical lymphocytic leukemia.

Five cases of atypical lymphocytic leukemia were investigated with regard to their membrane-associated light chains. Detection and quantitation of antigenic determinants were performed by means of peroxidase-labeled antibodies according to Avrameas et al. The cases studied had clinical and cytologic features in common: an active clinical course, marked splenomegaly, severe anemia and thrombocytopenia, little or no lymph node enlargement, and very high white blood counts with small mature lymphocytes and poorly differentiated lymphoid cells. Blood lymphocytes of all patients carried a single type of light chain, and 90%-100% of the cells were stained. The average number of antigenic sites per cell was 72,500 (range 40,000-97,500). These results differed from those previously found in typical CLL (mean value 9000) and approached the values of normal peripheral blood lymphocytes (90,000). The criteria investigated in this study could be of value for the diagnosis and prognosis of some atypical forms of lymphocytic leukemia.

Aged↗