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A Lukowsky

Publications and source records attributed to A Lukowsky.

At least 37 records · Page 2Linked to original sources
PubMed1994

VH/VL gene expression in polyreactive-antibody-producing human hybridomas from the fetal B cell repertoire.

Among a panel of nearly 3,000 IgM-producing hybridomas obtained from 22 independent fusions of human fetal lymphocytes (liver/spleen; 15th-36th gestational week) a high number (5-10%) produced autoantibodies, independently of the gestational age. A significant portion of these autoantibodies was found to be polyreactive, i.e. capable of binding to more than two antigens, when tested against a set of five antigens of the internal (ssDNA, thrombocytes, keratin) and external (lipid A, tetanus toxoid) environment. Analyzing the IgVH genes utilized in eight polyreactive and two putatively nonpolyreactive hybridomas, members of the VHI, III, IV and VI families were found once, seven times, once and once, respectively, mostly with germline identity. All but one of the utilized gene elements could be related to the biased VH gene repertoire said to be expressed during the early ontogeny of the human immune system. We also noted a bias for the utilization of DN1 (3/10), DHQ52 (3/10), JH2 (4/10) and JH6 (4/10) elements, whereas all heavy-chain CDR3 regions manifest a diversity by addition of N nucleotides and/or exonuclease activity on coding segments. In addition, VL segments which belong to different subgroups of both isotypes were found to be used. The molecular basis of polyreactive immunoglobulin specificities in human fetuses is discussed.

Antibodies, Bispecific↗
PubMed1992

An enzyme-linked immunosorbent assay for the quantification of solubilized CD14 in biological fluids.

A simple and robust two site-binding ELISA for the quantification of solubilized CD14 in human and animal body fluids is described. The principle of the assay depends on the specific binding of sCD14 to two monoclonal antibodies (MEM-18, RoMo-1) recognizing different epitopes of this glycoprotein. The detection limit for sCD14 was 1 ng/ml. The method was used to quantify sCD14 in different biological fluids, giving an intra-assay coefficient of variation and an interassay coefficient of variation of about 9%. The assay was used to measure sCD14 in human serum and plasma and other body fluids in health and disease, and in cell culture supernatants. With the exception of monkeys there was no reactivity with 29 other species screened. In healthy volunteers the sCD14 serum level had a mean value of 3.98 +/- 0.3 micrograms/ml (mean SEM, n = 102).

Antibodies, Monoclonal↗
PubMed1992

CD3+ CD57+ lymphocytes are not likely to be involved in antigen-specific rejection processes in long-term allograft recipients.

Cytofluorometric investigation of peripheral blood lymphocytes in 380 long-term (greater than 1 year posttransplantation) allograft recipients showed a significant increase in the proportion of CD3+57+ lymphocytes (greater than 20%) in 20% of patients with renal allografts, 66% of patients with cardiac allografts and 44% of patients with liver allografts. Most of these CD3+57+ cells expressed the CD8 antigen and a variable proportion the HLA-DR antigen. A retrospective analysis showed a poorer prognosis for the clinical outcome in those patients with elevated numbers of CD3+57+ cells in peripheral blood. However, CD57+ lymphocytes could rarely be detected in renal infiltrates by immunohistology. Using the Southern blot technique to analyse the T cell receptor rearrangement of separated CD57+ cells, no clonal or oligoclonal expansion of T cell clones could be detected. Nevertheless, there might be a bias towards the use of particular TCR-V beta gene families in at least some patients, as shown by analysis with monoclonal antibodies. In summary, CD57+ T cells are not likely to be directly involved in the rejection process. The data support the idea of a polyclonal and/or superantigen-driven expansion, but not of an antigen-driven expansion of these cells.

Antigens, CD↗
PubMed1991

Human hybridomas derived from CD5+ B lymphocytes of patients with chronic lymphocytic leukemia (B-CLL) produce multi-specific natural IgM (kappa) antibodies.

Great numbers of CD5+ B lymphocytes were detected in the peripheral blood of patients with B-CLL. To study the antibody repertoire of this immune cell subpopulation on a monoclonal level, we fused the lymphocytes derived from five different donors to a highly efficient HAT-sensitive heteromyeloma line (CB-F7). A fusion frequency of up to 10(-5) allowed us to analyse hundreds of initial hybridoma lines per fusion. In all culture supernatants in three out of five fusions IgM lambda antibodies were detected, in two experiments only IgM kappa was measured, suggesting monoclonality of the primary hybridoma cell lines. The later fusions resulted in hybridomas producing multi-specific antibodies against both an autoantigen and an infectious agent: (i) dsDNA/influenza virus haemagglutinin; (ii) dsDNA/class V outer membrane protein type C from Neisseria meningitidis. However, no antibodies of the described specificity were detected in blood sera of patients, indicating a 'switch-on' of the immunoglobulin secretion capacity of malignant B cells during fusion to a myeloma partner. We discuss the results as further evidence for the natural multi-reactive antibody repertoire of CD5+ B cells.

Adult↗
PubMed1991

Development of a solid phase enzyme immunoassay for the detection of anti-Ro autoantibodies.

An enzyme immunoassay was developed to detect anti-Ro(SS-A) autoantibodies. Both Ro-antigen components (52 and 60 kD) were purified from a pig spleen extract, using fast protein liquid chromatography (FPLC). Anti-La, anti-RNP, anti-DNA and anti-Sm antibodies do not react to the purified antigen. There was a strong correlation between anti-Ro activity in EIA and the titers in counter immunoelectrophoresis (rs = 0.893). Anti-Ro antibodies were found in 54 (69.2%) of 78 SLE sera by the developed EIA.

Animals↗
PubMed1990

[Structure and function of the immunoglobulin Vh gene in man].

The present study provides a survey on the structure and functions of human Vh-genes. The more than 100 individual gene segments on chromosome 14 are classified, according to sequence homologies, into 6 families. They differ very much in size and contain pseudogenes, form an interspersed cluster, exhibit homologies with mouse genes and have phylogenetically developed from a single primordial gene. There seem to be no association of antibody specificities with distinct Vh genes or families. Reports of preferential VH gene usage in the fetal stage or in autoantibody synthesis require confirmation. Vh genes for Ig production in the adult mammalian organism are, most probably randomly selected.

Antibody Specificity↗
PubMed1989

Occurrence of hybridomas producing multispecific IgM in human x (human-mouse) fusions with lymphocytes from different human immune compartments.

Human lymphocytes derived from peripheral blood, the spleen and lymph nodes were fused to the HAT-sensitive heteromyeloma cell line CB-F7. The Ig-producing initial cell lines were selected, and the supernatants were further analyzed for specific antigen binding (ELISA). IgM-antibodies were found which reacted with self- and non-self antigens of different molecular origin (nucleotides, proteins, carbohydrate structures). These antibodies were called multireactive (multispecific). The multispecific IgM-producing human hybridomas occurred with higher frequencies in the spleen (6.9% of IgM-producers) cell fusions than in experiments where peripheral blood-derived lymphocytes were fused (2.7%). There were no hybridomas producing multireactive antibodies detected in fusion material from lymph nodes. The greatest number of multireactive IgM was seen when PBL from SLE or anti-HIV-positive patients were hybridized to CB-F7 cells. Representative cell lines were cloned and recloned. The multireactivity of the IgM produced by really monoclonal cells, however, was preserved.

Animals↗
PubMed1987

[Fibronectin concentrations in the plasma of newborn infants and their mothers and various plasma preparations].

The article describes a method for the quantification of plasma fibronectin (FN) by means of electroimmunodiffusion after Laurell. By this means the fibronectin concentrations of healthy, mature newborns as well as of their mothers were determined. The average FN-level of the newborns lies at 33% related to the value for adults and at 48%, respectively, related to the maternal FN-content. There is no difference between male and female newborns. The FN-concentrations of the adults stated by us with 330 and 314 mg/l, respectively, for males and females correspond to the data in literature. Furthermore, the FN-content in plasma preparations was determined, with an average value of 2,356 mg/l this was highest in the factor-VIII-concentrate. The expediency and the prerequisites for a possible fibronectin substitution are discussed.

Blood Transfusion↗
PubMed1986

[The role of fibronectin in nonspecific defense from the immunologic viewpoint].

The present article gives a review of the essential data of literature concerning the importance of fibronectin (Fn) for the unspecific defence. In this case the function of Fn postulated as unspecific opsonin stands in the foreground. Fn mediates the binding of gelatine particles, bacteria and other above all particular materials on phagocytizing cells (monocytes, macrophages and neutrophils). Up to now it is, however, controversial whether or not this binding causes an increased endocytosis. The participation of cofactors or inhibitors and the problem whether Fn or certain proteolytic Fn-fragments are effective still need a further clarification. Fn, its fragments or Fn-substrate-complexes can activate phagocytes and have a chemotactic effect on them. The mechanism of activation is still unknown, for monocytes in increased expression of Fc- and C3b-receptors is supposed. Fn might consequently perform a defence function as an unspecific cell activator and at the same time have a pro-inflammatory influence. There are controversial opinions as to the questions which phagocytes are activated and which Fn-molecules (complete plasma-Fn or fragments) are responsible. The high sensitiveness of Fn to proteolytic enzymes and denaturating processes is supposed to be one of the causes for the different results.

Animals↗
PubMed1986

Pokeweed mitogen induced synthesis of human IgG and IgM in vitro. Technical aspects and the role of adherent cells.

The Pokeweed mitogen (PWM)-inducing in vitro synthesis of human IgG and IgM was determined by enzyme immunoassay (EIA) in culture supernatants of PWM-stimulated peripheral blood lymphocytes (PBL) from 83 healthy donors ranging from 24-46 years. Seventy five per cent were characterized as normal responders (200-2000 ng/ml IgG and IgM), 10% classified as high responders (2000-3000 ng/ml), and another 10% had a very high response (more than 5000 ng/ml of both IgG and IgM). One of 83 donors was shown to be a PWM non-responder. In 83 unstimulated cultures from the same donors 660 +/- 75 ng/ml IgG and 60 +/- 10 ng/ml IgM were measured after 8 days of incubation. Ten donors exhibited similar dose dependence of PWM-induced Ig synthesis but differed in time kinetics (optimum between 8 and 12 days of culture). Regression analysis of IgG and IgM production in 83 PWM-stimulated lymphocyte cultures from different healthy donors showed a correlation coefficient of r = 0.627. Intracellular Ig in PWM-stimulated cells was quantified by EIA technique after cell lysis in time kinetic experiments. Reproducibility and accuracy of the test system are described in detail. An excess of monocytes of more than 20% in the culture caused an inhibition of the Ig synthesis (calculated on constant numbers of B cells). Monocytes were further immobilized in FCS-coated culture plates and pulsed with PWM for 2 h. Adding unstimulated, nonadherent cells to the plates after removing the mitogen resulted in an Ig production comparable to that with the classical method.

Adult↗
PubMed1984

No inhibition of the lymphocyte transformation by pregnancy-associated alpha 2-glycoprotein (PAAG).

Fractions of retroplacental sera containing pregnancy-associated alpha 2-glycoprotein (PAAG) inhibited the lymphocyte transformation. The inhibitory effect did not correlate to the amount of this protein. It remained even after a specific depletion of the PAAG without altering the composition of the other proteins in the sera fractions. These results rule out a suppressive activity of the PAAG in the lymphocyte transformation.

Humans↗
PubMed1982

Quantitation of a pregnancy associated globulin in the rat by two-site binding enzyme immunoassay.

An indirect two-site binding enzyme immunoassay has been developed to quantify the pregnancy associated globulin (PAG) in rats. Anti-PAG from guinea pig is adsorbed to solid phase and binds serum-PAG, which then reacts with its remaining free determinants with anti-PAG from rabbit. Sheep anti-rabbit IgG, labeled with horse radish peroxidase (HRP), binds to the rabbit anti-PAG antibody and the enzymic activity of the solid phase is measured by incubation with the appropriate chromogenic substrate. The optical density is directly related to the quantity of PAG to be measured. Reproducible results are obtained in the range from 5 to 200 micrograms/l. The test detects 12 fmoles of PAG. Female rats show a 1000-fold higher serum level of PAG than male rats. Strain differences of the distribution of the PAG serum concentration were only found between male rats.

Animals↗
PubMed1981

Preparation of human alpha-2-macroglobulin by chromatography on Cibacron Blue Sepharose in the presence of pregnancy- associated alpha-2-glycoprotein.

The simple and efficient procedure for the isolation of alpha-2-macroglobulin (alpha-2-M) from human sera (hp-type 1-1) by means of affinity chromatography on Cibacron Blue Sepharose is not convenient to separate it from pregnancy-associated alpha-2-glycoprotein (alpha-2-PAG) which is present in high amounts in sera of estrogen-treated women, at pregnancy, and under other conditions. With this method both proteins are eluted in the same fractions; gel filtration of these fractions does not lead to their separation. Therefore, the use of male sera (tesed by monospecific antisera to alpha-2-PAG) with low alpha-2-PAG, content (hp-type 1-1) is recommended for alpha-2-M preparation.

Anthracenes↗