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Biomedical subjects

L Borecký

Publications and source records attributed to L Borecký.

At least 37 records · Page 2Linked to original sources

Monoclonal antibodies neutralizing the antiviral and the antiproliferative activities of human interferon gamma.

Spleen cells from BALB/c mice immunized with human leukocyte interferon gamma (HuIFN-gamma) were fused with mouse NSO myeloma cells. Nine hybridoma lines were found secreting monoclonal antibodies (MoAb) which were able to neutralize the antiviral activity of HuIFN-gamma. All nine MoAb inhibited also the antiproliferative activity of HuIFN-gamma. The ability of tested MoAb to inhibit both the antiviral and antiproliferative activities of HuIFN-gamma supports the suggestion that a common domain on HuIFN-gamma molecule might be responsible for both biological activities. However, ELISA and/or RIA proved unsuitable for detection of these specific MoAb.

Animals↗

The effect of postfusion cell density on establishment of hybridomas.

The effect of postfusion cell density on establishment of hybridomas in primary microculture was studied. Following fusion of BALB/c spleen and NS0 myeloma cells in the ratio of 5:1 we demonstrated that seeding the cells at a concentration of about 20-25 X 10(4) spleen cells per well resulted in maximal number of wells containing only one growing hybridoma clone (40.1-43.7% plated wells). Importance of generation of microculture with one clone for the effectiveness of preparation of mAb-secreting hybridomas is discussed.

Animals↗

Current view on the perspectives of interferon therapy.

In recent years, impressive progress has been made towards the understanding of the molecular biology of interferon. Unfortunately, this progress was not accompanied by a parallel elucidation of the role of interferon in the animal organism. The feeling prevails that what we know about interferon today is only the peak of an iceberg showing interferon types and subtypes as a part of an insufficiently delineated system of cell-regulatory polypeptides (lymphokines, hormones) acting in a concerted way with other regulatory cells (such as NK-cells, macrophages) and their products (such as IL-2 etc.). An imbalance of this system may probably itself lead to disease (autoimmune diseases) and its disturbed functioning may hinder the therapeutic exploitation of its components in substitutive therapy (cancer).

Animals↗

Preparation and characterization of hybridomas secreting monoclonal antibodies to tick-borne encephalitis virus.

Monoclonal antibodies (MA) were prepared to two strains of tick-borne encephalitis (TBE) virus: strain 4072 isolated from a patient in the U.S.S.R. and low-pathogenic for mice strain Skalica, isolated from a bank vole (Clethrionomys glareolus) in Slovakia. MA specific to the 4072 and Skalica strains were produced by hybridomas of the KEN (60 clones) and NEK (65 clones) series, respectively. Chromosomal analysis of MA producing 114 hybridoma clones of both series revealed a great variability in the number of chromosomes either in the range of given clones or between individual clones. The hybridoma cells under study possessed a high degree of transformation manifested by good growth in the mouse peritoneal cavity and marked accumulation in ascitic fluid (AF).

Animals↗

Preparation and characterization of hybridomas producing monoclonal antibodies against human alpha interferon.

Hybridomas producing monoclonal antibodies against human alpha interferon (hu-IFN alpha) were constructed by fusion of NSO myeloma cells with spleen cells of BALB/c mice immunized with purified hu-IFN alpha. Altogether, 527 hybridomas were prepared in two separate experiments. From this cohort of hybridomas, 51 produced monoclonal antibodies against hu-IFN alpha. Seventeen out of fifty one hybridomas produced antibodies with neutralizing capacity for IFN while 34 hybridomas produced monoclonal antibodies with binding ability not accompanied with the neutralization of biological activity of IFN. The specificity of antibodies was determined with 3 types of tests: ELISA, ELISAN (modified ELISA) and neutralization test. Using isotype analysis, it has been found that 23 monoclonal antibodies were of IgM class, 20 were of IgG1 subclass, 4 were of IgG2b and 4 of IgG3 subclass. The average number of chromosomes in hybridomas was between 61.35 and 78.55. Their average doubling time was between 13.95 and 25.76 hrs.

Animals↗

Clinical and immunological characterization of systemic lupus erythematosus in patients with circulating interferon and migration inhibitory factor.

The simultaneous occurrence of interferon and migration inhibitory factor was found in sera from 9 patients with systemic lupus erythematosus (SLE). Their clinical picture was characterized by a moderate course of the disease. In 7 patients the inflammatory tendoarticular manifestations were accentuated. Glomerulonephritis was found only in 3 patients and was successfully suppressed by immunosuppressive therapy. In the peripheral blood of most of these patients, normal or moderately increased levels of active E-rosettes were found. Therefore we consider these SLE patients as a group with characteristic signs of activated cell-mediated immunity (lymphokine release, active E-rosettes). Although the reason for this activation remains unknown, we suppose that some concomitant bacterial infection, perhaps mycobacterial, may contribute to this immunological phenomenon.

Adult↗

Interferon as therapeutic agent.

The article summarizes the present status of interferon (IFN) research from therapeutical point of view. This includes its understanding as an antiviral agent and a cell regulator of hormonal- and/or cytokine-type. The IFN seems to represent a part of a balanced multisystem of unsharp contoures. In addition to the analysis of published therapeutical trials, the conclusion is made that without a deeper insight in the functioning of this system, it is difficult to create a rational base for IFN therapy of viral, oncological and/or autoimmune diseases of man.

Animals↗

Interferon-induced changes in the expression and topography of H-2 antigens and receptors for SRBC in tumour cells.

The expression of H-2 antigens has been investigated in methylcholanthrene-transformed C3H embryonic fibroblasts of clones 36 and 57. Private specificities H-2.23 and H-2.32, typical of the H-2k haplotype, were present on cells of the two clones but differed considerably in their expression. After interferon treatment, the expression of H-2 antigens increased in both clones, though more markedly in clone 57. Interferon treatment also affected the topography of H-2 antigenic determinants on the cell membrane. The blocking index for antigenic determinants coded by a single region of the H-2 complex increased in both clones. Between antigenic determinants controlled by two regions of H-2 the blocking index remained unaltered in clone 36 but decreased significantly in clone 57. Rosette formation with SRBC was consistent with the results of the blocking test between H-2K and H-2D antigenic determinants; rosette formation decreased slightly in clone 36 but increased in clone 57 after interferon treatment. All the results suggest that alterations in expression of H-2 antigens following interferon treatment are due to the rearrangement of the cell membrane rather than to the virtual increase in the number of H-2 antigenic determinants. Cells of clone 57 exhibiting more pronounced changes in the topography of H-2 antigens were more resistant to the inhibitory effect of interferon on cell growth.

Animals↗

Production of interferon and other lymphokines during murine tumour growth. III. Characterization of microbial growth inhibitory activity in cell-free supernatants of rat Zajdela ascites hepatoma.

A microbial growth inhibitory factor (MGIF) detected in the cell-free fluid of Zajdela ascites hepatoma of the rat was characterized by means of gel filtration, ion exchange chromatography and isoelectric focusing. It was shown that MGIF is a nondialysable protein with a molecular weight of about 19,000 to 25,000. Charge heterogeneity was revealed by isoelectric focusing which demonstrated pI of 3.8--4.5 and 5.0--6.0. MGIF seems to differ from tumour cell-derived MIF detected in the same ascitic fluids.

Ammonium Sulfate↗