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J Bubeník

Publications and source records attributed to J Bubeník.

At least 19 recordsLinked to original sources
PubMed1992

Use of IL-2 gene transfer in local immunotherapy of cancer.

Insertion of functional interleukin-2 (IL-2) gene into a plasmacytoma cell line X63-Ag8.653 substantially reduced tumorigenicity of the resulting cloned cells, designated as X63-m-IL-2. Peritumoral administration of the X63-m-IL-2 cells, producing constitutively large quantities of IL-2, resulted in regressions of established X63-Ag8.653 plasmacytomas growing in the peritoneal cavity of syngeneic mice. In vitro activation of BALB/c spleen cells by co-culture with X63-m-IL-2 cells or their supernatants gave rise to cytotoxic lymphocytes with lymphokine-activated killer (LAK) activity against syngeneic X63-Ag8.653 plasmacytoma and other tumor targets. In contrast, peritumoral administration of X63-Ag8.653 cells carrying an inserted interleukin-4 (IL-4) gene (designated X63-m-IL-4 cells) and producing constitutively large quantities of IL-4 did not result in a therapeutic effect. Moreover, the admixture of the X63-m-IL-4 and X63-m-IL-2 cells substantially diminished the X63-m-IL-2 cell-mediated therapeutic effect. Similarly, IL-4-containing supernatants generated from X63-m-IL-4 cell cultures substantially diminished LAK activation by X63-m-IL-2 cell produced supernatants.

Animals↗
PubMed1992

Chemoimmunotherapy of cancer: cyclophosphamide-resistant tumour cells are equally sensitive as the original tumour cell population to local IL-2 immunotherapy.

Chemotherapy and IL-2-mediated biotherapy represent two modalities of cancer treatment; combination of the two modalities could theoretically help to increase the efficacy of the treatment and decrease the doses as well as toxicity of both components if it could be shown that the chemotherapy-resistant tumour cells selected by treatment with cytostatics are not less sensitive to IL-2-mediated biotherapy than the original chemotherapy-sensitive tumour cell population. In this report we have tried to investigate whether the population of tumour cells selected by chemotherapy and resistant to a chemotherapeutic agent is more, equally, or less sensitive to IL-2 treatment than the parental tumour cell population. For these purposes, we have used a pair of homologous tumour cell lines differing in sensitivity to cyclophosphamide. It could be shown that both tumour cell lines, the CY-sensitive (MC 14) and CY-resistant (MC 14/8R) line were equally sensitive to local IL-2 immunotherapy. Similarly, comparison of the cyclophosphamide-sensitive and cyclophosphamide-resistant tumour target cells to LAK cell-mediated cytolysis in vitro revealed that both tumour cell populations were equally sensitive to the LAK cell effect.

Animals↗
PubMed1992

Interaction of interleukin 2 and interleukin 4 during LAK cell generation.

Immunoregulatory lymphokines IL-2 and IL-4 produced by IL-2- and IL-4-cDNA-transformed somatic cells were used for LAK cell generation. The cytolytic effect of LAK cells activated for 3 days with IL-2 and measured by 51Cr release of three types of target cells, YAC-1 (NK-sensitive), C1498 (NK-resistant) and X63-Ag8.563 (plasmocytoma cell line utilized for insertion of the IL-2 and IL-4 genes), was significantly depressed by adding IL-4 during the activation period.

Animals↗
PubMed1991

IL-2 gene transfer in immunotherapy of cancer: local administration of IL-2-activated lymphocytes and X63-m-IL-2 cells constitutively producing IL-2 inhibits growth of plasmacytomas in syngeneic mice.

Peritumoral administration of X63-m-IL-2 cells, transformed by IL-2 cDNA and constitutively producing large quantities of IL-2, was effective in mediating regression of X63-Ag8.653 plasmacytomas transplanted in syngeneic mice. Injection of killer cells with LAK activity substantially enhanced the tumor-inhibitory effect of IL-2-producing cells. In vitro activation of murine bone marrow and spleen cells with IL-2 produced by the X63-m-IL-2 cell line resulted in generation of lymphocytes with oncolytic activity against X63-Ag8.653 plasmacytomas and a variety of other target cell lines. The cytolytic activity of adherent IL-2-activated killer cells (A-LAK) was substantially higher than that of a nonadherent subset. Bone marrow and spleen cells from both healthy control and tumor-bearing mice contained LAK precursors, but the cytolytic activity derived from tumor-bearing mice was lower than that from healthy controls.

Animals↗
PubMed1990

Immunotherapy of cancer using local administration of lymphoid cells transformed by IL-2 cDNA and constitutively producing IL-2.

Peritumoral administration of X63-m-IL-2 cells transformed by IL-2 cDNA and constitutively producing large quantities of recombinant IL-2 mediated regression of X63-Ag8.653 plasmocytoma and MC14 sarcoma transplanted in syngeneic mice. Injections of the IL-2-producing cells containing an inserted, modified IL-2 gene effectively inhibited tumour growth also in allogeneic recipients. Activation of murine spleen cells in vitro by co-cultivation with X63-m-IL-2 cells gave rise to lymphokine-activated killer (LAK) cell populations cytotoxic for the X63-Ag8.653 plasmocytoma and MC14 sarcoma. The results suggest that peritumoral administration of lymphoid cells transformed with IL-2 cDNA and constitutively producing IL-2 in the immediate tumour vicinity is sufficient for the effective activation of local IL-2-dependent tumour defence mechanisms and, therefore, can be considered a novel, genetic approach to the immunotherapy of cancer.

Animals↗
PubMed1989

[Perspectives in immunotherapy of malignant tumors].

The paper summarizes the perspectives of experimental tumour immunotherapy with immunomodulatory cytokines; it points out that some polypeptidic cytokines, which can be prepared with recombinant DNA technology and display immunoregulatory properties, seem to be suitable for treatment of human cancer. In conclusion, two recent trends of experimental tumour immunotherapy are being stressed: Chemoimmunotherapy using the combination of some cytostatics and interleukin 2, and combination setting of those lymphokines which were shown to be efficient as single agent in controlled clinical trials, such as interleukin 2, alpha interferon and tumour necrosis factor.

Humans↗
PubMed1989

Solid phase enzyme immunoassay of human interleukin 2 utilizing antibodies against synthetic IL-2 peptides.

In the present study, solid phase enzyme immunoassay utilizing antibodies against synthetic IL-2 peptides was used for quantitative measurements of human recombinant and lymphoid IL-2 preparations. The 27-peptide MCF-III-6 (Leu-Glu-His-Leu-Leu-Leu-Asp-Leu-Gln-Met-Ile-Leu-Asn-Gly-Ile-Asn-Asn-- Tyr-Lys-Asn-Pro-Lys-Leu-Thr-Arg-Met-Leu) that comprises the region 14-40 from the IL-2 amino acid sequence was synthesized and used for immunization of rabbits. Resulting anti-MCF-III-6 polyvalent rabbit antibodies reacted specifically in EIA up to dilution of 10(-7) with the MCF-III-6 peptide used for immunization as well as with 16-peptide I-16 (Cys-Nle-Gly-Ile-Asn-Asn-Tyr-Lys-Asn-Pro-Lys-Leu-Thr-Arg-Met-Leu) that comprises the region 27-40 from the IL-2 amino acid sequence. The anti-MCF-III-6 antibody reacted also with human recombinant IL-2 preparations obtained from three producers (Cetus, Riga and Amersham), to the concentration of 0.1 ng/ml, and with various human lymphoid IL-2 preparations. Direct correlation was observed between quantitative measurements of human lymphoid IL-2 by EIA and by CTLL bioassay. It can be concluded that utilization of synthetic IL-2 peptides provides a suitable and comparatively unexpensive immunogen for the production of IL-2 antibodies and that the solid phase EIA using such antibodies can be employed as a rapid, reproducible, and sensitive method for quantitative examination of both recombinant and lymphoid IL-2 preparations.

Amino Acid Sequence↗
PubMed1989

Chemoimmunotherapy of MC-induced mouse sarcomas with human recombinant interleukin 2 and cyclophosphamide: age-dependent decline of the therapeutic efficacy.

Age-dependent decline of the anti-tumour efficacy of local IL-2 immunotherapy and chemoimmunotherapy utilizing human recombinant interleukin 2 and cyclophosphamide was investigated in B10 mice bearing syngeneic MC-induced sarcoma. Repeated peritumoral injections of rIL-2 substantially inhibited growth of transplantable MC-induced sarcomas in syngeneic young adult mice whereas no effect was observed in the aged mice. Chemoimmunotherapy of the MC-induced sarcomas in the young adult and in the aged mice treated with cyclophosphamide plus rIL-2 revealed that subthreshold doses of CY were capable of significantly potentiating the immunotherapeutic effect of rIL-2 in young adult mice but not in the aged mice.

Aging↗
PubMed1988

Expression of mouse embryonic epitope TEC-2 on human carcinoma-derived cell lines and characterization of its glycoprotein carriers.

Monoclonal antibody TEC-02, raised against mouse embryonal carcinoma cells, has been shown to react with murine preimplantation embryos and with a very limited number of adult mouse tissues. The target epitope, TEC-2, is a carbohydrate carried in mouse embryonal carcinoma cells by large glycoprotein-bound glycan. We report here the expression of TEC-2 epitope on human carcinoma-derived cell lines, HeLa and HS, and the properties of its carbohydrate carriers. Immunolabeling of Nonidet P-40 lysates of HeLa cells separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that TEC-2 antigens are polydispersed glycoconjugates of high molecular weight (mostly above 100,000). TEC-2 antigens detected by the two-site sandwich assay, in which the antigen is immobilized and detected with the same antibody, had a slightly higher molecular weight than those detected by the solid-phase assay. This suggests heterogeneity in the number of TEC-2 epitopes per carrier molecule. When the cells were lysed by Triton X-114 and the detergent and aqueous phases were separated by warming and centrifugation, most of the TEC-2 antigenic activity was found in the aqueous phase. TEC-2 antigens isolated by indirect precipitation from [3H]galactose-labeled HeLa cells were degraded by extensive pronase digestion or mild alkaline treatment to glycopeptides or oligosaccharides of low molecular weight. Thus, TEC-2 epitope in human HeLa cells is carried by carbohydrates of only several monosaccharide units. TEC-02 antibody was also found to bind to Tamm-Horsfall glycoprotein isolated from human urine and its binding was enhanced by desialylation. Combined data indicate that TEC-02 antibody recognizes the GalNAc beta 1----4Gal beta 1----4 structure which may be carried on different types of molecule, according to the site of their synthesis.

Animals↗
PubMed1988

Defect in lectin-induced interleukin 2 production by peripheral blood lymphocytes of patients with invasive urinary bladder carcinoma.

The production of interleukin 2 (IL-2) by phytohaemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMC) from 21 patients with transitional cell carcinoma of the urinary bladder (BTCC) and 16 control blood donors was measured with a solid phase enzyme immunoassay based on the dual antibody immunometric sandwich principle. PBMC from patients with invasive BTCC (grade III-IV) showed a defect in the production of IL-2. The concentration of IL-2 in the supernatants of PBMC cultures from these patients was substantially lower (0.4 +/- 0.1 U/ml) than that observed in the supernatants of PBMC cultures from patients with non-invasive BTCC, grade II (1.5 +/- 0.7 U/ml), and from tumour-free controls (1.4 +/- 0.8 U/ml). These results suggest an immune dysfunction based on quantitatively impaired IL-2 production in patients with invasive BTCC and indicate that exogenous IL-2 could be used as an immunological response modifier for the treatment of these patients.

Aged↗
PubMed1988

A new cell line, GS, derived from a human renal cell carcinoma.

A new cell line, GS, of human renal cell carcinoma was established and characterized. It was derived from a metastasis of a human renal cell carcinoma, which appeared 6 years after nephrectomy. The GS cells exhibit basic characteristics of renal cell carcinoma: epithelial cell character, PAS and glycogen positivity, typical ultrastructural features. The cells have a pseudotriploid stemline with a modal number of 75 chromosomes and two marker chromosomes. GS cells formed neither colonies in soft agar nor transplantable tumours in nude mice but produced a factor(s) stimulating growth and colony forming activity of indicator cells.

Aged↗
PubMed1988

Anti-tumour efficacy of IL-1 and IL-2.

The potential value of RIL-1 and RIL-2 for local immunotherapy of cancer was compared in the experimental model of MC-induced sarcomas growing in syngeneic (B10) mice. Highly purified recombinant human RIL-1 (Hoffmann-La Roche) and RIL-2 (Amersham) were administered s.c. into the area of lymph nodes draining the growing tumour. Within the dose range examined, RIL-2 was capable of inducing inhibition of tumour growth or complete regression of tumours and the cure of the majority of treated mice. In contrast, RIL-1 could neither inhibit tumour growth nor potentiate the tumour-inhibitory effect of RIL-2.

Animals↗
PubMed1988

Generation of LAK cells depends on the age of LAK cell precursor donors.

Age-related changes in generation of lymphokine-activated killer cells were examined in the experimental system of B10 murine effector cells activated with human recombinant interleukin 2 that were allowed to react with a panel of murine and human target cell lines. The percentage of specific 51Cr release displayed by the LAK cells derived from 6- and 12-month-old donors was consistently lower than that displayed by the 2-month-old mice. However, even the LAK cells from 12-month-old mice still showed a significant cytolytic activity.

Aging↗
PubMed1987

The anti-tumour efficacy of human recombinant interleukin 2. Correlation between sensitivity of tumours to the cytolytic effect of LAK cells in vitro and their susceptibility to interleukin 2 immunotherapy in vivo.

Experiments were designed to test what percentage of experimental MC-induced murine sarcomas were sensitive to the local tumour inhibitory effect of IL-2 and whether any correlation existed between the sensitivity of these sarcomas to the immunotherapeutic effect of IL-2 and their susceptibility to the cytolytic effect of IL-2-activated killer cells. It was found that the sensitivity of MC-induced sarcomas to local IL-2 immunotherapy was a general phenomenon. Repeated peri-tumoural injections of RIL-2 inhibited the growth of five (MC11, MC13, MC14, MC15, MC16) out of six sarcomas in syngeneic mice. The sixth murine sarcoma (MC12) was found to be resistant to the tumour inhibitory effect of IL-2. Similarly, five (MC11, MC13, MC14, MC15, MC16) out of six murine sarcoma cell lines were sensitive to the cytolytic effect of IL-2-activated syngeneic killer spleen cells when examined in vitro, whereas the sixth (MC12) sarcoma cell line was resistant. These results suggest that LAK cells represent the effector cell mechanism responsible for the anti-tumour efficacy of local IL-2 immunotherapy and that in vitro testing of sensitivity to the LAK cell-mediated cytolysis may be used to detect tumours responding to IL-2 immunotherapy in vivo.

Animals↗
PubMed1987

Recombinant interleukin-2 inhibits growth of human tumor xenografts in congenitally athymic mice.

Administration of human recombinant interleukin-2 (RIL-2) into congenitally athymic (nu/nu) mice carrying subcutaneous transplants of HeLa, HU 609T and T24B human carcinoma cells partially inhibited growth of the human tumor xenografts. In vitro activation of nu/nu spleen cells with human RIL-2 resulted in generation of killer cells showing in the 51Cr cytotoxicity assay similar levels of cytolysis as RIL-2-activated spleen cells from heterozygous (nu/+) mice. The RIL-2-activated (LAK) cells were cytotoxic for a variety of mouse and human tumors, reaching the peak of their cytotoxic activity after 3 days of cultivation in the RIL-2-containing medium. The cytotoxic activity of activated nu/nu spleen cells was significantly reduced by treatment with antibody against glycolipid asialo GM1, the differentiation antigen of natural killer (NK) cells. This finding suggests that in addition to the conventional, asialo GM1- LAK cells, asialo GM1+ activated NK cells participated in the cytotoxicity displayed by the IL-2-activated nu/nu killer spleen cells.

Animals↗