Dendritic cell therapy in glioblastoma multiforme

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Background: Malignant brain tumors belong to the tumors with unfavorable prognosis. The most aggressive form, glioblastoma multiforme (GBM WHO grade IV glioma), is categorized as incurable with median survivals less than 12–18 months and 90–95% of patients surviving less than 2 years. Here we show that immunotherapy with monocyte-derived dendritic cells (MoDC) can induce a clinical response in advanced GMB, especially when combined with the non human pathogenic oncolytic virus NDV (New Castle Disease Virus). Methods: After isolating monocytes from peripheral blood of n=21 patients dendritic cells were generated ex vivo in the presence of recombinant cytokines (IL-4, GM-CSF) and 2,5% autologous serum. If tumor tissue was available the MoDC were primed on day 5 with tumor- lysate and co-cultured with poly:IC and IFN-alpha. The MoDC were harvested on day 7 of culture and administered to the patients, intradermally. In 5 patients NDV was added to the MoDC for one hour prior to administration. These patients received an infusion with NDV one day before vaccination. Results: We were able to induce a clinical response in 33% (n=7) of the treated patients. The median survival after onset of DC-therapy was 10 months. With respect to primary diagnosis the median survival was 19 months with 1- and 2-years survival rates of 81% and 14%, respectively. Improvement of the clinical response can be observed by combination of NDV. None of the 5 patients treated with this combination therapy died of the disease (9–19 months after primary diagnosis). Three of them (60%) show a response with 2 clear partial remissions (40%). Conclusions: Taken together, a dendritic-cell based therapy can be successful in the treatment of GBM. Enhancement of the therapeutically outcome can be induced by a combination therapy with New Castle Disease Virus leading to the suggestion that there may be an interaction between the dendritic cells and the NDV.

No significant financial relationships to disclose.

Cancer therapy with tumor cell lysate pulsed monocyte-derived dendritic cells in patients with metastastic colon cancer: Improvement by danger signals

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Background: The prognosis of colon cancers with hematogenous spread remains poor at 12–20 months. We report the use of a dendritic cell based immunotherapy to improve patient survival, especially with cell culture conditions mimicking infection. Methods: After isolating monocytes from the blood of 39 patients with metastasized colon cancer, dendritic cells were generated ex vivo in the presence of recombinant cytokines (IL-4; GM-CSF) and autologous serum. The DC loaded with tumor cell lysate were administered to the patients intradermally. Culture conditions were tested for upregulation of costimulatory molecules, downregulation of IL-10 and upregulation of IL-12 secretion by ELISPOT and fluorescence cytometry. Results: DC vaccination induced a clinical response in 9 (23%) patients with a median overall survival after onset of DC-therapy of 12 months (11–44 months for responders and 1–20 months for non-responders) and 23 months after diagnosis of metastases (16–63 months for responders and 1–23 months for non-responders). These data show that a dendritic cell based immunotherapy may prolong the patients overall survival. However, complete remissions are rare. This can be due to weak stimulation of CTL response due to insufficient antigen presentation, lack of costimulatory molecules as well as secretion of IL-10 rather than IL-12 by the DC’s. Here we could show that Toll-like receptors (TLR) ligands like Poly-I:C or lipopeptides as so called danger signals in combination with interferons can induce an upregulation of costimulatory molecules accompanied by inhibition of IL-10 and induction of IL-12 secretion in vitro. By using these culture conditions we induced a clinical complete remission of liver metastases after failure of standard therapy in one patient (overall survival after onset of DC-therapy 13 months, after diagnosis 24 months). Conclusions: According to Matzinger’s hypothesis an effective immune response occurs only by responding to a danger signal associated with infection or stress. Thus, cell culture condition should be used with TLR ligands mimicking a bacterial or viral infection. In general, a dendritic cell based immunotherapy can be successful in advanced stages of colon cancer patients.

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Anaphylactic reactions to ingested carmine (E120)

We report five cases of anaphylactic reaction to carmine (cochineal, E120) after patients drank an alcoholic beverage. By means of positive skin prick tests (SPT) and positive RAST to carmine. IgE-mediated sensitization could be established. One nonatopic patient showed also a great amount of serum IgE antibodies to the carmine acid-albumin conjugate. Due to its widespread use in the food and cosmetic industry, carmine should be tested in the allergy work-up in case of allergic reactions after a drink or a meal.

Determination of S-phenylmercapturic acid in the urine--an improvement in the biological monitoring of benzene exposure

In an inhalation study rats were exposed to different doses of benzene, ranging from 1 to 500 p.p.m. The urine was sampled during the inhalation period of 8 h and for 24 h after exposure. S-Phenylmercapturic acid (S-PMA) in the urine was determined by amino acid analysis. Phenol was measured by gas chromatography/mass spectrometry. In both cases the correlation between benzene uptake and the excretion of the urinary metabolites was significant at the level of P = 0.01. The same significant correlation (P = 0.01) was demonstrable after i.p. administration of benzene at doses between 0.7 and 140.0 microliters/kg body weight. In the case of two collectives of workers who were exposed to air concentrations of up to 0.15 p.p.m. for 8 h and of up to 1.13 p.p.m. for 12 h respectively, the amount of S-PMA in the first urine samples after the shift was significantly higher than in samples collected at the beginning of the shift (P = 0.01). In the first collective the mean values and the standard deviations of the S-PMA concentrations in the samples at the beginning of the shift were 12.0 +/- 16.7 compared with 48.5 +/- 64.5 micrograms/g creatinine at shift end. In the second collective they were 25.1 +/- 25.1 compared with 70.9 +/- 109.2 micrograms/g creatinine. The level of significance of the difference between the concentration values of S-PMA at the beginning and end of the shift was P = 0.01. The phenol concentration did not differ significantly. These results suggest that S-PMA can be regarded as a useful indicator for monitoring individuals and collectives exposed to benzene at levels even less than 1 p.p.m.

Biomonitoring of benzene exposure by trace analyses of phenylguanine

From preliminary experiments it was known that radiolabelled benzene and some of its metabolites during its metabolic activation process produce different in vitro DNA-phenyladducts in mitoplasts. As we reported previously at least one of these adducts, N-7-phenylguanine, is excreted in the urine of rats in measurable amounts, probably through an excision-repair mechanism after an inhalation experiment. Now we found, after i.p. application of benzene in the urine of rats, a compound separated by cation-exchange chromatography that behaves like a synthesized N-7-phenylguanine reference substance with respect to its retention index and the UV-absorption. This finding could be confirmed by HPLC-measurements with reversed-phase carrier materials. Silylation and gas chromatographic/mass spectrometric (GC/MS) separation of the fraction, which contains the phenylguanine, revealed that these fractions contain further phenyl adducts. Furthermore we studied the time-dependent excretion of the DNA-base adduct. Surprisingly the excretion dropped to zero on the fourth day and showed a new increase thereafter.

Urinary excretion of mutagens in passive smokers

Six healthy young volunteers with no history of active smoking were asked to keep on their Western diets avoiding the consumption of alcoholic beverages, excess coffee, any sort of medicament, and the known pro- and/or anti-mutagen-containing foods and drinks, 24 h before and during the experiments. They were exposed passively to cigarette smoke produced by 4 habitual smokers in an unventilated 48.6 m3 room for 8 h. The carbon monoxide concentration was 18.85 +/- 7.3 ppm during the 8-h exposure. Frameshift mutagens were isolated from 10-h urine samples using chloroform and were tested for mutagenicity in the Salmonella/mammalian microsome assay employing Salmonella typhimurium TA98. Although clearly enhanced, no significant mutagenic activity could be found with 25 ml equivalent urine/plate after passive exposure to cigarette smoke. The weak mutagenicities found were highly significant when 50 ml equivalent urine/plate was tested. No direct correlation was observed between urine mutagenicity and the urinary cotinine concentration. The results obtained are discussed with reference to inconsistent reports in the literature concerning the mutagenicity of urine after passive smoking.