Effect of anticancer drugs on the release of interleukin-6 in vitro

Thalidomide suppressed interleukin-6 but not tumor necrosis factor-alpha in volunteers with experimental endotoxemia

An early rationale for using thalidomide to treat erythema nodosum leprosum had been based on some reports that it suppresses tumor necrosis factor-alpha (TNF-alpha). However, in vivo and in vitro studies have yielded variable results, having shown that thalidomide can either enhance or suppress TNF-alpha. Since the course of circulating cytokines like TNF-alpha after infusion of endotoxin into volunteers is reproducible and characteristic, we investigated the effect of thalidomide on endotoxin-induced synthesis of TNF-alpha, interleukin (IL)-6, and IL-8. The cytokine response from 18 placebo-treated subjects who had undergone the endotoxin challenge were pooled with a placebo-treated subject from the current study and were compared with 4 subjects who received thalidomide (100 mg) every 6 h for 5 doses before endotoxin challenge. Thirty minutes after the last dose of thalidomide or placebo, volunteers were infused with 4-ng/kg endotoxin. Plasma was collected and assayed for cytokines by enzyme-linked immunosorbent assay. Endotoxin evoked the synthesis of the cytokines in all volunteers. The peak response for TNF-alpha was 1.5 h, 2.5 h for IL-8, and 3.0 h for IL-6. Thalidomide did not significantly delay the release of cytokines into the circulating blood. At the peak response, thalidomide reduced the concentration of the cytokines in the plasma. Using the area under the dose response curve (AUC(0 to 24) h), thalidomide reduced the AUC for IL-6 by 56%, for IL-8 by 30%, and TNF-alpha by 32%. In this model, thalidomide did not suppress TNF-alpha or IL-8, but it did suppress IL-6 at 4-h postinfusion with lipopolysaccharide (P=0.004), at 6 h (P=0.014), at 12 h (P=0.001), and at 16 h (P=0.012).

Immunostimulatory combinations: designing the next generation of vaccine adjuvants

Agents that activate dendritic cells are essential components for vaccines and can be conceptualized as molecular adjuvants. Other molecular adjuvants affect downstream factors that shape the resulting immune response. This review provides a compendium of recently studied molecular adjuvants, focusing on CD8+ T cell responses, which have important roles in HIV vaccines. Reference is also made to CD8+ T cell antitumor responses, where parallel studies of molecular adjuvants are being pursued. Molecular adjuvants can be considered in the following groups: TNF superfamily molecules such as CD40 ligand; agonists for TLRs; agonists for NAIP, CIITA, HET-E, TP-1-leucine-rich repeat pathway receptors, such as nucleotide-binding and oligomerization domain (NOD)1, NOD2, and cryopyrin; chemokines; ILs; CSFs; IFNs; alarmins; and purinergic P2X7 receptor agonists. Complementing these positively acting agents are strategies to reduce the immunosuppressive effects of CD4+CD25+ regulatory T cells and negatively acting factors such as TGF-beta, IL-10, suppressor of cytokine signaling 1, and programmed cell death-1 using neutralizing antibodies, antisense, and small interfering RNA. Especially effective are combinations of molecular adjuvants, which can elicit a massive expansion of antigen-specific CD8+ T cells and show unprecedented efficacy in vaccine and tumor models. Taken together, these new approaches provide significant incremental progress in the development of vaccines to elicit cell-mediated immunity against HIV and other pathogens.

Sonoporation with doxorubicin enhances suppression of intimal hyperplasia in a vein graft model

BACKGROUND

The purpose of the present study is to examine whether sonoporation with doxorubicin enhances suppression of intimal hyperplasia (IH) in a vein graft model.

MATERIALS AND METHODS

After the administration of 1.5 mg/kg doxorubicin intravenously, the right external jugular vein of six rabbits was exposed at 2 W/cm2 and 1 MHz of ultrasound for 2 min (Sonoporation group). Tissue doxorubicin concentration was measured. In 48 rabbits, the right common carotid artery was ligated after performing a vein graft bypass. The animals were divided into the following four groups: the C0 group (surgical procedure only); the C0S (sonoporation without doxorubicin); the C1 (doxorubicin administration only); the C1S (sonoporation with doxorubicin). Twenty-four grafts were subjected to Elastic van Gieson staining for morphometric analysis 4 weeks after the operation; others were subjected to TdT-mediated X-dUTP nick end-labeling for detection of apoptic cells and to staining with a monoclonal antibody against the proliferating cell nuclear antigen for assessment of cell proliferation 1 week after.

RESULTS

The tissue doxorubicin concentration was significantly higher in the Sonoporation group than in the Control group. Compared with the C0 group, IH was not suppressed in the C1 group but was significantly suppressed in the C1S group. Sonoporation with doxorubicin administration suppressed IH significantly (C1 group versusC1S group: P < 0.05). Cell apoptosis was induced and cell proliferation was suppressed significantly in the C1S group.

CONCLUSIONS

Sonoporation with doxorubicin suppressed IH of the vein graft. Sonoporation may be effective in coronary or peripheral revascularization using vein grafts.

Application of nanoparticle technology for the prevention of restenosis after balloon injury in rats

Restenosis after percutaneous coronary intervention continues to be a serious problem in clinical cardiology. Recent advances in nanoparticle technology have enabled us to deliver an antiproliferative drug selectively to the balloon-injured artery for a longer time. NK911, which is a core-shell nanoparticle of polyethyleneglycol-based block copolymer encapsulating doxorubicin, accumulates in vascular lesions with increased permeability. We first confirmed that balloon injury caused a marked and sustained increase in vascular permeability (as evaluated by Evans blue staining) for a week in the rat carotid artery. We then observed that intravenous administration of just 3 times of NK911, but not doxorubicin alone, significantly inhibited the neointimal formation of the rat carotid artery at 4 weeks after the injury in both a single- and double-injury model. Immunostaining demonstrated that the effect of NK911 was due to inhibition of vascular smooth muscle proliferation but not to enhancement of apoptosis or inhibition of inflammatory cell recruitment. Measurement of vascular concentrations of doxorubicin confirmed the effective delivery of the agent to the balloon-injured artery by NK911 in both a single- and double-injury model. RNA protection assay demonstrated that NK911 inhibited expression of several cytokines but not that of apoptosis-related molecules. NK911 was well tolerated without any adverse systemic effects. These results suggest that nanoparticle technology to target vascular lesions with increased permeability is a promising and safe approach for the prevention of restenosis after balloon injury. The full text of this article is available at http://www.circresaha.org.

Effect of anticancer drugs on the release of TGF-beta in vitro

Some conventional and experimental anticancer drugs were tested for their effect on Concanavalin A (Con A)-induced Transforming Growth Factor-beta (TGF-beta) release from BALB/c splenocytes, lipopolysaccharide (LPS)-induced TGF-beta release from Nude mouse splenocytes and BALB/c peritoneal exudate cells stimulated by LPS in vitro. When 5 x 10(6) BALB/c and Nude mouse splenocytes/ml stimulated with 1 microgram/ml Con A, 50ng/ml LPS respectively, and 5 x 10(6)/ml peritoneal exudate cells stimulated with 50ng/ml LPS were incubated with various non-cytotoxic concentrations of the vinca alkaloid Vincristine, there was an inhibition of the release of TGF-beta in culture supernatants of both BALB/c splenocytes and peritoneal exudate cells. But, in Nude mouse Vincristine did not alter the release of TGF-beta. The antitumour antibiotic Bleomycin, the immunoactive peptide FK565 and the immunosuppressive agent Cyclosporin A (CsA) were found to have no effect on the release of TGF-beta from all culture supernatants.

The in vitro action of FK 565, bleomycin and cyclosporin A on different cell populations, with respect to the release of GM-CSF in the mouse

The experimental immunostimulatory tripeptide FK 565, the anti-tumor antibiotic Bleomycin and the immunosuppressive agent Cyclosporin A were examined for their in vitro effects on granulocyte-macrophage colony stimulating factor (GM-CSF) production utilizing different cell populations from three distinct murine stains. FK 565 produced an increase in GM-CSF release in all three experimental models used, providing evidence that FK 565 is among other things, a macrophage stimulating agent. Bleomycin increased GM-CSF release in the BALB/c and the 'Scid' mouse. Paradoxically with cells from the 'nude' mouse a significant decrease was observed, indicating that Bleomycin may induce a suppressive effect on B-cells. Cyclosporin A was found to inhibit the release of GM-CSF from BALB/c mice, however, no effect was observed in either 'nude' or 'Scid' mice.