Biomedical subjects

Lyle L Moldawer

Publications and source records attributed to Lyle L Moldawer.

At least 55 records · Page 3Linked to original sources

PubMed2005

Genome-wide monocytic mRNA expression in polytrauma patients for identification of clinical outcome.

Immune activation in multiple trauma is closely linked to the development of multiple organ dysfunction and failure, and consequently, has a profound influence on patient outcome. Although peripheral blood monocytes play a critical role in this immune response, the biological significance of changes in genome-wide expression immediately after traumatic injury have not been explored previously. Thirteen patients presenting with multiple blunt trauma were studied. Peripheral blood monocytes were obtained within 90 min and at 6, 12, 24, 48, and 72 h after trauma. Apparent genome-wide expression was determined with Affymetrix U133A microarrays. Supervised analysis identified 698 probe sets that were differentially expressed in the 13 trauma subjects (P < 0.001) over the 72-h study period. An additional 763 probe sets were differentially expressed in patients who died (n = 3) compared with those who survived (n = 10). The ability of these probe sets to function as a classifier of survival was significantly demonstrated with six prediction models. Using pathway analysis, a network of proinflammatory genes and intracellular signaling pathways leading to c-JUN activation were consistently overexpressed in patients who died. Genome-wide mRNA expression patterns in circulating peripheral blood monocytes from multiple-injured patients can discriminate clinical outcome. The pattern of gene expression in patients who died suggests that in these individuals, there is a reprioritization of gene expression consistent with an early activation of selected genes involved in the initiation and propagation of a proinflammatory response.

Adult↗

PubMed2005

Preclinical models of shock and sepsis: what can they tell us?

The goal of translational research is to transform biologic knowledge into new treatments for human disease. Although preclinical models replicate some of the features of the disease process modeled, they invariably fail to reproduce the complexity of human illness, and by their very experimental nature, they are readily manipulated to maximize evidence of efficacy. The result is that successful translation from preclinical models to clinically effective therapy is uncommon, and that clinical trials are often undertaken without a comprehensive and realistic preclinical portfolio of studies to optimize their design. The lethal and morbid human conditions of sepsis and shock are attractive targets for new therapies and enormously challenging processes to translate because they entail considerable clinical heterogeneity, require emergent effective intervention, and are shaped not only by the initial insult, but by approaches to subsequent resuscitation and support. A colloquium jointly sponsored by the Shock Society and the International Sepsis Forum in June 2004 addressed the challenges of translational research in shock and sepsis. Through a comprehensive review of a broad variety of model approaches, and vigorous debate about the merits of differing strategies, a series of common themes emerged. We concluded that there is no single ideal model of shock or sepsis, but rather a large number of complementary models that recapitulate some discrete features of the disorders while minimizing others. Consequently, successful preclinical investigation mandates the use of a panel of preclinical studies consciously designed to address specific questions of relevance to the clinical setting. A corollary of this conclusion is that preclinical studies can shape concepts of disease and can be used to refine decisions regarding optimal patient populations for therapeutic interventional trials. We further recognized that the design and reporting of preclinical studies is highly variable, thereby limiting effective data interpretation and integration between studies. Hence, greater model standardization would aid in interpreting data and in pooling results into systematic data syntheses: such efforts should be promoted and undertaken.

Animals↗

PubMed2005

Differential maturation of murine bone-marrow derived dendritic cells with lipopolysaccharide and tumor necrosis factor-alpha.

Dendritic cells (DCs) play a key role in the interface between the innate and acquired immune systems. In response to both exogenous as well as endogenous signals, DCs undergo a programmed maturation to become an efficient, antigen-presenting cell. Yet little is known regarding the differential responses by endogenous versus exogenous stimuli on DC maturation. In the present report, we have compared the phenotypic, functional, and genome-wide expression responses associated with maturation by bone marrow derived DCs to either an endogenous danger signal, tumor necrosis factor-alpha (TNF-alpha), or a microbial product, bacterial lipopolysaccharide (LPS). Examination of the cell surface expression of DCs as well as cytokine production demonstrated that patterns of DC maturation varied dramatically depending upon the stimulus. Whereas LPS was highly effective in terms of inducing phenotypic and functional maturation, TNF-alpha exposure produced a phenotypically distinct DC. Gene expression patterns in DCs 6 and 24 h after LPS and TNF-alpha exposure revealed that these activation signals produce fundamentally different genomic responses. Supervised analysis revealed that the expression of 929 probe sets discriminated among the treatment groups, and the patterns of gene expression in TNF-alpha stimulated DCs were more similar to unstimulated cells at both 6 and 24 h post-stimulation than to LPS-stimulated cells at the same time points. These findings reveal that DCs are capable of a varying phenotypic response to different antigens and endogenous signals.

Animals↗

PubMed2005

Plasma cytokine measurements augment prognostic scores as indicators of outcome in patients with severe sepsis.

Despite recent advances in the prospective identification of the patient with sepsis who may benefit from anti-inflammatory or antithrombotic therapies, successful treatment regimens have been fairly modest. We have explored whether determination of several proinflammatory cytokine or mediator concentrations can complement physiologic scoring systems to identify patients with severe sepsis who will survive or expire within 28 days. The design of the study included an exploratory analysis performed in conjunction with a prospective, randomized, double-blind, placebo-controlled, multicenter, clinical trial and involved 33 academic institutions in the United States. One hundred twenty-four patients with severe sepsis with or without septic shock were included in this analysis. Blood samples were obtained at baseline and on days 1 through 4, and were evaluated for proinflammatory and anti-inflammatory cytokine concentrations, as well as for procalcitonin and total protein C levels. Baseline concentrations and changes in the concentrations of these mediators were evaluated in relationship to the Acute Physiology and Chronic Health Evaluation (APACHE) II and multiple organ dysfunction (MOD) scores, and 28-day all-cause mortality. Using univariate logistic regression analyses, APACHE II and MOD scores, age (but not gender), and baseline plasma interleukin (IL)-6 and soluble tumor necrosis factor receptor (sTNFR) 1 (log transformed) concentrations were all predictive of increased 28-day all-cause mortality (P < 0.01). Baseline total protein C, IL-8, IL-10, TNF-alpha, and procalcitonin concentrations, and the change in plasma cytokine concentrations from baseline over the initial 4 days were not useful in predicting outcome. Selected baseline proinflammatory cytokine concentrations and APACHE II score were correlated (P < 0.01). IL-6 concentration is a strong candidate for predicting clinical outcome in patients with severe sepsis alone, or when combined with the APACHE II or MOD scores. The potential usefulness of the combination of cytokine measurements and prognostic scores to identify patients who may benefit from treatment with anti-inflammatory or antithrombotic therapies should be further evaluated.

Aged↗

PubMed2005

Functional modification of dendritic cells with recombinant adenovirus encoding interleukin 10 for the treatment of sepsis.

Control of dendritic cell (DC) function is critical for strategies to modulate innate and acquired immune responses. We examined whether transduction of murine DCs with adenoviral vectors (Adv) expressing interleukin (IL)-10 could alter their phenotype and T cell stimulatory function. Murine bone marrow-derived DCs were transduced with AdV encoding human IL-10 or green fluorescent protein (GFP). Whereas transduction of immature DCs with AdV/GFP resulted in dose-dependent maturation, DCs transduced with Adv/IL-10 maintained an immature state with low major histocompatibility complex (MHC) class II, CD86, and IL-12 expression. The Adv/IL-10 transduced DCs were phenotypically unique, characterized by suppression of IL-12 expression, failure to stimulate Th1 or Th2 cytokine responses, and retained capacity to endocytose antigen. Importantly, Adv/IL-10-transduced DCs were biologically active in vivo, in that administration of these DCs into mice before a generalized peritonitis significantly improved survival. We conclude that Adv/IL-10 transduction of DCs provides an efficient means to modulate DC function. The capacity to modify DCs by adenoviral expression of IL-10 may provide a novel ex vivo or in vivo approach to mitigate acute and chronic inflammatory diseases like sepsis.

Adenoviridae↗

PubMed2004

Whole blood and leukocyte RNA isolation for gene expression analyses.

The analysis of gene expression data in clinical medicine has been plagued by the lack of a critical evaluation of accepted methodologies for the collection, processing, and labeling of RNA. In the present report, the reliability of two commonly used techniques to isolate RNA from whole blood or its leukocyte compartment was compared by examining their reproducibility, variance, and signal-to-noise ratios. Whole blood was obtained from healthy subjects and was either untreated or stimulated ex vivo with Staphylococcus enterotoxin B (SEB). Blood samples were also obtained from trauma patients but were not stimulated with SEB ex vivo. Total RNA was isolated from whole blood with the PAXgene proprietary blood collection system or from isolated leukocytes. Biotin-labeled cRNA was hybridized to Affymetrix GeneChips. The Pearson correlation coefficient for gene expression measurements in replicates from healthy subjects with both techniques was excellent, exceeding 0.985. Unsupervised analyses, including hierarchical cluster analysis, however, revealed that the RNA isolation method resulted in greater differences in gene expression than stimulation with SEB or among different trauma patients. The intraclass correlation, a measure of signal-to-noise ratio, of the difference between SEB-stimulated and unstimulated blood from healthy subjects was significantly higher in leukocyte-derived samples than in whole blood: 0.75 vs. 0.46 (P = 0.002). At the P < 0.001 level of significance, twice as many probe sets discriminated between SEB-stimulated and unstimulated blood with leukocyte isolation than with PAXgene. The findings suggest that the method of RNA isolation from whole blood is a critical variable in the design of clinical studies using microarray analyses.

Adolescent↗

PubMed2004

Continuous flow microfluidic device for rapid erythrocyte lysis.

Leukocyte isolation from whole blood to study inflammation requires the removal of contaminating erythrocytes. Leukocytes, however, are sensitive to prolonged exposure to hyper/hypoosmotic solutions, temperature changes, mechanical manipulation, and gradient centrifugation. Even though care is taken to minimize leukocyte activation and cell loss during erythrocyte lysis, it is often not possible to completely avoid it. Most procedures for removal of contaminating erythrocytes from leukocyte preparations are designed for bulk processing of blood, where the sample is manipulated for longer periods of time than necessary at the single-cell level. Ammonium chloride-mediated lysis is the most commonly used method to obtain enriched leukocyte populations but has been shown to cause some activation and selective loss of certain cell types. The leukocyte yield and subsequent activation status of residual leukocytes after NH(4)Cl-mediated lysis have been shown to depend on the time of exposure to the lysis buffer. We have developed a microfluidic lysis device that deals with erythrocyte removal at nearly the single-cell level. We can achieve complete lysis of erythrocytes and approximately 100% recovery of leukocytes where the cells are exposed to an isotonic lysis buffer for less than 40 s, after which the leukocytes are immediately returned to physiological conditions. Theoretically, this process can be made massively parallel to process several milliliterss of whole blood to obtain a pure leukocyte population in less than 15 min.

Animals↗

PubMed2004

Characterization of the systemic loss of dendritic cells in murine lymph nodes during polymicrobial sepsis.

Dendritic cells (DCs) play a key role in critical illness and are depleted in spleens from septic patients and mice. To date, few studies have characterized the systemic effect of sepsis on DC populations in lymphoid tissues. We analyzed the phenotype of DCs and Th cells present in the local (mesenteric) and distant (inguinal and popliteal) lymph nodes of mice with induced polymicrobial sepsis (cecal ligation and puncture). Flow cytometry and immunohistochemical staining demonstrated that there was a significant local (mesenteric nodes) and partial systemic (inguinal, but not popliteal nodes) loss of DCs from lymph nodes in septic mice, and that this process was associated with increased apoptosis. This sepsis-induced loss of DCs occurred after CD3(+)CD4(+) T cell activation and loss in the lymph nodes, and the loss of DCs was not preceded by any sustained increase in their maturation status. In addition, there was no preferential loss of either mature/activated (MHCII(high)/CD86(high)) or immature (MHCII(low)/CD86(low)) DCs during sepsis. However, there was a preferential loss of CD8(+) DCs in the local and distant lymph nodes. The loss of DCs in lymphoid tissue, particularly CD8(+) lymphoid-derived DCs, may contribute to the alterations in acquired immune status that frequently accompany sepsis.

Animals↗

PubMed2004

Genomic and proteomic determinants of outcome in patients undergoing thoracoabdominal aortic aneurysm repair.

Thoracoabdominal aortic aneurysm repair, with its requisite intraoperative mesenteric ischemia-reperfusion, often results in the development of systemic inflammatory response syndrome, multiorgan dysfunction syndrome (MODS), and death. In the present study, an adverse clinical outcome following thoracoabdominal aortic aneurysm repair was identified by blood leukocyte genomic and plasma proteomic responses. Time-dependent changes in the expression of 146 genes from blood leukocytes were observed (p < 0.001). Expression of 138 genes (p < 0.001) and the concentration of seven plasma proteins discriminated between patients who developed MODS and those who did not, and many of these differences were evident even before surgery. These findings suggest that changes in blood leukocyte gene expression and plasma protein concentrations can illuminate pathophysiological processes that are subsequently associated with the clinical sequelae of systemic inflammatory response syndrome and MODS. These changes in gene expression and plasma protein concentrations are often observed before surgery, consistent with either a genetic predisposition or pre-existing inflammatory state.

Aged↗

PubMed2004

Temporal patterns of gene expression in murine cutaneous burn wound healing.

The global changes in gene expression in injured murine skin were characterized following a second-degree scald burn. Dorsal skin was harvested from uninjured and from burned mice at 2 h and at 3 and 14 days following immersion in 65 degrees C water for 45 s. Gene expression was surveyed using an Affymetrix U74Av2 GeneChip, and patterns of gene expression were analyzed using hierarchical clustering and supervised analysis. Burn injury produced significant alterations in the expression of a number of genes, with the greatest changes seen 3 and 14 days after the scald burn. Using a supervised analysis with a false discovery rate of 1% or 5%, differences in the expression of 192 or 1,116 genes, respectively, discriminated among the unburned skin and the three time points after the burn injury. Gene expression was primarily a transient and time-dependent upregulation. The expression of only 24 of the 192 discriminating genes was downregulated after the burn injury. No gene exhibited a sustained increase in expression over the entire 14 days following the burn injury. Gene ontologies revealed an integrated upregulation of inflammatory and protease genes at acute time intervals, and a diminution of cytoskeletal and muscle contractile genes at 3 or 14 days after the injury. Following a second-degree scald burn, global patterns of gene expression in the burn wound change dramatically over several weeks in a time-dependent manner, and these changes can be categorized based on the biological relevance of the genes.

Animals↗

PubMed2004

Aberrant signaling in the TNFalpha/TNF receptor 1 pathway of the NZM2410 lupus-prone mouse.

The purpose of this study was to evaluate the ability to induce TNFalpha-dependent apoptosis in vivo in predisease lupus-prone NZM2410 and derived B6.NZM congenic mouse strains. An endotoxicosis model that utilizes LPS and d-galactosamine to induce mortality by TNFalpha/TNFR1-dependent hepatocyte apoptosis was used to assess TNFalpha production, apoptotic signaling, and effects on the production of IL-6 and IL-10. NZM2410 was found to be resistant to endotoxicosis and to produce significantly less TNFalpha-induced IL-6 and IL-10. At low doses of LPS, partial resistance was associated with the Tnfa(w) allele. At higher doses of LPS, partial resistance cosegregated with lupus-susceptibility loci and functionally mapped downstream of caspase 3. Additional partial resistance in NZM2410 was also found upstream of FADD. These results demonstrate the existence of multiple defects in the TNFalpha/TNFR1 signaling pathway in the NZM2410 mouse and their relevance to lupus pathogenesis is discussed.

Animals↗

PubMed2004

Inducible nuclear factor-kappaB activation contributes to chemotherapy resistance in gastric cancer.

BACKGROUND: Activation of nuclear factor-kappaB (NF-kappaB) inhibits chemotherapy-induced apoptosis in some cancer cell lines. Inhibition of NF-kappaB by adenoviral delivery of an IkappaBalpha superrepressor (Ad.IkappaBalpha-SR) should potentiate 5-fluorouracil (5-FU) and irinotecan chemotherapy in gastric cancer cells. STUDY DESIGN: NCI-N87 and AGS human gastric cancer cells were studied. Chemotherapy-induced NF-kappaB activation was assessed using a luciferase reporter assay. Inhibition of NF-kappaB was assessed by luciferase reporter assay and by electrophoretic mobility shift assay. Cells were pretreated for 1 hour with Ad.IkappaBalpha (25 MOI) and incubated with 5-FU or the active metabolite of irinotecan (SN-38). Cell growth was assessed by cell proliferation assay and induction of apoptosis was determined by flow cytometry and caspase 3/7 assay. RESULTS: 5-FU and SN-38 significantly induced NF-kappaB activation as measured by luciferase reporter assay (p < 0.001). Ad.IkappaBalpha-SR treatment inhibited NF-kappaB binding as demonstrated by electrophoretic mobility shift assay and by luciferase reporter assay. In AGS cells, pretreatment with Ad.IkappaBalpha-SR followed by 5-FU (0.005 mmol/L) or SN-38 (10 ng/mL) led to increased growth inhibition of 13% and 59%, respectively (p < 0.001). Similarly, growth inhibition in NCI cells was significantly increased by pretreatment with Ad.IkappaBalpha followed by 5-FU (0.001 mmol/L) or SN-38 (0.5 ng/mL) (p < 0.001). In both cell lines, Ad.IkappaBalpha-SR enhanced apoptosis by both flow cytometry and caspase 3/7 assay as compared with chemotherapy alone. CONCLUSIONS: NF-kappaB is activated in human gastric cancer in response to chemotherapy and may result in inducible chemoresistance. Inhibition of NF-kappaB by Ad.IkappaBalpha-SR enhances the antitumor effects of chemotherapy and has potential as a novel antineoplastic strategy.

Antimetabolites, Antineoplastic↗

PubMed2004

Inhibition of NF-kappa B augments sensitivity to 5-fluorouracil/folinic acid in colon cancer.

BACKGROUND: 5-fluorouracil (5-FU), the most common antimetabolite used for the treatment of colorectal cancer, exerts its cytotoxic effects through the induction of apoptosis. Folinic acid potentiates the effect of 5-FU. Drug activity is currently limited as a result of inducible chemoresistance. Limited research suggests that the transcription factor nuclear factor kappa-B (NF-kappaB), which has antiapoptotic properties, may play a major role in inducible chemoresistance. MATERIALS AND METHODS: SW48 colon cancer cells were used for all experiments. Cell growth was determined by cell proliferation assay. Apoptosis was assessed by measuring caspase 3 activity. Activation of NF-kappaB was ascertained by electrophoretic mobility shift assay, luciferase reporter assay, and Western blot analysis. RESULTS: Treatment with 5-FU (0.001-10 mm), not only inhibited growth and induced apoptosis but significantly activated NF-kappaB in SW48 cells. Folinic acid alone (0.01-100 mg/L) did not inhibit growth but improved the cytotoxic effect of 5-FU in a dose-dependent manner. Likewise, folinic acid alone did not activate NF-kappaB or induce apoptosis but enhanced 5-FU-mediated NF-kappaB activation and cell apoptosis. Transfection with adenovirus IkappaBalpha super-repressor strongly inhibited constitutive activation of NF-kappaB and significantly enhanced 5-FU and 5-FU/Folinic acid-mediated growth inhibition (P < 0.05). CONCLUSIONS: Treatment with 5-FU activates NF-kappaB. Folinic acid enhances 5-FU-mediated activation of NF-kappaB. Inhibition of NF-kappaB enhances the cytotoxic effect of 5-FU with or without Folinic acid in colon cancer cells.

Adenoviridae↗

PubMed2004

Anti-cytokine and anti-inflammatory therapies for the treatment of severe sepsis: progress and pitfalls.

The medical care of patients with sepsis or severe inflammatory response syndromes has seen tremendous technological advancements in recent years; yet, several clinical studies with anti-cytokine therapies targetted to this population have met with disappointing results. Four primary factors have been identified that represent potential pitfalls involving the use of biological response modifiers in critically-ill patients. First, the physiological response in the stressed patient is complex. Redundancy within this system may not allow a single intervention to produce a clinical response. Second, the critically-ill patient population is heterogenous and important factors including the age of the patient, associated co-morbidities, the nature of the original injury and the presence or absence of an ongoing injury can modulate the effectiveness of a specific therapy. Third, the timing of the therapeutic intervention can be difficult to standardize among patients and can often produce differing results. A greater understanding of the physiological response to injury has shown that there are both proinflammatory and anti-inflammatory processes ongoing simultaneously. Determining the optimal time to intervene within this framework can be problematic. Fourth, the presence of genetic polymorphisms within the general population has identified subsets of individuals who may have different physiological responses to similar stresses. The relative proportions of patients with these polymorphisms within clinical trials may affect outcome and data analysis. Thus, a better understanding of these issues will result in improvement of the experimental design of clinical trials involving anti-cytokine therapies and critically-ill patients. Avoidance of these pitfalls will enhance the quality and utility of outcomes research in this subset of patients.

Anti-Infective Agents↗

PubMed2004

CD14 receptor occupancy in severe sepsis: results of a phase I clinical trial with a recombinant chimeric CD14 monoclonal antibody (IC14).

OBJECTIVE: Binding of bacterial cell wall components to CD14 and co-receptors on myeloid cells results in cellular activation and production of proinflammatory mediators. A recombinant anti-CD14 monoclonal antibody (IC14) has been shown to decrease lipopolysaccharide-induced responses in animal and human models of endotoxemia. This study was performed to evaluate the safety, pharmacokinetics, pharmacodynamics, and clinical pharmacology of IC14 in patients with severe sepsis. DESIGN: Randomized, double-blind, placebo-controlled, dose-ranging, multiple-center trial. SETTING: Six medical and surgical intensive care units located in Germany and The Netherlands. PATIENTS: Forty patients with severe sepsis. INTERVENTIONS: IC14 was administered intravenously to eight patients/cohort as single (1 mg/kg or 4 mg/kg) or multiple doses (4 mg/kg daily for 4 days, or 4 mg/kg on day 1 followed by 2 mg/kg daily for 3 days). A placebo group (two patients/cohort) was also included. MEASUREMENTS AND MAIN RESULTS: The overall incidence and types of adverse events were similar among treatment groups. One patient in the group receiving multiple-dose IC14 4 mg/kg daily for 4 days experienced an anaphylactic reaction after receiving the first dose of study drug. IC14 did not induce antibody formation or increase the incidence of secondary bacterial infection. A mean IC14 serum concentration of approximately 1 microg/mL was required to achieve 50% of maximum membrane-bound CD14 receptor occupancy on peripheral blood monocytes. The pattern of proinflammatory and anti-inflammatory cytokines, chemokine, soluble receptor, soluble E-selectin, and acute phase proteins in response to treatment was highly variable by patient and IC14 treatment group. CONCLUSIONS: Single and multiple doses of IC14 were generally well tolerated and did not induce antibody formation or increase the incidence of secondary bacterial infection. The results suggest that CD14 blockade with IC14 warrants further clinical investigation to determine its ability to attenuate the proinflammatory response due to infection.

Acute-Phase Proteins↗

PubMed2004

Increased lymphoid tissue apoptosis in baboons with bacteremic shock.

The molecular mechanisms of immune cell apoptosis during sepsis remain unclear. Two young adult baboons (Papio sp.) received a lethal dose of live Escherichia coli and were sacrificed at either 16 (for animal welfare concerns) or 24 h post-septic shock. An additional baboon, which received no bacteria, served as a control. Necropsy was performed immediately with subsequent immunohistochemical staining of lymphoid tissue. Immunohistologic analysis of tissues from the septic baboons revealed marked systemic lymphocyte apoptosis occurring in all lymphoid tissues examined. Focally, pyknotic and karyorrhectic lymphocytes demonstrated activation of a mitochondrial-dependent cell death pathway (active caspase 9 and apoptosis-inducing factor). Other regions demonstrated apoptotic lymphocytes with activation of a death receptor-dependent cell pathway (Fas ligand). Thus, we have demonstrated for the first time in primates that overwhelming gram-negative bacteremia produces an early and profound lymphocyte death that occurs through multiple cell death pathways. Bacteremic shock in the baboon may be an appropriate model for studying experimental therapies aimed at blocking lymphocyte apoptosis because their response appears comparable to humans dying from sepsis.

Animals↗

PubMed2004

Biology of tumor necrosis factor-alpha- implications for psoriasis.

Numerous recent investigations have pointed to a key role of the proinflammatory, pleiotropic cytokine tumor necrosis factor-alpha (TNF-alpha) in host defense and inflammatory processes. TNF overexpression has been found in lesional skin and in the circulation of psoriatic patients, and it was suggested that TNF-alpha is crucial in this and other immune diseases. Several approaches to inhibit TNF-alpha activity have been developed. These include three different neutralizing antibodies to TNF-alpha as well as three different soluble TNF-alpha receptors with characteristic properties designed to bind the 17-KDa soluble trimeric TNF-alpha and the 26-KDa membrane-bound form of TNF-alpha. Clinical trials have demonstrated significant antipsoriatic effects, and it is likely that blocking TNF-alpha will become an important therapeutic option. The data available from these trials contribute to further understanding of the disease by demonstrating the major role of TNF-alpha. An in-depth understanding of the regulation of TNF gene expression, protein production, receptor expression, and signaling pathways may lead to further, potentially important novel therapeutic strategies and antipsoriatic active small molecules, suitable for oral application in the future. Here we review the current knowledge of TNF biology, the approaches to inhibit TNF activity, and their clinical and immunological effects in psoriasis. In addition, the host-defense effects and chronic TNF-blocking activity are discussed.

Animals↗

PubMed2004

Influence of recombinant adenovirus on liver injury in endotoxicosis and its modulation by IL-10 expression.

Adenovirus-based gene therapy offers a unique opportunity to target gene expression to the liver by systemic delivery. However, systemic administration of a first generation adenoviral construct elicits an inflammatory response leading to TNF-alpha-dependent liver injury. The aim of this study was to evaluate whether the systemic administration of recombinant adenovirus exacerbates a subsequent TNF-alpha-dependent liver injury induced by D-galactosamine and lipopolysaccharide. Surprisingly, low-dose adenovirus administration (10(5) particles) protects, while high-dose adenovirus (10(10) particles) is associated with an exaggerated hepatic inflammatory response from a subsequent D-galactosamine and lipopolysaccharide challenge. This exacerbation is TNF-alpha dependent, since treatment with a TNF inhibitor fully protects against the liver injury. Moreover, intravenous administration of an adenoviral construct expressing the anti-inflammatory protein interleukin-10 reduces TNF-alpha appearance and attenuates the increased hepatocyte injury. Taken together, this report demonstrates potential additive effects of TNF-alpha responses induced by adenovirus and other inflammatory signals, and suggests that the response can be mitigated by relative adenovirus particle dose or by inhibitors, such as TNF-binding protein or interleukin 10.

Adenoviridae↗