Recruiting and retaining first-year college students in online health research: Implementation considerations

Objective: Decreasing participation in intervention research among college students has implications for the external validity of behavioral intervention research. We describe recruitment and retention strategies used to promote participation in intervention research across a series of four randomized experiments. Method: We report the recruitment and retention rates by school for each experiment and qualitative feedback from students about recommendations for improving research participation. Results: There was considerable variation among schools' recruitment (4.9% to 64.7%) and retention (12% to 67.8%) rates. Student feedback suggested study timing (e.g., early in the semester), communication strategies (e.g., social media), and incentive structure (e.g., guaranteed incentives) could improve research participation. The highest survey participation rate was observed at the university which mandated students to complete the intervention (but not the survey). Conclusions: Intervention scientists must consider the population and study context to make informed decisions related to recruitment and retention strategies.

COVID-19 booster vaccination during pregnancy enhances maternal binding and neutralizing antibody responses and transplacental antibody transfer to the newborn

The immune response to COVID-19 booster vaccinations during pregnancy for mothers and their newborns and the functional response of vaccine-induced antibodies against Omicron variants are not well characterized. We conducted a prospective, multicenter cohort study of participants vaccinated during pregnancy with primary or booster mRNA COVID-19 vaccines from July 2021 to January 2022 at 9 academic sites. We determined SARS-CoV-2 binding and live virus and pseudovirus neutralizing antibody (nAb) titers pre- and post-vaccination, and at delivery for both maternal and infant participants. Immune responses to ancestral and Omicron BA.1 SARS-CoV-2 strains were compared between primary and booster vaccine recipients in maternal sera at delivery and in cord blood, after adjusting for days since last vaccination. A total of 240 participants received either Pfizer or Moderna mRNA vaccine during pregnancy (primary 2-dose series: 167; booster dose: 73). Booster vaccination resulted in significantly higher binding and nAb titers, including to the Omicron BA.1 variant, in maternal serum at delivery and in cord blood compared to a primary 2-dose series (range 0.44-0.88 log10 higher, p < 0.0001 for all comparisons). Live virus nAb to Omicron BA.1 were present at delivery in 9 % (GMT ID50 12.7) of Pfizer and 22 % (GMT ID50 14.7) of Moderna primary series recipients, and in 73 % (GMT ID50 60.2) of mRNA boosted participants (p < 0.0001), although titers were significantly lower than to the D614G strain. Transplacental antibody transfer was efficient for all regimens with median transfer ratio range: 1.55-1.77 for IgG, 1.00-1.78 for live virus nAb and 1.79-2.36 for pseudovirus nAb. COVID-19 mRNA vaccination during pregnancy elicited robust immune responses in mothers and efficient transplacental antibody transfer to the newborn. A booster dose during pregnancy significantly increased maternal and cord blood binding and neutralizing antibody levels, including against Omicron BA.1. Findings support the use of a booster dose of COVID-19 vaccine during pregnancy.

Intensive drug therapy versus standard drug therapy for symptomatic intestinal Crohn's disease strictures (STRIDENT): an open-label, single-centre, randomised controlled trial

BACKGROUND

Strictures are the most common structural complication of Crohn's disease. Surgery and endoscopic balloon dilation are the main treatments; drug therapy has been considered contraindicated. Given that most strictures have an inflammatory component, we aimed to find out whether strictures are responsive to drug treatment and whether intensive drug therapy is more effective than standard drug therapy.

METHODS

This open-label, single-centre, randomised controlled trial was performed in one specialist inflammatory bowel disease centre in Australia. Patients aged 18 years or older with Crohn's disease were included. Eligible patients had a de novo or postoperative anastomotic intestinal stricture on MRI or ileocolonoscopy, symptoms consistent with chronic or subacute intestinal obstruction (postprandial abdominal pain in the presence of a confirmed stricture), and evidence of active intestinal inflammation. Patients were randomly assigned (2:1) to receive intensive high-dose adalimumab (160 mg adalimumab once per week for 4 weeks followed by 40 mg every 2 weeks, with escalation of dose at 4 months and 8 months if assessment of disease activity indicated active inflammation) plus thiopurine (initial dose of azathioprine 2·5 mg/kg or mercaptopurine 1·5 mg/kg, with dose adjustment based on thiopurine metabolite testing) or standard adalimumab monotherapy (160 mg at week 0, 80 mg at week 2, then 40 mg every 2 weeks) using stratified fixed block randomisation. Stratification factors were stricture dilation at study baseline colonoscopy and current biologic drug use. The primary endpoint was improvement (decrease) in the 14-day obstructive symptom score at 12 months by one or more points compared with baseline. This trial is registered with ClinicalTrials.gov, NCT03220841, and is completed.

FINDINGS

Between Sept 10, 2017, and Sept 6, 2019, 123 patients were screened and 77 randomly assigned to intensive adalimumab plus thiopurine treatment (n=52) or standard adalimumab treatment (n=25). At 12 months, improvement in obstructive symptom score was noted in 41 (79%) of 52 patients in the intensive treatment group and 16 (64%) of 25 in the standard treatment group (odds ratio [OR] 2·10 [95% CI 0·73-6·01]; p=0·17). Treatment failure occurred in five (10%) patients in the intensive treatment group versus seven (28%) in the standard treatment group (OR 0·27 [95% CI 0·08-0·97]; p=0·045); four patients in each group required stricture surgery (0·44 [0·10-1·92]; p=0·27). Crohn's Disease Activity Index was less than 150 in 36 (69%) patients in the intensive treatment group versus 15 (60%) in the standard treatment group (1·50 [0·56-4·05]; p=0·42). MRI at 12 months showed improvement using the stricture MaRIA score (≥25%) in 31 (61%) of 51 versus seven (28%) of 25 patients (3·99 [1·41-11·26]; p=0·0091). MRI complete stricture resolution was seen in ten (20%) versus four (16%) patients (1·28 [0·36 to 4·57]; p=0·70). Intestinal ultrasound at 12 months showed improvement (>25%) in bowel wall thickness in 22 (51%) of 43 versus seven (33%) of 21 patients (2·10 [0·71 to 6·21]; p=0·18). Faecal calprotectin normalised in 32 (62%) versus 11 (44%) patients (2·04 [0·77-5·36]; p=0·15). Normalisation of CRP was seen in 32 (62%) versus 11 (44%) patients (2·04 [0·77-5·36]; p=0·15). Eight (15%) patients in the intensive treatment group and four (16%) in the standard treatment group reported serious adverse events. No deaths occurred during the study.

INTERPRETATION

Crohn's disease strictures are responsive to drug treatment. Most patients had improved symptoms and stricture morphology. Treat-to-target therapy intensification resulted in less treatment failure, a reduction in stricture-associated inflammation, and greater improvement in stricture morphology, although these differences were not significantly different from standard therapy.

FUNDING

Australian National Health and Medical Research Council, Gastroenterological Society of Australia Ferring IBD Clinician Establishment Award, Australasian Gastro Intestinal Research Foundation, AbbVie, and the Spotlight Foundation.

Magnetic resonance enterography for predicting the clinical course of Crohn's disease strictures

BACKGROUND AND AIMS

Strictures are the most common Crohn's disease complication, but their natural history is unknown. This study aimed to characterize inflammation, predict prognosis, and understand the impact of drug therapy using magnetic resonance enterography (MRE).

METHODS

Patients with a stricture diagnosed on MRE over a 5-year period were reviewed for MRE disease extent and inflammation, clinical course, C-reactive protein, response to anti-TNF therapy, endoscopic dilatation, hospitalization, and surgery.

RESULTS

136 patients had 235 strictures (77, one and 59, ≥ 2 strictures).

TREATMENT

46% of patients underwent surgery after a median 6 months; median follow-up for those not requiring surgery was 41 months. Predictors of surgery: Hospitalization because of obstruction predicted subsequent surgery (OR 2.50; 95% CI 1.06-5.90) while anti-TNF therapy commenced at stricture diagnosis was associated with a reduced risk (OR 0.23; 95% CI 0.05-0.99). MRE characteristics associated with surgery were proximal bowel dilatation ≥ 30-mm diameter (OR 2.98; 95% CI 1.36-6.55), stricture bowel wall thickness ≥ 10-mm (OR 2.42; 95% CI 1.11-5.27), and stricture length > 5-cm (OR 2.56; 95% CI 1.21-5.43). 81% of patients with these three adverse MRE features required surgery versus 17% if none were present (P < 0.001). Accuracy for these three MRE variables predicting surgery was high (AUC 0.76).

CONCLUSION

Magnetic resonance enterography findings in Crohn's disease strictures are highly predictive of the disease course and the need for future surgery. MRE may also identify who would benefit from treatment intensification. Anti-TNF therapy is associated with reduced risk of surgery and appears to alter the natural history of this complication.

0322 Napping, Inhibitory Control, and Self-Regulation in 2-Year-Old Children

Introduction

Poor sleep in early childhood is linked to reduced school readiness. This study examined the role of acute sleep loss in behavioral self-regulation using a delay of gratification task. We hypothesized that after acute nap deprivation, toddlers would have worse inhibitory control and resort to more maladaptive self-regulation strategies than after a nap.

Methods

25 healthy children (11 males, 34.1±2.3 months-old) followed a strict sleep schedule for ≥5 days before a baseline (nap) and an acute nap deprivation condition (no-nap). After being introduced to an age-appropriate toy, children were instructed not to touch the toy and left alone for 3-minutes. To assess inhibitory control, videos of the waiting period were behaviorally coded for latency to touch and 11 self-regulation strategies. We combined strategies into adaptive and maladaptive composites; higher scores on each composite indicated greater use.

Results

During the nap condition, 19 children touched the toy (latency to touch=70.0±60.7 sec); during the no-nap condition, 18 children touched the toy (latency to touch=65.4±71.6 sec). The adaptive composite score was 1.58±0.25 for the nap condition and 1.17±0.27 for the no-nap condition. The maladaptive score was 0.92±0.17 for the nap condition and 0.83±0.19 for the no-nap condition. We found no differences between conditions in the number of children who touched the toy (X2=0, p=0.50), mean latency to touch (t=0.27, p=0.39), or the composite scores of adaptive (z=0.35, p=0.12) and maladaptive strategies (z=0.09, p=0.69).

Conclusion

Findings indicate that acute nap deprivation may not have an immediate impact on inhibitory control and self-regulation in toddlers. 30-36 months old children may not have sufficient cognitive resources to exert inhibitory control and self-regulate whether or not they have obtained adequate daytime sleep. Future research should examine developmental changes in the effects of acute sleep restriction on behavioral self-regulation.

Support

Research support from NIH R01-MH086566 to MKL.

Endothelial Pannexin 1 Channels Control Inflammation by Regulating Intracellular Calcium

The proinflammatory cytokine IL-1β is a significant risk factor in cardiovascular disease that can be targeted to reduce major cardiovascular events. IL-1β expression and release are tightly controlled by changes in intracellular Ca²⁺ ([Ca²⁺]_i), which has been associated with ATP release and purinergic signaling. Despite this, the mechanisms that regulate these changes have not been identified. The pannexin 1 (Panx1) channels have canonically been implicated in ATP release, especially during inflammation. We examined Panx1 in human umbilical vein endothelial cells following treatment with the proinflammatory cytokine TNF-α. Analysis by whole transcriptome sequencing and immunoblot identified a dramatic increase in Panx1 mRNA and protein expression that is regulated in an NF-κB-dependent manner. Furthermore, genetic inhibition of Panx1 reduced the expression and release of IL-1β. We initially hypothesized that increased Panx1-mediated ATP release acted in a paracrine fashion to control cytokine expression. However, our data demonstrate that IL-1β expression was not altered after direct ATP stimulation in human umbilical vein endothelial cells. Because Panx1 forms a large pore channel, we hypothesized it may permit Ca²⁺ diffusion into the cell to regulate IL-1β. High-throughput flow cytometric analysis demonstrated that TNF-α treatments lead to elevated [Ca²⁺]_i, corresponding with Panx1 membrane localization. Genetic or pharmacological inhibition of Panx1 reduced TNF-α-associated increases in [Ca²⁺]_i, blocked phosphorylation of the NF-κB-p65 protein, and reduced IL-1β transcription. Taken together, the data in our study provide the first evidence, to our knowledge, that [Ca²⁺]_i regulation via the Panx1 channel induces a feed-forward effect on NF-κB to regulate IL-1β synthesis and release in endothelium during inflammation.

Genomic variability of Pantoea ananatis in maize white spot lesions assessed by AFLP markers

Measures to control maize white spot (MWS) caused by Pantoea ananatis are preferentially based on resistant cultivars. A lack of knowledge on the genetic variability of pathogens could interfere with the development and utilization of controlling strategies in this pathosystem. The main goals of this study were to investigate the genetic variability of 90 P. ananatis isolates from three different eco-geographical regions of Brazil by amplified fragment length polymorphism (AFLP), and to determine the presence of a universal P. ananatis plasmid in isolates from tropical Brazil. Analysis of genetic similarity by AFLP allowed us to categorize the 90 isolates into two groups. However, no correlation between the collecting sites and genetic groupings was observed. The polymorphism percentage found in P. ananatis ranged between 24.64 and 92.46%, and genetic diversity was calculated to be 0.07-0.09. The analysis of molecular variance showed that 99.18% of genetic variability was within the populations, providing evidence that evolutionary forces were acting on these populations. All P. ananatis isolates showed the P. ananatis universal plasmid (280 or 352 kb). This is the first report on the presence of a universal P. ananatis plasmid from MWS lesions in the tropical area.

The role of microRNA-155/liver X receptor pathway in experimental and idiopathic pulmonary fibrosis

Background

Idiopathic pulmonary fibrosis (IPF) is progressive and rapidly fatal. Improved understanding of pathogenesis is required to prosper novel therapeutics. Epigenetic changes contribute to IPF; therefore, microRNAs may reveal novel pathogenic pathways.

Objectives

We sought to determine the regulatory role of microRNA (miR)-155 in the profibrotic function of murine lung macrophages and fibroblasts, IPF lung fibroblasts, and its contribution to experimental pulmonary fibrosis.

Methods

Bleomycin-induced lung fibrosis in wild-type and miR-155^−/− mice was analyzed by histology, collagen, and profibrotic gene expression. Mechanisms were identified by in silico and molecular approaches and validated in mouse lung fibroblasts and macrophages, and in IPF lung fibroblasts, using loss-and-gain of function assays, and in vivo using specific inhibitors.

Results

miR-155^−/− mice developed exacerbated lung fibrosis, increased collagen deposition, collagen 1 and 3 mRNA expression, TGF-β production, and activation of alternatively activated macrophages, contributed by deregulation of the miR-155 target gene the liver X receptor (LXR)α in lung fibroblasts and macrophages. Inhibition of LXRα in experimental lung fibrosis and in IPF lung fibroblasts reduced the exacerbated fibrotic response. Similarly, enforced expression of miR-155 reduced the profibrotic phenotype of IPF and miR-155^−/− fibroblasts.

Conclusions

We describe herein a molecular pathway comprising miR-155 and its epigenetic LXRα target that when deregulated enables pathogenic pulmonary fibrosis. Manipulation of the miR-155/LXR pathway may have therapeutic potential for IPF.

miR-34a(-/-) mice are susceptible to diet-induced obesity

OBJECTIVE

MicroRNA (miR)-34a regulates inflammatory pathways, and increased transcripts have been observed in serum and subcutaneous adipose of subjects who have obesity and type 2 diabetes. Therefore, the role of miR-34a in adipose tissue inflammation and lipid metabolism in murine diet-induced obesity was investigated.

METHODS

Wild-type (WT) and miR-34a(-/-) mice were fed chow or high-fat diet (HFD) for 24 weeks. WT and miR-34a(-/-) bone marrow-derived macrophages were cultured in vitro with macrophage colony-stimulating factor (M-CSF). Brown and white preadipocytes were cultured from the stromal vascular fraction (SVF) of intrascapular brown and epididymal white adipose tissue (eWAT), with rosiglitazone.

RESULTS

HFD-fed miR-34a(-/-) mice were significantly heavier with a greater increase in eWAT weight than WT. miR-34a(-/-) eWAT had a smaller adipocyte area, which significantly increased with HFD. miR-34a(-/-) eWAT showed basal increases in Cd36, Hmgcr, Lxrα, Pgc1α, and Fasn. miR-34a(-/-) intrascapular brown adipose tissue had basal reductions in c/ebpα and c/ebpβ, with in vitro miR-34a(-/-) white adipocytes showing increased lipid content. An F4/80(high) macrophage population was present in HFD miR-34a(-/-) eWAT, with increased IL-10 transcripts and serum IL-5 protein. Finally, miR-34a(-/-) bone marrow-derived macrophages showed an ablated CXCL1 response to tumor necrosis factor-α.

CONCLUSIONS

These findings suggest a multifactorial role of miR-34a in controlling susceptibility to obesity, by regulating inflammatory and metabolic pathways.

Characterization of the inaA gene and expression of ice nucleation phenotype in Pantoea ananatis isolates from Maize White Spot disease

Maize White Spot (MWS), a foliar disease caused by Pantoea ananatis, could cause up to 60% yield loss. Some strains of P. ananatis harboring the ice nucleation gene inaA catalyze the formation of ice nuclei, causing tissue damage at temperatures slightly below freezing. Little is known about the relationship between the presence of the ina gene in this maize pathogen and its expression during the phenomenon of ice nucleus formation. Here, we attempted to verify the presence of the inaA gene and the expression of phenotype in vitro. The identity of the isolates and the presence of the inaA gene were determined by P. ananatis species-specific primers. The expression of the inaA gene was assessed in vitro by the visualization of ice-crystal formation in water at subzero temperatures. A total of ninety P. ananatis isolates from MWS lesions were characterized. The presence of the inaA gene was confirmed by gel electrophoresis of the 350-400-bp PCR products. The inaA primers did not lead to DNA fragment amplification in three isolates. The ice nucleation phenotype was expressed in 83.34% of the isolates carrying the inaA gene. Our study showed that the ice nucleation in P. ananatis isolated from MWS lesions was dependent on the presence of a functional ina gene in the genome. We also found evidence indicating that some P. ananatis strains have a mutated form of the inaA gene, producing a non-functional ice nucleation protein. This is the first report on inaA gene characterization in P. ananatis isolates from Maize White Spot.

MiR-155 has a protective role in the development of non-alcoholic hepatosteatosis in mice

Hepatic steatosis is a global epidemic that is thought to contribute to the pathogenesis of type 2 diabetes. MicroRNAs (miRs) are regulators that can functionally integrate a range of metabolic and inflammatory pathways in liver. We aimed to investigate the functional role of miR-155 in hepatic steatosis. Male C57BL/6 wild-type (WT) and miR-155^−/− mice were fed either normal chow or high fat diet (HFD) for 6 months then lipid levels, metabolic and inflammatory parameters were assessed in livers and serum of the mice. Mice lacking endogenous miR-155 that were fed HFD for 6 months developed increased hepatic steatosis compared to WT controls. This was associated with increased liver weight and serum VLDL/LDL cholesterol and alanine transaminase (ALT) levels, as well as increased hepatic expression of genes involved in glucose regulation (Pck1, Cebpa), fatty acid uptake (Cd36) and lipid metabolism (Fasn, Fabp4, Lpl, Abcd2, Pla2g7). Using miRNA target prediction algorithms and the microarray transcriptomic profile of miR-155^−/− livers, we identified and validated that Nr1h3 (LXRα) as a direct miR-155 target gene that is potentially responsible for the liver phenotype of miR-155^−/− mice. Together these data indicate that miR-155 plays a pivotal role regulating lipid metabolism in liver and that its deregulation may lead to hepatic steatosis in patients with diabetes.

Impaired renal function impacts negatively on vascular stiffness in patients with coronary artery disease

BACKGROUND

Chronic kidney disease (CKD) and coronary artery disease (CAD) are independently associated with increased vascular stiffness. We examined whether renal function contributes to vascular stiffness independently of CAD status.

METHODS

We studied 160 patients with CAD and 169 subjects without CAD. The 4-variable MDRD formula was used to estimate glomerular filtration rate (eGFR); impaired renal function was defined as eGFR <60 mL/min. Carotid-femoral pulse wave velocity (PWV) was measured with the SphygmoCor® device. Circulating biomarkers were assessed in plasma using xMAP® multiplexing technology.

RESULTS

Patients with CAD and impaired renal function had greater PWV compared to those with CAD and normal renal function (10.2 [9.1;11.2] vs 7.3 [6.9;7.7] m/s; P < 0.001). In all patients, PWV was a function of eGFR (β = -0.293; P < 0.001) even after adjustment for age, sex, systolic blood pressure, body mass index and presence or absence of CAD. Patients with CAD and impaired renal function had higher levels of adhesion and inflammatory molecules including E-selectin and osteopontin (all P < 0.05) compared to those with CAD alone, but had similar levels of markers of oxidative stress.

CONCLUSIONS

Renal function is a determinant of vascular stiffness even in patients with severe atherosclerotic disease. This was paralleled by differences in markers of cell adhesion and inflammation. Increased vascular stiffness may therefore be linked to inflammatory remodeling of the vasculature in people with impaired renal function, irrespective of concomitant atherosclerotic disease.

Galectin-3 and cardiac function in survivors of acute myocardial infarction

BACKGROUND

Galectin-3 is a biomarker associated with inflammation and fibrosis that predicts adverse outcome and relates to biomarkers of extracellular matrix turnover in patients with heart failure, particularly when left ventricular (LV) systolic function is preserved. Whether galectin-3 is related to LV remodeling after acute myocardial infarction is unknown.

METHODS AND RESULTS

Circulating galectin-3 and various extracellular matrix biomarkers were measured in 100 patients (age, 58.9±12.0 years; 77% men) admitted with acute myocardial infarction and LV dysfunction, at baseline (mean 46 hours) and at 24 weeks, with cardiac MRI at each time-point. LV remodeling was defined as change in LV end-systolic volume index. Relationships among galectin-3, biomarkers, and LV remodeling were analyzed across the entire cohort, then according to median baseline LV ejection fraction. Galectin-3 levels were elevated in 22 patients (22%) at baseline and increased significantly over time from 14.7±5.5 to 16.3±6.6 ng/mL (P=0.007). Baseline galectin-3 did not correlate with any LV parameters at baseline or change in any parameter over time. Galectin-3 was positively associated with remodeling in patients with supramedian baseline LV ejection fraction (ie, >49.2%; r=0.40; P=0.01) but not when LV ejection fraction was ≤49.2%. Galectin-3 correlated significantly with matrix metalloproteinase-3 and monocyte chemoattractant protein-1 at baseline, biomarkers that have been shown to relate to LV remodeling in this cohort.

CONCLUSIONS

Galectin-3 correlated significantly with certain biomarkers involved in extracellular matrix turnover, although no definite relationship was identified with LV remodeling. Whether galectin-3 plays a pathological role in remodeling remains unclear but merits further study.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00132093.

Soluble ST2 is regulated by p75 neurotrophin receptor and predicts mortality in diabetic patients with critical limb ischemia

OBJECTIVE

The p75 neurotrophin receptor (p75(NTR)) contributes to diabetes mellitus-induced defective postischemic neovascularization. The interleukin-33 receptor ST2 is expressed as transmembrane (ST2L) and soluble (sST2) isoforms. Here, we studied the following: (1) the impact of p75(NTR) in the healing of ischemic and diabetic calf wounds; (2) the link between p75(NTR) and ST2; and (3) circulating sST2 levels in critical limb ischemia (CLI) patients.

METHODS AND RESULTS

Diabetes mellitus was induced in p75(NTR) knockout (p75KO) mice and wild-type (WT) littermates by streptozotocin. Diabetic and nondiabetic p75KO and WT mice received left limb ischemia induction and a full-thickness wound on the ipsilateral calf. Diabetes mellitus impaired wound closure and angiogenesis and increased ST2 expression in WT, but not in p75KO wounds. In cultured endothelial cells, p75(NTR) promoted ST2 (both isoforms) expression through p38(MAPK)/activating transcription factor 2 pathway activation. Next, sST2 was measured in the serum of patients with CLI undergoing either revascularization or limb amputation and in the 2 nondiabetic groups (with CLI or nonischemic individuals). Serum sST2 increased in diabetic patients with CLI and was directly associated with higher mortality at 1 year from revascularization.

CONCLUSIONS

p75(NTR) inhibits the healing of ischemic lower limb wounds in diabetes mellitus and promotes ST2 expression. Circulating sST2 predicts mortality in diabetic CLI patients.

Soluble ST2 associates with diabetes but not established cardiovascular risk factors: a new inflammatory pathway of relevance to diabetes?

Preliminary data mostly from animal models suggest the sST2/IL-33 pathway may have causal relevance for vascular disease and diabetes and thus point to a potential novel inflammatory link to cardiometabolic disease. However, the characterisation of sST2 levels in terms of metabolic or vascular risk in man is completely lacking. We sought to address this gap via a comprehensive analysis of risk factor and vascular correlates of sST2 in a cross-sectional study (pSoBid). We measured sST2 in plasma in 639 subjects and comprehensively related it to cardiovascular and diabetes risk factors and imaged atherosclerosis measures. Circulating sST2 levels increased with age, were lower in women and in highest earners. After adjusting for age and gender, sST2 levels associated strongly with markers of diabetes, including triglycerides [effect estimate (EE) per 1 standard deviation increase in sST2:1.05 [95%CI 1.01,1.10]), liver function (alanine aminotransaminase [ALT] and γ-glutamyl transferase [GGT]: EE 1.05 [1.01,1.09] and 1.13 [1.07,1.19] respectively), glucose (1.02 [1.00,1.03]) and sICAM-1 (1.05 [1.02,1.07]). However, sST2 levels were not related to smoking, cholesterol, blood pressure, or atheroma (carotid intima media thickness, plaque presence). These results suggest that sST2 levels, in individuals largely without vascular disease, are related principally to markers associated with diabetes and ectopic fat and add support for a role of sST2 in diabetes. Further mechanistic studies determining how sST2 is linked to diabetes pathways may offer new insights into the inflammatory paradigm for type 2 diabetes.

Interleukin-21--a biomarker of importance in predicting myocardial function following acute infarction?

INTRODUCTION

Following acute myocardial infarction (AMI), the acute inflammatory response contributes to wound healing but also to progressive myocardial injury. Interleukin-21 (IL-21) plays a key role in immunoregulation; whether IL-21 is associated with left ventricular (LV) remodelling after AMI is unknown.

METHODS

Plasma IL-21 concentrations were measured in 100 patients (age 58.9 ± 12.0 years, 77% male) admitted with AMI and LV dysfunction, at baseline (mean 46 h) and again at 24 weeks; cardiac magnetic resonance and measurement of B-type natriuretic peptide, monocyte chemoattractant protein-1, matrix metalloproteinase (MMP)-2, -3, -9, and tissue inhibitor of metalloproteinase (TIMP)-1, -2, -4 occurred at both time-points. Remodelling was defined as change in LV end-systolic volume index (ΔLVESVI).

RESULTS

Plasma IL-21 concentration was unchanged over time (48.1 [SD 35.4]pg/mL at baseline vs. 48.8 [61.3]pg/mL at 24 weeks, p=0.92). Baseline IL-21 correlated significantly with ΔLVESVI (r=0.30, p=0.005) and change in LV end-diastolic volume index (r=0.33, p=0.003). On multivariate analysis, plasma IL-21 was an independent predictor of remodelling. IL-21 was also significantly associated with higher TIMP-4 concentrations and lower MMP-9 concentrations at baseline.

CONCLUSIONS

IL-21 predicts adverse remodelling following AMI in patients with LV dysfunction. Whether it plays a direct pathophysiological role in remodelling merits further study.

Biodistribution and inflammatory profiles of novel penton and hexon double-mutant serotype 5 adenoviruses

The use of adenovirus serotype 5 (Ad5) vectors in the clinical setting is severely hampered by the profound liver tropism observed after intravascular delivery coupled with the pronounced inflammatory and innate immune response elicited by these vectors. Liver transduction by circulating Ad5 virions is mediated by a high-affinity interaction between the capsid hexon protein and blood coagulation factor X (FX), whilst penton–α_vintegrin interactions are thought to contribute to the induction of anti-Ad5 inflammatory and innate immune responses. To overcome these limitations, we sought to develop and characterise for the first time novel Ad5 vectors possessing mutations ablating both hexon:FX and penton:integrin interactions. As expected, intravascular administration of the FX binding-ablated Ad5HVR5*HVR7*E451Q vector (AdT*) resulted in significantly reduced liver transduction in vivo compared to Ad5. In macrophage-depleted mice, increased spleen uptake of AdT* was accompanied by an elevation in the levels of several inflammatory mediators. However ablation of the penton RGD motif in the AdT* vector background (AdT*RGE) resulted in a significant 5-fold reduction in spleen uptake and attenuated the antiviral inflammatory response. A reduction in spleen uptake and inflammatory activation was also observed in animals after intravascular administration of Ad5RGE compared to the parental Ad5 vector, with reduced co-localisation of the viral beta-galactosidase transgene with MAdCAM-1 + sinus-lining endothelial cells. Our detailed assessment of these novel adenoviruses indicates that penton base RGE mutation in combination with FX binding-ablation may be a viable strategy to attenuate the undesired liver uptake and pro-inflammatory responses to Ad5 vectors after intravascular delivery.

Role of IL-33 in inflammation and disease

Interleukin (IL)-33 is a new member of the IL-1 superfamily of cytokines that is expressed by mainly stromal cells, such as epithelial and endothelial cells, and its expression is upregulated following pro-inflammatory stimulation. IL-33 can function both as a traditional cytokine and as a nuclear factor regulating gene transcription. It is thought to function as an 'alarmin' released following cell necrosis to alerting the immune system to tissue damage or stress. It mediates its biological effects via interaction with the receptors ST2 (IL-1RL1) and IL-1 receptor accessory protein (IL-1RAcP), both of which are widely expressed, particularly by innate immune cells and T helper 2 (Th2) cells. IL-33 strongly induces Th2 cytokine production from these cells and can promote the pathogenesis of Th2-related disease such as asthma, atopic dermatitis and anaphylaxis. However, IL-33 has shown various protective effects in cardiovascular diseases such as atherosclerosis, obesity, type 2 diabetes and cardiac remodeling. Thus, the effects of IL-33 are either pro- or anti-inflammatory depending on the disease and the model. In this review the role of IL-33 in the inflammation of several disease pathologies will be discussed, with particular emphasis on recent advances.

Simultaneous activation of the liver X receptors (LXRα and LXRβ) drives murine collagen-induced arthritis disease pathology

BACKGROUND

It has previously been shown that dual activation of the Liver X Receptors (LXRα and LXRβ) by the agonist, GW3965, enhances pathology in a murine model of collagen-induced arthritis.

OBJECTIVE

To determine whether LXRα or LXRβ have discrete roles in driving articular inflammation.

METHODS

Arthritis was induced in male C57BL/6 wild-type (WT), LXRα-/-, LXRβ-/- and LXRα/β double KO mice by injection with type II collagen and treated with 30 mg/kg of the LXR agonist GW3965 or vehicle control. The mice were monitored for articular inflammation and cartilage degradation by scoring for clinical signs of arthritis and by histological examination of the joints.

RESULTS

Administration of 30 mg/kg GW3965 significantly increases the severity of arthritis in WT but not LXRα-/-, LXRβ-/- or LXRα/β KO mice as assessed by an increase in the clinical score, paw thickness and articular histological analysis.

CONCLUSION

The proinflammatory effects associated with the administration of GW3965 are mediated specifically through LXRs. The absence of increased disease severity in the LXRα-/- and LXRβ-/- GW3965-treated groups shows for the first time that agonism of both LXRα and LXRβ is required to drive proinflammatory pathways in vivo.

Cytokines as therapeutic targets to reduce cardiovascular risk in chronic inflammation

Patients with chronic inflammatory diseases, such as rheumatoid arthritis (RA), systemic lupus erythematosus, psoriasis and Crohn's disease have an increased atherosclerotic risk which cannot be explained by traditional cardiovascular risk factors alone. Inflammatory pathways are implicated in this increased vascular risk. The involvement of cytokine-related signaling pathways in inflammatory diseases has prompted the development of many therapeutic strategies aimed at their modulation to limit disease severity and progression. Whether modulation of these pathways would similarly alter the inflammatory processes related to accelerated atherosclerosis remains unknown. In this review we will focus on the role of pro-inflammatory cytokines and their inhibitors in RA, and whether they may be causal in the accelerated atherosclerosis seen in these patients.

IL-33 induces skin inflammation with mast cell and neutrophil activation

Psoriasis is a common chronic autoimmune condition of the skin characterized by hyperplasia of epidermal keratinocytes associated with pro-inflammatory cytokines. IL-33 is a new member of the IL-1 superfamily that signals through the ST2 receptor and was originally defined as an inducer of T helper 2 (Th2) cytokines. Recently, broader immune activatory potential has been defined for IL-33 particularly via mast cell activation and neutrophil migration. Here, we show that ST2(-/-) mice exhibit reduced cutaneous inflammatory responses compared with WT mice in a phorbol ester-induced model of skin inflammation. Furthermore, injections of IL-33 into the ears of mice induce an inflammatory skin lesion. This inflammatory response was partially dependent on mast cells as mast cell-deficient mice (Kit(W-sh/W-sh) ) showed delayed responses to IL-33. IL-33 also recruited neutrophils to the ear, an effect mediated in part by increased production of the chemokine KC (CXCL1). Finally, we show that IL-33 expression is up-regulated in the epidermis of clinical psoriatic lesions, compared with healthy skin. These results therefore demonstrate that IL-33 may play a role in psoriasis-like plaque inflammation. IL-33 targeting may provide a new treatment strategy for psoriasis.

Interleukin-33 induces protective effects in adipose tissue inflammation during obesity in mice

RATIONALE

Chronic low-grade inflammation involving adipose tissue likely contributes to the metabolic consequences of obesity. The cytokine interleukin (IL)-33 and its receptor ST2 are expressed in adipose tissue, but their role in adipose tissue inflammation during obesity is unclear.

OBJECTIVE

To examine the functional role of IL-33 in adipose tissues and investigate the effects on adipose tissue inflammation and obesity in vivo.

METHODS AND RESULTS

We demonstrate that treatment of adipose tissue cultures in vitro with IL-33 induced production of Th2 cytokines (IL-5, IL-13, IL-10) and reduced expression of adipogenic and metabolic genes. Administration of recombinant IL-33 to genetically obese diabetic (ob/ob) mice led to reduced adiposity, reduced fasting glucose and improved glucose and insulin tolerance. IL-33 also induced accumulation of Th2 cells in adipose tissue and polarization of adipose tissue macrophages toward an M2 alternatively activated phenotype (CD206(+)), a lineage associated with protection against obesity-related metabolic events. Furthermore, mice lacking endogenous ST2 fed high-fat diet had increased body weight and fat mass and impaired insulin secretion and glucose regulation compared to WT controls fed high-fat diet.

CONCLUSIONS

In conclusion, IL-33 may play a protective role in the development of adipose tissue inflammation during obesity.

Apolipoprotein E-deficient mice are resistant to the development of collagen-induced arthritis

OBJECTIVE

To determine whether elevated serum lipid levels resulting from feeding animals a high-fat diet can affect the inflammatory process in C57BL/6 (B6) wild-type (WT) and B6 ApoE(-/-) mouse models of collagen-induced arthritis (CIA).

METHODS

Male B6 WT or ApoE(-/-) mice were fed either a normal chow diet or a high-fat diet. CIA was induced in mice at 12 weeks of age using type II chicken collagen, Freund's complete adjuvant, and, on occasion, a lipopolysaccharide boost. Expression levels of autoantibodies and cytokines were measured using enzyme-linked immunosorbent assay and multiplex assay, respectively.

RESULTS

Whereas B6 WT mice developed severe articular inflammation after collagen immunization, ApoE(-/-) mice developed no clinical or histologic evidence of disease regardless of whether they had been fed a high-fat diet or a normal chow diet. The fact that arthritis was not present in ApoE(-/-) mice did not result from inadequate production of serum IgG2a collagen antibodies, since levels observed in ApoE(-/-) mice were similar to those observed in arthritic B6 WT control mice. Critically, development of atherosclerosis in ApoE(-/-) mice was not affected by the CIA protocol.

CONCLUSION

Our findings suggest that ApoE(-/-) mice are resistant to the development of CIA. Intriguingly, induction of host autoimmunity in the absence of articular inflammation had no effect on atherosclerosis progression, suggesting that articular inflammatory load may be a critical risk factor in vascular pathology.

Liver X receptor agonism promotes articular inflammation in murine collagen-induced arthritis

OBJECTIVE

Liver X receptors (LXRs) have previously been implicated in the regulation of inflammation and have, in general, been ascribed an antiinflammatory role. This study was therefore undertaken to explore the biologic mechanisms of LXRs in vivo and in vitro in an experimental inflammatory arthritis model.

METHODS

Male DBA/1 mice were immunized with type II collagen and treated from an early or established stage of arthritis with 2 different concentrations of the LXR agonists T1317 and GW3965 or vehicle control. The mice were monitored for articular inflammation and cartilage degradation by scoring for clinical signs of arthritis, histologic examination of the joints, and analysis of serum cytokine and antibody levels. In vitro, primary human monocytes and T cells were cultured in the presence of GW3965 or T1317, and the concentrations of proinflammatory cytokines were measured by multiplex assay.

RESULTS

Contrary to expectations, LXR agonism with the use of 2 discrete, specific molecular entities led to substantial exacerbation of articular inflammation and cartilage destruction in this murine collagen-induced arthritis model. This was associated ex vivo with elevated cytokine expression, with enhanced Th1 and Th17 cellular responses, and with elevated collagen-specific autoantibody production. In vitro, LXR agonists, in concert with lipopolysaccharide, promoted cytokine and chemokine release from human monocytes, and similar effects were observed in a T cell-macrophage coculture model that closely recapitulates the pathways that drive synovial cytokine release.

CONCLUSION

Since LXRs are present in rheumatoid arthritis (RA) synovium, these results suggest that LXR-mediated pathways could exacerbate the chronic inflammatory response typical of RA.

[Efficacy of vitaprost forte in patients with prostatic adenoma]

The trial of a new bioregulatory peptide vitaprost forte (100 mg rectal suppositoria) in 30 patients with prostatic adenoma demonstrated that this drug attenuates clinical symptoms of the disease, improves quality of life, uroflowmetric parameters and reduces size of the prostate. Vitaprost forte is more effective in patients with prostatic adenoma in combination with chronic prostatitis, has antiaggregant and anticoagulant properties, stimulates synthesis of antihistamine and antiserotonine antibodies, improves microcirculation in the prostate resulting in regressioin of edema, activity of inflammation in prostatic diseases.

Cell-specific nuclear import of plasmid DNA in smooth muscle requires tissue-specific transcription factors and DNA sequences

Two shortcomings of nonviral gene therapy are a lack of tissue-specific targeting of vectors and low levels of gene transfer. Our laboratory has begun to address these limitations by designing plasmids that enter the nucleus of specific cell types in the absence of cell division, thereby enhancing expression in a controlled manner. We have shown that a 176 bp portion of the smooth muscle gamma-actin (SMGA) promoter can mediate plasmid nuclear import specifically in smooth muscle cells (SMCs). Here, we demonstrate that the binding sites for serum response factor (SRF) and NKX3-1/3-2 within this DNA nuclear targeting sequence (DTS) are required for plasmid nuclear import. Knockdown of these factors with siRNA abrogates plasmid nuclear import, indicating that they are necessary cofactors. In addition, coinjection of recombinant SRF and Nkx3.2 with the vector in TC7 epithelial cells rescues import. Finally, we show that the SRF nuclear localization sequence (NLS) is required for vector nuclear import. We propose that SRF and NKX3-1/3-2 bind the SMGA DTS in the cytoplasm, thus coating the plasmid with NLSs that mediate translocation across the nuclear pore complex. This discovery could aid in the development of more efficient nonviral vectors for gene transfer to SMCs.

IL-33 reduces the development of atherosclerosis

Atherosclerosis is a chronic inflammatory disease of the vasculature commonly leading to myocardial infarction and stroke. We show that IL-33, which is a novel IL-1-like cytokine that signals via ST2, can reduce atherosclerosis development in ApoE(-/-) mice on a high-fat diet. IL-33 and ST2 are present in the normal and atherosclerotic vasculature of mice and humans. Although control PBS-treated mice developed severe and inflamed atherosclerotic plaques in the aortic sinus, lesion development was profoundly reduced in IL-33-treated animals. IL-33 also markedly increased levels of IL-4, -5, and -13, but decreased levels of IFNgamma in serum and lymph node cells. IL-33 treatment also elevated levels of total serum IgA, IgE, and IgG(1), but decreased IgG(2a), which is consistent with a Th1-to-Th2 switch. IL-33-treated mice also produced significantly elevated antioxidized low-density lipoprotein (ox-LDL) antibodies. Conversely, mice treated with soluble ST2, a decoy receptor that neutralizes IL-33, developed significantly larger atherosclerotic plaques in the aortic sinus of the ApoE(-/-) mice compared with control IgG-treated mice. Furthermore, coadministration of an anti-IL-5 mAb with IL-33 prevented the reduction in plaque size and reduced the amount of ox-LDL antibodies induced by IL-33. In conclusion, IL-33 may play a protective role in the development of atherosclerosis via the induction of IL-5 and ox-LDL antibodies.

[The experience in postoperative administration of alpha-adrenoblockers]

The study of efficacy of alpha-blocker alfuzosine (dalphaz CP) in a dose 10 mg/day for treatment of postoperative complications after transurethral resection (TUR) of the prostate and open adenomectomy (OAE) and in quality of life (QoL) improvement enrolled 22 patients after TUR of the prostate and 18 patients after OAE. Examination of the patients was carried out before the operation 10 days and 1 month after surgery. The assessment was performed according to IPSS, QoL index, V and RU. It is shown that patients treated without the alpha-blocker had more urination defects. Administration of alpha-blocker on day 1 after surgical treatment of prostatic adenoma leads to earlier regress of urination disorders. This improves the course of the postoperative period, lowers the risk of urogenital infection and risk of acute urine retention. Therefore QoL rises significantly.

CD4+CD25high T cells are enriched in the tumor and peripheral blood of prostate cancer patients

In this study, we investigated whether CD4+CD25high regulatory T cells (Treg) are increased in the tumor tissue and peripheral blood of early-stage prostate cancer patients undergoing prostatectomy. We show that the prevalence of CD4+CD25high T cells inside the prostate was significantly higher in the tumor compared with benign tissue from the same prostate. Furthermore, the frequency of CD4+CD25high T cells in peripheral blood was significantly higher in prostate cancer patients compared with normal donors. A proportion of the CD4+CD25high T cells was also shown to be glucocorticoid-induced TNF receptor, ICOS, and FOXP3 positive. Moreover, CD4+CD25+ T cells from blood and supernatants from cultured prostate tumor tissue samples exhibited immunosuppressive function in vitro. Furthermore, supernatants from cultured prostate tissue samples and prostate cancer ascites fluid induced migration of CD4+CD25+ T cells and were shown to contain the regulatory T cell chemokine CCL22 by ELISA. Our findings indicate that Tregs are an important cellular component of early-stage prostate tumors, and thus new therapeutic strategies aimed at inhibition or depletion of Tregs may improve prostate cancer immunotherapy.

CD4+CD25high T cells are enriched in the tumor and peripheral blood of prostate cancer patients

In this study, we investigated whether CD4+CD25high regulatory T cells (Treg) are increased in the tumor tissue and peripheral blood of early-stage prostate cancer patients undergoing prostatectomy. We show that the prevalence of CD4+CD25high T cells inside the prostate was significantly higher in the tumor compared with benign tissue from the same prostate. Furthermore, the frequency of CD4+CD25high T cells in peripheral blood was significantly higher in prostate cancer patients compared with normal donors. A proportion of the CD4+CD25high T cells was also shown to be glucocorticoid-induced TNF receptor, ICOS, and FOXP3 positive. Moreover, CD4+CD25+ T cells from blood and supernatants from cultured prostate tumor tissue samples exhibited immunosuppressive function in vitro. Furthermore, supernatants from cultured prostate tissue samples and prostate cancer ascites fluid induced migration of CD4+CD25+ T cells and were shown to contain the regulatory T cell chemokine CCL22 by ELISA. Our findings indicate that Tregs are an important cellular component of early-stage prostate tumors, and thus new therapeutic strategies aimed at inhibition or depletion of Tregs may improve prostate cancer immunotherapy.

In vitro assessment of dendritic cells pulsed with apoptotic tumor cells as a vaccine for ovarian cancer patients

Surgery and chemotherapy are standard treatments in ovarian cancer, but patients have a high rate of relapse. Dendritic cell (DC)-based vaccines are a new treatment option for elimination of residual tumor disease. We aim to explore the feasibility and immunogenicity of DC vaccines pulsed with autologous irradiated tumor cells from ovarian cancer patients. Monocyte-derived DC were generated and pulsed with autologous tumor-derived bodies, matured and subsequently cocultured with autologous lymphocytes. The ability of DC to activate lymphocytes was evaluated by proliferation and IFN-gamma ELISPOT. Induction of tumor cell apoptosis was optimal at 24 h, and DC pulsing optimal at 4 h. Maturation of DC and proliferation of lymphocytes were achieved in 75% of patients tested. Lymphocyte IFN-gamma production increased in response to tumor antigen-pulsed DC. We show the feasibility of preparing individual DC-based vaccines in ovarian cancer patients and the potential for induction of lymphocyte responses.

Tumor escape mechanisms in prostate cancer

Numerous immunotherapy trials have been carried out in prostate cancer (PC) patients, with induction of antigen-specific T cells in some cases. Despite this capability, limited success is seen in terms of tumor regression or survival. In this review, we discuss the evidence for tumor escape strategies that may contribute to vaccine failure in the setting of PC. These include defects in antigen presentation, production of immunosuppressive substances, induction of T cell death, T cell receptor dysfunction, and the presence of tolerogenic dendritic cells and regulatory T cells inside prostate tumors. It is clear that novel strategies aimed at preventing tumor escape, such as small molecular weight inhibitors of immunosuppressive molecules, adoptive transfer of TCR transgenic T cells, removal of Tregs, combined with anti-androgen therapy and prostate-specific vaccines, need to be examined further in PC patients.

The effect of erythromycin on video capsule endoscopy intestinal-transit time

BACKGROUND

Video capsule endoscopy (VCE) will fail to reach the cecum in 20% of patients within the 8-hour battery life. The use of prokinetics to improve VCE completion rates to the cecum remains unclear. The objective of this study was to determine whether erythromycin increases the completion rate of VCE to the cecum without adversely affecting image quality.

METHODS

This was a prospective, randomized, single-blinded control trial at St. Vincent's Hospital, Melbourne, Australia. A total of 86 consecutive patients referred for VCE were considered for entry; 45 patients met the entry criteria. These 45 patients were prospectively randomized to no erythromycin (controls, n = 23) or 250 mg erythromycin (n = 22). Two gastroenterologists, who were unaware of which group the patients were randomized into, reported all VCEs. The number of VCEs that reached the cecum within the 8-hour study period, gastric emptying time (GET), and small-bowel transit time (SBTT) were calculated for each group.

RESULTS

There was no significant difference in the number of VCEs that reached the cecum (32% failed to reach the cecum in the erythromycin group compared with 22% in the control group), GET, or SBTT between the two groups. Image quality was not adversely affected by the use of erythromycin. The dose and the preparation of erythromycin used in this study may have possibly had an effect on GET and SBTT.

CONCLUSIONS

The use of erythromycin did not significantly increase the likelihood of the capsule reaching the cecum or affect the degree of visible peristalsis or the interpretation of capsule findings.

Presence and specificity of tumor associated lymphocytes from ascites fluid in prostate cancer

BACKGROUND

In the present study, we had the rare opportunity to study immunological responses of TAL from ascites fluid in a patient with hormone-refractory prostate cancer.

METHODS

We evaluated tumor antigen-specific T-cell responses, induced by either prostate specific antigen (PSA) pulsed dendritic cells (DCs) or PSA peptides, in TAL and peripheral blood lymphocytes.

RESULTS

DC stimulation with PSA protein induced recognition of naturally processed PSA epitopes by both blood and ascites T cells. In contrast, only ascites T cells recognized the PSA-3 peptide, after stimulation with PSA-pulsed DCs or peptides. Finally, although IFNgamma secreting T cells were detectable in both blood and ascites by ELISPOT, multiplex cytokine assay detected the presence of predominantly Th2 cytokines.

CONCLUSIONS

Although tumor antigen-specific TAL were detected in ascites fluid, these cells were producing immunosuppressive cytokines which may contribute to tumor escape from recognition and/or destruction by the immune system.

Immune Monitoring in a Phase 1 Trial of a PSA DNA Vaccine in Patients with Hormone-Refractory Prostate Cancer

Prostate cancer remains a leading cause of cancer illness and death among men in Europe. No curative treatment exists when the disease has spread beyond the prostate. Immunotherapy with DNA vaccines has emerged as a potential therapeutic approach for the induction of antitumor specific cytotoxic T lymphocytes. In this study six patients with hormone-refractory prostate cancer were monitored for their ability to mount PSA-specific cellular responses after receiving a pVAX/PSA DNA vaccine (patients 1-3, 100 microg; patients 7-9, 900 microg) with recombinant GM-CSF and IL-2 as adjuvants. IFNgamma ELISPOT showed that naturally processed PSA protein and PSA peptides are recognized by T cells in the blood of some prostate cancer patients after a PSA DNA vaccine. Analysis of other cytokines showed the production of IL-4 and IL-6 but importantly did not show an increase in the number of IL-10-producing cells after vaccination in any of the patients. The authors conclude that a pVAX/PSA DNA vaccine can induce PSA-specific cellular immune responses in patients with hormone-refractory prostate cancer, thus emphasizing the potential for PSA as a target molecule for the immunotherapy of prostate cancer.

TNFα increases the inflammatory response to vascular balloon injury without accelerating neointimal formation

There is now clear evidence for a contributory role of inflammatory processes to restenosis following vascular balloon injury and stent implantation. The aim of the present study was to study the effects of TNFalpha, administered locally in vivo immediately following balloon angioplasty, on the leukocyte adhesive response and extent of neointimal formation in a rabbit model of subclavian artery injury. Initial in vitro studies were performed with normal isolated artery rings to assess the vascular adhesive response to TNFalpha or IL-1beta. Pre-incubation with either cytokine prior to addition of (51)Cr-labelled leukocytes enhanced the adhesion of leukocytes to the artery in both a time- and concentration-dependent manner. Although both cytokines induced an increase in the expression of the adhesion molecules ICAM-1 and VCAM-1, only antibodies to ICAM-1 blocked the enhanced adhesion induced by the cytokines. In artery segments retrieved from rabbits that had previously undergone subclavian artery angioplasty either 24 h or 8 days previously, there was an injury-induced increase in adhesion of leukocytes assessed ex vivo. In segments obtained from rabbits that received a 15 min local infusion of TNFalpha (2 ng/min) to the injured artery immediately after the angioplasty procedure, leukocyte adhesion assessed ex vivo was further significantly enhanced. The pro-adhesive effect of TNFalpha was associated with an increased expression of both ICAM-1 and VCAM-1. However, TNFalpha administration did not alter the extent of neointimal formation observed 8 days after injury. These findings suggest that while TNFalpha may play a role following vascular injury, it does not act alone to induce neointimal formation. Thus anti-inflammatory strategies targeted at multiple cytokines may be more appropriate than targeting a single cytokine to reduce the response to vascular injury.

A phase I trial of DNA vaccination with a plasmid expressing prostate-specific antigen in patients with hormone-refractory prostate cancer

Prostate-specific antigen (PSA) is a serine protease secreted at low levels by normal luminal epithelial cells of the prostate and in significantly higher levels by prostate cancer cells. Therefore, PSA is a potential target for various immunotherapeutical approaches against prostate cancer. DNA vaccination has been investigated as immunotherapy for infectious diseases in patients and for specific treatment of cancer in certain animal models. In animal studies, we have demonstrated that vaccination with plasmid vector pVAX/PSA results in PSA-specific cellular response and protection against tumour challenge. The purpose of the trial was to evaluate the safety, feasibility and biological efficacy of pVAX/PSA vaccine in the clinic. A phase I trial of pVAX/PSA, together with cytokine granulocyte/macrophage-colony stimulating factor (GM-CSF) (Molgramostim) and IL-2 (Aldesleukin) as vaccine adjuvants, was carried out in patients with hormone-refractory prostate cancer. To evaluate the biologically active dose, the vaccine was administered during five cycles in doses of 100, 300 and 900 μg, with three patients in each cohort. Eight patients were evaluable. A PSA-specific cellular immune response, measured by IFN-γ production against recombinant PSA protein, and a rise in anti-PSA IgG were detected in two of three patients after vaccination in the highest dose cohort. A decrease in the slope of PSA was observed in the two patients exhibiting IFN-γ production to PSA. No adverse effects (WHO grade >2) were observed in any dose cohort. We demonstrate that DNA vaccination with a PSA-coding plasmid vector, given with GM-CSF and IL-2 to patients with prostate cancer, is safe and in doses of 900 μg the vaccine can induce cellular and humoral immune responses against PSA protein.

Correlation of changes in nitric oxide synthase, superoxide dismutase and nitrotyrosine with endothelial regeneration and neointimal hyperplasia in the balloon-injured rabbit subclavian artery

OBJECTIVES

Alterations in nitric oxide (NO) and superoxide production within the wall of injured vessels may modulate the development and eventual extent of neointima after balloon injury.

METHODS

In this study we have characterized a rabbit model of subclavian artery injury and have used immunocytochemistry to detect NO synthase (NOS) isoforms, Cu-Zn superoxide dismutase (SOD) and nitrotyrosine in the injured vessel from 2 h to 28 days after injury.

RESULTS

At 48 h after injury, when cellular proliferation that will ultimately form the neointima is commencing, there was upregulation of inducible NOS, Cu-Zn SOD and nitrotyrosine. Recovery of endothelial NOS occurred at 28 days after injury, when the neointima is stabilizing and cellular proliferation has slowed down. There was no increase in neuronal NOS at any time point studied.

CONCLUSIONS

NO may serve to limit the development of neointima while superoxide may attenuate the effect of NO by formation of peroxynitrite, detected as increased nitrotyrosine staining. Upregulation of Cu-Zn SOD would limit superoxide both at sites of inflammation in the vessel wall from 48 h and in the adventitia up to 28 days after injury. Very early intervention to protect NO may reduce neointimal size.

Altered immune system glycosylation causes colitis in alpha1,2-fucosyltransferase transgenic mice

BACKGROUND AND AIMS

Altered glycosylation of the mucosal barrier has been proposed as a primary defect in the pathogenesis of IBD. Glycosylation defects however may also have a profound influence on immune function. Mice transgenic for human alpha1,2-fucosyl-transferase (hFUT1) have widespread disturbances in cell surface glycosylation and spontaneously develop colitis. The aims of this study were to characterize colitis in hFUT1 mice and to determine whether glycosylation-induced changes of the mucosal barrier or the immune system were critical for its pathogenesis.

METHODS

The pathologic features of hFUT1 transgenic mice were characterized. The mucosal barrier was assessed by lectin binding and permeability studies. T-cells and the thymus were assessed by FACS analysis and histology. To isolate the hFUT1 mucosal barrier from the hFUT1 immune system, bone marrow chimeras were generated.

RESULTS

Seventy percent of hFUT1 mice raised in SPF conditions developed histologic evidence of colitis. The mucosal barrier demonstrated altered glycosylation but intestinal permeability was preserved. HFUT1 mice were profoundly lymphopenic, with aberrant T-cell markers and thymic medullary hypoplasia. Reconstitution with wild type bone marrow restored thymic morphology and prevented colitis in hFUT1 mice.

CONCLUSION

Altered glycosylation in hFUT1 mice has a profound influence on T-cell development and this defect, rather than a mucosal barrier defect, is crucial for the development of colitis.